The research study conducted by Ward et al., [1] has effectively marked an understandable association between frailty, lifestyle and genetics as factors of dementia in adults aged 60 and above. The findings of this study could potentially have major implications in the field of neuropsychiatric research in the field of geriatric studies.
One of the concerns regarding the methodology of classification of a healthy lifestyle score was that participants who were currently non-smokers were identified as a valid classification in the healthy subgroup. This is questionable due to the fact that, for this classification, no reference was cited to accept non current smokers as a valid factor in the healthy lifestyle score. According to several studies, smoking was indicated as one of the major risk factors for dementia among the elderly. [2] A 2019 Lancet commission identified that smoking was the third among nine modifiable risk factors for dementia. Furthermore a review of 37 studies in the field of association of smoking as a risk factor for dementia identified that compared to never smokers, smokers had a 30% higher chance of developing dementia in general along with a 40% higher chance of developing Alzheimers. [3] So to associate non-current smokers into a healthy lifestyle category is concerning but instead, the classification should have been rather as never-smokers and smokers (both current and non-current). An appropriate classification of smokers and non-smokers...
The research study conducted by Ward et al., [1] has effectively marked an understandable association between frailty, lifestyle and genetics as factors of dementia in adults aged 60 and above. The findings of this study could potentially have major implications in the field of neuropsychiatric research in the field of geriatric studies.
One of the concerns regarding the methodology of classification of a healthy lifestyle score was that participants who were currently non-smokers were identified as a valid classification in the healthy subgroup. This is questionable due to the fact that, for this classification, no reference was cited to accept non current smokers as a valid factor in the healthy lifestyle score. According to several studies, smoking was indicated as one of the major risk factors for dementia among the elderly. [2] A 2019 Lancet commission identified that smoking was the third among nine modifiable risk factors for dementia. Furthermore a review of 37 studies in the field of association of smoking as a risk factor for dementia identified that compared to never smokers, smokers had a 30% higher chance of developing dementia in general along with a 40% higher chance of developing Alzheimers. [3] So to associate non-current smokers into a healthy lifestyle category is concerning but instead, the classification should have been rather as never-smokers and smokers (both current and non-current). An appropriate classification of smokers and non-smokers accordingly would’ve made the findings of the study more accurate and proportionately more significantly authentic than as it currently stands.
Furthermore, an appropriate identification of non-current smokers was also absent as there was no time gap range provided as to what could be considered as current versus non-current smokers. As participants who quit smoking a month before the administering of the questionnaire versus those who quit 20 years prior to administration of the questionnaire would both be eligible to be considered as non-current smokers. In the same way, smokers who quit after 1 year of smoking and those who quit after 30 years of smoking will both be considered non current smokers but the relative effect on the lifestyle and mental health corresponding to the facet of dementia is not proportionately accountable as per the study classification. Utilising a better defined statement in the prospect of classification will give more eligibility in the view of geriatric healthy lifestyle features. It is suggested that in future studies, that the authors provide a correspondingly satisfactory classification in the terms of appropriately defined reference intervals to positively substantiate their findings.
