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P001 JUVENILE HUNTINGTON’S DISEASE: PROGRAMME OF THE EURO-HD WORKING PARTY
O. W. J. Quarrell1,2, H. Brewer1,3 on behalf of the working party1Huntington’s Disease Association (England & Wales); 2Department of Clinical Genetics, Sheffield Children’s Hospital, Sheffield UK; 3School of Psychology, Birkbeck College, London University, London UK
Juvenile Huntington’s disease (JHD), defined as onset of the condition before the age of 20 years, is recognised as being at one end of the phenotypic spectrum seen in HD. In most surveys of HD, the percentage of cases meeting this definition varies between 2–10%. At any one time, many of those who had an onset in their late teenage years will be in their twenties; consequently, most professionals have limited experience of managing children/families in which the affected individual is still a child or teenager. The Euro-HD working party has identified three strands of work: firstly, to modify the UHDRS so that relevant tools are developed to monitor the natural history of JHD; secondly, to extend the qualitative research, assessing the impact of JHD from the perspective of the family, to different countries; thirdly, to organise a symposium or discussion group to increase the understanding and research base focused on the needs of this group of patients/families. Given the relative rarity of JHD, it is essential that the research activity is broadly based, especially if modified rating scales are to be widely adopted; to that end, we are seeking international collaborators to help with these strands of work.
P002 THE UK HUNTINGTON’S DISEASE NETWORK
J. J. Naji1, O. J. Handley1, P. S. Harper1,2, S. B. Dunnett1, A. E. Rosser1,2.1Cardiff University, Cardiff; 2University Hospital of Wales, Cardiff, UK
UKHDN Steering Committee: (Roger A Barker (Cambridge Brain Repair Group), Gillian Bates (King’s College, London), David Craufurd (University of Manchester, St Mary’s Hospital, Manchester) Patrick J Morrison (Queen’s University, Belfast), Oliver Quarrell (Sheffield Children’s Hospital) Sheila A Simpson (Grampian University Hospital, Aberdeen), Sarah Tabrizi (National Hospital for Neurology and Neurosurgery, London).
Established in January 2003, the United Kingdom Huntington’s disease Network (UKHDN) brought clinicians and basic scientists together in order to work towards effective management and treatment of people either at risk of, or affected by Huntington’s disease (HD). One of the major driving forces behind the establishment of the network was recognition that historically, large clinical trials with this patient population have been difficult because of small population samples. Hence, the aims of the UKHDN are twofold; firstly, to establish a large cohort of well characterised patients with a view to rapid implementation of clinical trials as and when new therapies emerge; and secondly, to facilitate clinical studies aimed at increasing understanding of the pathogenic processes underlying the neural damage seen in HD. The network is coordinated from Cardiff University, where management and communication of network activities is conducted for over 20 UK member sites. We are founder members of the international European Huntington’s disease Network (EHDN; http://www.euro-hd.net for contacts and present activities). To date, the UKHDN has facilitated national and European research initiatives in collaboration with EHDN, hosted forums for discussion of relevant scientific findings, and mediated the development and review of ethical considerations surrounding research and clinical management of HD. The UKHDN was founded with financial support from the Dunhill Trust as well as a range of specific project grants and awards. We thank the High-Q Foundation and the Huntington’s Disease Association for additional financial support.
Keywords: UKHDN; UK
P003 ASSESSING HUNTINGTON’S DISEASE PATIENTS FOR THE EURO-HD REGISTRY: BEGINNING THE EXPERIENCE AT ROME STUDY SITE
P. Zinzi1, F. Soleti2, A. Elia2, A. Fasano2, T. Ialongo2, M. Spadaro3, M. Frontali3, A. Bentivoglio2, G. Jacopini1.1Institute of Cognitive Sciences and Technologies, CNR, Rome, Italy; 2Institute of Neurology, UCSC, Rome, Italy; 3Institute of Neurobiology and Molecular Medicine, CNR, Rome, Italy
Two study sites in Rome participate in Euro-HD Net: one at the National Research Council (Institute of Cognitive Sciences and Technologies and Institute of Neurobiology and Molecular Medicine) and one at the Neurology Department of Università Cattolica del S Cuore. The two sites cooperate in an outpatient clinic for Huntington’s disease (HD) patients started in 1989; since 1994 the service has been a multidisciplinary clinic. Neurologists, psychologists, and nutritionists are available for consultation, and geneticists, physical therapists, and psychiatrist are available for referral.
The clinical evaluation includes: routine neurological examination twice a year (UHDRS-motor section); Shoulson scale; MMSE; patient and family psychological support; nutritionist counselling; body weight monitoring. This interdisciplinary cooperation provides a continuum in the management of physical, psychological, and familial problems.
The subjects afferent to the clinic number 220, from all Italian regions. Of these 65% are subjects affected by HD, 20% are subjects at risk (pre-test clinical evaluations), 15 are presymptomatic gene carriers (post-test follow up).
During the last eight months (Sept 2004–April 2005) we have performed 70 clinical examinations for the Euro-HD project involving 38 patients: 36 symptomatic patients and two presymptomatic gene carriers.
A complete collection of the data for each patient required a considerable amount of time and personnel involved. A single visit was often insufficient and a second visit was necessary to complete all the assessments.
Keywords: Euro HD Network; clinical assessment; public policy
Clinical care and management I
P004 PROBLEMS AND PITFALLS OF EARLY DIAGNOSIS FOR HUNTINGTON’S DISEASE
E. M. Howard1, C. Stopford2, J. C. Thompson2, D. Craufurd1.1Academic Unit of Medical Genetics and Regional Genetic Service, St Mary’s Hospital, Manchester; 2Greater Manchester Neuroscience Centre, Hope Hospital, Salford, UK
The diagnosis of Huntington’s disease (HD) remains a clinical one, based on the presence of motor abnormalities, but the timing of diagnosis is inevitably subjective and dictated to some extent by circumstances. The introduction of mutation analysis enables diagnostic uncertainty to be rapidly dispelled, allowing clinicians to make the diagnosis with confidence at a much earlier stage in the illness, where in the past more hard evidence might have been sought to avoid a false positive diagnosis.
Before the progressive illness many individuals display prodromal signs of HD, including motor restlessness and occasional low amplitude choreiform movements. It is recognised that increased emotional arousal can worsen involuntary movements, and predictive testing, marital disharmony, or stressful working conditions may be sufficient to provoke physical signs which subsequently subside or even disappear. If there are subtle cognitive changes or behavioural symptoms like depression or irritability, the temptation to make a diagnosis may be further increased. In retrospect some diagnoses may be regarded as premature.
We present a number of case reports illustrating this point. In two, presentation was due to problems at work caused by early cognitive changes affecting speed and accuracy of performance in their relatively demanding jobs, but both have remained virtually asymptomatic in other respects for several years after stopping work. A 33 year old man presenting with irritability, aggression, and early motor and cognitive signs was diagnosed early as a consequence of marital disharmony secondary to the behavioural symptoms; he gave up his job, stopped driving, and adopted a sick role almost immediately, but has shown little evidence of progression over several years since diagnosis. Another, aged 39 at diagnosis, subsequently underwent divorce but has otherwise remained stable, working, driving, and coping well five years on. These cases suggest that early diagnosis in HD should be approached with caution.
Key words: early diagnosis; clinical aspects
P005 VALPROATE IN HUNTINGTON’S DISEASE: DOSE DEPENDENT IMPROVEMENT OF MYOCLONIFORM HYPERKINESIA
C. Saft, T. Lauter, P. H. Kraus, H. Przuntek, J. E. Andrich.Department of Neurology, Huntington-Center NRW, St Josef Hospital, Bochum, Germany
Background: Huntington’s disease (HD) is usually characterised by choreatic movements. Chorea usually is treated with antidopaminergic neuroleptics like tiaprid and tetrabenazine. Particularly in patients with signs of parkinsonism, antidopaminergic medication often leads to worsening of symptoms. In past studies valproate showed no beneficial effect on involuntary movements. Myoclonus is rare in HD and often overseen or misdiagnosed as chorea. It does not sufficiently respond on antidopaminergic medication.
Method: In our centre we had the chance to accompany about 600 different HD patients over the past 10 years. About 90% of these showed symptoms of chorea; about 60% suffered from choreatic movements as the main clinical symptom. Only seven of the patients suffered from myoclonus or from myocloniform hyperkinesia as the main symptom and were treated with sodium valproate. All HD subjects were scored by using UHDRS motor score before and after treatment with valproate. Three patients accepted to be additionally videotaped.
Results: In six cases myocloniform hyperkinesias and, therefore, UHDRS scores improved in a dose dependent manner. In three of these patients antidopaminergic medication could be reduced; in the remaining patients antidopaminergic treatment was basically unchanged. One patient with a daily dose of only 300 mg valproate did not improve.
Conclusion: In a subgroup of HD patients suffering from myocloniform hyperkinesias valproate might be a possible alternative treatment. Valproic acid seems to be more efficient than antidopaminergics in those patients. Also, sodium valproat has fewer side effects on the extrapyramidal system than neuroleptics. Short videotapes and patients’ handwriting will be presented.
Keywords: valproate; myocloniform; hyperkinesias
P006 DIAGNOSTIC AND PRESYMPTOMATIC TESTING FOR HUNTINGTON’S DISEASE IN THE PRISON SETTING
S. M. Huson1,2, F. Hayden1, E. Blair1.1Department of Clinical Genetics, Oxford Radcliffe Hospital; 2Academic Unit of Medical Genetics and Regional Genetic Service, St Mary’s Hospital, Manchester, UK
Although we have only had 10 referrals for people at risk of Huntington’s disease (HD) in prison in the last five years, the majority of them have proved time consuming and presented a variety of complex clinical and counselling issues. We present a review of our experience and suggestions for future practise.
The referrals have fallen into two groups: (1) people already known to the service (n = 2), who have been straightforward to manage and (2) those who have moved into our area during their sentence and often known to other genetic services (n = 8). This group have been very problematic. They include an identical twin requesting presymptomatic testing. His twin was in another prison and declined testing. One person was in a maximum security prison and requesting diagnostic testing. In this setting all assessments were done with a group of prison officers observing proceedings through a glass panel.
Although the majority of counselling issues were similar to those in the general population, from a medical perspective our lack of psychiatric training proved problematic. This was compounded by the lack of experience of HD in the prison medical staff.
Learning the rules of the prison system takes time and a great deal of patience. As health professionals trying to mediate with an institution that by its very purpose has very strict rules and regulations, the following points are critical: (1) the category of the prisoner, as it determines the stipulated staffing levels required for an access visit. Visits can be cancelled at short notice if staff shortages occur; (2) the need to obtain security clearance to visit; (3) patient confidentiality is difficult to maintain; (4) personal safety; (5) manipulative behaviour by the patient and pre-existing psychiatric problems. If initial assessments suggest complex psychiatric issues in the future we would involve a psychiatrist with HD experience; (6) the complexity of arranging visits makes it tempting to curtail the testing programme, we found this patient group needed more support and assessment; (7) learning the prison language: fraggles, fluffies, and co-defs!
P007 BENEFITS OF ENTERAL FEEDING FOR PATIENTS WITH HUNTINGTON’S DISEASE
D. Calvert1, G. Butterworth2, L. Campos2, L. Harrison3, E. M. Howard4, D. Craufurd4.1Abbott Laboratories Ltd. (Nutritional Products Division), Abbott House, Norden Road, Maidenhead; 2Dietetics Department, Royal Preston Hospital, Preston; 3Dietetics Department, Cumberland Infirmary, Carlisle; 4Academic Unit of Medical Genetics and Regional Genetic Service, St Mary’s Hospital, Manchester, UK
Enteral feeding by percutaneous endoscopic gastrostomy (PEG) has been increasingly used in recent years for patients with swallowing difficulties due to Huntington’s disease (HD) and other neurological disorders. As long ago as 1995 it was estimated that more than 120 000 elderly patients in the USA had a gastrostomy tube inserted,1 and there is evidence that in the UK the number of patients receiving PEG feeding has increased fourfold in the past decade.2 Meeting the nutritional needs of HD patients in this way can arrest the progressive weight loss which usually occurs as a consequence of metabolic changes and dysphagia in the later stages of the illness, reducing distress and helping to prevent secondary complications of malnutrition and cachexia.
Most patients with HD do not have a PEG tube inserted until they have reached a point where swallowing is very difficult and there is a significant risk of aspiration. However, some clinicians have argued for earlier intervention while the patient is still able to take some nutritional intake by mouth. We present case reports of 12 HD patients with gastrostomies in the North West of England, illustrating the potential advantages of this approach. Almost all had a long history of progressive dysphagia and weight loss together with behavioural symptoms such as irritability and agitation which improved markedly when enteral feeding was instituted. PEG feeding may have a useful role in alleviating behavioural symptoms and distress which are in part secondary to hunger, anxiety, and fatigue caused by chronic malnutrition.
Keywords: behavioural symptoms; nutrition; percutaneous gastrostomy; peg feeding
P008 SLEEP PATTERNS IN HUNTINGTON’S DISEASE
C. Stephen1, S. A. Simpson2, S. M. Hersch3, H. D. Rosas3, Y. Kaneko3, L. Muir3.1University of Aberdeen, UK; 2Department of Clinical Genetics, University of Aberdeen, UK; 3Department of Neurology, Boston, MA, USA
Background: Sleep disturbance is believed to be common in Huntington’s disease (HD), but only few and limited studies in a small number of subjects have been reported. Several sleep disturbances that have been reported include increased sleep onset latency, increased number of awakenings per night, and more hours spent awake at night.1–3
Hypothesis: We hypothesise that sleep disturbances in HD are more common than generally appreciated, are a significant source of morbidity, and that the stage of HD correlates with severity of sleep disturbance.
Methods: Fifty patients were recruited M = 23, F = 27 mean age 50 (SD 12) years. Subjects were in early stage of disease (stage 1 or 2) or presymptomatic. Subjects completed a questionnaire based on previously validated sleep surveys. Areas covered by the questionnaire included general sleep quality, problems associated with sleep onset, factors involved with sleep disturbance, and daytime somnolence. All subjects were evaluated by the UHDRS.
Results: Average modified Pittsburgh Sleep Quality Index (PSQI) score was 6.88 (SD 4.04) (⩾5 indicating poor sleeper). 34% prescribed regular medication for sleep problems. 78% reported significant sleep disturbance either involving sleep initiation, maintenance or daytime somnolence. 36% of patients had a sleep onset latency of >30 mins and 56% patients waking at least twice each night. Commonest causative factors for nocturnal awakenings included nocturia, restlessness of limbs, excessive sweating, and leg cramps/muscle spasm. 74% patients reported some degree of daytime sleepiness with 50% of these individuals experiencing episodes of irresistible sleepiness. There was a correlation between clinical measures and severity of sleep disturbance.
Conclusion: There is a significant proportion of poor sleep indicators reported in HD both in symptomatic and presymptomatic patients. Poorer sleep correlated with clinical measures.
Keywords: sleep patterns
P009 REHABILITATION: NEUROPSYCHOLOGICAL DIFFERENTIATION OF HUNTINGTON’S DISEASE AND THE DEMENTIAS
M. S. Sefton.Whittier Rehabilitation Hospital, Westborough, MA & Clinton Hospital, Department of Geriatric Psychiatry, Clinton
Huntington’s disease presents unique difficulties for rehabilitation hospitals. Neuropsychological differentiation of cognitive profiles is valuable in providing for the needs of patients who receive acute, restorative therapies after falls, orthopaedic surgery, and other gross decline in functioning. With a goal of improving “carry over” of rehabilitation strategies neuropsychological testing is of value to potentiate interdisciplinary goals through better understanding of unique differences among patients with Huntington’s and other dementias.
Keywords: neuropsychological testing; attention; executive functioning
P010 A PILOT STUDY OF MUSIC THERAPY IN HUNTINGTON’S DISEASE
C. Hyson, R. Oliva, K. A. LaDonna, F. Akwaa, J. Richards, O. J. Sahler.University of Rochester, NY, USA
Background: Recent studies show that music therapy (MT) helps improve the symptoms of Parkinson’s disease. Few studies have looked at the symptomatic benefits of MT in patients with Huntington’s disease (HD).
Objective: To examine the tolerability of a MT programme for patients with HD, and to determine if MT improves the mood and motor features of subjects with HD.
Methods: HD subjects were recruited to participate in a six week MT study that included one individual and one group session per week. The MT protocols were adapted from those of the Colorado State University Neurological Music Therapy programme. HD symptoms targeted included balance and posture, fine motor skills, memory and attention, vocalisation, and mood. In particular, the protocols included Rhythmic Auditory Stimulation (RAS), Pattern Sensory Enhancement (PSE), and Therapeutic Instrumental Music Playing (TIMP). The primary outcome of tolerability was to be assessed by the subjects’ adherence to the therapeutic protocol, attendance, and the results of an exit survey inquiring about their feelings toward the use of MT in HD. A secondary outcome of the study was the change in the Unified Huntington’s Disease Rating Scale (UHDRS) score between baseline and study completion.
Results: Five subjects were recruited for study participation (one female and four males). MT was a well tolerated intervention for subjects with HD (100% adherence and 98% attendance). Exit surveys demonstrated strongly positive feelings toward the benefit of MT in four of five subjects (one survey was completed with contradicting answers by the subject). Although there was improvement in UHDRS scores for finger tapping, pronation/supination, and the Luria, these changes did not achieve statistical significance with the small sample size in this study.
Conclusions: MT was well tolerated among subjects with HD. Future efficacy studies for MT in this population are being planned.
Keywords: music therapy
P011 A DISENGAGE DEFICIT OF ATTENTION IN HUNTINGTON’S DISEASE?
M. Couette1, P. Bartolomeo1, A-CBachoud-Lévi2, P. Brugières3, E. Siéroff4.1Neuroscience Department, Mondor; Inserm U610, Pitié-Salpétrière; 2Neuroscience Department, Mondor; LSCP, EHESS, CNRS, Paris; 3Neuroradiologie, Mondor, 4CNRS URA 8581, Paris, France
The aim was to characterise the attentional deficits in Huntington’s disease (HD) with reference to Posner’s model of attention. Posner postulates three attentionnal networks: an executive network devoted to attentional control, involving the cingulate cortex and frontal areas; an orienting network involving posterior areas, and an alerting network. In this theory, orienting of attention implies three mechanisms: (1) disengaging attention, (2) moving, and (3) engaging to a new target. Attention can be either exogenously captured by an external sudden stimulus or endogenously oriented by the subject himself. Because of the frequent frontal impairment in HD, we hypothesised an executive network alteration. Twelve patients and their controls performed a cued reaction time (RT) task to targets which could appear in one of two lateral boxes. The target followed the cue at 100, 500, or 1000 ms stimulus onset asynchrony (SOA). When the cue was not informative about the localisation of the target and elicited an exogenous orienting of attention, controls showed a facilitation of the cue at short SOA and an Inhibition of Return at longer SOA. Patients showed a persisting validity effect, resulting from a huge cost for invalid conditions, suggesting a disengage deficit. When 80% of the cues were valid and thus induce first an exogenous and later an endogenous attentional shift toward the cued box, patients showed a larger validity effect resulting from a disproportionate cost for invalid trials. And when only 20% of the cues were valid, inviting subjects endogenously orienting attention toward the box opposite to the cued one, controls could take advantage of invalid cues at 500 ms SOA. Patients were also able to do so at 1000 ms SOA.
These results suggested that Huntington’s patients show an alteration of the endogen attention (anterior impairment) but also a disengage deficit in both exogenous and endogenous conditions.
P012 SOCIAL INFERENCE IN HUNTINGTON’S DISEASE
C. L. Stopford1, J. C. Thompson1, J. S. Snowden1, C. L. Julien, R. Corcoran2, D. Neary1, D. Craufurd3.1Cerebral Function Unit, Greater Manchester Neuroscience Centre, Hope Hospital, Salford; 2Psychology Department, University of Manchester; 3University Department of Medical Genetics, St Mary’s Hospital, Manchester, UK
Changes in social conduct and breakdown in interpersonal relationships are commonly reported in Huntington’s disease (HD). Previous studies have confirmed impairments in social cognition, and have proposed that HD patients show poor interpretation of situations and failure to act upon others’ mental states. It is argued that this contrasts with performance in frontotemporal dementia (FTD) patients, who display genuine impairments in theory of mind.
A “hinting task” was used to explore the ability of patients with HD and FTD to infer intentions behind indirect speech. Participants were presented with 10 short passages describing an interaction between two characters. At the end of each passage, a subtle “hint” was produced by one of the characters, and participants were asked to explain what the character meant by their utterance. If the hint was not fully abstracted, a more obvious hint and directed question were provided.
Both patient groups displayed significant impairment. HD participants displayed difficulties in abstraction of subtle hints, although were often able to make inferences from more direct information. Contrastingly, FTD patients showed high failure rates on both “subtle” and “obvious” tasks. Both HD and FTD patients produced “faulty” inferences. However FTD patients were more likely to make no inference at all, even when presented with obvious hints. Patients with FTD exhibited difficulties in “abstracting” information from the stories, and failed to use story information to inform their responses.
The results confirm that both HD and FTD patients show impaired ability to infer intentions behind indirect speech. The robust nature of the impairment in FTD supports the hypothesis that FTD patients have impaired theory of mind, whereas HD patients tend to make “incomplete” inferences, requiring more obvious hints to abstract meanings fully. The study has practical implications regarding social interaction and communication advice that may be beneficial to patients’ relatives and carers.
Keywords: social inference
P013 MOTOR SEQUENCING IN HUNTINGTON’S DISEASE: A DEFICIT IN AUTOMATICITY?
J. C. Thompson1, J. S. Snowden1, D. Craufurd2.1Greater Manchester Neuroscience Centre, Hope Hospital, Salford; 2Department of Medical Genetics, St Mary’s Hospital, Manchester, UK
Individuals with Huntington’s disease (HD) show impaired performance on skill learning tasks that involve the execution of repeating movements, such as maintaining contact with a stylus on a rotating turntable, but not on tasks that require perceptuo-motor remapping, such as mirror tracing. A possible reason for this is that HD patients are impaired in the automation of repetitive actions. In order to explore this hypothesis we compared the performance of HD patients and normal controls on a novel motor sequencing task. The procedure used a response box consisting of six touch sensitive discs each with an LED in the centre. One disc was located centrally with five discs arranged equidistant from it. Participants were instructed to touch the discs as quickly as possible when they became illuminated. The first three trials consisted of a repeating sequence clockwise around the response board, alternating between the central and radial discs. In the final trial the sequence alternated between the central and radial discs but in a random rather than clockwise fashion. Learning of the repeating sequence was defined as improvement in performance across the repeating sequence trials. The extent to which participants had automated the task was defined as the difference in reaction time between the final repeating sequence trial and the random trial. Both groups showed significant improvement across the three repeating sequence trials, indicating sequence learning. Both groups also showed an increase in reaction time on the random sequence; however, this was significantly less marked in the HD group. These results suggest that although the HD patients were able to learn the sequence they were not able to gain the additional benefit of “automating” the response. The results support the hypothesis that HD is associated with an impairment in the ability to automate motor actions.
Keywords: motor; sequencing
P014 ATTENTION TO VISUAL FEEDBACK AFFECTS MOVEMENT IMPAIRMENTS IN HUNTINGTON’S DISEASE
M. Lemay1,2, C. Boulet1,2, C. Lafrance1,2, S. Chouinard2, F. Richer1,2.1Université du Québec à Montréal, Montréal; 2Centre hospitalier de l’université de Montréal, Movement Disorders Unit, Montreal (QC), Canada
Huntington’s disease (HD) impairs voluntary movement. Three studies examined the role of task demands linked to visual feedback in this impairment. In a first study, early HD patients and controls executed pointing movements on a tablet while monitoring their movement on a screen. In a baseline condition, patients showed normal precision. However, in 180° inverted movements, patients made more errors in the initial direction and final corrections suggesting that HD impairs feedback based error correction during the attention demanding portions of movements. In another study, early HD patients and controls traced circles as fast and accurately as possible within a 5 mm annulus. When the movement was monitored on a vertical screen without direct vision of the hand, patients deviated more often from the annulus than controls and showed larger corrections toward the target. However, patients and controls showed similar movements when visual feedback was direct. Again, error feedback control was affected in situations requiring attention and multiple corrections. In a third study, we examined the correlation between sensorimotor cortex activation and visuomotor task performance in early HD in a task requiring minimal or extensive feedback based control. Early HD patients and controls traced circles while attempting to remain within a 2.5 or 15 mm annulus. Patients strayed farther and longer outside of the boundaries during tracing than controls and these difficulties were exacerbated by increased precision demands. fMRI activation was significantly reduced in sensorimotor cortex in patients during tracing compared to similar movements involving minimal precision requirements. The present results indicate that HD affects movements when attention to feedback is more essential.
Supported by HDSA and FRSQ.
Keywords: movement; attention; feedback
P015 THE ROLE OF THE STRIATUM IN RULE EXTRACTION AND LEXICAL SEGMENTATION: THE HUNTINGTON’S DISEASE MODEL
R. de Diego Balaguer, A-CBachoud-Lévi.Equipe Avenir, INSERM U421/IM3, Paris XII & Département d’Etudes Cognitives, Ecole Normale Supérieure, Paris, France
Although different models have assumed that the frontostriatal system is involved in rule based knowledge, little is still know about the specific role of the striatum in rule extraction, and more specifically in the acquisition of rule based knowledge of language. In order to address this issue we studied Huntington’s disease (HD) patients in stage I and II as models of striatal and cortical frontal (frontostriatal) dysfunction, respectively. We used an adaptation of the segmentation task by Peña et al (2002) that allowed us to evaluate two essential functions in language processing: the extraction of adjacent co-occurrences, at the basis of speech segmentation and thus of lexical acquisition and the extraction of non-adjacent dependencies, more abstract rules at the basis of the acquisition of morphology and syntax. Forty six HD patients and 20 control subjects, matched in age and educational background, were tested with this task. Results showed that control subjects were significantly better than chance to both extract co-occurrences and extract abstract rules. HD patients showed different patterns according to the stage of the disease. In patients at stage I only word extraction differed from controls performance although it remained better than chance. In patients at later stage of the disease both co-occurrence and rule extraction dropped to chance level. In fact, while performance for co-occurrence extraction was correlated and clustered in a factorial analysis with motor UHDRS scores, rule extraction performances did it with frontal lobe neuropsychological tasks (Stroop, symbol digit code and fluency). The differences in the pattern of performance between stages point to the implication of the striatum in associative learning (co-occurrences) as oppose the frontal lobe function presumably devoted to the extraction of more abstract rules.
Keywords: language; rules; associative learning
P016 ASSESSMENT OF LIMB APRAXIA IN HUNTINGTON’S DISEASE
A. K. Hödl1, E. E. Hödl2, R. Ille1, R. M. Bonelli2.1Department of Psychiatry, Medical University Graz, Auenbruggerplatz 31, Graz; 2Department of Neurology, Hospital of Barmherzige Brüder, Bergstraße 7, Graz, Austria
Objectives: Ideomotor limb apraxia in patients with genetically diagnosed Huntington’s disease (HD) has been rarely investigated, neuropsychological experts differ over the occurrence of apraxia in HD.
Methods: Thirty five outpatients with genetically diagnosed HD (21 men, 14 women) and 32 age and sex matched controls (14 men, 18 women) were examined. Patients and controls underwent a test battery consisting of (1) the Mini Mental State Examination (MMSE), (2) the De Renzi Test for apraxia, (3) a test for imitation of hands’ movements, (4) a test for imitation of fingers’ movements, (5) a test for execution of gestures on demand, and (6) a test for pantomimic movements. Student’s t tests or Mann-Whitney U tests were used for independent measures of group comparison, the Friedman test was used for the comparison of related samples.
