Dear Editor,
Re: A response from Noble et al. to e-letter by Psychology Task Force of the International League Against Epilepsy
Cognitive behavioural therapy (CBT) has been recommended for treating depression in people with epilepsy (PWE).[1, 2] The clinical significance of the effects of CBT for PWE has though, not been considered. We therefore systematically searched the literature for randomised controlled trials of CBT for PWE [3] and used Jacobson’s criteria [4] to empirically determine whether PWE made clinically reliable improvement. We compared this to that seen in the control arms of these trials.
Our main findings were that the likelihood of statistically reliable improvement in symptoms of depression was significantly higher for those PWE randomised to CBT compared to control conditions. The overall proportion of PWE achieving reliable improvement was low – 30% compared to 10% in the control arms. For most PWE, symptoms were unchanged.
The proportion of PWE who improve following CBT is limited. It should serve as a clarion call for the development of more effective treatments. Indeed, our review may have inflated CBT’s benefit since some trials included PWE without clinical distress at baseline and so it was not possible to apply Jacobson’s second, more stringent criterion and calculate for what proportion CBT also resulted in recovery.
The Psychology Task Force of the International League Against Epilepsy submitted a response to ou...
Dear Editor,
Re: A response from Noble et al. to e-letter by Psychology Task Force of the International League Against Epilepsy
Cognitive behavioural therapy (CBT) has been recommended for treating depression in people with epilepsy (PWE).[1, 2] The clinical significance of the effects of CBT for PWE has though, not been considered. We therefore systematically searched the literature for randomised controlled trials of CBT for PWE [3] and used Jacobson’s criteria [4] to empirically determine whether PWE made clinically reliable improvement. We compared this to that seen in the control arms of these trials.
Our main findings were that the likelihood of statistically reliable improvement in symptoms of depression was significantly higher for those PWE randomised to CBT compared to control conditions. The overall proportion of PWE achieving reliable improvement was low – 30% compared to 10% in the control arms. For most PWE, symptoms were unchanged.
The proportion of PWE who improve following CBT is limited. It should serve as a clarion call for the development of more effective treatments. Indeed, our review may have inflated CBT’s benefit since some trials included PWE without clinical distress at baseline and so it was not possible to apply Jacobson’s second, more stringent criterion and calculate for what proportion CBT also resulted in recovery.
The Psychology Task Force of the International League Against Epilepsy submitted a response to our article. [5] We are pleased that our article has drawn attention to the issue of what currently available treatments are able to offer PWE and that is has stimulated a needed discussion on the topic. Our paper agreed with many of the points raised by the Task Force:
1. More well conducted trials of psychological interventions are needed. Methodologically weak trials are known to overestimate treatment effects;
2. CBT can alleviate depression for some PWE in clinical practice, but substantial room for improvement exists;
3. Participant samples need to be better described and standardised criteria should be used to do this. Evaluations of sample representativeness can then be made, and potential treatment moderators identified;
4. Trials need to test the benefit of treatments for the full range of clinical depression. Trials have so far tended to exclude those with severe levels of depression, and some have included PWE without depression at baseline;
5. Trials should use measures of depression that are valid and reliable for the epilepsy population and for the context in which they are used.
However, there were several comments in the Task Force’s response which misrepresented our position. The Task Force also presented some reasons that they felt might explain the low rate of improvement in depression detected by our review. Below we clarify our position and address the explanations forwarded by the Task Force.
MISREPRESENTATIONS
Comment 1 by Task Force: “...we hope to encourage health professionals to continue to refer patients for psychotherapy... We argue that if just under 1 in 3 PWE reliably improve with CBT, which has no known side-effects, this is better than a possible alternative of unmanaged depression... the ILAE Psychology Task Force believes that it is inaccurate to label CBT as ‘ineffective’.”
Nowhere in our article did we recommend not referring PWE who are distressed for CBT or psychotherapy. Our review explicitly states that CBT does lead to statistically reliable improvement for some PWE and is preferable to offering no treatment. Depression has many deleterious effects and should not be left unmanaged.
Our review indicates that substantial room for treatment improvement exists. Consequently, we said “that it seems reasonable to conclude that when only 30% of treated patients make an improvement that highly effective CBT treatments for distress in epilepsy do not exist.” We did not, as asserted, label CBT as ineffective. Rather, we said the approach was “largely ineffective”.
Comment 2 by Task Force: “the authors suggest CBT... could even lead to lower ‘self–esteem’ and ‘helplessness’... the latter conclusions were based on hypothetical reactions to treatment, rather than empirically supported outcomes.”
Here a discussion point is mistaken for a conclusion. In our discussion we appropriately considered what implications our results have for what therapists should tell PWE considering CBT and related this to ethical and professional guidelines. We questioned how patients might feel if they were not informed about likely treatment response and went on to experience no benefit. Based on clinical experience amongst our team, and evidence from the literature,[6] we suggested possible reactions might include increased feelings of helplessness and hopelessness and lower expectations of therapy being successful in the future.
REASONS PRESENTED BY TASK FORCE TO ACCOUNT FOR LOW RATE OF IMPROVEMENT:
Comment 3 by Task Force: “we offer alternative interpretations of the findings...we would like to highlight the heterogeneity of the studies pooled and how this impacts the findings... First, the interventions were very diverse... Interestingly, one trial that utilised a standardised CBT protocol, resulted in 50% reliable change reductions in depressive symptoms... Second, over 10% of patients in the analyses had depressive symptoms within the non-clinical ranges.”
The pooled risk difference (RD) across the trials in our review was 0.20 – meaning 20% more PWE randomised to the CBT treatment arms reliably improved compared to the control arms. The trials in our review used different modes of treatment delivery and had samples with different levels of pre-treatment distress. We acknowledged this in our article and to explore whether this heterogeneity obscured higher rates of improvement in some trials, we presented RDs for the individual trials and also pooled RDs for trials using similar treatments and/or samples.
Unfortunately, regardless of how one approached the dataset (i.e., just looking at change in individuals who received face to face treatments or focusing on change in just participants who were distressed at baseline) only around 20% more patients in the CBT groups reliably improved compared to the control arms (see supplementary Figures 1-2 of our review [3]).
The Task Force highlighted the rate of reliable change reported by one trial in our review and implied that it’s results better reflect the potential of CBT for PWE. The trial in question was by Ciechanowski et al.[7]. Unfortunately, the benefit of CBT in that trial was actually not much better than indicated by the pooled RD. The Task Force correctly point out that the proportion of reliable change in the treatment arm of Ciechanowski et al.’s trial was 50%. They neglected to consider though that the proportion who reliably improved in that trial’s (treatment as usual) control arm was 24%. Thus, the RD for Ciechanowski et al.’s trial is 0.26 – not that much different to the pooled RD of 0.20.
Comment 4 by Task Force: “One important limitation of previous trials is the relatively short duration of psychotherapy offered to PWE, a factor that Noble et al. [1] acknowledge... it is very likely that participants did not receive a sufficient dosage of CBT... many PWE experience cognitive difficulties, including memory impairment, which may require more intensive and tailored CBT [5].”