REFERENCES
1. Ward DD, Ranson JM, Wallace LMK, et al Frailty, lifestyle, genetics and dementia risk. Journal of Neurology, Neurosurgery & Psychiatry 2022;93:343-350
2. Peters R, Poulter R, Warner J, et al. Smoking, dementia and cognitive decline in the elderly, a systematic review. BMC Geriatr 2008;8:36. doi:10.1186/1471-2318-8-36
3. All you need to know about smoking and dementia. Alzheimer’s Research UK. 2020.https://www.alzheimersresearchuk.org/blog/all-you-need-to-know-about-smo... (accessed 18 Mar 2022)
Ward et al.'s recent study on frailty, lifestyle, genetics and dementia risk (1) is a major contribution to the growing multimorbidity approach towards dementia. But it is not clear why the authors exclusively frame their discussion on practical steps to reduce dementia risk around healthy lifestyle. They paradoxically argue that "adherence to national guidelines for healthy lifestyle behaviours is central to dementia risk reduction recommendations," while also recognising that multi-domain lifestyle interventions have a weak evidence base in favour of them. An exclusive focus on lifestyle to achieve reduction of frailty and dementia overlooks social gradients of health, particularly the unequal distribution of access to the kind of safe and stimulating living and working environments in which risk reduction can take place through high-quality stimulation and the absence of stressors like noise and air pollution (2). The authors make no mention of social determinants. People with higher income are more likely to part in lifestyle interventions (3), and focusing exclusively on conscious behavioural change to achieve dementia risk reduction may therefore worsen inequalities in dementia risk (4). Therefore, to address not only dementia risk reduction but also the reduction of health inequities, as well as promoting lifestyle changes, the research community ought to stress the need for action against the social determinants of frailty and dementia (5).
Ward et al.'s recent study on frailty, lifestyle, genetics and dementia risk (1) is a major contribution to the growing multimorbidity approach towards dementia. But it is not clear why the authors exclusively frame their discussion on practical steps to reduce dementia risk around healthy lifestyle. They paradoxically argue that "adherence to national guidelines for healthy lifestyle behaviours is central to dementia risk reduction recommendations," while also recognising that multi-domain lifestyle interventions have a weak evidence base in favour of them. An exclusive focus on lifestyle to achieve reduction of frailty and dementia overlooks social gradients of health, particularly the unequal distribution of access to the kind of safe and stimulating living and working environments in which risk reduction can take place through high-quality stimulation and the absence of stressors like noise and air pollution (2). The authors make no mention of social determinants. People with higher income are more likely to part in lifestyle interventions (3), and focusing exclusively on conscious behavioural change to achieve dementia risk reduction may therefore worsen inequalities in dementia risk (4). Therefore, to address not only dementia risk reduction but also the reduction of health inequities, as well as promoting lifestyle changes, the research community ought to stress the need for action against the social determinants of frailty and dementia (5).
References
1 - Ward DD, et al. Frailty, lifestyle, genetics and dementia risk Journal of Neurology, Neurosurgery & Psychiatry Published Online First: 21 December 2021. doi: 10.1136/jnnp-2021-327396
2 - Daly T. Giving a fairer face to urban space: Progress on the long road to dementia prevention. Int J Geriatr Psychiatry. 2022 Jan;37(1). doi: 10.1002/gps.5657.
3 - Coley N, et al. Disparities in the participation and adherence of older adults in lifestyle-based multidomain dementia prevention and the motivational role of perceived disease risk and intervention benefits: an observational ancillary study to a randomised controlled trial. Alzheimers Res Ther. 2021 Sep 24;13(1):157. doi: 10.1186/s13195-021-00904-6.
4 - Walsh S, et al. A whole-population approach is required for dementia risk reduction. The Lancet Health Longevity 2022 3(1), E6-E8. doi: 10.1016/S2666-7568(21)00301-9.
5 - Daly T. The vital need for action against the social determinants of frailty. Aging Medicine. 2022 doi: 10.1002/agm2.12195
Ward et al. reported the relationships between frailty index, healthy lifestyle and polygenic risk scores, and incident all-cause dementia (1). The adjusted hazard ratio (HR) (95% CI) of participants with high frailty for incident dementia was 3.68 (3.11 to 4.35). In addition, the adjusted HR (95% CI) of participants with high genetic risk and high frailty for incident dementia was 5.81 (4.01 to 8.42).The authors emphasized of controlling frailty for dementia prevention strategies, even among subjects at high genetic risk. I have two comments about their study.