Results: Patients with HD showed a highly significant worse result in the MMSE. They scored significantly lower in the De Renzi test, in imitation of hand movements, in gestures on demand, and in pantomimic movements. Patients performed gestures on demand “easier” (that is, the test is less selective) than the pantomimic movements. The test for pantomimic movements diagnosed patients more frequently apraxic than the test gestures on demand (McNemar test: p<0.05).
Conclusions: Ideomotor limb apraxia occurs in patients with HD in all examined items except for imitation of finger movements. These results are confirmed by the studies of Hamilton et al (2003) and Shelton et al (1991) although not all findings are comparable. Different from most neuropsychological experts’ opinions in HD a lesion of subcortical pathways or the thalamus could trigger ideomotor limb apraxia. The different selectiveness of the tests gestures on demand and imitation of pantomimic movements shows that patients diagnosed as apraxic by the test gestures on demand are more strongly impaired than patients who received this diagnosis by the test pantomimic movements.
Keywords: neuropsychology; apraxia; dementia
P017 RANDOM NUMBER GENERATION IN PATIENTS WITH SYMPTOMATIC AND PRESYMPTOMATIC HUNTINGTON’S DISEASE
A. K. Ho1,2, B. J. Sahakian2, T. W. Robbins2, R. A. Barker2.1University of Reading; 2University of Cambridge, UK
Random number generation (RNG), which involves producing lists of numbers at random requires response selection and inhibition which are aspects of executive function mediated by the frontal lobe. This study examined RNG performance in a group of mild to moderate Huntington’s disease (HD) patients, asymptomatic gene positive HD patients, and controls. The HD symptomatic group was significantly less random in their choices than controls. The gene positive asymptomatic HD patients also showed a tendency towards abnormal RNG measures compared with controls, although this did not reach statistical significance after correcting for multiple comparisons. However analysing the HD group as a whole showed that the frequency of errors, preferential selection of favourite numbers, and counting in ones correlated significantly with the degree of symptom severity. Furthermore, counting in ones correlated with degree of vulnerability to symptoms. A subset of patients and controls was retested six months later and all RNG measures showed high correlations over time highlighting the robust reliability of this test. The data therefore suggest that RNG is a useful brief and reliable test of executive function and may be of value in studies investigating the longitudinal effects of disease modifying treatment in HD.
Keywords: presymptomatic; random number generation; executive function
Pathogenic mechanisms I
P018 GENOTYPE DEPENDENT ABNORMALITIES IN HUNTINGTON’S DISEASE LYMPHOBLASTOID CELL LINES
F. Squitieri1, V. Maglione1, M. Cannella1, E. Morgante2, M. A. Russo2, L. Frati2, G. Solaini3, F. Fornai4.1Neurogenetics Unit, IRCCS Neuromed, Pozzilli, IS, Italy; 2Department of Experimental Medicine and Pathology, University La Sapienza of Rome, Italy; 3Department of Biochemistry, University of Bologna, Italy; 4Department of Human Morphology and Applied Biology, University of Pisa, Italy
Huntington’s disease (HD) is caused by mutated huntingtin (htt), a toxic protein ubiquitously expressed in nervous and non-nervous system tissues. Fragmentation of htt by caspases and further accumulation in cells of protein aggregates contribute to cell dysfunction and death. In the attempt to elucidate whether this mechanism depends on patients’ genotype, we analysed the pattern of htt fragmentation, the caspase 3, 8, and 9 activities, and their variation in lymphoblasts with heterozygous and homozygous CAG mutation and in controls. Cells homozygous for expanded mutation showed greater amount of mutated fragments than heterozygotes and controls, caspase 3, 8, and 9 activities greater in mutated than control cell lines, after cyanide treatment; the caspase 3 and 8 particularly increased in homozygotes. As energetic metabolism is impaired in HD and other neurodegenerative diseases and human HD lymphoblasts have provided clear cut data on mitochondrial disruption, we here also report morphological, morphometric, and membrane potential differences in mitochondria from lymphoblasts obtained from patients homozygous and heterozygous for the CAG mutation, and controls. Homozygotes, who despite a similar age at onset show a more aggressive phenotype than heterozygotes, had giant mitochondria and a reduced membrane potential. These data offer a biological explanation to the clinical inpatient evidence of mutation homozygosity associated with more severe phenotype.
Keywords: lymphoblasts; homozygous and heterozygous mutations; mitochondria
P019 MUSCULAR CELL CULTURES SHOW FEATURES OF DYSFUNCTION AND APOPTOSIS IN HUNTINGTON’S DISEASE
A. Ciammola1, J. Sassone1, V. Silani1, G. Meola2, E. Mancinelli3, F. Squitieri4.1Department of Neurology and Laboratory of Neuroscience, “Dino Ferrari” Center, University of Milan Medical School, Milan, Italy; 2Department of Neurology, University of Milan Medical School, San Donato Hospital, San Donato, Italy; 3Department of Biomolecular Sciences and Biotechnologies, University of Milan, Milan, Italy; 4Neurogenetics Unit, IRCCS Neuromed, Pozzilli, Italy
Mutated huntingtin is widely expressed in tissues of Huntington’s disease (HD) patients. In the brain, mutated protein leads to neuronal death and formations of huntingtin positive inclusions. To gain insight into the cellular abnormalities induced by endogenous mutated huntingtin in tissues of HD patients, the authors analysed huntingtin immunoreactivity, viability, and apoptotic system activation in myoblast cultures obtained from seven HD patients (two presymptomatic patients) and nine controls. Myoblasts, from both presymptomatic and symptomatic HD patients, present robust cellular abnormalities in vitro, namely htt positive inclusion formation and apoptotic event, including mitochondrial depolarisation and increased caspase activities. Our findings strongly suggest that mutant huntingtin is toxic to cells early in life, even outside the central nervous system.
Keywords: dysfunction in Huntington’s disease; cell death in Huntington’s disease; myoblasts
P020 HUNTINGTON’S DISEASE-LIKE 2 (HDL2) IS ASSOCIATED WITH RNA INTRANUCLEAR INCLUSIONS
D. D. Rudnicki1, A. Pavlovich1, H. Hwang1, M. Lin1, C. A. Thornton2, O. Pletnikova3, S. E. Holmes1, J. Troncoso3, C. A. Ross1, R. L. Margolis1.1Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, USA; 2Department of Neurology, University of Rochester Medical Center, Rochester, USA; 3Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, USA
Huntington’s disease-like 2 (HDL2) is clinically and pathologically very similar to Huntington’s disease (HD). HDL2 is caused by a CTG repeat expansion located in the variably spliced exon 2A of junctophilin-3 (JPH3) on chromosome 16q24.3. Our question is whether HDL2 results from a toxic expansion at the amino acid level, and if not, what other mechanism may initiate the pathogenic process. Presence of 1C2 positive inclusions in HDL2 patient brain suggested that a potential open reading frame on the strand opposite to JPH3 could encode expanded polyglutamine. However, there is no evidence that this ORF is contained in a gene, and the 1C2 antibody does not detect expansion on Western blots with HDL2 protein extracts. An antibody against the polyglutamine ORF does not detect protein in human brain or stain HDL2 inclusions. In the JPH3 reading frame, the repeat alternatively encodes polyalanine, polyleucine, or resides in the 3′ UTR. We raised antibodies specific to epitopes within the polyalanine and polyleucine ORFs of the JPH3, but did not find evidence of polyalanine or polyleucine expansions in HDL2 brain. To explore the alternative hypothesis of toxicity at the RNA level, we examined HDL2 brain with a CAG riboprobe. To our surprise, we detected RNA inclusions similar to those observed in DM1. The inclusions were also detected by a riboprobe specific to exon 2A of JPH3. As in DM1, the inclusions stain for the protein muscleblind. Preliminary data indicate that overexpression of mutated exon 2A transcripts in HEK293 cells leads to their nuclear retention. Our results suggest that HDL2 pathogenesis may be at least partly mediated by RNA toxicity.
Support: Hereditary Disease Foundation, NS16375.
Keywords: RNA inclusions; toxicity
P021 RETINAL INVOLVEMENT IN HUNTINGTON’S DISEASE
E. Petrasch-Parwez1, S. Weickert1, C. Saft2, J. Andrich2, S. Annegrit1, L. Arning3, M. Napirei4, S. Wieczorek3, R. Dermietzel1, J. T. Epplen3.1Department of Neuroanatomy and Molecular Brain Research, Ruhr-University Bochum, Germany; 2Department of Neurology, St Josefs-Hospital, Ruhr-University Bochum, Germany; 3Department of Human Genetics, Ruhr-University Bochum, Germany; 4Department of Anatomy and Embryology, Ruhr-University Bochum, Germany
Retinal dystrophy has been shown in mouse models for Huntington’s disease (HD; R6) in a similar degeneration pattern as in SCA7 affected patients and SCA7 mice. Therefore, the visual involvement should be compared in transgenic animal models and HD patients. In the present study we extended the retinal investigations of adult R6/2 mice and investigated also the retina from a patient with clinical HD phenotype. Light microscopical analysis revealed retinal dystrophy all over the R6/2 retina with major affection of central areas. Electron microscopy showed severe degenerations of outer and inner photoreceptor segments, shrinkage of cell somata in the outer nuclear layer and degenerations in photoreceptor terminals. N-terminal huntingtin and ubiquitin were expressed in all retinal neurons, the pigment epithelium and in neuropil structures. Tunel labeling showed hints of apoptosis confirmed by electron microscopical documentation of apoptotic photoreceptor cells. Calbindin and Connexin 45 immunoreactivity was reduced in the inner plexiform layer. In addition, fainter signals of Cx45 mRNA documented by in situ hybridysation and a lower level of mCx45 cDNA as obtained by RT-PCR suggested functional deficits in spatial processing of Cx45 mediated gap junction coupling due to transgene induced retinal degenerations. In contrast, macroscopical fundus inspection of the investigated human HD eye gave no hints of pathological affection. Light and electron microscopy revealed regular morphology of all retinal layers according to age. N-terminal huntingtin or specific ubiquitin or polyglutamine immunostaining was not identified in the human HD retina. Calbindin presented the same immunostaining as in age matched human control individuals. Apoptotic cells also occurred in the controls. We conclude that the human HD retina is—in contrast to the retina of the R6/2 mouse—not obligatorily involved in the degeneration process. Furthermore, behavioural investigations of animal models demand a precise investigation of their visual performance.
Keywords: retina; R6/2 mouse; histopathology
P022 VALUE OF NEURONAL INTRANUCLEAR INCLUSIONS AND NEUROPIL INCLUSIONS FOR PATHOLOGICAL ASSESSMENT OF HUNTINGTON’S DISEASE: THE LEIDEN EXPERIENCE
M. L. C. Maat-Schieman, S. G. van Duinen, M. Losekoot, J. C. Dorsman, M. H. Breuning, R. A. C. Roos.Leiden University Medical Center, Leiden, the Netherlands
This study evaluated the usefulness of neuronal intranuclear inclusions (NII) and neuropil inclusions (NI), as recently identified in Huntington’s disease (HD) brain, for HD pathology assessment. Therefore, using ubiquitin and N-terminal huntingtin immunohistochemistry their presence or absence in neocortex was assessed and correlated with striatal pathology, CAG repeat length, and the original neuropathological diagnosis in a consecutive autopsy series of 190 individuals either with clinically certain or doubtful HD or “at risk” of the disease. One hundred and eighty three cases showed HD inclusions—that is, both NII and NI. These included 181 (80 expanded-repeat, 101 unknown-repeat) symptomatic and two unknown-repeat “at risk” cases. All of the 181 symptomatic cases had HD pathology (Vonsattel grades I–IV), while the “at risk” cases showed grade 0 and grade I pathology, respectively. Seven cases lacked HD inclusions. These included four (3 non-expanded-repeat, 1 unknown-repeat) grade 0 “at risk” cases, two (1 non-expanded-repeat, 1 unknown-repeat) symptomatic cases with non-HD neuropathologies, and one unknown-repeat symptomatic case with striatal pathology reminiscent but not quite typical of HD. The original pathologic diagnosis appeared to be (1) false positive for HD in the latter inclusion-negative case, (2) false negative for HD in 12 (4 expanded-repeat, 8 unknown-repeat) inclusion-positive symptomatic cases, and (3) wrongly inconclusive in three unknown-repeat inclusion-positive symptomatic cases. In addition, the original pathological assessment did not allow the identification of the inclusion-positive grade 0 “at risk” case as a possible HD gene carrier. The HD grade I “at risk” case had gone without assessment. Altogether, HD frequency in this HD autopsy series has been underestimated. Immunohistochemistry to detect HD inclusions is of value for HD pathology assessment.
Keywords: neuronal intranuclear inclusions; neuropil inclusions
P023 MUTANT HUNTINGTIN REPRESSES CBP, BUT NOT P300, BY BINDING AND PROTEIN DEGRADATION
S. Cong1, B. A. Pepers1, G-JB. van Ommen1, J. C. Dorsman1, R. A. C. Roos2, B. O. Evert3, D. C. Rubinsztein4.1CBG-Center of Human and Clinical Genetics, Leiden University Medical Center, Leiden, the Netherlands; 2Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands; 3Department of Neurology, University of Bonn, Bonn, Germany; 4Department of Medical Genetics, Cambridge Institute for Medical Research, Cambridge, UK
Huntington’s disease can be used as a model to study neurodegenerative disorders caused by aggregation prone proteins. It has been proposed that the entrapment of transcription factors in aggregates plays an important role in pathogenesis. We now report that the transcriptional activity of CBP was already repressed at the early time points by soluble mutant huntingtin, whereas the histone acetylase activity of CBP/p300 was gradually diminished over time. Mutant huntingtin bound much stronger to CBP than normal huntingtin, possibly contributing to repression. Especially at the later time points, CBP protein level was gradually reduced via the proteasome pathway. In sharp contrast, p300 was unaffected by mutant huntingtin. This selective degradation of CBP was absent in spinocerebellar ataxia 3. Thus, mutant huntingtin specifically affects CBP and not p300 both at the early and later time points, via multiple mechanisms. In addition to the reduction of CBP, the altered ratio of these closely related histone acetyltransferases may also affect chromatin structure and transcription and thus contribute to neurodegeneration.
Keywords: CBP/p300; transcription deregulation
P024 EXPANDED POLYGLUTAMINE REPRESSES THE TRANSCRIPTIONAL COACTIVATOR JAB1
S. Cong1, B. A. Pepers1, G-JB. van Ommen1, J. C. Dorsman1, R. A. C. Roos2.1CBG-Center of Human and Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands; 2Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
Expansion of CAG trinucleotide repeats that encode polyglutamine is the underlying cause of at least nine inherited human neurodegenerative disorders, including Huntington’s disease (HD). The molecular mechanism of polyglutamine induced cytotoxicity is still controversial. It is, nevertheless, widely accepted that transcriptional deregulation plays an important role in molecular pathogenesis. In this study, we report on a novel target of expanded polyglutamine stretches, Jun activation domain-binding protein 1 (Jab1). This protein was originally identified as a coactivator of the AP-1 transcription factor, but appears to have multiple functions including playing a major role in the degradation of the cyclin dependent kinase inhibitor and putative transcription cofactor p27/CIP. We found that Jab1 can accumulate in aggregates formed by either N-terminal fragments of mutant huntingtin (htt) or expanded polyglutamine stretches. In line with these results, the coactivator function of Jab1 was indeed suppressed by both types of polyglutamine proteins. Moreover, in an exon1 HD cell model at a late time point sequestration of Jab1 in aggregates formed by mutant htt was accompanied by the accumulation of p27/CIP. Interference with the Jab1 pathway may have important effects on transcriptional regulation and thereby contribute to the pathogenesis of polyglutamine diseases.
Keywords: polyglutamine diseases; Jab 1; transcription deregulation
P025 GABAB RECEPTORS IN THE HUNTINGTON’S DISEASE BASAL GANGLIA
K. L. Allen, H. J. Waldvogel, R. L. M. Faull.Department of Anatomy with Radiology, University of Auckland, Auckland, New Zealand
Huntington’s disease (HD) is a disease of the basal ganglia which primarily results in the loss of GABAergic medium spiny projection neurons of the striatum. Studies on the pathogenesis of the disease have particularly focused on GABAA receptors and have shown that these ligand gated ionotropic receptors are up regulated in the HD globus pallidus (GP). There have been no studies on GABAB receptors which are G protein coupled GABA receptors localised on striatal GABAergic interneurons and projection neurons. The aim of this project was to use immunohistochemical methods to investigate GABAB receptor changes in the GP in the HD brain. The results have shown that, like GABAA receptors, GABAB receptors are upregulated in the HD GP and that the upregulation increases with neuropathological grade. Density analysis showed that in advanced neuropathological grades (grade 4) there was an overall increase of 139/130% in GABAB immunohistochemical staining in the GPe/GPi respectively. These results provide the first report on the immunohistochemical distribution of GABAB receptors in the HD brain. As with the upregulation of GABAA receptors, the upregulation of GABAB receptors may be involved in increasing the sensitivity of the GP neurons to the decreased GABA levels in HD.
Keywords: neuroanatomy; GABAB receptors; immunohistochemistry
P026 CELL CHANGES IN THE HUMAN VISUAL CORTEX IN HUNTINGTON’S DISEASE
A. L. Nana, H. J. Waldvogel, R. L. M. Faull.Department of Anatomy with Radiology, Faculty of Medicine and Health, Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
Background: Huntington’s disease (HD) is an inherited neurodegenerative disorder characterised by the loss of medium spiny neurons in the striatum. Recent research shows that the cerebral cortex is also affected. The cortical degeneration observed in the cerebral cortex in HD varies throughout the cortex and may be related to the symptoms of the disease (Rosas et al, 2002).1 This project aims to investigate the neuronal changes in the primary (area 17) and secondary (area 18) visual cortices (VC) in HD human brains compared to control brains.
Methods and Results: Neuronal changes in the human primary and secondary VC in HD brains were studied using immunohistochemical procedures. The overall pattern of neuronal loss in the visual cortex in Huntington’s disease was determined using the marker Neuronal N and the pattern of loss of pyramidal cells was analysed using the antibody SMI-32. Unbiased stereological counting techniques were used to obtain neuron numbers. Preliminary results demonstrated no change in total neuron numbers in the primary VC of the HD brains but showed a major neuronal loss in the secondary VC of HD cases. Secondary VC from grade 2 and 3 HD cases showed neuronal loss of approximately 40%. A loss of cells and a change in the morphology of the cell body and dendrites of SMI-32 immunoreactive cells in layer III was observed in the secondary VC but not primary VC of grade 2 and 3 HD cases.
Conclusion: This study showed that the human primary VC is relatively spared in HD, while the secondary VC shows prominent neuronal loss.
Keywords: immunohistochemistry; visual cortex
Clinical characteristics and markers
P027 COGNITIVE AND MOTOR IMPAIRMENTS IN HUNTINGTON’S DISEASE: PATIENTS WITH “REDUCED PENETRANCE” CAG REPEAT LENGTHS
B. Bibb1, E. A. McCusker2.1Deptartment of Medical Psychology; 2Department of Neurology, Westmead Hospital Westmead, Australia
Background: The aim of this study was to document the cognitive and motor status of patients with reduced penetrance (RP) CAG repeat lengths. Patients with a repeat number in the RP range (CAG 36–39) are regarded as likely to have less severe, later onset Huntington’s disease (HD), possibly surviving to late age without clinical signs. Studies predicting onset from CAG length rely on motor onset but cognitive onset has been reported to precede motor onset. We report findings in seven patients in whom the repeat length fell in the RP range when determined by PCR of CAG only.
Method: Patients attending the HD Clinic underwent motor and functional assessment using the UHDRS and detailed neuropsychological testing that assessed attention, memory and learning, psychomotor speed, and executive functions.
Results: Nine patients had CAG repeats of 38 or less, seven (4 female, 3 male) were tested in detail. Mean age was 58.4 years (range 43–71); education 10.0 years (range 6–16). Two patients had significant motor signs, three had subtle signs, and two had no motor features. Neuropsychological testing revealed significant impairments across the cognitive domains, although some variability was evident. Deficits in memory and learning functions were evident in six patients. Multivariate analyses (Mahalanobis distance) revealed abnormal learning curves and serial position effects on the Rey auditory verbal learning task. Recall and recognition (discriminability) were also impaired. Psychomotor speed (SDMT; TMT) was impaired in four patients. Deficits in executive functions (Stroop Interference; Confrontation Naming) were evident in four patients. Verbal fluency and visuoconstruction skills were impaired in three patients.
Conclusion: A full assessment of the phenotype in the RP range should include cognitive testing. Significant cognitive impairment may precede motor signs. Cognitive as well as motor impairment must be considered when determining HD onset.
Keywords: cognitive reduced penetrance
P028 NATURE OF ANOSOGNOSIA IN HUNTINGTON’S DISEASE
D. Paridi1, C. Mariotti1, A. Albanese1, F. Girotti1, G. Geminiani2, P. Soliveri1.1Istituto Nazionale Neurologico Carlo Besta, Via Celoria 11, 20133 Milano, Italy; 2Dipartimento di Psicologia Università di Torino, Via Lagrange 15, 10123 Torino
It is a common finding that patients with Huntington’s disease (HD) tend to neglect or dismiss their motor signs, especially at disease onset. To investigate this problem we examined 30 patients with HD with a scale that assessed anosognosia by asking patients to give a rating of his/her motor symptoms, which was then compared with the examiner’s rating. Patients also underwent a cognitive examination (attention, verbal memory, visuospatial ability, and executive functions), the Brief Psychiatric Rating Scale (BPRS), the Hamilton anxiety and depression scales, and scales assessing negative and positive symptoms in schizophrenia (SNPS and SPPS).
In only five cases (15%) did the patient’s assessment coincide with that of the examiner, confirming that anosognosia is pervasive in HD. Anosognosia scores did not correlate with depression, global cognitive test score, or disease duration, but did correlate significantly with items examining negative symptoms (apathy) of schizophrenia. This finding suggests that two mechanisms could account for the nature of anosognosia in HD: in advanced disease stage it could be related to apathy which is very pronounced, while its presence in early stage disease could be due to the psychological strategy of denial.
Keywords: anosognosia; apathy
P029 RELATION BETWEEN DEPRESSION, MOTOR, AND COGNITIVE IMPAIRMENT IN HUNTINGTON’S DISEASE
J. Klempir, N. Spackova, O. Novakova, J. Roth.Department of Neurology, Charles University, Prague, Czech Republic
Objectives: We assessed 29 patients with Huntington’s disease (HD) in initial and mid stages; mean age 45 years (SD 12.4), mean age at onset of HD 43.1 years (SD 12.1), mean duration of HD 6.7 years (SD 3.2), mean number of CAG triplet repeats 45.3 (SD 4.3). For clinical assessment we used the Unified Huntington’s Disease Rating Scale (UHDRS) and the neuropsychological battery.
Results: Beck Depression Inventory score (BDI-II) correlated with the UHDRS motor assessment subscore (UHDRS-M) (r = 0.443, p<0.021). The BDI-II score also correlated with performance in Auditory Verbal Learning Test (AVLT) total recall (r = −0.404, p<0.037), AVLT-B list trial (r = −0.462, p<0.015), AVLT-recognition (r = −0.5, p<0.008). We observed correlations between severity UHDRS-M and cognitive performance: Symbol Digit Modalities Test (r = −0,716, p<0,00001), Trail Making Test A (r = 0.606, p<0.0004) and B (r = 0.498, p<0.007), Verbal Fluency (r = −0.499, p<0.005) and Stroop Test (Color naming (r = 0.551, p<0.004), Word reading (r = 0.484, p<0.014), Interference (r = 0.454, p<0.022). We also found significant correlations between UHDRS-M and cognitive tests which are not deeply dependent on psychomotor speed or motor performance: Mini Mental State Examination (r = −0.585, p<0.0007), Clock Test (r = −0.429, p<0.018), AVLT total recall (r = −0.407, p<0.023), Mattis Dementia Rating Scale (r = −0.473, p<0.0095).
Conclusion: The most affected functions in our sample of HD patients are attention, learning, memory, psychomotor speed, and executive function. Increasing dysexecutive syndrome influences not only cognitive but also motor performance. Depression affects negatively total motor performance and memory.
Study was supported by grant IGA MZ CR 7623-3.
Keywords: motor impairment; executive function; depression
P030 ALTERED ISOMETRIC FORCE CONTROL DURING OBJECT RELEASE IN PATIENTS WITH HUNTINGTON’S DISEASE
F. Kirsten1, S. Bohlen1, T. Merl2, D. Auer2, T. Klopstock3, A. Bender3, M. Dose4, A. Weindl5, E. B. Ringelstein1, R. Reilmann1.1Department of Neurology, University of Muenster, 2NMR Group, Max Plack Institute for Psychiatry, Munich; 3Department of Neurology LMU Munich; 4Huntington Unit, Hospital Taufkirchen; 5Department of Neurology, TU Munich, Germany
Background: Objective markers for the severity of motor dysfunction are warranted for clinical trials in patients with Huntington’s disease (HD). Specific impairments in the control of isometric grip forces were found in grasping, holding, and transport tasks in HD. In previous studies we identified “grip force variability” (GFV) as a measure correlated to (1) the clinical severity of the disease as assessed in the UHDRS, (2) the amount of neurodegeneration in MRI volumetry, and (3) the CAG repeat length when corrected for the age of patients. Thus GFV may be a surrogate marker to objectively assess the severity of HD. Although the initiation and maintenance of grip forces in grasping and lifting has intensively been investigated in HD, it is unknown if specific impairments occur during object release in HD.
Objective: To investigate whether impairments of isometric force control can be objectively assessed during the replacement and release of an object in patients with HD compared to controls.
Methods: Sixteen patients with genetically confirmed HD and 15 controls were instructed to grasp, lift, hold, and replace an object on a table using the precision grip. Replacement of the object was initiated by an auditory cue. Thirteen trials were performed with 250 g and 500 g object weights. Grip forces were recorded using precalibrated force transducers (Nano 17, ATI, USA). Object position was recorded using an electromagnetic position sensor (Fastrack, Polhemus, USA). Data recording and analysis was performed using a flexible laboratory computer system (SC/ZOOM, University of Umea, Sweden). Statistical analysis was performed using MANOVA (SPSS 10.1).
Results: HD patients showed a normal object replacement phase. However, after object replacement HD patients exhibited a prolonged unload phase and load force decrease phase (p<0.05 for both object weights), and a prolonged digit release phase (p<0.01 for both weights).
Conclusions: Isometric force release in HD patients shows robust impairments in the timing of force coordination—that is, bradykinesia and sequencing problems in the final phases of grip release. Further studies are warranted to investigate whether these impairments are useful surrogates to assess the overall severity of motor dysfunction and the stage of disease in HD.
Keywords: motor; neurophysiology; biomarker
P031 MULTIMODAL OBJECTIVE ASSESSMENT OF MOTOR DEFICITS IN HUNTINGTON’S DISEASE USING ISOMETRIC FORCE ANALYSIS
R. Reilmann1, F. Kirsten1, S. Bohlen1, P. Saemann2, T. Merl2, D. Auer2, T. Klopstock3, A. Bender3, M. Dose4, A. Weindel5, E. B. Ringelstein1.1Department of Neurology, University of Muenster; 2NMR Group, Max-Planck-Institute of Psychiatry, Munich; 3Department of Neurology, LMU Munich, 4Huntington Unit, Hospital Taufkirchen, 5Department of Neurology, TU Munich, Germany
Background: Variability of isometric grip forces in Huntington’s disease (HD) was shown to correlate with the severity of motor deficits in HD as assessed in the UHDRS (Gordon et al, Exp Neurol 2000) and to increase in the course of HD (Reilmann et al, Neurology 2001).