Our review could only comment on the extent of change elicited by CBT treatments so far evaluated for PWE by trials. On average, the treatments offered by the trials in our review lasted 8.8 sessions. The Task Force suggest more treatment sessions may be required for PWE due to the presence of cognitive impairment. Whilst some PWE do experience such difficulties, this explanation does not appear to be able to account for the low rate of improvement seen in the trials in our review since most of them excluded patients with such difficulties.
Comment 5 by Task Force: “One advantage of CBT is that many of the behavioural skills; such as problem solving, sleep hygiene and controlled relaxation can also be tailored to assist with the self-management of epilepsy... which Noble et al. did not consider.”
We focused on trials for which the primary outcome measure was depression and examined the degree of change achieved
We thank you for the opportunity to respond to the Task Force’s letter. We trust that we have clarified our position on a range of points, including the need at present to continue to refer PWE who are distressed for CBT. We stand by our position though that there remains an urgent need for more effective treatments to be developed.
Yours sincerely,
Adam J. Noble
James Temple
James Reilly
Peter L. Fisher.
REFERENCES
[1] Kerr MP, Mensah S, Besag F, de Toffol B, Ettinger A, Kanemoto K, Kanner A, Kemp S, Krishnamoorthy E, LaFrance WJ, Mula M, Schmitz B, van Elst LT, Trollor J, Wilson SJ. International consensus clinical practice statements for the treatment of neuropsychiatric conditions associated with epilepsy. Epilepsia 2011;52: 2133-2138.
[2] Barry JJ, Ettinger AB, Friel P, Gilliam FG, Harden CL, Hermann B, Kanner AM, Caplan R, Plioplys S, Salpekar J, Dunn D, Austin J, Jones J, Advisory Group of the Epilepsy Foundation as part of its Mood Disorder. Consensus statement: the evaluation and treatment of people with epilepsy and affective disorders. Epilepsy & Behavior 2008 13: S1-29.
[3] Noble AJ, Reilly J, Temple J, Fisher PL. Cognitive-behavioural therapy does not meaningfully reduce depression in most people with epilepsy: a systematic review of clinically reliable improvement. Journal of Neurology, Neurosurgery & Psychiatry 2018; doi: 10.1136/jnnp-2018-317997.
[4] Jacobson NS, Truax P. Clinical significance: a statistical approach to defining meaningful change in psychotherapy research. Journal of Consulting and Clinical Psychology 1991;59: 12-19.
[5] Gandy M, Reuber M, LaFrance Jr WC, Modi A, Wagner JL, Goldstein LH, Tang V, Donald KA, Valente KD, Michaelis R. Why it’s still important to consider referring patients with epilepsy (PWE) with depression for psychotherapy – including Cognitive Behaviour Therapy. Response from the Psychology Task Force of the International League Against Epilepsy. Journal of Neurology, Neurosurgery & Psychiatry 2018; Published on: 11 July 2018.
[6] Crawford MJ, Thana L, Farquharson L, Palmer L, Hancock E, Bassett P, Clarke J, Parry GD. Patient experience of negative effects of psychological treatment: results of a national survey. The British Journal of Psychiatry 2016;208: 260-265.
[7] Ciechanowski P, Chaytor N, Miller J, Fraser R, Russo J, Unutzer J, Gilliam F. PEARLS depression treatment for individuals with epilepsy: a randomized controlled trial. Epilepsy & Behavior 2010;19: 225-231.
We read with interest the study presented by Berg et al [1] that showed that prolonged mechanical ventilation (more than 2 months) in Guillain-Barre syndrome (GBS) was associated with poorer outcome and more residual deficits compared to non-ventilated GBS patients.
We recently found very similar results in the same population of patients. Nevertheless, it should be precised that despite this, we could not found any difference in quality of life compared to the general French population [2]. Berg et al. also found that ventilated patients were less likely to have residual fatigue symptoms compared to non-ventilated GBS patients, respectively 20% versus 54% (p=0.007). Among 13 prolonged mechanically ventilated GBS, we could show that 22% of patients displayed DSM IV criteria for long-term post-traumatic stress disorder (PTSD) [2]. Since one of our main hypothesis was that PTSD symptoms were mainly related to the mechanical ventilation, we assessed long-term PTSD in 20 non-ventilated GBS patients (Table). Unexpectedly, 65% of these non-ventilated patients had PTSD as compared to 22% in the ventilated group found in our previous study (Table). As for fatigue, we would have expected a correlation between the severity of the disease (especially mechanical ventilation), and the incidence of PTSD.
One explanation of these unexpected results could be that the acute stress induced by the temporary paralysis, the traumatic aspects of intubation an...
We read with interest the study presented by Berg et al [1] that showed that prolonged mechanical ventilation (more than 2 months) in Guillain-Barre syndrome (GBS) was associated with poorer outcome and more residual deficits compared to non-ventilated GBS patients.
We recently found very similar results in the same population of patients. Nevertheless, it should be precised that despite this, we could not found any difference in quality of life compared to the general French population [2]. Berg et al. also found that ventilated patients were less likely to have residual fatigue symptoms compared to non-ventilated GBS patients, respectively 20% versus 54% (p=0.007). Among 13 prolonged mechanically ventilated GBS, we could show that 22% of patients displayed DSM IV criteria for long-term post-traumatic stress disorder (PTSD) [2]. Since one of our main hypothesis was that PTSD symptoms were mainly related to the mechanical ventilation, we assessed long-term PTSD in 20 non-ventilated GBS patients (Table). Unexpectedly, 65% of these non-ventilated patients had PTSD as compared to 22% in the ventilated group found in our previous study (Table). As for fatigue, we would have expected a correlation between the severity of the disease (especially mechanical ventilation), and the incidence of PTSD.
One explanation of these unexpected results could be that the acute stress induced by the temporary paralysis, the traumatic aspects of intubation and the need for prolonged mechanical ventilation (MV) could promote a stronger resilience process, a mental ability which enables adaption to a stressful event [3], in severe GBS patients compared to milder ones. Nevertheless, to our knowledge, no study has shown that the length of stay or the severity of a traumatic event could be associated to higher resilience. In our studies, median length of stay (LOS) was longer in ventilated versus non-ventilated GBS patient, respectively at 102 days [72-126] and 12 days [11-16) (p<0.0001). In the contrary of most ICU patients, GBS patients with prolonged MV are admitted for a transitory impairment of the peripheral nervous system responsible of respiratory failure, without multiple organ dysfunctions. During their LOS, they are, with full consciousness, hostages to their paralyzed bodies, before the recovering. We can make the hypothesis that this uncommon stressful experience could promote in some patients a resilience process in order to deal transiently with they’re inexorable status, with the hypothesis that higher LOS could promote this resilience process. Such changes in mental status have been described in war prisoners and hostages with prolonged captivity [4, 5].
We totally agree with the authors that based on the actual available studies the prediction of which patients with prolonged mechanical ventilation may reach good outcome is impossible and that prospective studies are mandatory. In such studies, detailed psychological and psychiatric evaluation focusing on PTSD and resilence processes would be valuable.
Figure Legend:
Table : Characteristics of the patients.
References
1. van den Berg, B., et al., Clinical outcome of Guillain-Barre syndrome after prolonged mechanical ventilation. J Neurol Neurosurg Psychiatry, 2018. 7(317968): p. 2018-317968.
2. Le Guennec, L., et al., Post-traumatic stress symptoms in Guillain-Barre syndrome patients after prolonged mechanical ventilation in ICU: a preliminary report. J Peripher Nerv Syst., 2014. 19(3): p. 218-23. doi: 10.1111/jns.12087.