Objective: To investigate whether isometric force variability in (1) a grasping and holding task and in (2) an isometric tongue protrusion task were correlated to the CAG repeat length in HD when normalised to the age of patients.
Method: (1) In the grasping and holding task 17 patients with HD were instructed to grasp and lift an object (weight 250 g and 500 g, respectively) in the precision grip and hold it next to a marker 10 cm high for 30 seconds. Ten trials were performed in each weight condition. Grip forces were recorded using force transducers. Mean grip force and its coefficient of variation were calculated during a 20 second period in the static holding phase. (2) In the tongue protrusion task 20 HD patients were instructed to protrude their tongue and push on a force transducer 2 cm in front of their mouth. They were told to match force levels of 0.25 N, 0.5 N, and 1.0 N, presented on a monitor, for 30 seconds (five trials in each condition). Mean tongue force and its coefficient of variation were calculated during a 20 seconds period. All patients were assessed using the UHDRS. CAG repeat length of the Huntington gene was determined in all patients. Correlation analysis was performed using Spearman correlations.
Results: (1) Grip force variability normalised for the age of the patients was positively correlated to the CAG repeat length in the 250 g and 500 g weight condition (r = 0.776 and r = 0.845, respectively, p<0.001 in both cases). (2) Tongue force variability normalised to the age of patients was correlated to the CAG repeat number in all force levels investigated (p<0.001).
Conclusions: The results suggest that subjects with longer CAG repeats develop a larger increase in grip force variability and tongue force variability per year and thus show a faster progression of HD. The study presents further evidence that analysis of force variability in various tasks may serve as a robust and objective neurophysiological measure to assess the stage and progression of HD.
Keywords: motor; neurophysiology; surrogate
P032 OLFACTORY RECOGNITION IN HUNTINGTON’;S DISEASE PATIENTS
D. Ecker, C. Sorg, A. Nieß, B. Landwehrmeyer.Department of Neurology, University of Ulm, Germany
Introduction: Several studies have suggested that Huntington’s disease (HD) patients have a reduced sense of smell even in the early stages of the disease. We wondered whether impaired smell recognition correlates with other phenotypical characteristics and whether there is a decline of the performance in the smell determination test (SDT) as HD progresses.
Methods: We examined 30 HD patients in early stages (stage I or II) and 30 age matched healthy controls with a commercially available smell screening test (“sniff sticks” by Burckhardt). We examined participants twice with an interval of 12–18 months. This test consists of 12 synthetic olfactory samples. The patient has to choose the correct answer out of four responses provided on a response card. Statistic analysis was done with the Mann-Whitney test.
Results: All 30 patients had reduced smell recognition compared with the control group. The severity of olfactory impairement did not correlate with the severity of disease measured by Total Functional Capacity or Motor score of the Unified Huntington Disease Rating Scale (UHDRS). There was no correllation between the age of the HD patients and the performance in the smell test. There was a trend towards lower cognitive subscores of the UHDRS and worse performance in the SDT.
Discussion: We confirmed previous results that in HD patients SDT is impaired already in stage I. The performance is low and there is the suspicion of a floor effect in SDT. Because we found no correlation with the severity of disease, SDT is not useful as a measurement of disease progression. It will be interesting to test presymptomatic patients to detect when smell disturbance starts.
Keywords: smell test; disease progression
P033 COGNITIVE AND PSYCHIATRIC FEATURES OF HUNTINGTON’S DISEASE PATIENTS IN RELATION TO AGE AT DISEASE ONSET
D. Paridi, A. Albanese, S. Genitrini, C. Mariotti, S. Di Donato, F. Girotti, P. Soliveri.Istituto Nazionale Neurologico Carlo Besta, Via Celoria, Milano, Italy
The severity of cognitive, psychiatric, and motor compromise vary greatly among Huntington’s disease (HD) patients, partly in relation to age at disease onset. Juvenile forms show greater akinesia rigidity and functional impairment, and late onset forms may have more pronounced cognitive impairment. However, the frequency and characteristics of psychiatric disorders in relation to age at onset are unknown.
We examined cognitive, psychiatric, and motor disturbances in a series of 70 adult HD patients in relation to age of disease onset. We excluded juvenile onset patients because they are directed to our department of paediatric neurology. The series was divided into early onset (between 20 and 30 years), typical onset (between 30 and 50 years), and late onset (age above 50 years). Cognitive function was evaluated by MMSE (cognitive screening test), the Raven test (non-verbal reasoning test), Phonemic and Semantic Verbal Fluency tests (strategic search for words in internal lexicon), the Visual Search test (spatial attention test), and the Short Tale test (verbal memory); all were adjusted for age and education. Psychiatric state was evaluated with the Brief Psychiatric Rating Scale (BPRS), the Hamilton anxiety and Hamilton depression scales, and scales assessing negative and positive symptoms in schizophrenia (SNPS and SPPS).
The main finding was a significantly higher score in the apathy related items in the SNPS in the early onset group. However these apathy scores did not correlate with either cognitive performance, or depression scores, or disease duration. More pervasive apathy related symptoms in early onset HD may be due to greater striatal atrophy—as documented in juvenile forms. Greater striatal atrophy could give rise to more precocious dysfunction of the anterior cingulate loop which modulates affectivity and which is usually involved in more advanced disease.
Keywords: apathy; age at disease onset
P034 MYOPATHY AS THE FIRST SIGN OF HUNTINGTON’S DISEASE IN A MARATHON MAN
C. M. Kosinski1, C. Schlangen1, B. Bellhaus2, G. B. Landwehrmeyer3, K. S. Lindenberg4.1University Hospital RWTH Aachen, Department of Neurology, Aachen, Germany; 2University Hospital RWTH Aachen, Department of Neuropathology, Aachen, Germany; 3University of Ulm, Department of Neurology, Ulm, Germany; 4Mass General Institute for Neurodegenerative Disease (MIND), Massachusetts General Hospital & Harvard Medical School, Charlestown, MA, USA
Existence of primary or secondary muscle involvement in Huntington’s disease (HD) has been controversially debated in the past. A 38 year old semiprofessional marathon runner at risk for HD started his training when he was 20 years old. His performance was documented stable over a length of time of about 10 years (1989–1997). Thereafter he started experiencing, after running, severe muscle pain which lasted for weeks and his running times gradually declined. In 1999 a neurological exam detected no HD symptoms. Blood tests showed elevated CK (458 U/l) and LDH (280 U/l). Genetic testing determined 41 CAG repeats in the IT15 gene. In 2004 the patient was first found to have mild clinical signs of HD (UHDRS: 8) with mild chorea and mild slowing of saccade velocity. A muscle biopsy showed a chronic necrotising myopathy. The electron microscopy demonstrated mitochondria increased in size and number and granular deposits suggestive of mitochondric myopathy but different from other mitochondrial myopathies. Additional examination of muscle from R6/2 HD mice and two postmortem HD muscle biopsies also revealed similar mitochondrial abnormalities, and also deposits of huntingtin immunoreactivity in z-discs, suggesting a specific muscle pathology in HD.
The clinical and histological findings of this case suggest that skeletal muscle can be affected early and primarily in HD. Challenging skeletal muscle by intensive training might have disclosed the occurrence of skeletal muscle damage years before the appearance of other neurological symptoms. Thus, clarifying the pathogenic mechanisms of muscle abnormalities in HD might help to identify early events resulting in mitochondrial dysfunction in this disease.
Keywords: mitochondria; biomarker; huntingtin aggregate
P035 SLEEP PATTERNS IN HUNTINGTON’S DISEASE: COULD IT BE THE CAUSE FOR BEHAVIOURAL DISTURBANCES?
M. Anca-Hershkovits1, A. Blonder2, N. Giladi3, A. D. Korczyn3.1Wolfson Medical Center, Holon; 2Maarag Worldclass Sleep Diagnostic Center; 3Tel Aviv Medical Center, Sackler School of Medicine, Tel Aviv, Israel
Background: Huntington disease (HD) and Parkinson’s disease (PD) are neurodegenerative disorders .The early symptoms in HD reflect selective degeneration of striatal GABAergic neurons. Eighty per cent of HD and 60% of PD patients complain about sleep disturbances. Sleep might be affected by movements, cognition, and mood. The few sleep studies done on small groups of HD patients were non-conclusive. We hypothesise that sleep disturbances are early signs of the disease that might have a prognostic value.
Objective: To assess the sleep pattern in genetically tested HD patients for correlate with clinical features and compare with sleep pattern in age matched normal people and PD patients.
Methods: Ten HD patients, with mean disease duration of 6 (SD 3) years, underwent one night polysomnographic (PSG) home assessment using the Embla system digital recorder of 16 channels. All patients had complex motor, mood disturbances, sleep complaints with low daily performances. They were assessed in Movement Disorder Unit for sleep quality, motor, behaviour, mood, and cognition scores using the Epworth Sleep Scale, the Unified HD Rating Scale, the Hamilton questionnaire, and the Mini-Mental State Examination (MMSE). Nine other age matched PD patients with sleep complaints underwent home PSG. The sleep scoring was done following Rechtschaffen and Kales protocol.
Results: The mean age was 51 (SD 13) years for HD and 63 (SD 11) years for PD patients. The HD group was characterised by a mean functional capacity of 9 (SD 2), MMSE score of 25 (SD 5), Hamilton score of 18 (SD 8), Epworth score of 35 (SD 11), and PD group by disease stage H&Y 1–3. All patients completed a whole night PSG. The sleep architecture in HD patients revealed significantly reduced REM (p = 0.00001) and prolonged NREM1. Heterogenous body movements recorded in HD patients in NREM2 disappeared in REM. The PD patients sleep revealed mild REM sleep reduction and preserved NREM1/2. No significant sleep respiratory disturbances were observed.
Conclusion: The HD patients have poor sleep with abnormal pattern showing significant reduction of REM sleep. This pattern is different from normal subjects and PD patients in the same age group. The presence of movements does not explain the poor sleep. This sleep pattern seems to be a consistent intrinsic feature of the disease.
Keywords: GABAergic neurons; sleep pattern; REM
P036 IDENTIFICATION OF AN OCULOMOTOR BIOMARKER OF PRESYMPTOMATIC HUNTINGTON’S DISEASE
C. V. P. Golding1, C. Danchaivijitr1, T. L. Hodgson2, S. J. Tabrizi3, C. Kennard1.1Department of Visual Neuroscience, Faculty of Medicine, Imperial College London; 2School of Psychology, Exeter University; 3Institute of Neurology, University College London, UK
Background: Disease modifying treatments may slow neuronal loss in Huntington’s disease (HD). Such treatments are likely to be most effective when given before significant neurodegneration has occurred, hence a reliable biological marker is required that will detect early neuropathological change in preclinical carriers of the HD gene mutation. We investigated whether oculomotor function could provide such a marker in genetically confirmed pre clinical and early HD.
Methods: Eye movements were recorded from 12 preclinical HD, 12 early HD (six clinical stage 1, six clinical stage 2) and 24 age matched controls during the performance of reflexive and voluntary guided saccades. In addition the Trail Making Test (TMT) was performed to determine motoric slowing and executive function.
Results: Prolonged and more variable saccadic latencies were observed for the voluntary guided saccades in the preclinical group. These initiation deficits correlated negatively with estimated disease severity [(CAG repeat length-35.5) × age], suggesting that this measure provides an early marker of preclinical disease progression. By contrast, the symptomatic group had significantly prolonged and more variable saccadic latencies in both reflexive and voluntary guided paradigms. Significant slowing of saccadic velocity was observed in the symptomatic group, with mean velocity correlating negatively with estimated disease severity. No difference in motoric speed or executive function (TMT) was observed between the PSC and control groups.
Conclusion: Initiation deficits of voluntary saccades precede overt clinical signs of HD, whereas saccadic slowing, initiation deficits of reflexive saccades and motoric slowing (TMT) may only emerge later with other clinical symptoms. We are currently conducting a longitudinal study to evaluate whether saccadic initiation deficits can accurately predict the clinical onset of HD.
Keywords: saccades; biomarker; preclinical HD
P037 BILATERAL SUBDURAL HEMATOMA TRIGGERING CHOREA IN A PATIENT WITH PREVIOUSLY UNKNOWN HUNTINGTON’S DISEASE
J. Kobal1, Z. Miloševic2, R. Bošnjak3, L. Lovre4, F. Bajrovi1.1Department of Neurology, Zaloška 2, Ljubljana; 2Institut of Radiology, Zaloška 7, Ljubljana; 3Department of Neurosurgery, Zaloška 7, Ljubljana; 4Department of Medical Genetics, Division of Gynecology, Šlajmerjeva 3, Ljubljana, Slovenia
Introduction: Chronic subdural haematoma may present in different ways, but generalised dyskinesias have been rarely reported. We describe a case of chronic bilateral subdural hematomas presenting with sudden onset of generalised choreatic dyskinesias. Chorea improved after surgical evacuation of hematoma. However, further course and examinations revealed Huntington’s disease.
Case report: A 71 year old male, treated for diabetes and prostatic hypertrophy developed sudden paraparesis and generalised choreatic dyskinesias a month after a minor head trauma. On admission the patient was alert and oriented (MMS 29/30). Cranial nerve examination revealed slightly enlarged left pupil. Reactions to light were preserved. Persistent mild to moderate choreatic dyskinesias in all four limbs, face, tongue, and neck were found. Lower extremities were weak, plantar responses in extension. CT scan revealed bilateral chronic subdural haematomas with impending transtentorial herniation. Subdural haematomas were evacuated via burholes, the content was liquified, with a coffee-like colour. After the surgery, patient’s choreatic movements subsided, but reappeared in two weeks. Six months later, control examination revealed mild mental deterioration (MMS 22/30), disarthria, unsuppressable blinking, and head movements on lateral gaze. Generalised mild, persistent choreatic dyskinesias were observed in patient’s face, tongue, neck, and extremities, and gait was wide based and bizarre. No consistent data on patient’s family were available due to non-paternity. Full blood count, electrolytes, biochemical profile, and urine were normal. Kaiser-Fleischer rings were absent, serum ceruloplasmin and TSH levels were normal. A control CT scan revealed mild brain atrophy, suggesting no further pathology. An expanded number of 41 CAG triplets in IT15 gene confirmed the diagnosis of Huntington’s disease. Further observations revealed slight aggravation of impulsiveness, choreatic dyskinesias, and development of broad based, dancing-like gait.
Conclusion: We speculate that in our patient bilateral subdural haematoma pressure to cortex and impending transtentorial herniation caused transient ischaemia and alteration of function of the cortex and/or striatum, which resulted in generalised chorea.
Keywords: subdural haematoma
P038 GASTROESOPHAGEAL REFLUX IN HUNTINGTON’S DISEASE
C. Saft1, C. Szymanski2, P. H. Kraus1, T. Lauter1, H. Przuntek1, J. E. Andrich1.1Department of Neurology, Huntington-Center NRW, St Josef Hospital, Bochum, Germany; 2Department of Gastroenterology, St Josef Hospital, Bochum, Germany
Introduction: Dysphagia is an important problem in Huntington’s disease (HD) and might be caused by hyperkinesia, dystonia, and motoric dysbalance of swallowing. Regurgitation and vomiting are common in advanced stages of HD and often cause severe complications like pneumonia or kachexia and gastro-oesophageal reflux disease (GORD). GORD is estimated to be present in 7–10% of the Western adult population whereas oesophagitis is diagnosed in 2–10%. As symptoms of GERD are unspecific it is often overlooked in mentally and physically disabled people. The aim of this study was to investigate whether there is a correlation between movement disorder, especially chorea of the trunk, in HD patients and GORD.
Methods: In our retrospective study, 43 patients (20 male, 23 female) symptomatic for HD were investigated by oesophagogastroscopy during 1998 to 2003. GORD was classified following classification of Savary-Müller. Clinical HD symptoms were evaluated according to UHDRS.
Results: There is no significant correlation between motor impairment in HD according to total motor score in UHDRS as well as total chorea and chorea of the trunk subscores and the occurrence, resp severity of GORD. Also, we could not reveal a correlation between Total Functional Capacity or Independence Scale and GORD. Cigarette smoking, history of alcohol abuse, and medication (neuroleptics, antidepressant drugs, and others) showed no correlation to the occurrence of GORD despite from a significant influence of antiphlogistic drugs (p = 0.038). We found, however, an increase in the occurrence of GORD in HD patients (30.2%) in comparison to normal Western population in literature.
Conclusion: GORD in HD patients is more frequent than in normal population. Movement disorder, especially trunk chorea seems not to be the origin of this gastrointestinal disturbance. Factors like autonomic dysregulation and dementia have been accused to cause GORD in other disabled people and may also explain the higher incidence in HD.
Keywords: gastro-oesophageal reflux disease
P039 DYSPHAGIA IN HUNTINGTON’S DISEASE
M. K. Magnet1, A. K. Hödl1, P. Hofmann1, H-PKapfhammer1, R. M. Bonelli1, W. Habermann2.1University Clinic of Psychiatry Graz; 2Hals-,Nasen-,Ohren-,Universitätsklinik Graz, Austria
Objective: To correlate the grade of dysphagia in Huntington’s disease (HD) with the stage of the disease.
Methods: Twenty five patients with genetically proved HD of all five stages were included in our study. A x ray video deglutition analysis was undertaken and the grade of dysphagia was correlated with the United HD Rating Scale (UHDRS), including motor function, neuropsychological function, and psychiatric symptoms as well as with the number of CAG (cytosin, adenin, guanin) repeats.
Results: Dysphagia is said to occur generally only in the late stages of the disease which leads to aspiration which could cause death. We found that the stage of HD, measured with the UHDRS, strongly correlates with the grade of dysphagia. However, surprisingly, also in the early stages of the disease impaired swallowing was notable in our patients.
Conclusion: HD is a rare, autosomal dominantly inherited neuropsychiatric disorder. That genetic defect causes an increased number of CAG repeats in the coding sequence. This leads to increased cerebral degeneration, especially of the basal ganglia. Clinically the patients show a triad of psychiatric, cognitive, and motor disturbances. These motor disturbances lead to hyperkinesia, sometimes parkinsonism and dysphagia, which is the subjective of our study. The results of our study lead to the conclusion that dysphagia does significantly depend on the stage of HD.
Keywords: dysphagia; deglutination
P040 SPEECH DELAY AS A CONSISTENT EARLY MANIFESTATION OF JUVENILE HUNTINGTON’S DISEASE
G. Yoon1, J. Kramer2, A. Zanko1, M. Guzijan2, S. Lin2, B. Miller2, A. Boxer2.1Department of Pediatrics, Division of Medical Genetics, UCSF; 2Department of Neurology, UCSF
The neurocognitive features of juvenile onset HD are not well understood. We present three patients with onset of HD symptoms before age 10. Early motor and speech development was normal in all patients, however speech delay was evident by 3 years of age. All had rigidity, dystonia, bradykinesia, global developmental delay with regression, aggressive behaviour, dysarthria, and paucity of speech.
Patient 1 had several words at 1 year of age but subsequently manifested language delay. At 3 years speech was minimal, consisting of 1–2 words. Difficulty with social skills was noted at 2 years. There were significant concerns regarding gross motor function at 3 years. CAG repeat length = 120. At 6 years and 7 months her language skills were <1% for age, visuospatial skills were 5% for age.
Patient 2 spoke her first word at one year but did not use phrases until 3 years. At age 5 she demonstrated behavioural and social difficulties. Gross and fine motor delays became apparent at age 8. CAG repeat length = 100. At 11 years and 1 month she scored<1% for age on all neuropsychological domains.
Patient 3 spoke his first word at 9 months but did not speak in full sentences until after 3 years. At 6 years and 2 months he sustained a streptococcal infection and since then has had a rapid decline in motor function and speech. CAG repeat length = 93. At 6 years and 7 months language skills were 21% for age and visuospatial skills were 1% for age.
Despite variability in clinical course, all three patients manifested speech delay as the first presenting symptom of HD. In this series, onset of speech delay predated motor symptoms by at least 2 years of age, and language function was consistently impaired. Screening and management of speech delay is particularly important in children with a family history of HD.
Keywords: juvenile HD; neurocognitive function; speech delay
P041 MR SPECTROSCOPIC AND CLINICAL HETEROGENEITY IN JUVENILE ONSET HUNTINGTON’S DISEASE
N. C. ReynoldsJr, R. W. Prost.The Medical College of Wisconsin, Milwaukee USA
Using the definition of juvenile onset Huntington’s disease (HD) as clinical onset before age 21 years and CAG repeats >60, we present six cases as examples of the variability encountered in this condition. Three males and three females aged of 3–21 years display a range of CAG repeats from 61–250. One is an example of maternal anticipation and five of paternal anticipation. The separate individuals showed variability in clinical presentation with examples of attention deficit disorder with obsessive behaviour, dementia, dementia with action myoclonus, L-dopa responsive rigidity, absence with enuresis, and myoclonic and generalised seizures with ataxia. MR spectroscopic profiles of the six cases are also presented to highlight the relative contributions of pathophysiological processes emphasised in HD animal models to the juvenile HD pathophysiology. Glutamate excitotoxicity is clearly the most prominent contributor, especially at higher CAG repeats, while deficits in endogenous creatine the least contributory. Some intermediate contribution was noted from mitochondrial insufficiency (lactate elevations) and spermine markers of apoptosis also noted. Prevalence of specific metabolite abnormalities might be indicative of specific neuroprotective requirements.
Keywords: juvenile-onset HD; spectroscopy
P042 PRECLINICAL DIAGNOSIS OF HUNTINGTON’S DISEASE
H. W. Lange1, A. Aulich2, N. Beenen3, H. -H. Friedemann3, H. Hefter3, V. Hömberg4, T. Kuwert5, J. Noth6, K. Podoll6.1Ambulantes Interdisziplinäres Rehazentrum Düsseldorf; 2Radiologisches Institut der Heinrich-Heine-Universität Düsseldorf; 3Neurologische Klinik der H.Heine-Universität Düsseldorf; 4Neurologisches Therapiecentrum Düsseldorf; 5Forschungszentrum Jülich der H Heine-Universität Düsseldorf; 6Neurologische Klinik der Technischen Hochschule Aachen, Germany
We present follow up data of 1087 patients seen at the Chorea-Center of the University of Düsseldorf between 1980 and 2005. 660 of these patients were symptomatic at the time of first evaluation. Of the 427 people at risk (PAR), 56 became symptomatic during the follow up period, 64 tested gene-positive and 72 gene-negative; 235 are not yet tested and still asymptomatic.
The patients participated in an ongoing project aiming at establishing reliable procedures of early clinical and presymptomatic detection of Huntington’s disease (HD) and to monitor the disease from the preclinical to advanced stage. We offered cranial 18FDG-PET and CT scanning, SEP, long loop reflex, measurement of the speed of saccadic eye movements and the speed of voluntary (fastest rapid alternating and single) and involuntary (tremor) movements, psychometric testing of cognitive, and mnestic functions. Most patients took part in a reduced number of examinations, due to personal and technical reasons.
All choreatic patients had reduced striatal glucose metabolism as seen in PET, and five of seven later symptomatic PAR had also reduced striatal measures, the earliest nine years before age of onset (AAO). All of the nine gene-free PAR had normal caudate measures in PET, but one had a reduced activity in the lentiform nucleus (this person was a non-paternity case on genetic marker testing, direct molecular test not performed so far). Four gene-positive PAR had normal PET readings in striatum, one had pathological values four years before the expected AAO. Thirty five of 438 choreatic patients had normal measures of caudate atrophy in CT scans (CC/IT). Cortical atrophy was more frequent and more prominent in the posterior parts of cerebral cortex and visible in 11 of 15 gene-positive PAR, none of them showing caudate atrophy.
SEP have a high diagnostic power: 13 of 40 later manifest PAR had low amplitude SEP up to 10 years before AAO. Eleven of 21 later manifest PAR had a cognitive deficit before motor AAO.
Keywords: PET; neurophysiology; cognition
P043 RATE OF DECLINE OF STRIATAL IMAGING PARAMETERS IN PRECLINICAL CARRIERS OF THE HUNTINGTON’S DISEASE MUTATION
J. C. H. van Oostrom1, R. P. Maguire1, C. C. Verschuuren-Bemelmans1, L. Veenma-van der Duin1, J. Pruim1, R. A. C. Roos2, K. L. Leenders1.1Department of Neurology, Department of Clinical Genetics and PET Center, Groningen University Medical Center, Groningen; 2Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands
Developing a reliable biomarker of neuronal dysfunction in presymptomatic and early Huntington’s disease (HD) is of pathophysiological and potentially therapeutic relevance. We studied 41 people at risk for HD with MRI and PET. We applied the Unified HD Rating Scale to exclude motor disease activity and used MRI for striatal volumetry, 11C-raclopride binding potential (RAC-BP) as a measure of dopamine D2 receptor availability and fluorodesoxyglucose metabolic index (GMI) for glucose metabolism.
Those investigators who were involved in data collection and data analysis were blinded to the results of genetic testing of the 27 preclinical mutation carriers (age, 39 (SD 6.6) years; sex, 59% females; CAGrepeats, 43 (SD 2.4)) and their 14 siblings without the repeat expansion (age, 45 (SD 11.6) years; sex, 57% females; all CAGrepeats <35).
At baseline, mutation carriers showed significantly reduced striatal glucose metabolism, dopamine D2 receptor availability, and volumes but more than half of subjects still had normal values: 50% for BP-RAC, 67% for GMI, and 80% for volumetry. The product of age and CAGrepeat length, a measure of cumulative biological disease load, did not correlate significantly with striatal GMI. In contrast, RAC-BP in putamen and caudate nucleus decreased significantly with increases in the product of age and CAG repeat length (p<0.0005). This suggests that the decreases in dopamine D2 receptor availability in presymptomatic HD are relatively larger than the equivalent changes in glucose metabolism.
We have repeated all clinical and imaging measurements after two years and will be unblinded shortly for the results of genetic testing. Results of this follow up study will be presented.
Keywords: preclinical; PET; imaging
P044 MRI FINDINGS IN HUNTINGTON’S DISEASE
M. K. Magnet1, A. K. Hödl1, H-PKapfhammer1, R. M. Bonelli1, F. Reisecker2.1University Clinic of Psychiatry, Medical University Graz, Auenbruggerplatz 31, 8036 Graz;2 Krankenhaus der Barmherzigen Brüder Graz, Eggenberg
Objective: To correlate the grade of cerebral atrophy in Huntington’s disease (HD) with the stage of the disease.
Methods: Thirty seven patients with HD in different stages were included in our study. MRI scans were performed and graded using the Vonsattel-criteria for neuropathological grading. Furthermore we have correlated the Vonsattel-grade with the United HD Rating Scale (UHDRS); this included motor function, neuropsychological function, and psychiatric symptoms, and with number of CAG (cytosin, adenin, guanin) repeats.
Results: As expected the correlation between UHDRS, CAG repeats, and Vonsattel-grade of neurodegeneration was highly significant; however, it did not correlate with psychiatric symptoms.
Conclusion: HD is an autosomal dominantly inherited neuropsychiatric disorder. It is caused by a genetic defect on the short arm of chromosome 4 at 4p16.3, leading to an increased number of CAG repeats in the coding sequence. This leads to degeneration of cerebral structures, especially of the basal ganglia. Our study proves that the grade of cerebral atrophy increases as the disease progresses.
P045 HUNTINGTON PATIENTS PRESENT ALTERED HABITUATION IN THE AUDITORY CORTEX AS MEASURED BY FMRI
C. Saft1, A. Habbel2, J. E. Andrich1, P. H. Kraus1, H. Przuntek1, B. Pfleiderer2.1Department of Neurology, Huntington-Center NRW, St Josef Hospital, Bochum, Germany; 2Department of Clinical Radiology, University of Münster, Germany
Background: Functional magnetic resonance imaging (fMRI) has been shown to be a useful tool to assess alterations in various cognitive functions in symptomatic patients with Huntington’s disease (HD). It was shown that depressed patients exhibited a disturbed habituation pattern (reduction of activation after prolonged or repeated exposure to auditory stimuli). It was postulated that HD patients not only present motor deficits, but might also have sensory impairment. The aim of this study was to measure habituation effects to auditory stimulation within the auditory cortex.
Methods: Seven symptomatic patients (age 39.2 (SD 14.3) years) were compared to seven age and sex matched healthy subjects (age 39.5 (SD 14.8) years). Images were acquired on a 3 Tesla Intera MR system (Philips, the Netherlands) in a block design. fMRI: 60 gradient echo-planar imaging (GE-EPI) images (TR = 10 sec, TE = 60 ms, matrix dimensions: 64×64, FOV = 210 mm, 16 oblique axial slices, slice thickness = 3.6 mm, scan time = 3.4 sec). Auditory stimulation paradigm: Three stimulation cycles A1-A3 of digitally generated pulsed (5 Hz) 800 Hz sine tones of 2 minutes’ duration (ON), which alternated with rest periods R1-R3 of 1 minute’s duration (OFF). Auditory stimulation was presented binaurally via pneumatic headphones. Analysis was done by SPM2 and SPSS 12.0. Clinical rating was performed according to UHDRS and extended neuropsychological testing.
Results: All patients presented the following abnormal habituation fMRI pattern. Compared with healthy controls who showed a characteristic signal decay to repeated acoustic stimulation (A2, A3) HD patients exhibited an activity increase in A2, followed by a signal decrease in A3. This was different from depressed patients which showed no habituation at all.
Conclusion: Our data provide the first indications that auditory sensory functions are altered in HD patients. Further investigations in presymptomatic mutation carriers are currently being performed.
Keywords: fMRI; auditory habituation
P046 HUNTINGTON PATIENTS PRESENT DIFFERENCES IN ACTIVATION PATTERNS TO MUSIC, TONE, AND SYLLABLES COMPARED WITH CONTROLS IN FMRI
C. Saft1, A. Habbel2, J. E. Andrich1, P. H. Kraus1, H. Przuntek1, B. Pfleiderer2.1Department of Neurology, Huntington-Center NRW, St Josef Hospital, Bochum, Germany; 2Department of Clinical Radiology, University of Münster, Germany
Background: Functional magnetic resonance imaging (fMRI) has been demonstrated to be a useful tool to measure alterations in various cognitive functions in symptomatic patients with Huntington’s disease (HD). It was postulated that HD patients not only present motor deficits, but might also have sensory impairment. The aim of the present study was to assess differences in activation patterns to various types of auditory stimulation by fMRI: music (emotional), tones (neutral), and syllables (speech preception).
Methods: Seven symptomatic patients (age 39.2 (SD 14.3) years) were compared with seven age and sex matched healthy subjects (age 39.5 (SD 14.8) years). Images were acquired on a 3 Tesla Intera MR system (Philips, the Netherlands) in a block design. fMRI: 60 gradient echo-planar imaging (GE-EPI) images (TR = 10 sec, TE = 60 ms, matrix dimensions: 64×64, FOV = 210 mm, 16 oblique axial slices, slice thickness = 3.6 mm, scan time = 3.4 sec). Auditory stimulation paradigm: Three stimulation cycles of 90 seconds’ duration each (ON); A1 = piano music (Barcarole, Alkan), A2 = of digitally generated pulsed sine tones (5 Hz) 800 Hz and A3 = syllables (bla-bla), which alternated with rest periods R1-R3 of 1 minute’s duration (OFF). Auditory stimulation was presented binaurally via pneumatic headphones. Analysis was done by SPM2 and SPSS 12.0. Clinical rating was performed according to UHDRS and extended neuropsychological testing.
Results: HD patients presented activation in distinct brain areas dependent on the given stimuli, which were not seen in controls. The most differences were seen for music in a trend (p = 0.07, χ2): BA 28 and 10 (right), BA 32 and 9, BA 10 (left). Syllables: BA 6 (left, p = 0.07)) and BA 21 (right, p = 0.021)). Tones: BA re (left, p = 0.06).
Conclusion: Auditory sensory functions are altered in HD patients.
Keywords: fMRI; auditory; music.
P047 STRUCTURAL AND METABOLIC CHANGES IN HUNTINGTON’S DISEASE BRAIN
F. Squitieri1, M. Cannella1, D. C. Rubinsztein2, L. Frati3, S. Lastoria4, AndreaCiarmiello4.1Neurogenetics Unit, IRCCS Neuromed, Pozzilli IS, Italy; 2Cambridge Institute for Medical Research, Addenbrooke’s Hospital, Cambridge, UK; 3Department of Experimental Medicine and Pathology, University “La Sapienza” of Rome, Rome, Italy; 4Nuclear Medicine Unit, IRCCS “G Pascale”, Naples, Italy
We studied the anatomical and functional changes in various brain areas during the course of Huntington’s disease (HD) in a large cohort of mutation-positive individuals (n = 71) encompassing the complete range of disability (presymptomatic through stages I–V), and in normal controls, with the aim to define both degenerative and dysfunctional brain changes in the same subjects. We used a magnetic resonance imaging (MRI) and unsupervised multiparametric segmentation procedure based on a relaxometric approach to measure in vivo brain tissue volumes in 71 subjects with presymptomatic to advanced HD stage. The same population was evaluated by [fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) scanning to assess variations in brain glucose metabolism. To predict age at onset in unaffected mutation carriers, we considered the estimated number of years from each subject’s age to manifested HD symptoms, for a given expanded triplet number. Age adjusted analyses confirmed that the 71 subjects as a group, as well as the subgroup of 24 unaffected presymptomatic subjects at risk for HD, had significantly smaller grey matter and white matter volumes and larger cerebrospinal fluid volumes than controls (p<0.0001). In the 24 presymptomatic subjects we observed a significant inverse linear correlation between white matter volume reduction and the estimated time to symptom onset (r2 = 0.39, p = 0.0011). Both clinically unaffected subjects at risk for HD and symptomatic patients had significantly decreased glucose uptake in the cortex (frontal and temporal lobes) and striatum (caudate and putamen). HD subjects who were followed up longitudinally showed progressive white matter reduction in the preclinical cases (n = 10) and decreased glucose uptake in the cortex and striatum in affected (n = 21) and preclinical (n = 10) subjects. White matter volume loss may precede grey matter atrophy and may be associated with neuronal dysfunction in early disease.
Keywords: magnetic resonance imaging (MRI); positron emission tomography (PET)
P048 IMPROVING BINDING POTENTIAL ANALYSIS IN [11C]-RACLOPRIDE BRAIN-PET STUDIES USING CLUSTER ANALYSIS
T. Schwarzlmueller1, G. Glatting2, B. J. Krause2, B. Neumaier2, S. N. Reske2, G. B. Landwehrmeyer3.1Department of Neurology/Nuclear Medicine, University of Ulm; 2Department of Nuclear Medicine, University of Ulm; 3Department of Neurology, University of Ulm, Germany
Introduction: [11C]-Raclopride (RAC) PET is used to determine brain dopamine-D2 receptor binding sites in vivo. To calculate [11C]Raclopride binding potentials (BPs), a reference tissue model is widely used. The generation of time activity curves (TACs) of a reference region—that is, cerebellum—is required. The reference model assumes that the region selected as reference does not contain dopamine-D2-receptor-like binding sites. Manually defined reference tissue ROIs are prone to increased variability due to focal inhomogenities and D2-like specific binding sites in the cerebellum. We therefore explored the use of cluster analysis to automatically identify volume elements (voxels) with similar biokinetics to more reliably define a reference region.
Methods: Four patients with genetically confirmed Huntington’s disease in early stages (stage I and II according to Shoulson and Fahn) were selected for this study. PET acquisition parameters were as follows: dynamic, in 3D mode (Siemens/CTI ECAT EXACT HR+, Knoxville, TN); 17 time frames (duration 5–600s) over 60 minutes, starting at the time of injection; [11C]RAC dosis: 247 (SD 27) MBq; specific activity: 29 (SD 15) GBq/μmol; attenuation correction, 3D filtered back-projection. Data-analysis: BP was estimated using a simplified reference region model. The cerebellar reference tissue ROIs were either defined manually (standard procedure) or using cluster analysis. The ratio of volumes of ligand distribution in the striatum relative to cerebellum according to
BP was calculated using the receptor parametric mapping (RPM) software developed by Gunn et al.
Result: The Wilcoxon matched pairs signed rank test demonstrated a significant difference between the manually and cluster defined reference tissue ROIs for both the BP and the standard deviation (p<0.05).
Conclusion: The semiautomated and observer independent cluster analysis allows to analyse in vivo receptor binding studies with [11C]RAC PET using a reference tissue model with high accuracy and reproducibility.
Keywords: [11C]-Raclopride PET; dopamine-D2 receptor binding; cluster analysis
P049 IRON ACCUMULATION IN BASAL GANGLIA OF HUNTINGTON’S DISEASE
D. Leske1, H. Stimmer2, H. G. von Einsiedel2, T. Mayer1, AWeindl1.Departments of 1Neurology and 2Radiology Technische Universität München, Germany
Iron accumulation (IA) in brain has been observed in neurodegenerative diseases including Alzheimer’s disease, multisystem atrophy, and neurodegeneration with brain IA (NBIA 1). Brain IA has been found postmortem using histochemistry and more recently in vivo using MRI (gradient echo sequence GRE). Huntington’s disease (HD) patients were investigated using MRI (1 mm axial sections) for regional brain atrophy, and GRE for determining IA. Only a part of the patients had signal changes typical for IA in caudate and putamen. The aim of this study was to determine (1) the reliability of the signal changes indicating IA, (2) whether correlations exist between HD patients with and without IA concerning biographical (age, sex, paternalism/maternalism) and clinical data (HDRS, AIMS, ADL, CGI, CERAD). MRI scans with GRE images of 40 molecular genetically proven HD patients were presented to two experienced neuroradiologists (GH, SH), independently. There was a high interrater correlation (kappa>0.6) in almost all cases suggesting that neuroradiological evaluation of signal extinction indicating IA in basal ganglia is highly reliable. In 25 of 40 HD patients IA of various intensity and distribution was found. This group was further investigated and compared with the group without IA. This revealed that both groups can be differentiated on clinical data. Group differences become more significant with increasing intensity and size of IA. Patients with IA are older and have more pronounced symptoms. They are more impaired (significant differences concerning AIMS, ADL, CGI, and partially UHDRS), manifest more frequently with motor symptoms; atrophy of the head of the caudate nucleus (bicaudatum index, BCI) is more pronounced. No significant differences were found concerning sex, paternalism/maternalism, and CAG repeat length. Concerning cognitive impairment, some items of the CERAD test showed significant differences. The findings suggest that IA in caudate and putamen in a subgroup of HD patients correlates with more pronounced symptoms and higher degree of impairment. Increased IA has been associated with neurodegenerative processes, especially in mitochondrial oxidative and energy metabolism. The question remains why IA is not apparent in all HD patients, particularly in later stages.
Keywords: iron accumulation; magnetic resonance imaging (MRI)
P050 CORRELATION OF STRIATAL AND INSULAR ATROPHY WITH EXECUTIVE DYSFUNCTION IN EARLY STAGES OF HUNTINGTON’S DISEASE
A. Peinemann1, S. Schuller2, M. Staedtler3, C. Pohl3, T. Jahn3, A. Weindl1, J. Kassubek4.1Department of Neurology, Technische Universität München, Munich, Germany; 2Department of Neurology, University of Regensburg, Germany; 3Department of Psychiatry (Clinical and Experimental Neuropsychology Unit), Technische Universität München, Munich, Germany; 4Department of Neurology, University of Ulm, Germany
The aim of the study was to clarify if cognitive dysfunction in early stages of HD is correlated with loco-regional structural changes in 3D-MRI. Twenty five patients (13 male, 12 female, mean age 44 (SD 8) years) with genetically confirmed HD were included, all in early clinical stages (I and II); the mean duration since onset of motor symptoms was 4.7 (SD 3.3) years. High resolution volume rendering MRI scans (MP-RAGE) were acquired on a 1.5 T clinical scanner. MRI data were analysed by voxel based morphometry (VBM) in comparison to an age matched normal database consisting of 25 healthy volunteers. Out of VBM results, the areas of highest significant differences (global maximum) in both hemispheres were defined as regions of interest (ROI). Moreover all patients underwent extensive neuropsychological testing, particularly including executive tasks (Tower of Hanoi, Stroop, modified Wisconsin Card Sorting Test). A correlation analysis was performed between these ROIs and the results of neuropsychological tests. Caudate and putamen bilaterally demonstrated robust regional decreases of grey matter volumes (p<0.05, corrected for multiple comparisons) in HD in the group analysis. Executive dysfunction was significantly correlated with the areas of highest significant differences out of VBM results which were located bilaterally in the caudate (ToH: r = 0.647, p<0.001; Stroop: r = 0.503, p<0.01; mWCST: r = 0.452, p<0.05). Moreover, subgroup analyses revealed marked insular atrophy (Talairach coordinates 43/-3/1; Z-score 5.64) in HD patients who performed worse in the single executive tasks. Two points must be stressed in this correlational study: (1) executive dysfunction in HD patients in early stages is accompanied by striatal atrophy and (2) the insular lobe seems to be involved in executive dysfunction as assessed by neuropsychological tests requiring for planning and problem solving, stimulus response selectivity, and concept formation.
Keywords: magnetic resonance imaging (MRI); neuropsychology
P051 FUNCTIONAL MRI AND VOXEL BASED MORPHOMETRY IN HUNTINGTON’S DISEASE
R. Petralli, C. Gavazzi, R. Della Nave, L. Guerrini, C. Tessa, S. Piacentini, M. Mascalchi.Department of Neurological and Psychiatric Sciences, University of Florence, Italy
Thinning of the cortical ribbon is an early finding in Huntington’s disease (HD) and is typically observed in the motorsensory cortex. We investigated with magnetic resonance the brain structure and function during a simple motor task in nine symptomatic HD patients and 11 healthy controls. They were examined with a T1 weighted 3D gradient echo sequence and an Echo Planar Imaging sequence exploiting blood oxygenation level dependent contrast during finger tapping of the dominant hand. Regional loss of the brain grey and white matter were explored with voxel based morphometry (VBM). Areas of relative activations were explored with Statistical Parametric Mapping 2 (SPM2) software. VBM showed bilateral regional grey matter loss involving caudate nucleus, lentiform nucleus, thalamus, insula, and the inferior frontal gyrus. Grey matter loss was also observed in the left middle occipital and middle temporal gyrus.White matter loss was observed in the extranuclear white matter. Patients showed significantly increased activation of contralateral intraparietal sulcus (Montreal Neurological Institute (MNI) coordinates: −20, −50, 38), ipsilateral secondary motor area (MNI coordinates: 48, −40, 40), and ipsilateral precentral gyrus (MNI coordinates: 18, −26, 54) and decreased activation of the contralateral caudate (MNI coordinates: −20, −16, 20) and in the contralateral frontal pole (MNI coordinates: −2, 62, 4). Our results indicate that brain structural changes typical of HD are associated with either increased or decreased cerebral activations, whose pathophysiological correlates deserve further investigation.
Keywords: functional MRI; voxel based morphometry; cortical atrophy
P052 IN VIVO IMAGING OF ACTIVATED MICROGLIA BY 11C-(R)-PK11195 PET. A BIOMARKER OF NEUROINFLAMMATION IN HUNTINGTON’S DISEASE?
N. Pavese1, A. Gerhard1, Y. F. Tai1, A. K. Ho2, F. Turkheimer1, R. A. Barker2, D. J. Brooks1, P. Piccini1.1Imperial College, London; 2Brain Repair Centre, Cambridge, UK
Postmortem evidences of progressive accumulation of activated microglia in Huntington’s disease (HD) brains and preliminary positive results of anti-inflammatory agents in animal models of the disease have led to several clinical trials of these agents, particularly minocycline, in HD patients. Unfortunately, the results of preliminary studies are conflicting, likely reflecting the different use of clinical scales and the lack of a sensitive biomarker for inflammation.
The aim of this study was to determine whether microglial activation observed in pathological studies in HD could be detected in vivo using PET and whether this technique provides a reliable biomarker of the pathological process.
Eleven HD patients were studied with 11C-(R)-PK11195 PET, a selective in vivo marker for activated microglia. Nine of them also underwent 11C-raclopride PET, a marker of the dopamine D2 receptor binding, which provides a measure of striatal functional integrity and is a highly sensitive biomarker of HD severity. A region of interest approach was employed to analyse PET images.
The HD patients compared with age matched controls showed increased mean 11C-(R)-PK11195 binding potential (BP) levels in the whole striatum (p<0.001), caudate (p<0.01), and putamen (p<0.01). Mean striatum, caudate, and putamen 11C-raclopride BPs were significantly decreased in the HD patients compared with the controls (p<0.001). Striatal 11C-raclopride BPs inversely correlated with striatal 11C-(R)-PK11195 BPs (p<0.05) in individual HD cases and clinical severity, rated with the UHDRS total motor score, correlated inversely with striatal 11C-raclopride (p<0.01), and positively with striatal 11C-(R)-PK11195 BPs (p<0.05).
These findings are consistent with the view that microglial responses may contribute to the ongoing neuronal degeneration in HD. They also show that microglial activation is a suitable biomarker for the inflammatory process in HD providing a method to assess the effects of anti-inflammatory agents and other neuroprotective therapies.
Keywords: biomarker; PET; inflammation
P053 HOLDING YOUR BREATH: INTERVIEWS WITH YOUNG PEOPLE WHO HAVE UNDERGONE PREDICTIVE TESTING FOR ADULT ONSET, UNTREATABLE CONDITIONS
R. E. Duncan1,3, J. Savulescu1,2, L. Gillam, R. Williamson, M. B. Delatycki1,3.1Murdoch Children’s Research Institute, Royal Children’s Hospital, Parkville, Victoria, Australia; 2Oxford Uehiro Centre for Practical Ethics, University of Oxford, UK; 3Bruce Lefroy Centre for Genetic Health Research, Royal Children’s Hospital, Flemington Road, Parkville, Victoria, Australia
Aim: Predictive genetic testing is offered to asymptomatic adults even when there is no prophylaxis or treatment available. However, testing of young people in similar circumstances is controversial and international guidelines recommend against it. Despite this, there has been considerable debate regarding the issue. Some perceive such testing as too potentially harmful to allow. Others perceive it as an opportunity for the promotion of benefit, an opportunity even for the prevention of harm. There is virtually no empirical evidence available to support either perception. Here, we report the findings of qualitative interviews performed with young people who have undergone predictive genetic testing.
Methods: Eighteen interviews were performed with young people between the ages of 14 and 26 years who had undergone predictive genetic testing for Huntington’s disease (eight individuals) and familial adenomatous polyposis (10 individuals). Thematic analysis was performed using the qualitative research software package NVIVO (NVIVO 2.0, QSR International Pty Ltd)
Results: For young people living at risk of a genetic condition, a specific coping mechanism is often employed. This entails living as though they are gene-positive and will develop the condition later in life, in order to cope with the possibility that this may occur in the future. Several harms are associated with such behaviour. For these young people, provision of a predictive genetic test may do no more than confirm an existing belief about gene-positive status or remove existing harms related to this perception, in the event of a gene-negative test result.
Conclusion: If further research corroborates the themes that have emerged during our interviews with young people who have undergone predictive genetic testing, such testing should be offered to mature minors requesting testing in the future. Accordingly, current guidelines should be revised.
Keywords: ethics; genetic testing; counselling
P054 QUALITATIVE INTERVIEWS IN A SUBSET OF PHAROS PARTICIPANTS
K. A. Quaid, M. Swenson1,2, S. Sims2, the PHAROSInvestigators and Coordinators.1Indiana University School of Medicine; 2Indiana University School of Nursing, Indianapolis, IN, USA
The Prospective Huntington At Risk Observational Study (PHAROS) is a longitudinal observational study of 1001 individuals at 50% risk for Huntington’s disease (HD) who have chosen not to be tested for the presence or absence of the HD gene mutation. As a condition of our funding from the Ethical, Legal and Social Implications Program (ELSI) of the National Center for Human Genome Research, we conducted 50 in depth face to face qualitative interviews with a subset of PHAROS participants. Five interviewers from top PHAROS recruiting sites were trained and each completed 10 interviews. Data collection took place between December of 2003 and April of 2005.
The mean age of the interviewees was 42 years (SD 7.8) and the mean education was 15.6 years (SD 2.3). Thirty five females were interviewed and 15 males reflecting the almost two to one ratio of females to males in the larger PHAROS population. The sample was 88% White, 8% Black, 2% Hispanic, and 2% Other.
ATLAS software is being used for data analysis and preliminary analysis has revealed several initial themes. These are: reasons for participating in research, reasons not to pursue genetic testing, reproductive decision making, sex differences in care taking, and the emotional burden of being at risk. These themes, and others, will be examined in greater detail.
Keywords: at risk; qualitative interviews
P055 COMPETENCE OR MATURITY? A CASE AGAINST PREDICTIVE TESTING OF MINORS FOR HUNTINGTON’S DISEASE
F. H. Richards.Department of Clinical Genetics, The Children’s Hospital at Westmead, Westmead, NSW 2145, Australia
Guidelines developed for the provision of direct mutation predictive testing for Huntington’s disease (HD) state that such testing should only be offered to individuals who have “... reached the age of majority”. The committee that formulated these guidelines consisted of professionals with expertise in HD, and representatives of HD families. Their extensive experience of HD convinced them that predictive testing had such potentially serious implications for an at risk person’s future that it should only be undertaken by fully informed, freely consenting adults.
Since the early 1990s, a number of authors have argued that predictive testing for conditions such as HD should be available to minors at the request of parents and/or at the request of younger adolescents themselves. Most of these authors have no clinical experience in the practice of predictive testing—they are ethicists, lawyers, and research psychologists using theoretical and legal arguments.
The case for allowing some adolescents younger than 18 years to proceed with testing is based on an assessment of competence. Although competence is a necessary condition for informed consent for predictive testing, the author has found that competence is not a sufficient criterion. The concepts of genuine psychosocial maturity (as opposed to pseudomaturity) and maturity of judgement are also highly relevant to predictive testing. It will be argued that, as a young person’s level of maturity is still evolving during adolescence, it is not developmentally possible for under 18 year olds to possess the maturity of judgement required to appreciate the potentially complex social and emotional implications of a carrier result. Research with adults undergoing predictive testing has identified profound long term psychological effects in areas such as (future) relationships, reproductive decision making, and family dynamics. Such evidence highlights the potential for harm in testing adolescents. Three case studies of 18 year olds requesting predictive testing will be presented to illustrate concerns about lowering the age for predictive testing.
Keywords: predictive testing minors
P056 TOO YOUNG??? EXPLORING REQUESTS FOR PRESYMPTOMATIC TESTING FOR HUNTINGTON’S DISEASE IN THOSE UNDER 18 YEARS
R. Glew.UK Huntington’s Disease Consortium
The UK Huntington’s Disease Prediction Consortium was established in 1987 and involves representatives from all 23 regional genetics centres in the UK. The group’s role has been in the discussion and recommendation of policies relating to HD, notably the guidelines for presymptomatic testing published in 1989, revised in 1993. The group also coordinates and discusses research projects and collects audit data relating to diagnostic, presymptomatic, and prenatal testing on a national level.
There has been much debate about the ability of under 18 year olds to give informed consent for presymptomatic testing. This abstract will discuss the 28 tests have been carried out on individuals below the age of 18 years (1993–2004). Also presented will be data collated during the last four years on requests for testing of “minors” received by UK regional genetics departments.
A small number of case vignettes will be presented to illustrate motivation for requesting presymptomatic testing in these individuals and whether they proceeded to test, or whether their requests were denied. The application of the guidelines for predictive testing in these particular cases will be explored.
Keywords: presymptomatic testing
P057 CASE REPORT. PREDICTIVE TESTING FOR HUNTINGTON’S DISEASE: AN UNEXPECTED FINDING AND INTERESTING COUNSELLING SCENARIO
A. Smith, R. Macleod, D. Craufurd.Academic Unit of Medical Genetics and Regional Genetics Service, St Mary’;s Hospital, Manchester, UK
Background: Huntington’s disease (HD) is an autosomal dominant condition that is caused by a CAG triplet repeat expansion in the huntingtin gene. Most affected individuals are heterozygotes for this expansion. However, there have been several reports suggesting that individuals who are homozygous for HD have a similar clinical picture to heterozygotes. These cases are often seen in the context of consanguinous relationships.
Case Report: We present the case of a 22 year old man who attended the clinic requesting predictive testing for HD. His mother had died from the condition at the age of 46 years. The proband had had no contact with his mother, or her side of the family, since being a small child. He was supported through the predictive testing process, during which there was a suggestion of some suspicious involuntary movements and cognitive problems. The predictive test result showed that the proband was actually homozygous for expanded HD alleles.
Discussion: This unexpected finding raised some difficult management and counselling challenges. The proband and his family were unaware of the relevance of his symptoms and it was decided that conveying an “unfavourable” result would be most appropriate in the first instance. This came as a complete shock to the family and they have had difficulties accepting it. The homozygous nature of the result was not broached as it was felt that the family should be given time to adjust to the situation. We discuss the implications of this result to this family and possible counselling strategies to approach this scenario.
Keywords: counselling; homozygous
P058 HUNTINGTON’S DISEASE IN PORTUGAL: SEVEN YEAR EXPERIENCE OF THE REFERENCE LABORATORY
P. Magalhães1, M. Carmo Costado1,8, F. Ferreirinha1, L. Guimarães1,9, C. Januário2, I. Gaspar3, L. Loureiro1,4, J. Vale3, C. Garrett5, F. Regateiro2, M. Magalhães3, A. Sousa1,7, P. Maciel1,8, J. Sequeiros1,7.1UnIGENe, IBMC, Univ Porto; 2Fac Medicina, Univ Coimbra, and HUC, Coimbra; 3Hosp Egas Moniz, Lisboa; 4Hosp S Teotónio, Viseu; 5Hosp S João, Porto; 6Hosp Sto António, Porto; 7ICBAS, Univ Porto; 8Univ Minho, Braga; 9Univ Fernando Pessoa, Porto, Portugal
Since 1988 our laboratory has been the reference laboratory for genetic testing of Huntington’s disease (HD) in Portugal. A total of 735 genetic tests were performed in people of Portuguese origin: 496 for confirmation or exclusion of a clinical diagnosis, 224 for presymptomatic, and 15 for prenatal testing; 80.2% of requesting physicians were neurologists; 310 (62.5%) of all diagnoses requested for confirmation or exclusion were confirmed, while 186 (37.5%) were excluded.