3. Wagnild, G.M. and H.M. Young, Development and psychometric evaluation of the Resilience Scale. J Nurs Meas, 1993. 1(2): p. 165-78.
4. Ranscombe, P., Fear, resilience, and tunnel vision. Lancet Neurol, 2015. 14(12): p. 1158.
5. Park, C.L., et al., Does Wartime Captivity Affect Late-life Mental Health? A Study of Vietnam-era Repatriated Prisoners of War. Res Hum Dev, 2012. 9(3): p. 191-209.
We appreciate Dr. Laura S. Boylan’s interest in our article. However, her viewpoint rather strikingly exemplifies the behaviors that she mistakenly believes we were guilty of in our report, beginning with the “eminence based” statements “in my view” occurring twice in the first paragraph and her conclusion with a personal “old saw I use in teaching”. We strongly disagree with her misinterpretation about our application of “cognitive bias” in the selection of our patients for this case-control study. In fact, most patients with Parkinson’s disease (PD) had functional complications ascertained after several visits –requiring a diagnostic revision once they fulfilled the appropriate positive criteria.1 The diagnostic “delay” in part may have highlighted the absent recognition of functional comorbidities in PD prior to our study, forcing a conservative approach before ascertaining what may be considered a “second” diagnosis in these patients. Furthermore, in contrast to Dr. Boylan’s suggestion, we did not select patients on the basis of comorbid depression, anxiety, cognitive symptoms, pain, nausea, or fatigue. Instead these features segregated more commonly among cases than controls after the patient selection had been completed. She argues that we considered them “supportive” for a diagnosis of functional movement disorder, but we did not. We have instead emphasized the potentially misleading influence of both history and psychiatric features and argued in favor of a diagnos...
We appreciate Dr. Laura S. Boylan’s interest in our article. However, her viewpoint rather strikingly exemplifies the behaviors that she mistakenly believes we were guilty of in our report, beginning with the “eminence based” statements “in my view” occurring twice in the first paragraph and her conclusion with a personal “old saw I use in teaching”. We strongly disagree with her misinterpretation about our application of “cognitive bias” in the selection of our patients for this case-control study. In fact, most patients with Parkinson’s disease (PD) had functional complications ascertained after several visits –requiring a diagnostic revision once they fulfilled the appropriate positive criteria.1 The diagnostic “delay” in part may have highlighted the absent recognition of functional comorbidities in PD prior to our study, forcing a conservative approach before ascertaining what may be considered a “second” diagnosis in these patients. Furthermore, in contrast to Dr. Boylan’s suggestion, we did not select patients on the basis of comorbid depression, anxiety, cognitive symptoms, pain, nausea, or fatigue. Instead these features segregated more commonly among cases than controls after the patient selection had been completed. She argues that we considered them “supportive” for a diagnosis of functional movement disorder, but we did not. We have instead emphasized the potentially misleading influence of both history and psychiatric features and argued in favor of a diagnosis of a functional movement disorder exclusively reliant on neurological examination (i.e., using positive criteria rather than applying a diagnosis of exclusion).2 Importantly, we did not review colleagues' charts; these were our own patients, who had been followed by movement disorders experts over several years. Dr. Boylan exercises far more of her own cognitive bias in highlighting how the diagnosis of functional disorders has been overly considered in females (despite considerable epidemiological evidence that these disorders are more common in women) and in her old teaching saw that “proper diagnosis” of movement disorders (including functional movement disorders) "is the one offered the most senior professor in the vicinity". Her viewpoint ignores modern literature that has shown a very low incidence of misdiagnosis using current evaluations and the application of positive criteria for the diagnosis of functional disorders.3 Thus, in citing old, historical literature and ignoring a growing body of work in the field,4 Dr. Boylan’s letter propagates old thinking and misinformation.
References
1. Gupta A, Lang AE. Psychogenic movement disorders. Curr Opin Neurol. 2009;22(4):430-436.
2. Espay AJ, Lang AE. Phenotype-specific diagnosis of functional (psychogenic) movement disorders. Curr Neurol Neurosci Rep. 2015;15(6):556.
3. Stone J, Carson A, Duncan R, et al. Symptoms 'unexplained by organic disease' in 1144 new neurology out-patients: how often does the diagnosis change at follow-up? Brain. 2009;132(Pt 10):2878-2888.
4. Hallett M, Stone J, Carson A. Functional Neurologic Disorders. Vol 139. Amsterdam, Netherlands. : Handbook of Clinical Neurology, Elsevier. ; 2016.
Boentert et al. investigated the prevalence of sleep apnoea and nocturnal hypoventilation (NH) in 250 patients with non-ventilated amyotrophic lateral sclerosis (ALS) by considering gender and severity of bulbar dysfunction (1). Prevalence of NH and apnoea-hypopnoea index (AHI) >5/hour was 40.0% and 45.6%, respectively, and 22.3% of patients had both NH and sleep apnoea. Sleep apnoea was significantly more common in male patients and negatively associated with bulbar function. I have some concerns with this study.
First, the authors did not conduct stratified analysis by gender. As the prevalence of sleep apnoea differs by gender, the association between sleep apnoea, NH and severity of bulbar dysfunction should be analyzed by stratification with gender.
Second, the authors conducted univariate analyses, and adjustment of independent variables cannot be made. Although the number of patients is limited, recommendation for the use of transcutaneous capnography should be based by appropriate adjustments of confounders.
Finally, Park et al. evaluated the relationship between nocturnal hypoxia and cognitive dysfunction in patients with ALS, and patients with nocturnal hypoxia showed poor memory retention and retrieval efficiency. They speculated that patients with ALS might be exposed to repeated episodes of deoxygenation-reoxygenation during sleep, because of the weakness of the respiratory muscles. In order to evaluate the effect of desaturation on ALS...
Boentert et al. investigated the prevalence of sleep apnoea and nocturnal hypoventilation (NH) in 250 patients with non-ventilated amyotrophic lateral sclerosis (ALS) by considering gender and severity of bulbar dysfunction (1). Prevalence of NH and apnoea-hypopnoea index (AHI) >5/hour was 40.0% and 45.6%, respectively, and 22.3% of patients had both NH and sleep apnoea. Sleep apnoea was significantly more common in male patients and negatively associated with bulbar function. I have some concerns with this study.
First, the authors did not conduct stratified analysis by gender. As the prevalence of sleep apnoea differs by gender, the association between sleep apnoea, NH and severity of bulbar dysfunction should be analyzed by stratification with gender.
Second, the authors conducted univariate analyses, and adjustment of independent variables cannot be made. Although the number of patients is limited, recommendation for the use of transcutaneous capnography should be based by appropriate adjustments of confounders.
Finally, Park et al. evaluated the relationship between nocturnal hypoxia and cognitive dysfunction in patients with ALS, and patients with nocturnal hypoxia showed poor memory retention and retrieval efficiency. They speculated that patients with ALS might be exposed to repeated episodes of deoxygenation-reoxygenation during sleep, because of the weakness of the respiratory muscles. In order to evaluate the effect of desaturation on ALS prognosis, cognitive function should also be included for the analysis.