In summary, 310 patients (274 families) have so far been molecularly diagnosed at our lab, including six infantile and six juvenile cases, one of whom had inherited it from the mother. Mean age at onset was 44.3 (SD 14.9) years. In 224 presymptomatic tests, an excess of females (63.8%) was again verified; 42% of the presymptomatic consultands were found to be carriers. Four fetuses were carriers: one request for PGD has been received from a couple who had two twins and a third fetus affected, in two consecutive pregnancies.
In conclusion, availability of genetic testing allowed the identification of HD for the first time in 88.4% of all the families known, including five patients with unusual presentation and 10 without any family history. Prevalence of HD in Portugal should be at least 3–5:100 000. Our patient population seems rather similar to others described so far, namely in terms of mean age at onset and (CAG)n distribution, except perhaps for a higher frequency of normal unstable (class 2) alleles (5.2%), an a slightly higher number of patients with onset over age 60 years (up to 79 years). Our experience identified cases with particular problems for genetic counselling, such as four “homozygotes”, who pose a serious ethical dilemma for counselling, carriers of unstable alleles with increased genetic risks (5%), and “homoallelism” for a same size normal allele (5.6%), which will demand further procedures and may delay results in presymptomatic and prenatal testing.
Keywords: genetic testing; counselling; ethics
P059 GENETIC EPIDEMIOLOGY AND FOUNDER EFFECT OF HUNTINGTON’S DISEASE MUTATION IN VALENCIA, SPAIN
J. A. Burguera1, P. Solís1, J. M. Millán, J. Garcia-Planells2, F. Palau2, C. Espinós2, D. Ginestar3.Hospital Universitari La Fe, Valencia, Spain, Instituto de Biomedicina, CSIC, Valencia, Spain, Polithecnic University of Valencia, Valencia, Spain
Huntington’s disease (HD) is an autosomal dominant neurodegenerative disorder characterised by progressive motor impairment, cognitive decline, and emotional deterioration, and caused by the abnormal expansion of a CAG trinucleotide repeat in the first exon of the huntingtin gene in chromosome 4p16.3. HD occurs with a frequency of 5–10/100 000 individuals in most White populations, although its frequency varies among populations. The disease is spread worldwide and it is generally accepted that few mutational events account for the origin of the pathogenic CAG expansion in most populations. We have investigated the genetic history of HD mutation in our series of 115 HD patients belonging to 83 families from the Land of Valencia, Eastern Spain (∼four million people). The five polymorphic markers, pter-D4S126-rs1313770-HD/CCG-rs82334-D4S3034-cen, located within or close to the huntingtin gene were analysed. The analysis of the HD/CCG repeat suggested that at least two main chromosomes were associated in the Valencian population, one associated with allele 7 (77 mutant chromosomes) and one associated with allele 10 (two mutant chromosomes). On the basis of rs1313770-HD/CCG-rs82334, haplotype A-7-A (H1) was observed in 47 out of 48 mutant chromosomes obtained by segregation analysis, as it also was in 120 out of 166 chromosomes constructed using the PHASE program. The genetic history and geographical distribution of the main haplotype H1 were both studied by constructing extended haplotypes with flanking STRs D4S106 and D4S3034. We observed a non-homogenous distribution in the different regions associated with the different extended haplotypes of the ancestral haplotype H1, suggesting that local founder effects have occurred. Finally, to further investigate the natural history of HD, we estimated the age of the founding haplotype H1 and we found that it was between 4700 and 10 000 years ago.
Keywords: genetic epidemiology; mutation allele age
P060 ON MODIFIER GENES FOR THE AGE AT ONSET IN HUNTINGTON’S DISEASE
L. Arning1, W. Hansen1, P. Jagiello1, S. Wieczorek1, S. Valentin1, J. T. Epplen C. Saft12, J. Andrich2, P. H. Kraus2.1Department of Human Genetics, Ruhr-University Bochum, Universitätsstr 150, 44801 Bochum, Germany; 2Department of Neurology, St Josef Hospital, Ruhr-University Bochum, Gudrunstr 56, 44791 Bochum, Germany
Huntington’s disease (HD) is a fully penetrant autosomal dominant disorder with the number of repeats in the HD locus being highly predictive of age at onset (AO); however, other aspects of the course of illness are not well understood. Circumstantial evidence suggests that additional features of the HD course are based on genetic traits. Like other heritable quantitatively distributed traits, genetic influence on AO is likely to be due to the combined action of several to many genes of small effect. Approaches to characterise putative modifier genes include studying physiological candidate genes combined with careful phenotyping of patient populations. Therefore, we investigated whether different subunits composing the multimeric complexes of NMDA receptors represent modulate AO in HD. In our study population of 167 unrelated patients with clinical diagnosis of HD, recruited from the Huntington Center (HZ) NRW, Bochum (Germany), the repeat range from 41–45 CAG accounted for 30.8% of the variance. 12.4% additional variance could be attributed to GRIN2B genotype variation, and 4.5% to GRIN2A genotype variation. These two genes, coding for the NR2B and NRA subtypes, are mainly expressed in the striatum.
In a further study, we analysed a panel of 305 candidate genes involved in apoptosis, cytokines, REDOX-, cell cycle regulators, JNK pathway, and neurotransmission for allelic associations of linked mircrosatellite markers with AO by pooling the DNAs of individuals from opposite ends of the trait distribution. Following the identification of the modifier genes, allelic variants of these gene(s) are characterised and responsible variations are determined for phenotypic variation. Consequently, neuroprotective strategies for HD patients and people at risk should be reconsidered in the light of these findings.
Keywords: modifier genes; age at onset; NR2B
P061 INTEGRATING BEHAVIOUR AND BRAIN GENE EXPRESSION IN HUNTINGTON’S DISEASE TRANSGENIC MOUSE MODELS
G. P. Hughes1, S. P. Brooks2, A. H. Hodges1, P. Holmans1, J. M. Thomas1, D. Goldstein3, S. B. Dunnett2, L. Jones1.1Department of Psychological Medicine, Cardiff University School of Medicine, Cardiff, Wales, UK; 2The Brain Repair Group, Cardiff University, School of Biosciences, Cardiff, Wales, UK; 3Institute of Mathematics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
We have been investigating the correlation between behaviour and gene expression in the R6/1 transgenic mouse model of Huntington’s disease (HD). We characterised the behaviour of the R6/1 mice and their wild type littermates using rotorod, exploration, acoustic startle and grip strength, at 18, 22, and 27 weeks. The most marked differences were noted between the R6/1 and wild type animals in the rotorod and initial exploration tests. We also took brains from these mice within one week of their last behavioural battery, extracted RNA, and analysed gene expression using the MOE430v2.0 GeneChip from Affymetrix. Data analysis was carried out using robust multichip average (RMA) and the Genespring (v7.2) package. Results from gene expression analysis revealed that there were effectively no differences in gene expression with respect to age of animal but a large number of dysregulated genes between R6/1 and wild type brain (4525 genes significantly dysregulated between brain types at p<0.05, with FDR multiple correction applied). The actual genes dysregulated by transgenic status have a strong similarity to the changes in expression previously reported in HD transgenic mouse models. To identify potentially significant correlations between behavioural variables and dysregulated genes we have been exploring a robust multistep procedure involving Pearson’s correlation, false discovery rate (FDR) multiple hypothesis correction, regression, and stepwise analysis correlating data from individual mice. Preliminary analyses indicate strong correlations between the rotorod and gene expression results, and significant correlations between initial exploration and gene expression results. The latter is particularly interesting as the differences in behaviour in the exploration test appear not to be entirely determined by R6/1 genotype.
Supported by the BBSRC.
Keywords: microarray; behaviour; analysis
P062 SIZE DISTRIBUTION, DYNAMICS, AND HAPLOTYPE STUDIES OF THE (CAG)N AT THE HD LOCUS IN 140 AFFECTED FAMILIES AND THE GENERAL PORTUGUESE POPULATION
M. Carmo Costado1,2, P. Magalhães1, L. Guimarães1,3, P. Maciel1,2, A. Sousa1,4, J. Sequeiros1,4.1UnIGENe, IBMC, Univ Porto; 2Univ. Minho, Braga; 3Univ Fernando Pessoa, Porto; 4ICBAS, Univ Porto, Portugal
The origins and mechanisms of the CAG expansion in Huntington’s disease (HD) are still under debate. We studied (1) the CAG repeat in a large control sample, randomly drawn from the general population (2000 chromosomes), from Guthrie cards covering all regions of Portugal, and (2) performed a haplotype study with the (CAG)n and (CCG)n in 140 HD families.
(1) In the general population, the (CAG)n ranged 9–40 repeats, with the (CAG)17 being the most frequent (37.9%). Large normal (class 2) represented 3.0% of all population alleles. Two expansions (0.11% of all population alleles) were found: one incomplete penetrant (class 3), with 36 CAGs, and one fully expanded (class 4) allele, with 40 CAGs.
(2) Among HD patients, there was no evidence for geographical clustering of expanded and/or intermediate alleles. Affected families showed three different haplotypes (7, 9, and 10-CCGs), suggesting the possibility of different origins for the HD expansions among this population. The 7-CCG repeat was the most frequent in normal and expanded haplotypes, but was preferentially associated with expansions. Mean age at onset in patients with 7-CCGs was lower (42.2 years) than in those with the 10-CCGs haplotype (51.4 years). There was no effect of the (CCG)n in “trans” on the age at onset (42.6 years in patients carrying 7-CCGs, “versus” 44.5 years in those having 10-CCGs in the normal chromosome).
In general, we propose that three mechanisms, occurring at different moments, may be concurring to the evolution of normal CAGs to full expansion: (1) a mutational bias towards larger alleles, giving rise to a higher variability of normal chromosomes; (2) a stepwise process that would explain the (CAG)n size distribution found in the more recent haplotypes; and (3) a pool of unstable large normal (class 2) alleles, possibly originated through that bias, which are more prone to further expansion (classes 3 and 4).
Keywords: CAG repeat evolution; HD founder haplotypes; pathogenic mechanisms; stepwise mutation process
P063 MOLECULAR ANALYSIS OF THE (CAG)N REPEAT CAUSING HUNTINGTON’S DISEASE IN 34 IRANIAN FAMILIES
F. Hormozian1, M. Houshmand2, M-HSanati2, R. Ghiasvand3.1Iranian Blood Transfusion Organization, Tehran, Iran; 2NRCGEB, Tehran, Iran; 3Shariati Hospital, Tehran, Iran
Huntington’s disease (HD) is an inherited neurodegenerative disorder characterised by chorea and progressive dementia. The mutation causing the disease has been identified as an unstable expansion of a trinucleotide(CAG)n at the 5′ end of the IT15 gene on chromosomes 4p16.3. We have analysed the distribution of CAG repeats in 71 Iranian individuals (34 patients and 37 unaffected family members) belonging to 31 unrelated families thought to segregate HD. We found one expanded CAG allele in 22 individuals (65%) belonging to 21 unrelated families. In these HD patients, expanded alleles varied from 40 to 83 CAG units and alleles inherited from the presumed unaffected parent were in the range 13–36. In addition, we genotyped 25 unrelated control individuals (total of 50 alleles) and found normal CAG repeats varying from 10 to 34 units. In conclusion our results showed that molecular confirmation of the clinical diagnosis in HD should be sought in all suspected patients making it possible for adequate genetic counselling. This study is the first report of molecular diagnosis of HD among an Iranian population and ever in Middle East and with regards to high frequency of consanguinity marriage in this region.
Keywords: Iranian families; CAG repeats
P064 CELL-AUTONOMOUS CHANGES IN GENE EXPRESSION IN AN IN VITRO LENTIVIRAL MODEL OF HUNTINGTON’S DISEASE
E. Regulier1, D. Zala1, P. Aebischer1, R. Luthi-Carter1, B. Sick2, T. Sengstag3, M. Delorenzi3, N. Deglon4.1Ecole Polytechnique Fédérale de Lausanne - EPFL, Lausanne, Switerland; 2DNA Array Facility, Lausanne University, Switzerland; 3NCCR/ISREC, Epalinges, Switzerland; 4Commissariat à l’Energie Atomique - CEA, Orsay, France
A chronic lentiviral model of Huntington’s disease (HD) has been developed in rat primary striatal neurons. In order to test whether properties intrinsic to medium spiny neurons might make them vulnerable to HD related transcriptional dysregulation, we have analysed these cells for polyglutamine length dependent changes in gene expression using microarrays. At six weeks post-transduction, a timepoint at which no significant cell death is observed, we detected significant decreases in the expression of a number of mRNAs known to be decreased in both R6/2 mice and human HD cases, including proenkephalin, cannabinoid receptor CB1, dopamine D1 receptor, and PCP4. Thus, such changes in gene expression may occur before striatal cell death and independent of corticostriatal input. These data strongly support the view that cell-autonomous transcriptional dysregulation in medium spiny striatal neurons is an early pathologenic mechanism in HD.
Keywords: genomic; lentivirus; transcription
P065 THE ROLE FOR BDNF POLYMORPHISMS IN DETEMINING AGE AT ONSET OF HUNTINGTON’S DISEASE: A PRELIMINARY ANALYSIS
E. Di Maria1, A. Marasco1, P. Ciotti1, M. Tartari2, E. Bellone1, E. Cattaneo2, P. Mandich1.1Department of Neuroscience, Ophthalmology and Genetics, University of Genova, Tartari; 2Department of Pharmacological Sciences and Center of Excellence on Neurodegenerative Diseases, University of Milano
Huntington’s disease (HD) is caused by the expansion of a CAG repeat tract located in the IT15 gene. Approximately 70% of the variance of age at onset in HD is accounted for by the number of CAGs; the remaining was demonstrated to be heritable and is supposed to be modulated by modifier genes. Several lines of evidence point to BDNF as a critical survival factor involved in neurodegeneration in HD; in fact striatal neurons are strictly dependent on BDNF delivery for their survival and BDNF transcription deficiency is an important landmark in HD. In particular, it was found that the Neural Restrictive Silencer Element (NRSE), located in the exon 2 of the BDNF gene, is the target of wild type huntingtin and that the wild type protein positively acts on the NRSE reducing its silencing activity and leading to BDNF transcription.
The objective of this work was to test the hypothesis that functional variants of the BDNF gene contribute to determine the age of onset of HD. As a first stage, we focused our attention on two parts of the BDNF gene: the NRSE, a regulatory element present in the non-coding region, and the already known Val66Met polimorphism located in the unique coding exon. The sample series included 252 HD patients, whose age at onset was determined by clinical records.
The genomic region spanning the human NRSE was screened for sequence variations. SSCP and direct sequencing analysis performed on 110 normal controls and 40 unrelated HD patients failed to reveal common polymorphisms.
One hundred and seventy carriers of the CAG expansion were then genotyped for the Val66Met polymorphism. For this preliminary analysis, we selected among HD carriers two groups, according to the deviation of age at onset from the regression based on CAG length: “earlier onset” (−5 years; n = 23) and “delayed onset” (+10 years; n = 66). Chi squared analysis carried out by CLUMP did not show any difference in allele and genotype frequencies of Val66Met between the two groups.
This preliminary evaluation did not provide any evidence for a possible effect attributable to BDNF variants. However, the approach reported was biased by a very limited power and did not take into account confounding factors. Further analyses are in progress.
Keywords: BDNF; modifier genes
Clinical care and management II
P066 A PATHWAY OF CARE FOR HUNTINGTON’S DISEASE: A MULTIDISCIPLINARY APPROACH
M. Wilson, S. Smith, E. Chipperfield.Nottingham City Primary Health Care NHS Trust, Nottingham, UK
The development of a care pathway for people affected by Huntington’s disease has led to a comprehensive and responsive service for the health community of Nottingham. The service offers care in a variety of settings while promoting support and independence as required. There is a great deal of collaborative team work between the specialisms including Clinical Genetics, Neurology, Psychiatry, Speech and Language Therapy, and Dietetics. The poster presentation will hopefully provide graphic details of the service and generate discussion with conference delegates. It is hoped also to attempt to strengthen networking and support amongst staff who work within other Huntington’s disease services.
Keywords: care; multidisciplinary
P067 A PILOT AUDIT OF CARE IN THE LAST ONE YEAR OF LIFE OF PEOPLE WITH HUNTINGTON’S DISEASE
J. K. Middleton, C. Clayton, H. Dipple.Leicester Partnership NHS Trust, Kegworth, Derbyshire, UK
The lack of palliative care for people with a non-cancer diagnosis is well recognised. There is also evidence specialist palliative care could be beneficial for people with dementia. Little is written about care of people in the final stages of Huntington’s disease. This may be due to the diversity of presentations and the course of the disease. An improved understanding of the illness trajectory may facilitate care planning to meet the individual’s varying needs. As a pilot study we considered the care of the people known to our service who had died in the year before the start of our study. This included people in health settings and the community. The information was obtained retrospectively from the multidisciplinary case notes. The aim was to develop an audit tool which could be used to look at current practice, with a view to developing good practice/care pathways for people with advanced Huntington’s disease.
Keywords: advanced Huntington’s disease
P068 LEICESTERSHIRE HUNTINGTON’S DISEASE SERVICE: 13 YEARS ON
C. Bourne, C. Clayton, H. Dipple, M. Ellinger, J. Grant, J. Middleton, A. Murch.Leicestershire Partnership NHS Trust, Leicestershire, UK
The Leicestershire Huntington’s Disease (HD) Service, part of Treatment and Recovery Services, within The Leicestershire Partnership NHS Trust has been operational since 1991. The impetus for its existence began following feedback from HD support group at consultation meetings regarding hospital closure plans of the two psychiatric institutions in Leicestershire. Coincidentally in 1991, a survey of 25 HD carers was undertaken. This recognised that service provision was poor and two basic needs of carers were improved residential care and access to long term follow up. At the outset, there were six beds (this was based on the uptake of the inpatient bed provision in the psychiatric hospitals in the preceding five years) in a non-adapted community psychiatric rehabilitation setting. Leicestershire has a population of one million, and based on family tree reconstruction, liaison with Genetics, and a visible, acceptable service the incident rates are higher than the reported national average. The service is for people with HD, families, those at risk, carers (formal and informal), and non-specialist providers, with a range of interventions provided. It is easily accessible, coordinated, and designed for flexibility to meet the range of needs. This poster aims to depict the gradual developments of the service over 13 years, some of the challenges faced, current service provision, and future direction. It will be of benefit to others who may be involved in the planning, commissioning, or development of an HD service.
Keywords: coordinated service; support; carers
P069 HUNTINGTON’S DISEASE IN RUSSIA: THE LONG TERM EXPERIENCE OF MEDICAL GENETIC MANAGEMENT OF AFFECTED FAMILIES
S. A. Klyushnikov, S. N. Illarioshkin, I. A. Ivanova-Smolenskaya, E. D. Markova, P. A. Fedin.Institute of Neurology, Russian Academy of Medical Sciences, Moscow, Russia
Huntington’s disease (HD) is a severe neurodegenerative autosomal dominant disorder characterised by motor, cognitive, and psychiatric symptoms, marked phenotypic polymorphism, and fatal clinical course. The management of affected HD families is very important because there is no effective HD treatment so far, and it is necessary to decrease the pathological “genetic burden” of HD in the population.
For over 10 years, under our observation, there have been 210 Russian families with HD or HD-like clinical features. We carried out complex examination of the patients and at risk people consisting of clinical and neuropsychological tests, EEG, cognitive evoked potentials P300, neuroimaging (CT, MRI), and direct DNA analysis of the expanded CAG-repeats in the IT-15 gene. In total, we examined 205 HD patients and 133 at risk persons from 188 families. The hyperkinetic form of HD was found in 97.6% patients, while the rare akinetic rigid form was found only in five juvenile patients (2.4%). There were 35 asymptomatic gene carriers among the at risk people (26.3%). We also conducted DNA analysis in 22 sporadic patients with HD-like clinical symptoms and negative or unclear family history; among them, 16 cases were HD mutation-positive. We performed two prenatal tests (one was positive and another negative). More then 90% of asymptomatic HD gene carriers had abnormal changes in P300 (low amplitudes and increased latencies) and poor results while performing a battery of neuropsychological tests. Our results confirm the data that asymptomatic carriers of the HD gene have some mild cognitive decline, as well as emotional and volitional disorders long before the overt clinical onset of HD. These findings were used for elaborating principles of medical genetic counselling of Russian HD families (including predictive testing protocols).
Acknowledgements: This study was supported in part by a grant from Russian Humanitarian Research Foundation (#04-06-00264).
Keywords: at risk people; genetic tests; medical genetic counselling
P070 EXAMPLES OF MULTIDISCIPLINARY TREATMENT IN A RESIDENTIAL SETTING
H. Claus, L. Liem, K. Bunnig, A-WHeemskerk.Nursinghome Overduin, the Netherlands
Psychogeriatric nursing home “Overduin” in the Netherlands offers residential care to 70 HD patients. Moreover, 15 patients with moderately impaired capacities (stage 3–4) receive daycare. Average duration of residential stay is between five and 10 years. A nursing home physician coordinates a multidisciplinary team of health specialists that aims to eliminate or to compensate the devastating effects of the disease as much as possible. A pivotal principle is that the patient is considered as a participant in organising his or her care. The multidisciplinary team consists of a nursing home physician, a psychologist, a social worker, physical therapists, a speech therapist, a dietician, and a staff of trained nurses, skilled to deal with behavioural disorders.
Two cases will be presented to show how the synergy of these health specialists helps to improve the quality of life.
The first case concerns a 40 year old man who showed aggressive behaviour. In the acute stage this behaviour has been treated by pharmacological means. Subsequently an aggression regulation programme has been installed, consisting of physical exercise supervised by the physical therapist and psychotherapy. Thanks to this programme medication could be gradually reduced in the course of the course of the following months.
The second case concerns a man of the same age whose quality of speech was severely impaired by articulation problems. He was motivated to undergo speech therapy, but refused all exercises that obliged him to look in the mirror. The psychologist found out that he suffered from an unrealistic self image. He thought he was much more affected by the disease than actually was the case. A few sessions of psychotherapy helped him to correct this image. At the end of therapy the method of desensitisation was applied to eliminate his fear of mirrors. Thanks to this intervention speech therapy became much more effective.
Keywords: residential care; multidisciplinary treatment; quality of life
P071 TEN YEARS OF HUNTINGTON’S DISEASE OUTREACH SERVICE IN NEW SOUTH WALES, AUSTRALIA
A. Lownie, E. A. McCusker.Huntington Disease Service, Department of Neurology, Westmead Hospital, Sydney, Australia
Introduction: The behavioural, cognitive, and motor changes occurring over the prolonged course of Huntington’s disease (HD) may make it difficult to access the hospital based clinic and other services. An estimated 400 patients reside in NSW (30 new presentations per year). Established in 1995 as part of a government funded HD Service, the Outreach nursing and allied health team links patients to HD clinic and community services as well as to specialist and generic, public and private, residential facilities. From 1995–2005, a comprehensive care network was developed for patients at all disease stages, in rural and metropolitan settings. Links with the AHDA (NSW) included funding a pilot rural outreach service.
Method: A 10 year retrospective review was undertaken providing measures of performance in human resources, service provision, and “adverse” events. Comparative outcome measures and descriptive data were generated.
Results: Over 10 years, contact was maintained with 454 patients (151 in generic, 55 in specialist residential care) and their families. Organisation evolved to a weekly intake with “key” worker assignment. Telephone assistance, crisis intervention, services, and education (in collaboration with HD Clinic) are provided to patients and families directly or through links to community services, aged, and psychiatric facilities. Support and education for professional care providers is available. In 2004 average weekly referral/occasions of service were 18, compared with 14 in 1996. Six regular respite/social groups are held at rural and metropolitan locations. Seventeen “high risk” profile patients are monitored closely. Statutory surrogate decision making was initiated for 110. Reliable resource provision is considered a key element to the success of outreach services.
Conclusion: The Outreach care model allows an essential link for patients to services while providing education and assistance to care providers over the course of the illness.
Keywords: outreach care network
P072 HUNTINGTON’S DISEASE: DIAGNOSTIC SPECIFIC INFORMATION FOR MEDICAL PERSONNEL WORKING IN PATIENTS’ LOCAL ENVIRONMENT
M. Bjerke, T. Bettum, K. Iversen, O. Solberg.SSSS/Rikshospitalet University Hospital, Oslo, Norway
The Centre for Rare Disorders (SSSS) at University Hospital Rikshospitalet/Radiumhospitalet in Oslo/Norway is a national resource centre, committed to providing a wide range of services connected to 16 specific rare disorders. Huntington’s disease (HD) is one of them. The centre is funded by and receives its assignments from The Norwegian Directorate for Health and Social Affairs, and its commission includes the following activities: knowledge dissemination/competence development, seminars, information activities, counselling/instruction, and research linked to the 16 diagnoses. All these activities are aimed at patients and their families as well as medical personnel at varying levels within the Norwegian health services.
Our aim is to strengthen the competence among medical personnel, and thereby contribute to an increased understanding for each patient’s particular needs. In line with this effort, SSSS has developed a model for a diagnostic specific seminar, aimed at medical personnel working with HD all over the country. Our aim is to strengthen the competence among medical personnel, and thereby contribute to an increased understanding for each patient’s particular needs.
During the last two years, we have arranged one day seminars all over Norway, attended by various occupational groups working with HD patients within the local health services and social welfare system. The one day seminars included lectures by advisers from SSSS, as well as contributions from the centre’s expert partners within the Norwegian health services. The topics were heredity, genetics, neurology, presymptomatic testing, the different phases of symptoms and pathological development, and remedial action and adjustments to the various stages of the pathological progress.
The poster in question would, in rough terms, describe our approach before, during, and after these seminars, as well as include some responses from seminar participants.
Additionally, we would like to add a presentation, illustrating how the support groups for HD patients in Norway are structured.
Keywords: knowledge dissemination/competence development; local environment
P073 EARLY COGNITIVE DEFICITS IN SWEDISH GENE CARRIERS OF HUNTINGTON’S DISEASE
T-BRobins Wahlin1, MLarsson1, A. Lundin2, K. Dear3.1Stockholm Gerontology Research Center and Institutionen Neurotec, Karolinska Institute, Stockholm, Sweden; 2Department of Rehabilitation Medicine, Danderyd Hospital, Karolinska Institute, Stockholm, Sweden; 3Centre for Mental Health Research, Australian National University, Canberra, Australia
Introduction: Conflicting reports in recent studies have raised questions regarding cognitive deficits in presymptomatic Huntington’s disease (HD).
Aim: The primary focus of this study was to examine very early neuropsychological impairment in HD.
Methods: A broad neuropsychological assessment battery was administered to a cohort of 55 persons at risk for HD; applying for genetic testing in Stockholm, Sweden. All subjects, 24 gene carriers (HD+) and 31 non-carriers (HD-), without any motor or behavioural signs of HD, were tested individually and the tasks were administered prior to molecular analysis. The cognitive domains assessed included episodic, prospective, visuospatial, and working memory, visuospatial abilities, psychomotor speed, reasoning, abstract thinking, attention, and problem solving. The mean predicted years to onset of HD for gene carriers was 15 years.
Results: The neuropsychological tests disclosed significantly inferior cognitive functioning in the gene carriers as compared with the non-carriers, primarily in learning and memory functions, psychomotor speed, and ability to shift conceptually. The remaining tasks showed a non-significant difference favouring the non-carriers. When the HD+ group was divided using the cutoff point of 15 predicted years to onset of disease, the gene carriers whose predicted years to onset were under 15 years (HD+ ⩽15pyto), performed significantly worse than the gene carriers whose predicted years to onset were more than 15 years (HD+ >15pyto) in all domains, but the ability to shift conceptually and visuospatial memory. The gene carriers, the HD+ >15pyto group, performed just as well as the non-carriers in all domains, except working memory.
Conclusion: This suggests that early cognitive deficits are detectable a decade before motor signs and symptoms, first in learning and memory functions, and then in executive functions and perceptual motor speed. These results support of a continuous model of cognitive deficit appearance early in a presymptomatic phase of HD.
Keywords: presymptomatic; cognition; memory
P074 NOVEL NEUROPSYCHOLOGICAL FINDINGS IN A GROUP OF GENE CARRIERS FOR HUNTINGTON’S DISEASE
F. Summers, L. Thorgrimsen, S. A. Simpson.NHS Grampian, Foresterhill, Aberdeen, UK
A review will be presented of the neuropsychological findings in a group of 31 individuals seen for assessment. One third had no neurological features of HD, one third had severe symptoms, and one third had mild to moderate features. Findings in those with diagnosed disease supported the literature with decreased processing speed and reduced executive functioning ability. Mental flexibility was also noted as commonly impaired. Poor problem solving was evident in the majority of individuals tested.
This cohort also demonstrated an unexpected level of poor visual memory, as well as impaired working and verbal memory, which is greater than that predicted by the literature. Declining verbal memory, processing speed, and set shifting/impulse inhibition was found to be associated with progression of disease.
These findings will be described and their significance discussed.
Keywords: early cognitive decline; presymptomatic
P075 COMPUTERISED COGNITIVE SCREENING IN PRESYMPTOMATIC CARRIERS OF HUNTINGTON’S DISEASE
K. Dobbelaere, S. de Wilde, K. Van Wallendael, B. Clincke, P. Cras.University Hospital of Antwerp, Edegem, Belgium
Background: Huntington’s disease (HD) is an autosomal dominant disease that gives rise to progressive, selective neural cell death associated with choreic movements and dementia. We studied presymptomatic HD carriers for subtle cognitive changes using a novel computerised assessment.
Method: Presymptomatic carriers (n = 10, age 39.0 (SD 11.4) years, scolarity 15.7 (SD 2.0) years), early HD patients (n = 5, age 53.6 (SD 10.6), scolarity 12.8 (SD 1.09) years) and sex and age matched, healthy volunteers (n = 10, age 39.1 (SD 11.5) years, scolarity 15.3 (SD 1.88) years) were subjected to a Brainspeech computerised cognitive battery consisting of the following tasks: word list learning (WLL) task immediate and delayed recall, recognition, continuous performance (CPT), paced serial addition (PaSAT), and Stroop test. Additionally, Beck depression inventory (BDI) and Mini Mental Status Examination were performed. Patients were examined clinically and the Unified Huntington’s Disease rating Scale was used to assess disease severity.
Results: All presymptomatic disease carriers and healthy volunteers showed a normal UHDRS score. Processing time in word colour part of Stroop test and CPT reaction time was prolonged in presymptomatic carriers compared with healthy controls. Also, accuracy was reduced in CPT and WLL, delayed recall. Early HD patients showed similar but more pronounced defects.
Conclusion: These findings are compatible with an early disturbance of frontal cognitive control processes in presymptomatic HD mutation carriers. A computerised cognitive measure could be useful in evaluating neuroprotective strategies.
Keywords: cognitive screening; reaction time; Stroop test
P076 BEHAVIOURAL AND COGNITIVE FUNCTIONING IN “PRESYMPTOMATIC” CARRIERS OF THE HUNTINGTON’S DISEASE GENE
C. K. Jurgens1, E. van Duijn2, E. M. Kingma2, M-NW. Witjes-Ané1, R. C. van der Mast2, R. A. C. Roos1.Department of Neurology1 and Psychiatry2 LUMC Leiden, Leiden University Medical Center
Objectives: The signs characteristic for Huntington’s disease (HD) differ in time of onset and severity. Research has focused on neuropsychological functioning and motor abnormalities in “presymptomatic” carriers but little is known about the behavioural changes as initial sign. Within a clinical setting these changes are often mentioned as initial symptom, even preceding the appearance of motor signs. Therefore Craufurd et al1 developed the Problem Behaviours Assessment for Huntington Disease (PBA-HD), as an extended alternative for the behavioural part of the Unified Huntington’s Disease Rating Scale (UHDRS). The PBA was translated and validated for a Dutch population and assessed for the purpose of the present study in “presymptomatic” carriers.
The following issues will be discussed:
Is there a difference between carriers and non-carriers in behavioural and cognitive functioning?
Is there a relation between behavioural and cognitive functioning in these groups?
Early recognition of these signs is essential to give the possibility to inform and support (pre)symptomatic individuals well and in view of potential future neuroprotective treatment in an early phase.
Patients and Methods: In a cross sectional observational study we recruited “presymptomatic” gene carriers and non-carriers. So far 34 carriers and 44 non-carriers have been included. Behavioural functioning was assessed using the Problem Behaviours Assessment for HD (PBA-HD). Motor and cognitive functioning (global cognitive functioning, memory, language, attention, psychomotor speed, and executive functioning) was evaluated as well. Definite subject number and results will be displayed in the poster.
Keywords: “presymptomatic” carriers; behaviour; cognition
P077 DECREASED PERFORMANCES ON PSYCHOMOTOR TASKS IN HUNTINGTON’S “PRESYMPTOMATIC” CARRIERS ARE DUE TO SUBTLE CHANGES IN BOTH MOTOR AND COGNITIVE FUNCTIONING
C. K. Jurgens, M-NW. Witjes-Ané, J. P. P. van Vught, H. A. M. Middelkoop, R. A. C. Roos.Leiden University Medical Center, Leiden, the Netherlands
Objective: In this study we examined the relations between motor impairment, cognitive deficits, and psychomotor functioning in Huntington’s disease (HD). The aim was to investigate if relations found in patients already occurred in “presymptomatic” carriers. We had a special interest in the influence of “pure” cognitive and motor functioning respectively on so called “psychomotor tasks”.
Patients and Methods: In a cross sectional study we evaluated 34 patients, 46 carriers and 88 non-carriers with the Unified Huntington’s Disease Rating Scale (UHDRS) and an extensive neuropsychological examination. With respect to psychomotor functioning we focussed on the following tasks: Trail Making Tests A and B, Symbol Digit Modalities test, and Stroop interference task.
Results: There was a marginal significant difference between carriers and non-carriers on psychomotor tasks. The following correlation patterns in carriers were comparable to patients: no direct associations were found between motor and cognitive functioning, however both domains correlated with psychomotor tasks.
Conclusion: Carriers showed a slightly decreased psychomotor functioning compared with non-carriers. Furthermore less functioning on either motor or cognitive domain resulted in decreased psychomotor functioning in patients and carriers. For the present we conclude that some carriers already displayed subtle changes in motor and/or cognitive functioning, which is expressed in decreased performance on psychomotor tasks in carriers compared with non-carriers. Altogether the results corroborate other findings in that deficits in psychomotor speed are a key feature in HD.
Keywords: psychomotor functioning; “presymptomatic” carriers; patients
P078 AN FMRI STUDY INDICATING INCREASED CORTICAL RECRUITMENT DURING A COGNITIVE INTERFERENCE TASK IN HUNTINGTON’S DISEASE PATIENTS
N. Georgiou-Karistianis1, A. Sritharan1, M. Farrow1, J. L. Bradshaw1, A. Churchyard2, E. Chiu3, P. Chua4, J. Stout5, R. Cunnington6, G. Egan6.1Experimental Neuropsychology Research Unit, Psychology Department, Monash University, Clayton 3800, Victoria, Australia; 2Department of Neurology, Monash Medical Centre, Clayton, Victoria, Australia; 3Department of Psychiatry, Melbourne University, Melbourne, Australia; 4Department of Neuropsychiatry, Royal Melbourne Hospital, Melbourne, Australia; 5Department of Psychology, University of Indiana, Indiana, USA; 6Howard Florey Institute, Melbourne, Australia
We used an event related fMRI design to study the BOLD response in Huntington’s disease (HD) patients during performance of a Simon interference task. We hypothesised that HD patients will demonstrate significantly slower RTs than controls, and that there will be significant differences in the pattern of brain activation between groups. Seventeen HD patients and 15 age and sex matched controls were scanned using 3T GE scanner (FOV = 24 cm2; TE = 40 ms; TR = 3 s; FA = 60°; slice thickness = 6 mm; in-plane resolution = 1.88×1.88 mm2). The task involved two activation conditions, namely congruent (for example, left pointing arrow appearing on the left side of the screen) and incongruent (for example, left pointing arrow appearing on the right side of the screen), and a baseline condition. Each stimulus was presented for 2500 ms followed by a blank screen for 500 ms. Subjects were instructed to press a button using the same hand as indicated by the direction of the arrow head and were given 3000 ms to respond. Data analysis was performed using SPM2 with a random effects analysis model. For each subject parameter estimates for combined task conditions (congruent and incongruent combined) were calculated. Comparisons such as these, based on block designs, have superior statistical power for detecting subtle changes in the BOLD response anywhere in the brain. The activations reported are significant at PFDR_corr <0.05. The anterior cingulate (AC), prefrontal, parietal, and premotor* *regions were significantly activated in the HD patients, whereas controls activated only parietal, premotor, and striatal regions. The lack of prefrontal involvement, and significant activation of striatum in the controls, is possibly associated with the over simplified interference task employed. This notion is supported by the activation in putamen for controls, a region involved in the execution of over learned automatic behaviours. In conclusion HD patients showed significant hyperactivity in fronto-striatal-parietal circuitry compared with controls.
Keywords: fMRI; cognition; neuropsychology
P079 MRI AND COGNITIVE CHANGES DETECTABLE OVER 6 AND 12 MONTHS IN EARLY HUNTINGTON’S DISEASE
S. M. D. Henley1, E. K. Warrington1, C. Frost1,2, D. G. MacManus3, T. T. Warner4, N. C. Fox1,5, S. J. Tabrizi5,6.1Dementia Research Centre, Institute of Neurology, University College London, Queen Square, London; 2Medical Statistics Unit, London School of Hygiene and Tropical Medicine, London; 3NMR Research Unit, Institute of Neurology, University College London, Queen Square, London; 4Department of Clinical Neurosciences, Royal Free and University College Medical School, London; 5Clinical Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London; 6Department of Neurodegenerative Disease, Institute of Neurology, Queen Square, London, UK
Huntington’s disease (HD) is a devastating and incurable inherited disorder that commonly affects adults in mid-life. Therapeutic trials in HD are challenging due to lack of surrogate biomarkers to track disease progression, which is relatively slow. Improvements in the precision of objective measurement of disease progression in HD could potentially lead to more informative clinical trials better able to detect the effects of therapeutic intervention. Imaging, clinical, and cognitive assessment have all been proposed as biomarkers, but few measures have been quantified over short time intervals. We measured clinical, cognitive, and MRI variables over one year in 13 early HD patients and seven age and IQ matched controls. We used the brain boundary shift integral to quantify volume loss from pairs of rigidly registered MRI scans as this method has previously been shown to be more robust and less susceptible to operator and scan error than simply subtracting one volume from another. Subjects underwent cognitive assessment at baseline, 6, and 12 months and volumetric imaging at baseline and 6 months. HD patients had significantly increased rates of whole brain atrophy compared with controls (mean (SD) HD, 1.10 (0.90)/year; controls, 0.26 (0.54) %/year). Relative to controls, HD patients showed a significant decline in short term memory (over 6 months) and short term memory and letter fluency (over 12 months). Among the HD patients, higher CAG repeat length, longer disease duration, and smaller brain volume were all associated with worse baseline performance on a number of cognitive and clinical variables. These findings show that using rigid registration of serial MRI it is possible to measure rates of whole brain atrophy in early HD patients over as little as 6 months. Rate of brain atrophy derived from registered serial MRI may be useful as outcome measures in trials of potentially disease modifying therapies.
Keywords: biomarkers; MRI; neuropsychology
P080 NEUROPSYCHOLOGICAL DEFICITS AND REGIONAL CEREBRAL GLUCOSE METABOLISM (RCMRGLC) IN HUNTINGTON’S DISEASE
T. Mayer1, C. Pohl2, T. Jahn2, A. Drzezga3, A. Weindl1.Departments of 1Neurology, 2Psychiatry and 3Nuclear Medicine Technische Universität München, Germany
The aim of the study is to evaluate the development of neuropsychological deficits and correlating rCMRGlc changes in HD. Twenty right handed patients with genetically comfirmed diagnosis of HD and a CGI score of 1–5 (mean 3.6) were examined clinically (HDRS, AIMS, ADL) and neuropsychologically using the CERAD test, frontal lobe tests such as FAS, supermarket, colour word interference, modified card sorting, Tower of Hanoi as well as the intelligence structure (IST-70) and multiple choice vocabulary intelligence test. FDG-PET scans were performed in close time distance. The neuropsychological results were correlated with clinical and PET data. Group analyses were made of FDG data of patients with short disease course and almost normal FAS test (four patients v eight controls, median age of 45.6 years, group A) and patients with longer course and pathological FAS test in later stages (10 patients v 10 age matched controls, group B). Of all neuropsychological tests used the FAS and the supermarket tests gave results of high significance. The only test correlating with disease duration is the FAS test (r = −0.57, p = 0.011). Analysis of A shows hypometabolism in striatum (l>r), thalamus, gyrus cinguli, dorsolateral prefrontal cortex (l>r), g temporalis sup, g rectus (l>r), and g parahippocampalis (r>l). Analysis of B shows increased hypometabolism in striatum, dorsolateral prefrontal cortex and g temporalis sup In thalamus, g rectus, and g parahippocampalis almost no hypometabolism (in addition to hypometabolism in BA 40 l>r) is present. While in A hypermetabolism occurs in cerebellar tonsils and occipital cortex, in B metabolism is normal. Verbal fluency, especially word generation, is impaired early in HD and appears useful for screening of evolving cognitive impairment. It is remarkable that in addition to increasing hypometabolism, particularly in striatum and prefrontal cortex, in early stages a compensatory hypermetabolism occurs in cerebellum and occipital cortex. The observation that in g parahippopcampalis metabolism initially is decreased and later is normal is subject of discussion.
Keywords: PET; neuropsychology
Pathogenic mechanisms II
P081 CA150 RESCUES STRIATAL CELL DEATH IN OVEREXPRESSION AND KNOCK-IN MODELS OF HUNTINGTON’S DISEASE
M. Arango1, S. Holbert1, D. Zala2, E. Brouillet3, E. Régulier2, A. Kumar Thakur4, P. Aebischer2, R. Wetzel4, N. Déglon5, C. Néri1.1INSERM, Avenir Group, Laboratory of Genomic Biology, Centre Paul Broca, Paris, France; 2Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland; 3URA CEA/CNRS, Service Hospitalier Frédéric Joliot and ImaGene Program Department of Medical Research, CEA, Orsay, France; 4Graduate School of Medicine, University of Tennessee, Knoxville, USA; 5Atomic Energy Commission (CEA), Department of Medical Research and ImaGene Program, Orsay, France
Huntington’s disease (HD) is a dominant neurodegenerative disorder associated with N-terminal expanded polyglutamines (polyGlns) in huntingtin (htt). The abnormal regulation of transcription may be central to HD neuronal pathology. We previously reported that the transcriptional regulator CA150 binds to htt and accumulates in a neuropathological grade dependent manner in the striatal and cortical neurons of HD patients, suggesting CA150 dysfunction in HD. Consistently, we report herein that CA150 overexpression rescued the toxicity of mutant htt in lentiviral overexpression (rat striatum) and knock-in (striatal cells from HdhQ111 mice) models of HD. In both systems, the rescue was dependent on the presence of the (Gln-Ala)38 repeat normally found in CA150. Our data indicate that the striatal pathology in HD may involve a loss of CA150 function. Additionally, our data provide a biological rationale for the previously reported influence of the enlarged and potentially hypomorphic repeat alleles on the age at onset in HD.
Keywords: pathogenic mechanisms; transcription; biomarker
P082 GENERATING MOLECULAR PROFILES OF EARLY MUTANT POLYGLUTAMINE CYTOTOXICITY IN C ELEGANS NEURONS
C. Tourette, A. Parker, S. Abderrahmane, E. Lambert, M. Mage, C. Néri.INSERM, Avenir Group, Laboratory of Genomic Biology, Centre Paul Broca, Paris, France
The limitations of cellular and rodent models preclude the detailed analysis of molecular and genetic factors involved in polyglutamine neuronal toxicity in vivo. Invertebrates provide convenient and robust experimental systems to study the modifiers of polyglutamine neuronal toxicity in whole organisms and at the genomic level. We have previously described a C elegans model of the early phases of mutant polyglutamine cytotoxicity in neurons, namely the dysfunction of mechanosensory neurons before cell death (Parker et al, PNAS 2001), a phenotype that correlates with axonal dystrophy. We have illustrated the value of this overexpression model in defining potentially interesting therapeutic targets and active compounds for neuroprotection in Huntington’s disease (Parker et al, Nature Genet 2005). Using this model, molecular and genetic screens are being performed in order to reach a detailed description of mutant polyglutamine pathogenicity at the neuronal cell and genomic level. An update describing the potential of this approach towards the identification of Huntington’s disease targets and biomarkers will be presented.
Keywords: Pathogenic mechanisms, neuronal cell, profiling
P083 EXPANDED POLYGLUTAMINE PEPTIDES DISRUPT EGF RECEPTOR SIGNALING AND GLUTAMATE TRANSPORTER EXPRESSION IN DROSOPHILA
J-CLiévens1, T. Rival1, M. Iché1, H. Chneiweiss2, S. Birman1.1LGPD-IBDM, Campus de Luminy, Marseille, France; 2Inserm U114, Collège de France, Paris, France
Huntington’s disease (HD) is a late onset heritable neurodegenerative disorder caused by expansion of a polyglutamine (polyQ) sequence in the protein huntingtin (htt). Transgenic models in mice have suggested that the motor and cognitive deficits associated to this disease are triggered by extended neuronal and possibly glial cell dysfunction, whereas neuronal death occurs late and selectively. Here we targeted the expression of a polyQ-containing domain of htt (httex1p) or an extended polyQ peptide alone in a subset of glial cells in Drosophila, where the only fly glutamate transporter dEAAT1 is detected. We observed that expanded polyglutamine expression did not induce massive glial cell death but formed nuclear inclusions and progressively decreased transcription of dEAAT1 in the adult brain. This resulted in a markedly reduced adult lifespan. We provide in vivo evidence showing that brain expression of dEAAT1 is upregulated by the epidermal growth factor receptor (EGFR) and ras/extracellular signal regulated kinase (ERK) pathways. We hypothesised that polyQ inhibits glutamate transporter expression by disrupting the EGFR mediated pathways. In accord with this view, we show that expanded polyQ peptides antagonize EGFR signaling in Drosophila and prevent dEAAT1 upregulation by activated Drosophila Egfr, but not activated Erk. These results indicate that disruption of EGF receptor signaling and ensuing glial cell dysfunction may play a direct role in the pathogenesis of HD and other polyQ diseases.
Keywords: expanded polyQ; glia dysfunction; epidermal growth factor receptor
P084 EXPRESSION OF HD EXON1 IN EXPERIMENTAL SYSTEMS SUGGESTS ALTERNATIVE TRANSLATION INITIATION OF THE HD GENE PRODUCT, HUNTINGTIN
L. Hasholt1, A. Nørremølle1, T. Løkkegaard1, S. A. Sørensen1, K. Abell2.1Department of Medical Biochemistry and Genetics, Section of Neurogenetics, The Panum Institute, University of Copenhagen, Denmark; 2Department of Pathology, University of Cambridge, UK
The first AUG codon in the Huntington’s disease (HD) gene is situated in a perfect Kozak context and is generally accepted to initiate translation of huntingtin (htt). We find from expression studies in cell-free systems and cell models that a downstream AUG can function as an alternative initiation site.
A HD gene sequence spanning −81 to + 252 (153 bp downstream of the CAG repeat) was cloned into pBluescriptSK+ and used for in vitro transcription and translation. SDS gel electrophoresis showed two bands corresponding to two translation products differing about 1 kDa in molecular weight. Both products, which originated from a single transcript, were shown by immunoprecipitation to represent htt derivatives. The second AUG in htt mRNA is positioned in a weak Kozak context, but our result indicates that it can function as initiator codon resulting in a peptide lacking the first seven amino acid residues. To prove this we introduced mutations in the first or the second AUG codon (AUG to AAG) and by creating a stop codon in the intervening sequence. In vitro expression of the three mutated sequences confirms that translation can also be initiated from the downstream AUG.
We have subcloned the inserts from the pBluescriptSK+ vector contructs into the pEGFP expression vector for transfection of NT2 precursor cells and NT2-N neurons. Our preliminary results indicate that the first as well as the second AUG codon initiate translation in cell cultures. Whether htt with alternative N-terminals are present in vivo is unknown, but post-transcriptional regulation through shift in translation initiation site may have a role in molecular pathogenesis.
This hypothesis is supported by recent observations of reduced nuclear export and accumulation of htt after deletion of 10 amino acids in the N-terminal region.1
Keywords: huntingtin expression; alternative translation initiation
P085 MITOCHONDRIAL FUNCTION IN HUNTINGTON’S DISEASE: A COMPARISON BETWEEN ISOLATED AND IN SITU MITOCHONDRIA
J. M. Oliveira1,2,3, M. B. Jekabsons3, S. F. Chen3, R. Riley3, A. Lin3, L. M. Ellerby3, A. C. Rego2, D. G. Nicholls3.1Department of Pharmacology, Faculty of Pharmacy, University of Porto, Portugal; 2Center for Neuroscience and Cell Biology, University of Coimbra, Portugal; 3Buck Institute for Age Research, CA, USA
Mitochondrial dysfunction and excitotoxicity are believed to play an important role in the pathology of Huntington’s disease (HD). This hereditary CAG triplet repeat disorder has 100% of penetrance and selectively targets striatal neurons, invariably progressing to motor abnormalities, dementia, and death. The development of animal models that accurately recapitulate HD is of utmost importance for the development of treatment strategies. In the present study we compared isolated forebrain mitochondria from different transgenic HD mice (R6/2, YAC128, and Hdh-CAG150). Maximal calcium loading capacity (MCLC) of state 4 mitochondria was similar for all wild type controls despite the different genetic backgrounds. Interestingly, MCLC was increased in R6/2 and YAC128 mice whereas no differences were found in Hdh-CAG150 mice. In order to assess mitochondrial function in intact neurons, we prepared primary striatal cultures from YAC128, Hdh-CAG150, and respective wild type littermates. Changes in mitochondrial membrane potential and intracellular calcium were monitored in single cells by fluorescence microscopy. Oxygen consumption by neuronal populations was monitored using a previously described respirometer (Jekabsons and Nicholls, JBC, 2004). Striatal neurons from HD mice presented a decreased maximal respiratory capacity and NMDA challenging resulted in mitochondrial depolarisation in association with delayed recovery of basal calcium. These results highly suggested mitochondrial dysfunction in HD striatal neurons. Conflicting results with experiments using isolated mitochondria may derive from: (1) mitochondria isolation from a mixed forebrain neuronal population, masking HD selective striatal pathology and/or (2) loss of interaction with soluble cytoplasmic htt in isolated mitochondria. These results stress the importance of addressing mitochondrial function in the cellular context.
Acknowledgements: High-Q Foundation (USA) and Calouste Gulbenkian Foundation (PT)
Keywords: mitochondria; excitotoxicity
P086 INCREASED CALCIUM SENSITIVITY OF RESPIRATION AND PERMEABILITY TRANSITION IN MITOCHONDRIA OF SKELETAL MUSCLE IN THE R6/2 MOUSE MODEL FOR HUNTINGTON’S DISEASE
F. N. Gellerich1, Z. Z. Gizatullina1, F. Striggow1, W. Schmidt1, Y. Chen2, S. Zierz2, K. S. Lindenberg3, B. G. Landwehrmeyer3, P. Harjes4, C. M. Kosinski5.1KeyNeurotec AG, ZENIT Technology Park Magdeburg; 2Muskellabor der Neurologischen Klinik der Martin-Luther-Universität Halle-Wittenberg; 3Neurologische Klinik der Universität Ulm, Germany; 4Max Delbrück Zentrum für Molekulare Medizin, Berlin,Germany; 5Neurologische Klinik der Universität Aachen, Germany
Huntington’s disease (HD) is a progressive neurodegenerative disorder caused by a CAG repeat expansion in the coding region of the IT15 gene resulting in an elongated polyglutamine stretch in huntingtin (htt) protein. Htt is expressed in all cell types but its biological role is unknown. To answer the question whether or not skeletal muscle is also affected in HD, we investigated mitochondria in skeletal muscle of transgenic R6/2 mice, an accepted model for HD in comparison to the wild type (WT) animals.
Atrophic type I and type II fibers with an increase of interfibrillar fuchsinophilic aggregates were detectable in HD muscle. In the absence of extramitochondrial Ca2+, functional properties of HD mitochondria were not different from WT despite of reduced cytochrome c oxidase activity (−17%). At Ca2+ overload, however, a sensitive impairment of HD mitochondria compared with the WT was detectable with three independent methods. (1) The pyruvate dependent respiration was much more inhibited by calcium in HD mitochondria. (2) With swelling measurements a decreased stability of HD mitochondria against Ca2+ induced permeability transition was found. (3) Fluorimetric Ca2+ uptake measurements by HD mitochondria revealed strongly decreased Ca2+ thresholds for opening of permeability transition pore.
It is concluded that due to the decreased stability of mitochondria to free Ca2+, HD tissues have an increased tendency to develop energetic depression and cell necrosis. The mechanism of the increased Ca++ sensitivity is unknown. HD htt could indirectly change the Ca2+ signaling of the cell or it could directly act on mitochondrial contact sites influencing via protein-protein interactions the oxidative phosphorylation and the permeability transition pore. Data further support the point of view that HD is not only a disease of CNS, but also of the skeletal muscle.
Keywords: mitochondria; calcium; energetic depression
P087 ALTERED DOPAMINERGIC FUNCTION IN A MOUSE MODEL OF HUNTINGTON’S DISEASE
G. M. Dallérac, A. J. Milner, D. M. Cummings, S. C. Vatsavayai, M. C. Hirst, K. P. S. J. Murphy.Open University, Milton Keynes, UK
Huntington’s disease (HD) is a genetic neurodegenerative disorder characterised by a progressive motor, psychiatric, and cognitive decline, usually manifesting in midlife. The advent of predictive testing combined with PET imaging has revealed a loss of dopamine receptors in asymptomatic gene carriers. Asymptomatic carriers also exhibit impairments in recognition memory, a process that involves the perirhinal cortex. We have reported that perirhinal synaptic plasticity is altered in the R6/1 mouse model of HD and that normal plasticity can be restored by a dopamine agonist. We have now examined the electrophysiological properties of dopaminergic neurones in R6/1 mice. Intracellular recording microelectrodes were used to assess the membrane properties of both transgenic and wild type dopaminergic neurones in slices prepared from 7 month old animals in accordance with UK legislation. While resting membrane potentials and input resistances were normal, transgenic dopaminergic neurones exhibited a significant decrease in the amplitude and duration of the slow AHP (p<0.001) and a marked increase in firing rate upon depolarisation (p<0.01). These data suggest that the firing pattern and responsiveness of transgenic dopaminergic neurones is altered and this may contribute to abnormal dopamine signalling, such as that seen in the perirhinal cortex.