Reference
1. Boentert M, Glatz C, Helmle C, et al. Prevalence of sleep apnoea and capnographic detection of nocturnal hypoventilation in amyotrophic lateral sclerosis. J Neurol Neurosurg Psychiatry 2018;89(4):418-424.
2. Park SY, Kim SM, Sung JJ, et al. Nocturnal hypoxia in ALS is related to cognitive dysfunction and can occur as clusters of desaturations. PLoS One 2013;8(9):e75324.
In my view the data presented in this study (1) which are interpreted as indicating a high prevalence of functional movement disorders (FMD) in PD might also be interpreted as suggesting that diagnostic delay is common in PD, particularly among women patients who present as "high maintenance" patients. The diagnosis of functional movement disorders is a matter of expert opinion and in my view problems with study design and interpretation support rather than minimize cognitive and confirmation bias in this study.
Subjects all met UK brain bank criteria for PD. Subjects diagnosed with FND in this study had high rates of family history of PD. They had depression, anxiety, cognitive symptoms, pain, nausea, fatigue all common complaints among the population in general and most particularly in PD. The presence of these symptoms before or after diagnosis of PD is considered by the authors as supportive for a diagnosis of FMD. However, these same symptoms are known to be associated with PD and might be considered supportive of a PD diagnosis.
Disparities in healthcare for women are well established (2). Neurology has a long history of mistakes distinguishing the "functional" from the "organic" (e.g.3). To choose one example people with blepharospasm, mostly women, were institutionalized long-term as the disease was not recognized as neurologic. Women commonly encounter dismissal in the medical context and this can occasion missed opportuni...
In my view the data presented in this study (1) which are interpreted as indicating a high prevalence of functional movement disorders (FMD) in PD might also be interpreted as suggesting that diagnostic delay is common in PD, particularly among women patients who present as "high maintenance" patients. The diagnosis of functional movement disorders is a matter of expert opinion and in my view problems with study design and interpretation support rather than minimize cognitive and confirmation bias in this study.
Subjects all met UK brain bank criteria for PD. Subjects diagnosed with FND in this study had high rates of family history of PD. They had depression, anxiety, cognitive symptoms, pain, nausea, fatigue all common complaints among the population in general and most particularly in PD. The presence of these symptoms before or after diagnosis of PD is considered by the authors as supportive for a diagnosis of FMD. However, these same symptoms are known to be associated with PD and might be considered supportive of a PD diagnosis.
Disparities in healthcare for women are well established (2). Neurology has a long history of mistakes distinguishing the "functional" from the "organic" (e.g.3). To choose one example people with blepharospasm, mostly women, were institutionalized long-term as the disease was not recognized as neurologic. Women commonly encounter dismissal in the medical context and this can occasion missed opportunities for established clinical interventions (e.g. 4, 5, 6)
Study subjects were selected for assessment for FMD on the basis of their doctors having used language suggesting a suspicion of an FMD in the chart. It sounds as if investigators were reviewing records of colleagues at their own institution. How many, if any, neurologists were considered to have made diagnostic error?
Evidence for the effects of cognitive bias in clinical medicine overshadows evidence for the reliability and validity of expert evaluation of functional movement disorders (4, 7 8).
In the 19th century there was debate over whether Parkinson's disease itself was functional or organic (9). While some cases are clear cut, an old saw I use in teaching is that the proper movement disorder diagnosis is the one offered by the most senior professor in the vicinity.
References:
(1) Wissel BD, Dwivedi AK, Merola A, et al. Functional neurological disorders in Parkinson disease. J Neurol Neurosurg Psychiatry. 2018 Jun;89(6):566-571.
(2) Hornbuckle LM, Amutah-Onukagha N, Bryan A, et al. Health Disparities in Women. Clinical Medicine Insights Women’s Health. 2017.
(3) Hamill EB, Yen MT. The History of Blepharospasm in Medicine. Int Ophthalmol
Clin. 2018 Winter;58(1):3-10.
(4) Schulman KA, Berlin JA, Harless W, et al. The effect of race and sex on physicians' recommendations for cardiac catheterization. N Engl J Med. 1999 Feb 25;340(8):618-26.
(5) Faigle R, Urrutia VC, Cooper LA, Gottesman RF. Individual and System
Contributions to Race and Sex Disparities in Thrombolysis Use for Stroke Patients in the United States. Stroke. 2017 Apr;48(4):990-997
(6) Dusenbery M. Doing harm. Harper Collins 2018.
(7) Vickrey BG, Samuels MA, Ropper AH. How neurologists think: A cognitive psychology perspective on missed diagnoses. Ann Neurol. 2010 Apr;67(4):425-33.
(8) Saposnik G, Redelmeier D, Ruff CC, Tobler PN. Cognitive biases associated with medical decisions: a systematic review. BMC Med Inform Decis Mak. 2016 Nov 3;16(1):138.
(9) Bechet E. Contribution a l'etude clinique des formes de la maladie de parkinson. Paris. Ancienne Maison Delahaye. 1892.
Conflict of Interest
Dr. Laura Boylan does medicolegal consulting work.
We read with great interest the research paper published recently by Lotia et al. entitled “Leg stereotypy syndrome: phenomenology and prevalence”. 1 The study brings important new information about an intriguing newly identified condition, previously designated by the same group as leg stereotypy disorder2, defined as repetitive, rhythmical, stereotypic leg movements, particularly noticeable while sitting.1,2 The authors describe the phenomenology and prevalence of leg stereotypy syndrome (LSS) by evaluating a total of 92 individuals, 57 from the general population (control group) and 35 with different movement disorders (Parkinson´s disease, restless legs syndrome, Tourette´s syndrome, and tardive dyskinesia).1 LSS was found in 7% of the control group and 17% of the movement disorders group, concluding that in terms of prevalence, this is a common condition.1 Another interesting finding was that all but one (83 %) of the patients with LSS from the movement disorders group also had a diagnosis of attention deficit hyperactivity disorder (ADHD).1 Lotia and colleagues do not believe in a relationship between ADHD and LSS1 stating in the discussion that “while certain movements or fidgetiness can be observed in individuals with anxiety or ADHD, the presence of typical stereotyped movements has not been previously described with ADHD”.1 Our group is currently studying the frequency of abnormal involuntary movements in patients with ADHD, compared a control group, and our pre...
We read with great interest the research paper published recently by Lotia et al. entitled “Leg stereotypy syndrome: phenomenology and prevalence”. 1 The study brings important new information about an intriguing newly identified condition, previously designated by the same group as leg stereotypy disorder2, defined as repetitive, rhythmical, stereotypic leg movements, particularly noticeable while sitting.1,2 The authors describe the phenomenology and prevalence of leg stereotypy syndrome (LSS) by evaluating a total of 92 individuals, 57 from the general population (control group) and 35 with different movement disorders (Parkinson´s disease, restless legs syndrome, Tourette´s syndrome, and tardive dyskinesia).1 LSS was found in 7% of the control group and 17% of the movement disorders group, concluding that in terms of prevalence, this is a common condition.1 Another interesting finding was that all but one (83 %) of the patients with LSS from the movement disorders group also had a diagnosis of attention deficit hyperactivity disorder (ADHD).1 Lotia and colleagues do not believe in a relationship between ADHD and LSS1 stating in the discussion that “while certain movements or fidgetiness can be observed in individuals with anxiety or ADHD, the presence of typical stereotyped movements has not been previously described with ADHD”.1 Our group is currently studying the frequency of abnormal involuntary movements in patients with ADHD, compared a control group, and our preliminary results have demonstrated that legs and foot stereotypies are actually very common in patients with ADHD (30 % ) (Teive et al., unpublished data). In fact, lower limbs stereotypies, such as fidgeting and foot movements (crossed-knee jiggle and uni or bilateral toe tap) was previously characterized by Wender, as a suggestive sign of ADHD in adult patients, often referred to as Wender´s sign.3 We believe that these findings may contribute to the understanding and phenomenological characterization of the new neurological syndrome described by Lotia et al.
References:
1. Lotia M, York MK, Strutt AM, Jankovic J. Leg stereotypy syndrome: phenomenology and prevalence. J Neurol Neurosurg Psychiatry 2018; 0: 1-4. Doi: 10.1136/jnnp-2017-317057
2. Jankovic J. Leg stereotypy disorder. J Neurol Neurosurg Psychiatry 2016; 87: 220-221.
3. Wender PH. Attention deficit hyperactivity disorder in adults. Oxford University Press, New York, 1995, pp. 23
Wissel and colleagues recently reported on a large retrospective case series of patients with functional neurological disorder (FND) and Parkinson's disease (PD) [1]. The authors only briefly touched upon the question of shared pathophysiology, noting that in principle certain structural brain diseases may predispose to FND. The study was not designed to tease out any shared or causal pathways between FND and PD, but some speculation based on the presented data could help formulate useful hypotheses concerning this interesting comorbidity. I propose that a disruption of the central noradrenergic system due to degeneration of the locus loeruleus (LC), the sole source of noradrenaline in the brain with far-reaching projections, is a good candidate for a causal link between FND and (prodromal) PD.
In the study by Wissel and colleagues FND antedated the diagnosis of PD in 26% of cases, often by several years [1]. This is significant, because it nearly eliminates the possibility that the comorbidity is entirely a matter of symptom modelling or functional overlay in all cases. Considering the typical neuroanatomical progression of Lewy pathology in PD, this suggests that neurodegenerative effects within the lower brainstem (Braak stage 1 or 2) are likely structural candidates for a causal pathway. Early LC pathology has been associated with other premotor manifestations of Lewy pathology and PD such as REM sleep behaviour disorder and cognitive decline. A study using...
Wissel and colleagues recently reported on a large retrospective case series of patients with functional neurological disorder (FND) and Parkinson's disease (PD) [1]. The authors only briefly touched upon the question of shared pathophysiology, noting that in principle certain structural brain diseases may predispose to FND. The study was not designed to tease out any shared or causal pathways between FND and PD, but some speculation based on the presented data could help formulate useful hypotheses concerning this interesting comorbidity. I propose that a disruption of the central noradrenergic system due to degeneration of the locus loeruleus (LC), the sole source of noradrenaline in the brain with far-reaching projections, is a good candidate for a causal link between FND and (prodromal) PD.
In the study by Wissel and colleagues FND antedated the diagnosis of PD in 26% of cases, often by several years [1]. This is significant, because it nearly eliminates the possibility that the comorbidity is entirely a matter of symptom modelling or functional overlay in all cases. Considering the typical neuroanatomical progression of Lewy pathology in PD, this suggests that neurodegenerative effects within the lower brainstem (Braak stage 1 or 2) are likely structural candidates for a causal pathway. Early LC pathology has been associated with other premotor manifestations of Lewy pathology and PD such as REM sleep behaviour disorder and cognitive decline. A study using neuromelanin-sensitive MRI sequences recently confirmed in vivo that degeneration of the LC is indeed closely associated with (and likely responsible for) the occurrence of REM sleep behaviour disorder, cognitive impairment, EEG slowing and ortostatic hypotension in PD patients [2]. So in terms of premotor progression of pathology, neuroanatomy and functional relevance of neurodegeneration, the LC seems to be a good candidate. But why should central noradrenergic dysfunction predispose to FND?
The LC noradrenergic system is critically involved in three interconnected cognitive domains that are highly relevant for FND: arousal, attention and affective learning [3]. The LC projects directly to the prefrontal cortex, where it is involved in selective attention and attentional shifts, as well as to various limbic structures including the hippocampus and amygdala, where it mediates arousal and affective learning. A persistent dysregulation of attention, arousal and affective learning can lead to abnormal stress responsivity and maladaptive behavioural changes. General hyperarousal is common in many forms of FND, and is assumed to be pivotal in the emergence and maintainance of functional and dissociative symptoms [4]. Dysregulated attentional control can lead to increased self-directed attention (attentional biases) and dissociative experiences, both common in FND [4]. Furthermore, current mechanistic frameworks of FND predict that disproportionate attentional weighting of sensory expectations and illness beliefs can distort or even override contradictory sensory inputs to produce functional symptoms beyond volitional control [5]. To summarize, if Lewy pathology critically disrupts LC function (possibly years before the dopaminergic system is affected) the resulting dysregulation of attentional control, arousal and affective learning can directly predispose to the development of functional sensory or motor symptoms. The additional findings by Wissel and colleagues that PD-FND patients had worse depression and anxiety than PD without FND, and that FND presented nearly always on the PD-affected side are also in line with the potential role of LC pathology.
Future studies could test this proposition by investigating the effect of noradrenergic medication on FND, and by prospectively evaluating patients with isolated/idiopathic REM sleep behaviour disorder (and no dopaminergic dysfunction) for FND.
References
1. Wissel BD, Dwivedi AK, Merola A, et al. Functional neurological disorders in Parkinson disease. J Neurol Neurosurg Psychiatry. Published Online First: 16 March 2018. doi: 10.1136/jnnp-2017-317378
2. Sommerauer M, Fedorova TD, Hansen AK, Knudsen K, Otto M, Jeppesen J, Frederiksen Y, Blicher JU, Geday J, Nahimi A, Damholdt MF, Brooks DJ, Borghammer P. Evaluation of the noradrenergic system in Parkinson's disease: an 11C-MeNER PET and neuromelanin MRI study. Brain. 2018 Feb 1;141(2):496-504. doi: 10.1093/brain/awx348.
3. Sara SJ. The locus coeruleus and noradrenergic modulation of cognition. Nat Rev Neurosci. 2009 Mar;10(3):211-23. doi: 10.1038/nrn2573. Epub 2009 Feb 4.
4. Roelofs K, Pasman J. Stress, childhood trauma, and cognitive functions in functional neurologic disorders. Handb Clin Neurol. 2016;139:139-155. doi: 10.1016/B978-0-12-801772-2.00013-8.
5. Edwards MJ, Adams RA, Brown H, Pareés I, Friston KJ. A Bayesian account of 'hysteria'. Brain. 2012 Nov;135(Pt 11):3495-512. doi: 10.1093/brain/aws129. Epub 2012 May 28.
I read the article entitled "Patients with Parkinson disease are prone to functional neurological disorders" by Hallett M published in the Journal of Neurology, Neurosurgery and Psychiatry (Published Online First: 16 March 2018. doi: 10.1136/jnnp-2017-317684). I want to congratulate the author for this successful article, and make some contributions.