Keywords: dopamine; substantia nigra; transgenic
P088 DOPAMINE INFLUENCES THE EMERGENCE OF HUNTINGTON’S DISEASE SYMPTOMS: A MOUSE MODEL
M. Cyr1, T. D. Sotnikova2, R. R. Gainetdinov2, M. G. Caron2.1Neuroscience Research Group, CP 500, UQTR, Trois-Rivières, Quebec, Canada; 2Department of Cell Biology, Center for Models of Human Disease, Duke University, Durham, USA
An expansion in the CAG repeat of the huntingtin gene underlies the development of Huntington’s disease (HD). Whether other molecular events contribute to the onset of HD pathogenesis has remained unknown. To examine the potential role of the dopamine system in the emergence of pathological conditions in HD, we generated a double mutant mouse strain with both striatal hyperdopaminergic tone and endogenous expression of the human huntingtin gene containing 92 CAG repeats (HdhQ92). This strain has been produced by mating a dopamine transporter knockout (DAT-KO) mouse, which exhibits elevated extracellular dopamine levels in the striatum and locomotor hyperactivity, to an HdhQ92 knock-in mouse that does not exhibit signs of neurodegeneration or behavioural abnormalities. When locomotor activity was evaluated, the double mutant mice exhibited subtle dysfunctions that included an age dependent decline of their horizontal hyperactivity observed at early age. In contrast, rearing (vertical activity) and stereotypy time were increased up to 8 months of age and decreased subsequently. No differences were observed between genotypes in the levels of dopamine, DOPAC, and HVA as evaluated by HPLC or in the extracellullar levels of dopamine as revealed by in vivo microdialysis. The most remarkable finding was that without the presence of a strong astrogliosis, the physical nature of mutant huntingtin proteins was different in brain regions receiving the dopaminergic input. In the double mutant mice, the huntingtin proteins aggregated much earlier and to a stronger extent compared with DAT-WT/Hdh-Q92 mice. These data suggest a role of dopamine in the temporal sequence of the aggregation of mutant huntingtin proteins.
Keywords: dopamine; mouse model; motor dyfunction
P089 HISTONE ACETYLATION AND RECOVERY FROM EXCITOTOXICITY IN STRIATAL CELLS EXPRESSING FULL LENGTH MUTANT HUNTINGTIN
J. M. Oliveira1,2,4, S. F. Chen2, S. Almeida4, R. Riley2, J. Gonçalves1, C. R. Oliveira4, M. R. Hayden3, D. G. Nicholls2, L. M. Ellerby2, A. C. Rego4.1Department of Pharmacology, Faculty of Pharmacy University of Porto, Portugal; 2Buck Institute for Age Research, Novato, California, USA; 3University of British Columbia, Vancouver, BC, Canada; 4Center for Neuroscience and Cell Biology, University of Coimbra, Portugal
Huntington’s disease (HD) is a dominant neurodegenerative disorder that selectively targets striatal neurons. HD is caused by a CAG expansion in the gene that codes for huntingtin (htt). Disturbed calcium homeostasis and transcriptional deregulation are believed to play an important role in HD pathology. Histone deacetylase (HDAC) inhibitors increase transcription and were shown to be neuroprotective in animal models of HD. However, the cellular changes that are responsive for neuroprotection remain to be fully understood. In the present study we established two HD cellular models of calcium induced toxicity and tested the hypothesis that the neuroprotective effects of HDAC inhibitors can be explained by an improved neuronal ability to recover from excitotoxic stimuli. Striatal cells from HdhQ111 mice and primary striatal neurons from YAC128 mice were challenged with 4Br-A23187 or NMDA, respectively, to evaluate changes in calcium homeostasis, mitochondrial membrane potential (MMP), and somatic swelling. Reestablishment of basal intracellular calcium following excitotoxic stimuli was influenced by mitochondrial inhibition, in the presence of oligomycin or rotenone. Mutant htt expression was associated with a slower restoration of intracellular calcium, MMP, and somatic swelling. These parameters were ameliorated by protracted treatment with HDAC inhibitors. These results suggest improvement in calcium homeostasis mechanisms, strengthening the use of HDAC inhibitors in HD treatment.
Acknowledgements: HighQ Foundation; Calouste Gulbenkian Foundation; Fundação para a Ciência e a Tecnologia
Keywords: excitotoxicity; HDAC inhibitors; mitochondria
P090 DYSREGULATION OF GENE EXPRESSION IN HUNTINGTON’S DISEASE BY EPIGENETIC CHANGES IN CHROMATIN STRUCTURE
X-XYang, T. Breit, P. J. Verschure.Swammerdam Institute for Life Sciences and Institute for Informatics, University of Amsterdam, Amsterdam, the Netherlands
Gene expression control is crucial for the maintenance of differentiated cell types in a multicellular organism, whereas aberrant gene regulation can lead to pathological situations. The cell nucleus is the site where the genetic material is stored and where key processes take place. Packaging of the eukaryotic genome into chromatin is a key aspect of epigenetic gene control. Histone modifications are proposed to constitute an “epigenetic code” that extends the information potential of the DNA sequence code. Histone modifications also affect DNA methylation. We are still largely ignorant how these levels of epigenetic gene regulation effect biological systems. Our research focuses on the functional organisation of chromosomes and chromatin in the mammalian interphase cell nucleus as visualised in living cells using light microscopical approaches.1–6
Many neurodegenerative disorders result from expansions of particular trinucleotides. The pathogenesis of repeat disorders is complex and multifactorial. It is intriguing that all “polyglutamine disease” phenotypes are primarily related to neurological and neuromuscular dysfunction. A further enigma is why only a subset of neurons or muscle fibres is vulnerable to “polyglutamine diseases”, despite ubiquitous expression of most of the mutant genes. At the protein level the expanded polyglutamine proteins tend to aggregate and form inclusion bodies that are frequently located in the nuclei of affected cells. Moreover, the expanded polyglutamine tracts have been shown to bind preferentially to specific transcriptional regulators and change the function of others. At the DNA level it is currently thought that expanded repeats may form DNA secondary structures that confer genetic instability and most likely alter the local chromatin configuration, leading to changes in gene activity.
Huntington’s disease (HD) is associated with CAG repeats present in the coding sequence of the HD gene on chromosome 4p16.3 that are translated into polyglutamine tracts. The size of the expanded repeat is inversely related to the age of onset of HD disease. However, the size of the CAG repeat cannot fully explain the course of the disease. Epigenetic gene control mechanisms are probably involved in the development and progression of HD disease. We recently started a research line to investigate whether changes in epigenetic gene control, affecting the chromatin structure via histone modification patterns and global reorganisation of nuclear architecture, play a role in HD disease. The ability to interfere with gene deregulation and eventually to correct pathological malfunctions of HD disease clearly depends on understanding the molecular mechanisms that underlie the disease.
P091 MINOCYCLINE IN PHENOTYPIC MODELS OF HUNTINGTON’S DISEASE
K. Bantubungi1, S. N. Schiffmann1, C. Jacquard2, E. Brouillet2, A. Greco3, L. Minghetti3, A. Pintor4, P. Popoli4, M-CGalas5, N. Déglon6, J. Brotchi7, M. Levivier7, A. Chtarto8, K. Tai8, L. Tenenbaum8, D. Blum8.1Laboratory of Neurophysiology, ULB-Erasme, Brussels, Belgium; 2URA CEA-CNRS 2210, Service Hospitalier Frédéric Joliot, CEA, Orsay, France; 3Department of Cell Biology and Neuroscience, Istituto Superiore di Sanita, Rome, Italy; 4Department of Drug Research and Evaluation, Istituto Superiore di Sanita, Rome, Italy; 5INSERM U422, Lille, France; 6Department of Medical Research and ImaGene Program, CEA, Orsay, France; 7Department of Neurosurgery and Laboratory of Experimental Neurosurgery, ULB-Erasme, Brussels, Belgium; 8Laboratory of Experimental Neurosurgery and IRIBHM, ULB-Erasme, Brussels, Belgium
Minocycline has been shown to be neuroprotective in various models of neurodegenerative diseases. However, its potential in Huntington’s disease (HD) models characterised by calpain dependent degeneration and inflammation has not been investigated. Here, we have tested minocycline in phenotypic models of HD using 3-nitropropionic acid (3NP) intoxication and quinolinic acid (QA) injections. In the 3NP rat model, where development of striatal lesions involves calpain, we found that minocycline was not protective, although it attenuated the development of inflammation induced after the onset of striatal degeneration. The lack of minocycline activity on calpain dependent cell death was also confirmed in vitro using primary striatal cells. Conversely, we found that minocycline reduced lesions and inflammation induced by QA. In cultured cells, minocycline protected against mutated huntingtin and staurosporine, stimulations known to promote caspase dependent cell death. Altogether, these data suggested that in HD minocycline may counteract the development of caspase dependent neurodegeneration, inflammation but not calpain dependent neuronal death.
Funding: Hereditary Disease Foundation, FNRS and VanBuuren Foundation.
Keywords: minocycline; cell death; inflamation
P092 LACK OF MINOCYCLINE EFFICIENCY IN GENETIC MODELS OF HUNTINGTON’S DISEASE
S. Mievis1, C. Ledent1, D. Blum1,2.1IRIBHM, ULB-Erasme, Brussels, Belgium; 2Laboratory of Experimental Neurosurgery
Minocycline is a tetracycline shown to display anti-apoptotic and anti-inflammatory effects in various models of neurodegenerative diseases. Controversy remains regarding Huntington’s disease models since a former study by Chen1 demonstrated beneficial effects of this antibiotic in the R6/2 model following daily i.p. administration whereas the latter study of Smith3 showed that minocycline failed to delay the phenotype following chronic delivery through drinking water in the same model. We therefore re-evaluated the protective effect of minocycline in another mouse model, the N171-82Q line81, and in an in vitro inducible model consisting in PC12 cells expressing exon 1 of human Htt103Q.
Minocycline, freshly prepared in saline, was given daily by i.p. injections at 10 mg/kg—that is, a dose shown to be effective with such paradigm in R6/2 mice1,2 and phenotypic HD models.4 N171-82Q mice were treated at the age of 2 months. At this time, animals were early symptomatic since they presented slight pathology with no rotarod alterations but altered grip strength and decreased gain weight. Our results showed that minocycline did not provide any protection along the treatment of N171-82 mice. Indeed, treatment did not improve mouse survival and failure to gain weight as well as it failed to improve decreased grip strength and spontaneous locomotion. In accordance with this observation, increasing concentrations of minocycline failed to reduce the death of PC12 cells expressing exon 1 of human Htt103Q as assessed by LDH release measurements. Altogether, the present data do not support minocycline as a protective agent in HD.
Funding: FNRS, Van Buuren Foundation and Hereditary Foundation. We thank Dr E Schweitzer for providing inducible cells.
P093 DOWNREGULATION OF HUNTINGTIN EXPRESSION IN A CELL MODEL USING LNA ANTISENSE
A. Nørremølle1, S. Kauppinen2, N. Jacobsen2, L. Hasholt1.1Department of Medical Biochemistry and Genetics, Section of Neurogenetics, The Panum Institute, University of Copenhagen, DK-2200 Copenhagen, Denmark; 2Department of Functional Genomics, Exiqon, Bygstubben 9, DK-2950 Vedbaek, Denmark
In Huntington’s disease (HD), the pathological processes are highly complex, and downregulation of expression of the mutant allele of the HD gene is therefore an obvious therapeutical strategy.
We have previously shown antisense mediated downregulation of huntingtin expression in a cell model, using phosphorothioated DNA antisense oligonucleotides. Locked nucleic acid (LNA) is a bicyclic RNA analogue with high affinity and specificity towards complementary DNA and RNA molecules. Substitution of DNA oligonucleotides with LNA monomers confers the molecule a high stability in cells. We tested LNA substituted antisense oligonucleotides in a human precursor cell model NT2 by comparing their efficacy on several target sequences, employing different LNA and/or phosphorothioate-based antisense designs. The target sequences were located in exon 1 of the HD gene with an expanded CAG repeat, inserted in pEGFP-N1 expression vector in frame with the EGFP gene. The expression construct and antisense or scrambled control oligonucleotides, respectively, were introduced into the cells by co-transfection. The expression level of the fusion mRNA and protein were estimated by quantitative RT-PCR, counting of inclusions induced by the expanded polyglutamine sequence, and by Western blotting using antibodies raised against either huntingtin or the EGFP tag. Toxicity of the antisense oligonucleotides was assessed by cell counts after transfection.
Sequence specific downregulation of the fusion protein expression was obtained with LNA substituted DNA oligonucleotides. The highest efficacy was observed using a LNA/DNA gapmer design with five LNA monomers at each end of the oligo, and target sequence just downstream of the AUG startcodon. The effect was concentration dependent, and evident at 10 nM antisense concentration. Effect of phosphorothioate modified LNA or DNA antisense oligonucleotides of the same sequence required higher concentrations. Quantitative RT-PCR assays showed no significant reduction of the HD-EGFP mRNA in the cells transfected with antisense oligos. This indicates that the antisense effect targets the translation process.
Keywords: antisense; LNA; downregulation
P094 LONGITUDINAL BEHAVIOURAL CHARACTERISATION OF THE Q92 MOUSE LINE
S. P. Brooks1, G. Higgs1, R. C. Trueman1, S. B. Dunnett1, P. Cheng2, A. R. Redfern2, L. Jones2.1Cardiff University, School of Biosciences, Cardiff; 2Department of Psychological Medicine, Cardiff University School of Medicine, Cardiff University, Cardiff, Wales, UK
The Q92 mouse model of Huntington’s disease, is a knock-in model constructed via the replacement of the Hdh exon 1 with a chimeric Hdh:HD exon 1 containing 90 CAG repeats. These mice exhibit nuclear inclusions at 12 months of age, in the absence of overt cell death, neural dysfunction, and overt pathology (Wheeler et al 2000).
To determine the suitability of this mouse line as a therapeutic tool, we have conducted a detailed behavioural assessment of the Q92 mouse line over an 18 month period. To compare the ability of Q92 homozygote mice with wild type (WT) littermates on motor parameters, the rotarod and the grip strength tests were used along with a general measure of light and dark phase locomotor activity. An acoustic startle and pre-pulse inhibition paradigm were also employed. To determine differences in cognitive ability a variant of the Morris water maze task that incorporated a reversal task was used.
Our preliminary results suggest that the homozygote Q92 mouse line does not exhibit marked motor deficits when compared with wild type littermates (as measured by rotarod, grip strength test, and locomotor activity), but that subtle cognitive deficits exist in homozygote Q92 mice as demonstrated by the poor performance of these mice to acquire the location of the hidden platform in the Morris water maze task.
These preliminary data demonstrate that the Q92 mouse line has a spatial memory deficit in the absence of an overt motor phenotype.
Keywords: Huntington’s mouse behaviour
P095 ARIPIPRAZOLE IN THE TREATMENT OF HUNTINGTON’S DISEASE: A CASE REPORT
A. K. Hödl, R. M. Bonelli.Department of Psychiatry, Medical University Graz, Auenbruggerplatz, Graz, Austria
We show a case report of a 54 year old man with genetically confirmed Huntington’s disease (HD) who presented with moderate chorea, dystonia, impairment of fine motor tasks, oculomotor function, and impairment of statics and gait. The motor scale of the Unified HD Rating Scale (UHDRS-I) revealed 47 of 124 points. Additionally the patient showed psychiatric instability with perseveration and incoherence of thoughts. After admission, we treated the patient with a standard dose of aripiprazole (15 mg daily). The chorea ameliorated significantly during the next two weeks, all other functions improved slightly (UHDRS-I of 36 points of 124). Aripiprazole was augmented to 30 mg per day. After two weeks of admission of 30 mg per day the chorea decreased once more, the improvement of the motor tasks included all seven categories of the UHDRS-I (UHDRS-I 25 of 124 points). Additionally the perseveration and incoherence of thoughts ceased. The patient was stable and no side effects appeared during 12 weeks of admission. We conclude that aripiprazole seems to be useful in a dysfunction of motor functions in HD.
Keywords: neuroleptic; chorea
P096 GENE EXPRESSION CHANGES IN HD TRANSGENIC RAT AND HD KNOCK-IN MOUSE BRAINS MEDIATED BY TREHALOSE TREATMENT
H. P. Nguyen1, M. Bonin1, M. Kuhn, C. Holzmann2, Svon Hörsten3, O. Rieß1.1Department of Medical Genetics, University of Tübingen; 2Department of Medical Genetics, University of Rostock; 3Department of Functional and Applied Anatomy, Medical School of Hannover, Germany
Huntington’s disease (HD) is a neurodegenerative disorder in which expanded polyglutamine induced transcriptional dysregulation has been proposed as an early pathogenic event. Previous studies have shown gene expression changes in several mouse models of HD, which express extreme numbers of CAG repeats. We have recently developed a transgenic rat model for HD, which carries a truncated rat huntingtin fragment with 51 CAG repeats. These rats show a slowly progressive neurological, neuropathological, and neurochemical phenotype closely resembling the common late manifesting type of human HD. For a further evaluation we have performed a microarray analysis on this transgenic rat model and compared it to a knock-in mouse model of HD (111Q). Additionally, we have studied the impact of trehalose treatment on gene expression in transgenic rats in order to elucidate the stunning effects of trehalose application, which have been recently observed in transgenic HD mice.
Although we found a considerable overlap in the alteration of gene expression, there were significant differences between both models. For example, we observed changes in mRNAs whose products regulate calcium homeostasis and calcium signaling. Comparable to former results, HD knock-in mice striata showed decreased expression of calcium related mRNAs such as the type1 inositol 1,4,5-triphosphate receptor (ITPR1). Surprisingly, microarray analysis of HD transgenic rats revealed an increase of ITPR1 and other calcium related mRNAs. On the other hand when treated with 2% trehalose we found a decrease of calcium related mRNAs compared to the non-treated transgenic rats. These findings confirm former results postulating that calcium dysregulation is an important component of HD pathology. Furthermore, our experiments provide new insights into the impact of trehalose treatment on cellular pathways.
Keywords: animal model; microarray; treatment
P097 CELLULAR FRET ASSAY FOR HUNTINGTIN AGGREGATION
A. Holloschi1, S. Ritz1, I. Schäfer1, S. Wälter2, E. Wanker2, M. Hafner1, P. Kioschis1.1University of Applied Sciences Mannheim, Mannheim, Germany; 2Max-Delbrück-Centrum für Molekulare Medizin, Berlin-Buch, Germany
At least nine neurodegenerative disorders are caused by expansion of polyglutamine repeats in various proteins which results in the misfolding and the aggregation of the affected proteins and the formation of inclusion bodies. Huntington’s disease is the most common polyglutamine disease and it illustrates many pathogenic principles of the group. Extension of the polyglutamine tract in exon 1 of the huntingtin (htt) protein over the normal range of 17–35 is associated with the appearance of aggregates and the development of the disease. The process of aggregation is not fully understood but its inhibition and its modulation provide an insight into the mechanism leading to aggregate formation which might be a target for the treatment of the disease.
Fluorescence resonance energy transfer (FRET) is a process that is strongly dependent on the distance between the donor and the acceptor fluorophore (typically<10 nm). That is why it is an ideal tool to study processes like aggregation where proteins get in close proximity. FRET microscopy of coexpressed htt exon 1 labelled with CFP and YFP revealed that energy transfer was only detectable in aggregates. Based on these findings we developed cell lines expressing both htt exon1 labelled with CFP and YFP to study the aggregation process by FRET. Several reported modulators of polyglutamine aggregation were tested and characterised using this cell lines.
Keywords: assay; huntingtin; aggregation
P098 CYCLOOXYGENASE INHIBITORS ATTENUATE 3-NITROPROPIONIC ACID-INDUCED OXIDATIVE STRESS AND MEMORY IMPAIRMENT IN AN ANIMAL MODEL OF HUNTINGTON’S DISEASE
S. N. Pattipati, P. Kumar, A. Kumar.Neuropsychopharmacology Division, University institute of pharmaceutical sciences, Panjab University, Chandigarg, India
Huntington’s disease (HD) is a progressive neurodegerative disorder associated with severe degeneration of basal ganglia, especially the intrinsic neurons of the striatum, and characterised by involuntary abnormal choreiform movement and progressive dementia. Studies of the HD brain indicate that long term inflammation plays a significant role in the progression of HD. The inflammatory response results in the activation of various types of cells and the production of different molecules that can lead to cell death. 3-nitropropionic acid (3-NP) is known to induce cellular energy deficit (irreversible inhibition of the mitochondrial enzyme succinate dehydrogenase (SDH)) and act on excitotoxic amino acid such as glutamate induce a direct activation and proliferation of cells involved in inflammation related-neurotoxicity. 3-Nitropropionic acid (3-NP) toxicity has gained as an animal model of HD. Cyclooxygenase (COX) enzyme is reported to play an important role in inflammation mediated neurodegeneration. The present study was aimed to study the effect of COX inhibitors on 3-nitropropionic acid induced toxicity in a rat model of HD. 3-Nitropropionic acid (20 mg/kg), was administered intraperitoneally for a period of 4 days. COX inhibitors, naproxen (10–20 mg/kg, twice daily), or valdecoxib (5–10 mg/kg, once daily) were given for a period of 8 days, beginning 4 days before 3-NP administration and co-administered 4 days along with 3-NP. Cognitive dysfunction was assessed by using Morris water maze and elevated plus maze paradigms. Locomotor activity, vacuous chewing movements (VCMs), tremors, and movement analysis were also measured. Rats were sacrificed on the eighth day for estimation of succinate dehydrogenase (SDH) and oxidative stress parameters (malodialdehyde (MDA), and reduced glutathione) in the whole brain immediately after completion of the behaviour tasks. 3-NP treatment produced significant behavioural deficits in rats. COX inhibitors significantly improved the memory impairment as well as motor activity in rats treated with 3-NP. 3-NP treatment also induced lipid peroxidation, decreased glutathione and SDH levels, which was reversed by both the COX inhibitors. The present finding indicates that inflammation plays a significant role in the progression of HD and pretreatment with COX inhibitors are effective in preventing 3-nitropropionic acid induced toxicity in rats.
Keywords: cyclooxygenase; oxidative stress
P099 DEFINING SIRTUIN ACTIVATION AS A NEUROPROTECTIVE STRATEGY IN MODELS OF HUNTINGTON’S DISEASE
A. Parker, M. Arango, S. Abderhamane, E. Lambert, C. Tourette, H. Catoire, C. Neri.INSERM, Laboratory of Genomic Biology, Centre Paul Broca, Paris, France
Several reports suggest that the regulation of signal transduction and transcription is central to Huntington’s disease (HD) pathogenesis and modification. We previously generated C elegans transgenics expressing N-terminal huntingtin toxicity in touch receptor neurons, a model system that shows polyglutamine dependent neuronal dysfunction and axonal dystrophy. We performed a genetic analysis of the cytotoxic pathways involved in this model. We found that Sir2 activation through increased sir-2.1 dosage or treatment with the sirtuin activator resveratrol specifically rescued early neuronal dysfunction phenotypes induced by mutant polyglutamines, two effects dependent on the transcription factor daf-16/FOXO. Additionally, resveratrol showed mutant polyglutamine specific rescue of cell death in neuronal cells derived from HdhQ111 knock-in mice, an effect abolished by the co-incubation with sirtuin blockers. Sirtuin activation may thus protect against mutant polyglutamines. Our data suggest that sirtuin activation may have therapeutic potential for HD and, potentially, other polyglutamine expansion neurodegenerative diseases.
Keywords: neuroprotection; model systems; sirtuin activation
P100 USING PROTEOMICS TO IDENTIFY PROGNOSTIC MARKERS FOR HUNTINGTON’S DISEASE
R. A. Lindner, L. Sebastian, S. Prasad, M. McKay, N. Wilson, S. Hunt, R-MOlsson, M. Wetterhall, C. Remediakis, A. Goodall, J. Harry.Proteome Systems Ltd, 1/35-41 Waterloo Road, North Ryde, NSW, 2113, Australia
Our aim is to detect and statistically validate biomarkers for Huntington’s disease (HD) using proteomic strategies which are highly reproducible and quantitative. We are using statistics to guide experimental design and customised sample preparation to maximise the likelihood of detecting potential biomarkers. Specifically, we:
Deplete abundant proteins in plasma to maximise detection of low abundant proteins
Fractionate by MW and pI (to increase separation and resolution of proteins, hence increasing protein spot detection)
Use formal randomisation procedures throughout to ensure that we detect disease relevant (as opposed to process dependent) differences
In collaboration with High Q, we are in the process of analysing a training set of plasma and CSF samples to identify candidate biomarkers to monitor disease progression and effectiveness of therapies. This training set has been designed based on a pilot study which was performed to determine sample numbers required to statistically validate differences detected. Early results indicate a number of protein isoforms which show statistically significant differential expression as a consequence of HD progression. These protein isoforms are being validated by rigorous statistical analysis. The application of these candidate biomarkers to identify HD progression will then be assessed in a blinded test set of clinical samples representing various stages of HD, and other neurodegenerative diseases, to assess their effectiveness to monitor HD status.
Keywords: proteomics; biomarkers
P101 ULTRASOUND GUIDED FETAL TISSUE RETRIEVAL IMPROVES YIELD OF VIABLE NEURAL CELLS FOR USE IN NEURAL TRANSPLANTATION SWIFT-HD (SOUTH WALES INITIATIVE FOR TRANSPLANTATION – HUNTINGTON’S DISEASE)
S. V. Precious1, C. M. Kelly1, A. Sims2, R. J. Penketh2, N. N. Amso2, S. B. Dunnett1, A. E. Rosser1.1Brain Repair Group; 2Department of Obstetrics and Gynaecology, Cardiff University, Cardiff, UK
Human fetal neural tissue offers a source of cells with a promising potential for neural transplantation as a treatment for Huntington’s disease (HD). Clinical studies to date have used human fetal brain tissue as the donor source for cells. Tissue obtained using standard high pressure aspiration methods results in fragmentation of the fetus making identification and dissection of the appropriate regions almost impossible. We have previously shown that employment of low pressure aspiration using a syringe and abdominal ultrasound markedly improved yield of identifiable striatal tissue. In this study vaginal ultrasound was used to guide the removal of the fetus by syringe aspiration and allowed for a less traumatic retrieval of the fetus. With such a method we have been able to yield a high percentage of viable brain tissue thus making dissection of the appropriate areas more accurate. This method also allows for more accurate morphometric estimation of fetal age at the time of retrieval. A comparison of the morphometric measurement age estimation against the ultrasound age estimation shows a high correlation, which is important in neural transplantation studies. Fetal tissue retrieved by this method may also be used to obtain embryonic germ (EG) cells, which also hold potential for use in neural transplantation.
Keywords: human; fetal; transplantation
P102 NEURAL STEM CELLS FOR CELL REPLACEMENT THERAPY IN HUNTINGTON’S DISEASE
C. M. Kelly, S. V. Precious, S. B. Dunnett, A. E. Rosser.Brain Repair Group, Museum Avenue, Cardiff University, Cardiff CF10 3US, UK
Neural stem (or precursor) cells are receiving consideration as a potential therapeutic element for neurodegenerative disorders, including Huntington’s disease. Such cells are an attractive option as donor cells for neural transplantation, because their proliferative capacity circumvents the problem of tissue availability while they retain the potential to develop differentiated phenotypes. They would also allow the quality control constraints that are associated with the use of primary fetal tissue to be addressed. Neural stem cells may be isolated from the fetal brain and can be encouraged to proliferate in culture using mitogens such as FGF-2. Proliferating fetal stem cells taken from the developing striatum can differentiate into neurons that express adenosine 3’:5’-monophosphate regulated phosphoprotein (DARPP-32), a marker of striatal medium spiny neurons in vivo. The ability to generate DARPP-32 positive neurons decreases with time in culture and with passaging. After short expansion times (10 days to 4 weeks) human striatal fetal tissue maintains the potential to generate a high proportion of DARPP-32 positive neurons in culture and also retain their striatal phenotype following transplantation into the adult rodent CNS, expressing striatal markers such as calbindin and parvalbumin as well as DARPP-32. As a prelude to considering this cell source for clinical application, we have attempted to optimise the proliferation conditions in order to increase the numbers of cells available, and have characterised the cells according to their gene expression over this expansion period.