The article particularly mentions certain aspects of the clinical presentation, medical history and examination of patients, which should raise the suspicion of a functional disorder (1). I think it is important to remember patients with functional disorders will not always adhere to these criteria and clinicians should perhaps consider trialling suspected patients on either cognitive behavioural therapy (CBT) or physiotherapy to assess if they experience any improvement with these strategies. There is increasing evidence to show CBT and physiotherapy are beneficial for patients with functional disorders, hence they may be useful in confirming the diagnosis (2)(3).
Furthermore, the author suggests patients with functional symptoms and no sign of Parkinson's Disease should not be pursued further for a diagnosis of Parkinson's Disease. I think a difficulty is often deciding what classifies as a sign of Parkinson's Disease. The cardinal symptoms of bradykinesia, resting tremor, muscular rigidity and postural instability are commonly subtle within patients, making...
I read the article entitled "Patients with Parkinson disease are prone to functional neurological disorders" by Hallett M published in the Journal of Neurology, Neurosurgery and Psychiatry (Published Online First: 16 March 2018. doi: 10.1136/jnnp-2017-317684). I want to congratulate the author for this successful article, and make some contributions.
The article particularly mentions certain aspects of the clinical presentation, medical history and examination of patients, which should raise the suspicion of a functional disorder (1). I think it is important to remember patients with functional disorders will not always adhere to these criteria and clinicians should perhaps consider trialling suspected patients on either cognitive behavioural therapy (CBT) or physiotherapy to assess if they experience any improvement with these strategies. There is increasing evidence to show CBT and physiotherapy are beneficial for patients with functional disorders, hence they may be useful in confirming the diagnosis (2)(3).
Furthermore, the author suggests patients with functional symptoms and no sign of Parkinson's Disease should not be pursued further for a diagnosis of Parkinson's Disease. I think a difficulty is often deciding what classifies as a sign of Parkinson's Disease. The cardinal symptoms of bradykinesia, resting tremor, muscular rigidity and postural instability are commonly subtle within patients, making them a challenge to distinguish from normal limits. This is made even more difficult if a functional disorder is also suspected. Clinicians should therefore consider demonstrating reduced levels of the presynaptic dopamine active transporter (DAT) using a DaTscan, if available, to aid their diagnosis of Parkinson's Disease as the author suggests in another of their articles (4). Guidance surrounding the use of a DaTscan from the National Institute for Health and Care Excellence (NICE) does not currently account for this indication, however it may be worth considering for future recommendations (5).
References:
1. Wissel BD, Dwivedi AK, Merola A, et al Functional neurological disorders in Parkinson disease J Neurol Neurosurg Psychiatry Published Online First: 16 March 2018. doi: 10.1136/jnnp-2017-317378.
2. Nielsen G, Stone J, Matthews A, et al Physiotherapy for functional motor disorders: a consensus recommendation J Neurol Neurosurg Psychiatry 2015;86:1113-1119.
3. Conwill M, Oakley L, Evans K, Cavanna A. CBT-based group therapy intervention for nonepileptic attacks and other functional neurological symptoms: A pilot study. Epilepsy & Behavior. 2014;34:68-72.
4. Hallett M. Psychogenic Parkinsonism. Journal of the neurological sciences. 2011;310(1-2):163-165. doi:10.1016/j.jns.2011.03.019.
5. National Institute for Health and Care Excellence. Parkinson’s disease in adults NICE guideline NG71 [Internet]. Nice.org.uk. 2017 [cited 12 April 2018]. Available from: https://www.nice.org.uk/guidance/ng71/chapter/Recommendations#diagnosing....
Imai et al. examined the association between the dosing regimen of oral prednisolone (PSL) and the achievement of minimal manifestation status or better on PSL <=5 mg/day lasting >6 months in patients with generalized myasthenia gravis (1). The authors classified 590 patients into high-dose, intermediate-dose and low-dose (n=166) groups, and logistic regression analysis was applied to know the prognosis of patients in low-dose group, by splitting observational period into 1 to 3 years of treatment. The authors concluded that a low-dose PSL regimen with early combination of other treatment options was significantly associated with good prognosis. I have two concerns about their study.
First, the dosing regimen of oral PSL should be considered with caution. Namely, the authors set the maximum dose of oral PSL in each group, and standard treatment schedule was selected after each patient was allocated. Mean daily dose of PSL does not become highest in high-dose group in the study, which happens in the study protocol. In addition, there is a possibility of higher frequency in patients with combination of other treatment options, when patients were registered into low-dose group. As the age of onset was higher and disease duration was shorter in patients with low-dose group, randomized allocation should be strictly conducted in further study.
Second, the number of events was not enough after 1 year observation, and higher odds ratios with wide ranges of con...
Imai et al. examined the association between the dosing regimen of oral prednisolone (PSL) and the achievement of minimal manifestation status or better on PSL <=5 mg/day lasting >6 months in patients with generalized myasthenia gravis (1). The authors classified 590 patients into high-dose, intermediate-dose and low-dose (n=166) groups, and logistic regression analysis was applied to know the prognosis of patients in low-dose group, by splitting observational period into 1 to 3 years of treatment. The authors concluded that a low-dose PSL regimen with early combination of other treatment options was significantly associated with good prognosis. I have two concerns about their study.
First, the dosing regimen of oral PSL should be considered with caution. Namely, the authors set the maximum dose of oral PSL in each group, and standard treatment schedule was selected after each patient was allocated. Mean daily dose of PSL does not become highest in high-dose group in the study, which happens in the study protocol. In addition, there is a possibility of higher frequency in patients with combination of other treatment options, when patients were registered into low-dose group. As the age of onset was higher and disease duration was shorter in patients with low-dose group, randomized allocation should be strictly conducted in further study.
Second, the number of events was not enough after 1 year observation, and higher odds ratios with wide ranges of confidence interval were observed. As the follow-up period become longer, odds ratios become small, although significance disappeared in comparison between low-dose and high-dose groups after 3 year observation. I suppose that confounders for the prognosis were not completely adjusted, and there is a limitation of study design in multicentre cross-sectional study.
Reference
1. Imai T, Utsugisawa K, Murai H, et al. Oral corticosteroid dosing regimen and long-term prognosis in generalised myasthenia gravis: a multicentre cross-sectional study in Japan. J Neurol Neurosurg Psychiatry 2017 Nov 24. doi: 10.1136/jnnp-2017-316625
In their recent article on the pathogenesis of dystonia, Kaji and colleagues argue that aberrant cerebellar inputs can induce dystonic movement mediated by the basal ganglia.[1] In this framework, the sensory trick (geste antagoniste) leads to a realignment between predicted and actual sensory information, thus reduces (or overrides) the sensorimotor mismatch forwarded to the basal ganglia, and in turn alleviates dystonic contractions.
A similar model of sensorimotor mismatch response has been implicated in the physiology of being tickled[2]. Specifically, it has been proposed that the inability to tickle oneself is related to a sensory attenuation mediated by the cerebellum during self-generated tactile sensation[3]. This attenuation is proportional to the precision of the sensory prediction[4]. Whether the same cerebellar processes are responsible for the alleviation of dystonia during a sensory trick would be an interesting question to explore experimentally. At the risk of straining the analogy, one could even describe the postures and movements one produces when being tickled as dystonic-like. Neurologists are reminded of this when interpreting ambiguous plantar responses in very ticklish patients -- a problem that can be avoided by employing the patient's cerebellar sensory attentuation[5].
1. Kaji R, Bhatia K, Graybiel AM. Pathogenesis of dystonia: is it of cerebellar or basal ganglia origin? J Neurol Neurosurg Psychiatry. 2017 Oct 31. pii: jnnp-20...
In their recent article on the pathogenesis of dystonia, Kaji and colleagues argue that aberrant cerebellar inputs can induce dystonic movement mediated by the basal ganglia.[1] In this framework, the sensory trick (geste antagoniste) leads to a realignment between predicted and actual sensory information, thus reduces (or overrides) the sensorimotor mismatch forwarded to the basal ganglia, and in turn alleviates dystonic contractions.
A similar model of sensorimotor mismatch response has been implicated in the physiology of being tickled[2]. Specifically, it has been proposed that the inability to tickle oneself is related to a sensory attenuation mediated by the cerebellum during self-generated tactile sensation[3]. This attenuation is proportional to the precision of the sensory prediction[4]. Whether the same cerebellar processes are responsible for the alleviation of dystonia during a sensory trick would be an interesting question to explore experimentally. At the risk of straining the analogy, one could even describe the postures and movements one produces when being tickled as dystonic-like. Neurologists are reminded of this when interpreting ambiguous plantar responses in very ticklish patients -- a problem that can be avoided by employing the patient's cerebellar sensory attentuation[5].
1. Kaji R, Bhatia K, Graybiel AM. Pathogenesis of dystonia: is it of cerebellar or basal ganglia origin? J Neurol Neurosurg Psychiatry. 2017 Oct 31. pii: jnnp-2017-316250. doi: 10.1136/jnnp-2017-316250. [Epub ahead of print]
2. Blakemore SJ, Wolpert D, Frith C. Why can't you tickle yourself? Neuroreport. 2000;11(11):R11-6.
3. Blakemore SJ, Wolpert DM, Frith CD. Central cancellation of self-produced tickle sensation. Nat Neurosci. 1998 Nov;1(7):635-40.
4. Blakemore SJ, Frith CD, Wolpert DM. Spatio-temporal prediction modulates the perception of self-produced stimuli. J Cogn Neurosci. 1999 Sep;11(5):551-9.
5. Sohrab SA, Gelb D. Value of self-induced plantar reflex in distinguishing Babinski from withdrawal. Neurology. 2016 Mar 8;86(10):977.
Dear Editor,
Show MoreRe: A response from Noble et al. to e-letter by Psychology Task Force of the International League Against Epilepsy
Cognitive behavioural therapy (CBT) has been recommended for treating depression in people with epilepsy (PWE).[1, 2] The clinical significance of the effects of CBT for PWE has though, not been considered. We therefore systematically searched the literature for randomised controlled trials of CBT for PWE [3] and used Jacobson’s criteria [4] to empirically determine whether PWE made clinically reliable improvement. We compared this to that seen in the control arms of these trials.
Our main findings were that the likelihood of statistically reliable improvement in symptoms of depression was significantly higher for those PWE randomised to CBT compared to control conditions. The overall proportion of PWE achieving reliable improvement was low – 30% compared to 10% in the control arms. For most PWE, symptoms were unchanged.
The proportion of PWE who improve following CBT is limited. It should serve as a clarion call for the development of more effective treatments. Indeed, our review may have inflated CBT’s benefit since some trials included PWE without clinical distress at baseline and so it was not possible to apply Jacobson’s second, more stringent criterion and calculate for what proportion CBT also resulted in recovery.
The Psychology Task Force of the International League Against Epilepsy submitted a response to ou...
Dear Editor,
We read with interest the study presented by Berg et al [1] that showed that prolonged mechanical ventilation (more than 2 months) in Guillain-Barre syndrome (GBS) was associated with poorer outcome and more residual deficits compared to non-ventilated GBS patients.
We recently found very similar results in the same population of patients. Nevertheless, it should be precised that despite this, we could not found any difference in quality of life compared to the general French population [2]. Berg et al. also found that ventilated patients were less likely to have residual fatigue symptoms compared to non-ventilated GBS patients, respectively 20% versus 54% (p=0.007). Among 13 prolonged mechanically ventilated GBS, we could show that 22% of patients displayed DSM IV criteria for long-term post-traumatic stress disorder (PTSD) [2]. Since one of our main hypothesis was that PTSD symptoms were mainly related to the mechanical ventilation, we assessed long-term PTSD in 20 non-ventilated GBS patients (Table). Unexpectedly, 65% of these non-ventilated patients had PTSD as compared to 22% in the ventilated group found in our previous study (Table). As for fatigue, we would have expected a correlation between the severity of the disease (especially mechanical ventilation), and the incidence of PTSD.
One explanation of these unexpected results could be that the acute stress induced by the temporary paralysis, the traumatic aspects of intubation an...
Show MoreWe appreciate Dr. Laura S. Boylan’s interest in our article. However, her viewpoint rather strikingly exemplifies the behaviors that she mistakenly believes we were guilty of in our report, beginning with the “eminence based” statements “in my view” occurring twice in the first paragraph and her conclusion with a personal “old saw I use in teaching”. We strongly disagree with her misinterpretation about our application of “cognitive bias” in the selection of our patients for this case-control study. In fact, most patients with Parkinson’s disease (PD) had functional complications ascertained after several visits –requiring a diagnostic revision once they fulfilled the appropriate positive criteria.1 The diagnostic “delay” in part may have highlighted the absent recognition of functional comorbidities in PD prior to our study, forcing a conservative approach before ascertaining what may be considered a “second” diagnosis in these patients. Furthermore, in contrast to Dr. Boylan’s suggestion, we did not select patients on the basis of comorbid depression, anxiety, cognitive symptoms, pain, nausea, or fatigue. Instead these features segregated more commonly among cases than controls after the patient selection had been completed. She argues that we considered them “supportive” for a diagnosis of functional movement disorder, but we did not. We have instead emphasized the potentially misleading influence of both history and psychiatric features and argued in favor of a diagnos...
Show MoreBoentert et al. investigated the prevalence of sleep apnoea and nocturnal hypoventilation (NH) in 250 patients with non-ventilated amyotrophic lateral sclerosis (ALS) by considering gender and severity of bulbar dysfunction (1). Prevalence of NH and apnoea-hypopnoea index (AHI) >5/hour was 40.0% and 45.6%, respectively, and 22.3% of patients had both NH and sleep apnoea. Sleep apnoea was significantly more common in male patients and negatively associated with bulbar function. I have some concerns with this study.
First, the authors did not conduct stratified analysis by gender. As the prevalence of sleep apnoea differs by gender, the association between sleep apnoea, NH and severity of bulbar dysfunction should be analyzed by stratification with gender.
Second, the authors conducted univariate analyses, and adjustment of independent variables cannot be made. Although the number of patients is limited, recommendation for the use of transcutaneous capnography should be based by appropriate adjustments of confounders.
Finally, Park et al. evaluated the relationship between nocturnal hypoxia and cognitive dysfunction in patients with ALS, and patients with nocturnal hypoxia showed poor memory retention and retrieval efficiency. They speculated that patients with ALS might be exposed to repeated episodes of deoxygenation-reoxygenation during sleep, because of the weakness of the respiratory muscles. In order to evaluate the effect of desaturation on ALS...