Keywords: neural stem cells;neural transplantation.
P103 AGGRESSION IN HUNTINGTON’S DISEASE: MEASURE INSTRUMENT FOR ASSESSMENT OF INTERVENTIONS AND GUIDELINES FOR STRATEGIES IN AGGRESSIVE BEHAVIOUR
S. Nyman, E. W. Almqvist.Department of Nursing, Karolinska Institutet, Huddinge, Sweden
Abstract: The management of aggressive behaviour in Huntington’s disease (HD) individuals is often identified as a nursing problem, causing great distress by the patient, family, and caregivers. The purpose of the present study was (1) to identify a user friendly measure instrument to measure aggressive behaviour in HD individuals for targeting and evaluation of interventions, (2) to test the instrument, and (3) to review the literature on nursing interventions in aggressive behaviour. The instruments identified as useful for the study were The Staff Observation Aggression Scale – Revised (SOAS-R),1 the extended version (SOAS-E),2 and Yudofsky Overt Aggression Scale for the Objective Rating of Verbal and Physical Aggression (YOAS).3 They were combined into a two page questionnaire with SOAS-R and E modified (with permission) to be filled out by the caregivers. It includes mapping of the aggressive event and scoring of the severity of the event. The instrument was tested in a pilot study by nursing home staff at one nursing home specialised in HD, and by a group of personal caregivers in a home setting. Their feedback resulted in further modifications to the original scales and is to be validated. The final instrument and the summary of strategies of management of aggressive behaviour can be used in the daily management of HD individuals and as a tool in future trials on nursing and/or pharmacological interventions of aggressive behaviour in HD individuals.
Keywords: measure instrument; aggression
P104 PREVALENCE OF PSYCHIATRIC DISORDER IN PRESYMPTOMATIC HUNTINGTON’S DISEASE GENE CARRIERS AND NON-CARRIERS
C. Julien1, J. C. Thompson1, G. Turner2, J. S. Snowden1, D. Craufurd3.1Greater Manchester Neuroscience Centre, Hope Hospital, Salford; 2Department of Clinical Genetics, St James’ University Hospital, Leeds; 3Academic Unit of Medical Genetics and Regional Genetic Service, St Mary’s Hospital, UK
Psychiatric symptoms are a common but non-specific feature of Huntington’s disease (HD) and often precede the onset of motor and cognitive impairments. Examining the rate of psychiatric disturbances in presymptomatic individuals may help to determine whether such symptoms represent a prodromal manifestation of the disease, or whether they occur as a result of social and psychological adversity associated with a family history of HD. To date, there have been very few prospective studies investigating psychiatric symptoms in presymptomatic at risk individuals, and these have only involved relatively small samples of patients or have not used appropriate control groups.
The present study compared the prevalence of psychiatric symptoms in two groups of at risk asymptomatic individuals (gene-positive and gene-negative) requesting predictive testing for HD between 1987 and 1999. Lifetime psychiatric histories of 195 at risk individuals (80 gene carriers and 115 non-carriers) were obtained using a structured clinical interview, the Composite International Diagnostic Interview (CIDI) (WHO, 1987). Diagnoses were determined according to the DSM-III-R criteria of the American Psychiatric Association. All participants were free from neurological or cognitive signs at the time of interview. Neither participants nor examiners were aware of gene status at the time of testing (double blind).
A preliminary analysis revealed no difference between the gene-positive and gene-negative groups in the lifetime frequency of either clinical psychiatric disorders or subclinical symptom scores. Many of those given unfavourable predictive test results have subsequently developed HD, and we will present the results of a further analysis currently in progress to investigate the relation between psychiatric symptoms and proximity to onset of HD in this subgroup of presymptomatic individuals carrying the HD mutation. This is the largest prospective study of psychiatric symptoms in presymptomatic at risk individuals, and the findings have important implications for the underlying basis of psychiatric disturbances in HD.
Keywords: psychiatric disorder; presymptomatic
P105 DEPRESSION AND SUICIDAL TENDENCIES AFTER PREDICTIVE TESTING FOR HUNTINGTON’S DISEASE
M. Larsson1,2, O. Almkvist1,3, T-HBui4, M. Luszcz5, A. Lundin6, T-BRobins Wahlin1, 2, 7.1Neurotec Department, Karolinska Institutet, Stockholm; 2Stockholm Gerontology Research Center, Stockholm; 3Stockholm University, Department of Psychology, Stockholm; 4Department of Molecular Medicine, Karolinska Institutet, Clinical Genetics Unit, Karolinska University Hospital, Solna, Sweden; 5School of Psychology, Flinders University, Adelaide, Australia; 6Department of Rehabilitation Medicine, Danderyds Hospital, Karolinska Institutet, Stockholm; 7KC-Kompetenscentrum, Research and Development Center in Elderly Care, Stockholm, Sweden
Introduction: Predictive testing for Huntington’s disease (HD) has been ongoing at the Karolinska University Hospital, Stockholm since 1990. A testing programme consistent with international recommendations was used.
Aim: The aim was to evaluate depression and psychosocial health of carriers and non-carriers for HD up to two years after the disclosure of results of predictive testing and to investigate predictors of psychological health.
Methods: A total of 93 participants—35 carriers and 58 non-carriers—answered a questionnaire before the genetic test and then 2, 6, 12, and 24 months afterwards. The questionnaires assessed depression, wellbeing, general health, suicidal thoughts and attempts, life satisfaction, and lifestyle. For analysis, multilevel models evaluating change and predictors of change over time were computed using Hierarchical Linear Modeling (HLM).
Results: Carriers demonstrated a tendency towards lower psychological health before test disclosure and over time they significantly increased in scores of depression and suicidal thoughts compared with non-carriers. Both groups fell within the normal limits for depression but general health was lower than normal for carriers before and after test disclosure. There were no differences in life satisfaction or lifestyle between the groups. Suicidal thoughts occurred frequently and a relatively high proportion of suicidal attempts in both groups were recorded before the predictive test.
Conclusion: Carriers seem to be more psychologically vulnerable before they learn that they are carriers of the mutation. The reason for this is not to be found in lifestyle factors, background, or other demographic differences. Suicidal thoughts being high in both groups at baseline are an indication that it is stressful to live at risk for HD. The significant increase in suicidal thoughts and symptoms of depression for carriers over time could be a sign of the test result itself or HD pathology. Assessing suicidal ideation and providing psychosocial support over time is emphasised.
Keywords: predictive test; psychosocial; suicidal tendencies
P106 THE RELATION BETWEEN APATHY, COGNITIVE IMPAIRMENT, AND STAGES OF HUNTINGTON’S DISEASE
M. S. van Herpen, Ç. dem Öztürk, E. van Duijn, C. K. Jurgens, R. A. C. Roos, R. C. van der Mast.Leiden University Medical Center, Leiden, the Netherlands
Objective: Behavioural problems in Huntington’s disease (HD) are common and varied. A study by Craufurd et al using the Problem Behaviour Assessment for HD (PBA-HD) showed that psychiatric and behavioural symptoms can be divided into three dimensions: apathy, depression, and irritability. Apathy is an amotivational syndrome characterised by diminished initiative and interest, indifference and low social engagement, blunted emotions, and lack of insight. Research has been published about the occurrence of apathy in neurodegenerative disorders. However, little is known about apathy in HD. The objective of this study is, first, to assess the prevalence and severity of apathy in different stages of HD and, second, to get insight into the relation between cognitive impairment and apathy.
Materials and Methods: This is a cross sectional observational study. Participants are presymptomatic and symptomatic gene carriers. Prevalence and severity of apathy in different stages of the disease were assessed using the Apathy Scale (AS). As apathy may be a symptom of depression, we also investigated the occurrence of depression.
To compare cognitive dysfunction in patients with and without apathy, global cognitive functioning (Mini-Mental State Examination), and specific cognitive functioning (Hopkins Verbal Learning Test-revised, Stroop Color-Word Test, and Symbol Digit Modalities Test) were determined. Statistical analysis (SPSS 12.0) was done using correlational coefficients and t tests, with and without corrections for age and depression.
Results: Results up to now show that apathy increases in severity with duration of illness. Also, a correlation between apathy and specific cognitive impairment has been found, but not with global cognitive impairment. We further expect that apathy will be present more frequently in the latter stage of HD.
Conclusion: The findings thus far indicate that apathy is more severe in the latter stages of the disease. Thus, it is possible that apathy may provide a useful behavioural marker of the progressive neurodegeneration in HD. The specific, mostly frontal lobe cognitive impairment is likely to result from dorsolateral prefrontal cortex hypofunction.
Keywords: apathy; cognitive impairment
P107 NEUROPSYCHIATRIC CHARACTERISTICS OF PATIENTS ATTENDING A HUNTINGTON’S DISEASE PREDICTIVE TESTING SERVICE IN MELBOURNE, AUSTRALIA: THE FIRST 10 YEARS
D. Velakoulis1, N. Cahill1, J. H. Lloyd1, R. Tassicker2.1Melbourne Neuropsychiatry Centre, Melbourne; 2Genetic Health Service, Murdoch Institute, Royal Children’s Hospital, Melbourne, Australia
The aim of this study was to investigate the demographic, genetic, clinical, and family history characteristics of patients seeking predictive testing for Huntington’s disease (HD) at the Genetic Health Service of Victoria, Murdoch Institute, Royal Children’s Hospital from 1993 to 2003. The study was based at the Neuropsychiatry Unit of Royal Melbourne Hospital where a proportion of individuals seeking testing are referred for the specialist neuropsychiatric consultation which forms part of the testing protocol. Data were collected from the medical files of 230 patients, and both asymptomatic and symptomatic patients were included in the study population. Results of the study revealed a predominance of females seeking the test, a higher percentage of positive results compared with negative results, and an age range of 30–40 years as the most common age to be tested. Individuals seeking testing were more likely to be married or in a significant relationship and to have children. However, when comparing groups, individuals who tested positive were less likely to be married and less likely to be employed compared with gene negative individuals. It was also found that the positive group were more likely to have children compared with the negative group. Examination of clinical variables revealed that there was no significant difference between psychiatric history and test result, and that the positive gene group was more likely to report experiencing neurological symptoms and to have abnormal neurological examination results.
Keywords: neuropsychiatry; predictive testing
P108 BEHAVIOURAL PROBLEMS IN HUNTINGTON’S DISEASE BEFORE AND AFTER ONSET OF MOTOR SYMPTOMS: A COMPARISON USING THE DUTCH TRANSLATION OF THE PROBLEM BEHAVIOUR ASSESSMENT
E. M. Kingma, E. van Duijn, R. A. C. Roos, R. C. van der Mast.Leiden University Medical Centre, Departments of Neurology, Psychiatry and Clinical Genetics, Leiden, the Netherlands
Background: Huntington’s disease (HD) is associated with motor changes, cognitive deterioration, and psychiatric disorders and behavioural problems. The Problem Behaviour Assessment (PBA) is designed to assess behavioural problems in HD. Since cognitive deterioration may precede onset of motor symptoms, we also expect behavioural problems to occur before motor changes.
Aims: (1) To determine interraterreliability, factor structure, and merits and disadvantages of the Dutch version of the PBA (PBA-NL). (2) To compare behavioural problems in three groups: HD patients, pre(motor)symptomatic gene carriers, and a control group of non-gene carriers originally at 50% risk.
Methods: The PBA was translated into Dutch and back-translated into English. The PBA-NL was administered in 66* gene carriers to determine its characteristics, and administered by two different raters in 18* subjects to assess interraterreliability. To study psychopathology the PBA-NL was administered in 47* subjects (22 symptomatic patients, 10 pre(motor)symptomatic gene carriers, and 15 non-gene carriers).
Results*: Interraterreliability of the PBA-NL is, using a weighted kappa, 0.67 for severity scores and 0.68 for frequency scores. If scoring differences of 1 point, deemed clinically irrelevant, are ignored, kappas are 0,91 and 0,83, respectively. The PBA-NL yields three factors: depression, apathy, and irritability/rigidity. Of the 66 gene carriers 97% reported at least one behavioural symptom. Symptomatic patients and pre(motor)symptomatic gene carriers both display significantly more (p<0.01) psychopathology than non-gene carriers. There is no significant difference between patients and pre(motor)symptomatic gene carriers.
Conclusions: The PBA-NL is a complete and sensitive instrument for use in patient care. As a research instrument it benefits from being elaborate and sensitive, but has some shortcomings: the interraterreliability could be improved. Using the PBA-NL, behavioural problems appear to precede onset of motor symptoms in some HD patients.
*These results are preliminary. Data of a group of approximately 150 participants will be analysed this summer and presented.
Keywords: Problem Behaviour Assessment (PBA); early clinical markers; disease onset
P109 OPENING DOORS FOR YOUNG PEOPLE IN HUNTINGTON’S DISEASE FAMILIES
K. Forrest-Keenan, S. A. Simpson, Z. Miedzybrodzka, E. van Teijlingen, L. McKee.University of Aberdeen, Medical School, Aberdeen, UK
Background: Clinical experience suggests that Huntington’s disease (HD) can considerably affect family life. There are also difficulties for young people as they come to realise that they too may develop the parental disease. The aim of this study was to explore and document the experiences of young people from these families in order to better inform professionals who deal with this vulnerable group.
Methods: Young people were identified through the Grampian Genetics Clinic and the Scottish Huntington’s Association (SHA). In-depth interviews were undertaken to explore how respondents found out about the family disease, what they knew about HD, the impact of HD on relationships with siblings, parents, extended family, and the wider society, and, if possible, their views of genetic testing. A grounded thematic analysis was undertaken.
Results: In total 33 young people aged 9–28 years were interviewed. Some children and young people experienced considerable difficulties, but for others growing up with HD was not a traumatic experience. The majority of participants had had little contact with professionals working with HD families—that is, SHA advisors or genetic counsellors. Some undertook a substantial caring role which had a detrimental impact upon their education, and their social and emotional wellbeing. Participants in families where there was more open communication appeared to cope better.
Discussion: Some young people growing up in a family with HD experienced considerable trauma and isolation, but this was dependent on the social, cultural, familial, and disease context. The issue of how to access and provide support to those who are most vulnerable needs further exploration. Ultimately, we hope that our study will suggest useful strategies to professionals who can help to support young people who are at risk, and that it will lead to more informed and effective genetic counselling practices.
The study was funded under the Wellcome Trust’s programme in Biomedical Ethics.
Keywords: young people; at risk
P110 A QUALITATIVE STUDY INTO THE NEEDS OF PARENT/GUARDIAN CARERS: THE EXPERIENCE OF CARING FOR A YOUNG PERSON WITH JUVENILE HUNTINGTON’S DISEASE
H. M. Brewer1,2, J. A. Smith2, V. Eatough2, O. W. J. Quarrell, C. A. Stanley31, N. W. Glendinning1.1Huntington’s Disease Association, London; 2Birkbeck College, University of London; 3North Trent Clinical Genetics Service, Sheffield Children’s Hospital
Objectives: To identify the needs of families affected by juvenile Huntington’s disease (JHD) and the issues they faced from the perspective of the parent/guardian by exploring their experiences.
Method: Semistructured interviews were carried out with 12 primary carers. The interviews explored the experiences of caring for a child with JHD from the perspective of the parents/guardians, and in particular their experiences of services. The interviews were transcribed verbatim and analysed using Interpretative Phenomenological Analysis (IPA).
Results: One of the main themes that emerged was the isolation that families felt. This sense of isolation resulted from an engagement in social comparison with a number of different groups (for example, adult onset Huntington’s disease and other teenagers without a major condition) and a sense of JHD as being different. This meant that the child with JHD and the parents were unable to normalise their experiences. This sense of isolation was exacerbated by a general lack of knowledge and understanding, as well as the reactions of other people and the way the family responded to this. Other themes included a definition of what was helpful and unhelpful support from the experiences of the families.
Conclusions: A number of issues were highlighted by the families in terms of their experiences and their needs. The results of this study have implications for those providing support for families affected by JHD, whether informally or professionally. There were also specific implications for the provision of support during the period before families receive a confirmed diagnosis, which families often highlighted as a particularly difficult time.
Keywords: juvenile; qualitative; experiences
P111 PERCEPTIONS AND EXPERIENCES OF BENEFIT, DISADVANTAGE, AND NEGATIVE TREATMENT IN A SAMPLE OF AUSTRALIAN ADULTS PRESENTING AT CLINICAL GENETIC SERVICES REGARDING PREDICTIVE TESTING FOR HUNTINGTON’S DISEASE
S. Taylor1, S. Treloar1,2, K. Barlow-Stewart3, M. Stranger4, M. Otlowski4.1School of Social Work & Applied Human Sciences, The University of Queensland; 2Queensland Institute of Medical Research, Brisbane; 3The Centre for Genetics Education, Royal North Shore Hospital, Sydney; 4The School of Law, University of Tasmania, Tasmania, Australia
The Genetic Discrimination Project (GDP) is a broad based research programme investigating genetic discrimination in Australia. Genetic discrimination is differential treatment, either positive or negative, of asymptomatic individuals based on real or assumed genetic status. Within the GDP, the Consumer Project has investigated the experiences of a sample of adults who presented at 15 Australian clinical services, between 1998 and 2003, regarding predictive testing for various genetic conditions. Of 2362 individuals receiving a questionnaire, 1185 (50.2%) responded. This paper reports perceptions and experiences of benefit, disadvantage, and negative treatment of the 351 respondents with Huntington’s disease (HD) as the main condition in their family. At the time of the survey, 33% (117/351) knew they were gene positive, 41% (143/351) knew they were gene negative, and 7% (23/351) did not know their status. In general, respondents strongly supported genetic testing technology. Regarding perceived benefit and disadvantage associated with genetic knowledge, on scales from 1 (“no benefit”/“no disadvantage”) to 11 (“great benefit”/“great disadvantage”), median scores were 10 and 3 respectively. Non-gene carriers perceived significantly greater benefit, but not disadvantage, than gene carriers; perceived disadvantage did not differ significantly. Data regarding perceived benefit and disadvantage are presented. “Some” or “a lot” of coercion to undertake testing was experienced from family members (82/277), doctors (26/268), geneticists/genetic counsellors (25/271), insurance companies (22/262), and employers (6/263). A range of insurance data is presented. Fifty seven per cent (200/351) of respondents did not know where to complain officially about negative treatment. Of 91 (8%) respondents to the wider survey reporting 258 incidents of alleged negative treatment of asymptomatic individuals, 51 (56%) were respondents with HD in the family; incidents involved insurance, family/other relationships, health professionals, and employment. Data regarding incidents, their impact, and perceived barriers to making complaints are presented. The GDP team is following up specific cases for verification.
Keywords: genetic discrimination; Australia
P112 ATTITUDES TOWARDS GENETIC TESTING FOR HUNTINGTON’S DISEASE IN PHAROS PARTICIPANTS
K. A. Quaid and the Huntington Study Group PHAROS Investigators.
The Prospective Huntington At Risk Observational Study (PHAROS) is a longitudinal observational study of 1001 participants at risk for Huntington’s disease (HD) who have chosen not to be tested for the presence or absence of the CAG repeat that causes HD. The study is being conducted at 43 sites in the United States and Canada. The goals of the study are to determine: (1) how many will develop signs of the illness over a period of 5–7 years; (2) what are the earliest signs of the illness; (3) how accurate are the evaluations that researchers use in detecting the onset of HD; and (4) which factors influence the age at which a person carrying the HD gene develops the illness.
Funding from the Ethical, Legal and Social Implications (ELSI) Program of the National Center for Human Genome Research allowed us to ask participants a variety of questions regarding their attitudes, perceptions, and beliefs on several topics including genetic testing. Participants were presented with 18 possible reasons for choosing not to be tested and were asked to indicate whether they considered each reason Extremely Unimportant, Somewhat Unimportant, Neutral, Somewhat Important, or Extremely Important. A total of 673 individuals completed the questionnaires. There were 457 (67.9%) females and 216 (32.1%) males. Their mean age was 41.5 (SD 7.5) and their mean educational level was 14.9 (SD 2.6). This cohort was 96.6% White.
The top five reasons for not being tested as measured by the percentage of participants endorsing the reason as Somewhat Important or Extremely Important were:
Cannot undo the knowledge (65. 8%)
There is no cure or treatment at this time (64. 8%)
I am comfortable being at risk (63. 8%)
I prefer not knowing (63. 5%)
Being tested would not increase my control (62.1%)
Keywords: attitudes; genetic testing
Other considerations included being tested would increase the risk to my children (58.3%) and concern about losing my health insurance (58%).
P113 A MULTIMETHOD, TWO CITIES, INTENSIVE IN-DEPTH QUALITATIVE STUDY OF HUNTINGTON’S CAREGIVERS IN COLOMBIA
To my knowledge, this is the first study to explore the psychosocial aspects of a devastating disease using multistrategic methods. Specifically, the proposed study, uses focus groups, interviewing, and participant observation in two Colombian cities. This study is important and significant. Firstly, Colombia has the second largest rate of Huntington’s disease in the Latin America. Specifically, in Juan de Acosta, a small town with only 13 000 people, 76 families are affected by Huntington’s. Secondly, this study is expected to increase awareness of both Huntington’s patients, and their female familial caregivers, who experience life threatening caregiving from uncooperative and neurological impaired Huntington’s suffers. Thirdly, women caregivers of Huntington’s patients live in a paradox; thus they are in a different category of caregivers. They often face the same fate as the Huntington patient in which they provide care (HDSA 2001; Pollard et al, 1999; Bird, 1999). The proposed research explores the Colombia Huntington’s caregiver experience through the Hispanic culture of caring. The Hispanic culture possesses a strong gender component of caring. Additionally, there is a positive valuation of the caregiving roles that enhances family cohesion and values home care more than that of other forms of care. Importantly, the Hispanic system of care relies on close relatives, specifically women (Lim et al, 2000; Cox and Monk, 1993). The proposed study emphasis has implications for caring in America. If care in Colombia is understood, then interventions could be developed in for American Hispanics who care for those suffering with such chronic diseases as cancer, or Alzheimer’s disease.
Keywords: caregiving; Huntington’s care in Hispanic culture; family care
P114 COPING WITH THE CHALLENGES OF HUNTINGTON’S DISEASE: EXPLORING THE PROCESS OF CYBER SUPPORT
N. S. Coulson1, H. Buchanan1, A. Aubeeluck2.1University of Derby, School of Education, Health & Sciences, Derbyshire; 2University of Nottingham, School of Nursing, Derby, UK
The aim of this study was to explore the nature and type of social support provided by participants of an Internet support group for individuals affected by Huntington’s disease (HD). In order to quantify the type of social support provided a content analysis was performed on all messages posted to the group’s bulletin board. The participants in this study were all members who posted messages during the study period (1997–2000). In total, 793 unique sender names were identified with 1313 posted messages representing the data for this study. The first stage of the analysis comprised a preliminary screening of all posted messages for evidence of social support. At this stage, social support was broadly defined as those offering caring, belonging, esteem, or assistance to the recipient (Cushman & King, 1986). One coder applied this definition to all messages and it was revealed that social support was evident in 98.9% of messages. Next, an adapted version of the Social Support Behaviour Code (Cutrona & Suhr, 1992) was used to undertake a content analysis of the posted messages. In total, five supracategories and 22 subcategories of social support were coded. The analysis revealed that group members most frequently offered informational (56.2%) and emotional support (51.5%) followed by network support (45.6) with esteem support (23.9%) and tangible assistance (21.9%) least frequently offered. The computer mediated group evidently provided a much needed source of information and emotional support to members. Implications for future research, methodological limitations, as well as practical implications will be discussed.
Keywords: communication; internet; support
P115 HEALTH RELATED QUALITY OF LIFE IN HUNTINGTON’S DISEASE
A. K. Ho1,2, A. O. G. Robbins2, S. J. Walters3, S. Kaptoge2, B. J. Sahakian2, R. A. Barker2.1University of Reading, UK; 2University of Cambridge, UK; 3University of Sheffield, UK
Although a number of clinical endpoints in monitoring the response to treatment in patients with Huntington’s disease (HD) have been explored, there has been a paucity of research in the quality of life in such patients. The aim of this study was therefore to validate the use of two generic health related quality of life instruments (the Short Form 36 health survey questionnaire (SF-36) and the Sickness Impact Profile (SIP)) and to evaluate their psychometric properties. We found that both instruments demonstrated acceptable convergent validity and reliability for patients and carers. However, there was an advantage in using the SF-36 because of its more robust construct validity and test-retest reliability; furthermore motor symptoms appeared to influence some strictly non-motor dimensions of the SIP. On a pragmatic level, the SF-36 is shorter and quicker to administer and so easier for patients at various stages of the disease to complete. Thus, the SF-36 would appear to be the recommended instrument of choice for patients with HD and their carers although further work needs to be done to investigate the sensitivity of the this instrument longitudinally.
Keywords: quality of life; SF-36; SIP; carers
P116 BUTO DANCE WORKSHOPS FOR HUNTINGTON’S DISEASE
K. Muto1,4, P. Chéhère2, J. Salgues2, M. Kokado3, T. Nakai4.1School of Health Sciences, Shinshu University, Japan; 2Association Huntington France, France; 3Center of Life Science and Society, Japan; 4Japanese Huntington’s Disease Network, Japan
Two French professional dancers and the Japanese Huntington’s Disease Network (JHDN) organised unique dance workshops for people with Huntington’s disease (HD) and their family members in Japan. These dancers are trained and inspired by Buto, a contemporary avant garde dance form that originated in Japan. The images are dark, slow, and contorted, evoking shifting images of decay and desperation and imaging our inner unconscious space. Coincidentally, “Huntington’s Chorea” in Japanese means “Huntington’s Buto-byo (Buto disease)”. We named our workshops as “Buto Dance Workshops for Buto-byo (for people with Chorea)”. We would like to present the historical and cultural encounter between “Chorea” and “Buto-byo” in Japan and the evaluation of our workshops.
According to literature reviews and interviews to Buto dancers, “Buto” came into use in Japanese in 1908 and the first medical paper on “Buto-Byo (Chorea)” was published in 1919, and the paper which specified “Huntington’s Buto-Byo” (HC) was published in 1938. On the other hand, Buto dance was originated in the late 1950s, which was irrelevant to HD in spite of its disabled-friendly form.
Our modern Buto dance workshops were held in Amagasaki-City, Kokubunji-City, and Ota-ku in September in 2004. Each workshop gathered 13–15 participants, aged 3–70 years, with HD, with risks for HD, and their spouses. Two French dancers facilitated the images to move and all participants moved under the direction of translator. Starting with a small discussion, they moved for two hours and shared their impressions at the end. After the workshops, the JHDN conducted the survey to assess participant satisfaction by open ended questions. We assessed that these workshops are significant to each participant. For people with HD, it contributed to lessen their tension to hide their movement disorders because all participants move suddenly and inconsistently during the workshop. For people with risks, it helped to mitigate their fear of involuntary movements. For other participants, their understanding of how those with HD and risks for HD feel and suffer has been promoted. In conclusion, we believe that the Buto workshops are significant for private rehabilitation, spiritual relaxation, and reduction of fear of HD.
Keywords: dance; therapy; spirituality; movement