Show MoreIn my view the data presented in this study (1) which are interpreted as indicating a high prevalence of functional movement disorders (FMD) in PD might also be interpreted as suggesting that diagnostic delay is common in PD, particularly among women patients who present as "high maintenance" patients. The diagnosis of functional movement disorders is a matter of expert opinion and in my view problems with study design and interpretation support rather than minimize cognitive and confirmation bias in this study.
Show MoreSubjects all met UK brain bank criteria for PD. Subjects diagnosed with FND in this study had high rates of family history of PD. They had depression, anxiety, cognitive symptoms, pain, nausea, fatigue all common complaints among the population in general and most particularly in PD. The presence of these symptoms before or after diagnosis of PD is considered by the authors as supportive for a diagnosis of FMD. However, these same symptoms are known to be associated with PD and might be considered supportive of a PD diagnosis.
Disparities in healthcare for women are well established (2). Neurology has a long history of mistakes distinguishing the "functional" from the "organic" (e.g.3). To choose one example people with blepharospasm, mostly women, were institutionalized long-term as the disease was not recognized as neurologic. Women commonly encounter dismissal in the medical context and this can occasion missed opportuni...
We read with great interest the research paper published recently by Lotia et al. entitled “Leg stereotypy syndrome: phenomenology and prevalence”. 1 The study brings important new information about an intriguing newly identified condition, previously designated by the same group as leg stereotypy disorder2, defined as repetitive, rhythmical, stereotypic leg movements, particularly noticeable while sitting.1,2 The authors describe the phenomenology and prevalence of leg stereotypy syndrome (LSS) by evaluating a total of 92 individuals, 57 from the general population (control group) and 35 with different movement disorders (Parkinson´s disease, restless legs syndrome, Tourette´s syndrome, and tardive dyskinesia).1 LSS was found in 7% of the control group and 17% of the movement disorders group, concluding that in terms of prevalence, this is a common condition.1 Another interesting finding was that all but one (83 %) of the patients with LSS from the movement disorders group also had a diagnosis of attention deficit hyperactivity disorder (ADHD).1 Lotia and colleagues do not believe in a relationship between ADHD and LSS1 stating in the discussion that “while certain movements or fidgetiness can be observed in individuals with anxiety or ADHD, the presence of typical stereotyped movements has not been previously described with ADHD”.1 Our group is currently studying the frequency of abnormal involuntary movements in patients with ADHD, compared a control group, and our pre...
Show MoreWissel and colleagues recently reported on a large retrospective case series of patients with functional neurological disorder (FND) and Parkinson's disease (PD) [1]. The authors only briefly touched upon the question of shared pathophysiology, noting that in principle certain structural brain diseases may predispose to FND. The study was not designed to tease out any shared or causal pathways between FND and PD, but some speculation based on the presented data could help formulate useful hypotheses concerning this interesting comorbidity. I propose that a disruption of the central noradrenergic system due to degeneration of the locus loeruleus (LC), the sole source of noradrenaline in the brain with far-reaching projections, is a good candidate for a causal link between FND and (prodromal) PD.
Show MoreIn the study by Wissel and colleagues FND antedated the diagnosis of PD in 26% of cases, often by several years [1]. This is significant, because it nearly eliminates the possibility that the comorbidity is entirely a matter of symptom modelling or functional overlay in all cases. Considering the typical neuroanatomical progression of Lewy pathology in PD, this suggests that neurodegenerative effects within the lower brainstem (Braak stage 1 or 2) are likely structural candidates for a causal pathway. Early LC pathology has been associated with other premotor manifestations of Lewy pathology and PD such as REM sleep behaviour disorder and cognitive decline. A study using...
Dear Editor,
I read the article entitled "Patients with Parkinson disease are prone to functional neurological disorders" by Hallett M published in the Journal of Neurology, Neurosurgery and Psychiatry (Published Online First: 16 March 2018. doi: 10.1136/jnnp-2017-317684). I want to congratulate the author for this successful article, and make some contributions.
The article particularly mentions certain aspects of the clinical presentation, medical history and examination of patients, which should raise the suspicion of a functional disorder (1). I think it is important to remember patients with functional disorders will not always adhere to these criteria and clinicians should perhaps consider trialling suspected patients on either cognitive behavioural therapy (CBT) or physiotherapy to assess if they experience any improvement with these strategies. There is increasing evidence to show CBT and physiotherapy are beneficial for patients with functional disorders, hence they may be useful in confirming the diagnosis (2)(3).
Furthermore, the author suggests patients with functional symptoms and no sign of Parkinson's Disease should not be pursued further for a diagnosis of Parkinson's Disease. I think a difficulty is often deciding what classifies as a sign of Parkinson's Disease. The cardinal symptoms of bradykinesia, resting tremor, muscular rigidity and postural instability are commonly subtle within patients, making...
Show MoreImai et al. examined the association between the dosing regimen of oral prednisolone (PSL) and the achievement of minimal manifestation status or better on PSL <=5 mg/day lasting >6 months in patients with generalized myasthenia gravis (1). The authors classified 590 patients into high-dose, intermediate-dose and low-dose (n=166) groups, and logistic regression analysis was applied to know the prognosis of patients in low-dose group, by splitting observational period into 1 to 3 years of treatment. The authors concluded that a low-dose PSL regimen with early combination of other treatment options was significantly associated with good prognosis. I have two concerns about their study.
First, the dosing regimen of oral PSL should be considered with caution. Namely, the authors set the maximum dose of oral PSL in each group, and standard treatment schedule was selected after each patient was allocated. Mean daily dose of PSL does not become highest in high-dose group in the study, which happens in the study protocol. In addition, there is a possibility of higher frequency in patients with combination of other treatment options, when patients were registered into low-dose group. As the age of onset was higher and disease duration was shorter in patients with low-dose group, randomized allocation should be strictly conducted in further study.
Second, the number of events was not enough after 1 year observation, and higher odds ratios with wide ranges of con...
Show MoreIn their recent article on the pathogenesis of dystonia, Kaji and colleagues argue that aberrant cerebellar inputs can induce dystonic movement mediated by the basal ganglia.[1] In this framework, the sensory trick (geste antagoniste) leads to a realignment between predicted and actual sensory information, thus reduces (or overrides) the sensorimotor mismatch forwarded to the basal ganglia, and in turn alleviates dystonic contractions.
A similar model of sensorimotor mismatch response has been implicated in the physiology of being tickled[2]. Specifically, it has been proposed that the inability to tickle oneself is related to a sensory attenuation mediated by the cerebellum during self-generated tactile sensation[3]. This attenuation is proportional to the precision of the sensory prediction[4]. Whether the same cerebellar processes are responsible for the alleviation of dystonia during a sensory trick would be an interesting question to explore experimentally. At the risk of straining the analogy, one could even describe the postures and movements one produces when being tickled as dystonic-like. Neurologists are reminded of this when interpreting ambiguous plantar responses in very ticklish patients -- a problem that can be avoided by employing the patient's cerebellar sensory attentuation[5].
1. Kaji R, Bhatia K, Graybiel AM. Pathogenesis of dystonia: is it of cerebellar or basal ganglia origin? J Neurol Neurosurg Psychiatry. 2017 Oct 31. pii: jnnp-20...
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