First, Lourida et al. investigated the association between healthy lifestyles and risk of dementia by considering genetic risk (2). The adjusted HR (95% CI) of participants with high genetic risk and unfavorable lifestyle for incident dementia was 2.83 (2.09 to 3.83). In addition, a favorable lifestyle was associated with a lower dementia risk among participants with high genetic risk. There was no significant interaction between genetic risk and lifestyle factors, and I suppose that unfavorable lifestyles and genetic factors independently contribute to the risk of dementia. The level of frailty may be related to lifestyles and contribute to subsequent progression of cognitive impairment.
Second, Kojima et al. conducted a meta-analysis regarding the effect of frailty on the incident dementia among community-dwelling older people (3). Th pooled HRs (95% CIs) of frailty for the incident Alzheimer disease...
Ward et al. reported the relationships between frailty index, healthy lifestyle and polygenic risk scores, and incident all-cause dementia (1). The adjusted hazard ratio (HR) (95% CI) of participants with high frailty for incident dementia was 3.68 (3.11 to 4.35). In addition, the adjusted HR (95% CI) of participants with high genetic risk and high frailty for incident dementia was 5.81 (4.01 to 8.42).The authors emphasized of controlling frailty for dementia prevention strategies, even among subjects at high genetic risk. I have two comments about their study.
First, Lourida et al. investigated the association between healthy lifestyles and risk of dementia by considering genetic risk (2). The adjusted HR (95% CI) of participants with high genetic risk and unfavorable lifestyle for incident dementia was 2.83 (2.09 to 3.83). In addition, a favorable lifestyle was associated with a lower dementia risk among participants with high genetic risk. There was no significant interaction between genetic risk and lifestyle factors, and I suppose that unfavorable lifestyles and genetic factors independently contribute to the risk of dementia. The level of frailty may be related to lifestyles and contribute to subsequent progression of cognitive impairment.
Second, Kojima et al. conducted a meta-analysis regarding the effect of frailty on the incident dementia among community-dwelling older people (3). Th pooled HRs (95% CIs) of frailty for the incident Alzheimer disease, vascular dementia, and all dementia were 1.28(1.00 to 1.63), 2.70 (1.40-5.23), and 1.33 (1.07 to 1.67), respectively. They also observed sex difference that frail women had a higher risk of incident Alzheimer disease than frail men. There is a report that the prevalence of Alzheimer disease in women is higher than that in men at the same generation (4), and frailty may also contribute to the risk of Alzheimer disease via sex-related factors.
References
1. Ward DD, Ranson JM, Wallace LMK, Llewellyn DJ, Rockwood K. Frailty, lifestyle, genetics and dementia risk. J Neurol Neurosurg Psychiatry 2021 Dec 21. doi: 10.1136/jnnp-2021-327396.
2. Lourida I, Hannon E, Littlejohns TJ, Langa KM, Hyppönen E, Kuzma E, Llewellyn DJ. Association of Lifestyle and Genetic Risk With Incidence of Dementia. JAMA 2019;322(5):430-437.
3. Kojima G, Taniguchi Y, Iliffe S, Walters K. Frailty as a Predictor of Alzheimer Disease, Vascular Dementia, and All Dementia Among Community-Dwelling Older People: A Systematic Review and Meta-Analysis. J Am Med Dir Assoc 2016;17(10):881-8.
4. Yoshida D, Ohara T, Hata J, Shibata M, Hirakawa Y, Honda T, Furuta Y, Oishi E, Sakata S, Kanba S, Kitazono T, Ninomiya T. Lifetime cumulative incidence of dementia in a community-dwelling elderly population in Japan. Neurology 2020;95(5):e508-e518.
We read with interest the letter by Bert-Marcaz et al., reporting on a 74-year-old man with vacuole, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome and chronic inflammatory demyelinating polyneuropathy [1]. We agree with the authors’ postulation that the simultaneous onset of the two diseases suggests a potentially causal link between VEXAS and the demyelinating abnormalities they observed on nerve conduction studies and nerve biopsy. We have previously reported a case of a 68-year-old man with VEXAS associated with neurological features, including ophthalmoplegia, sensorineural hearing loss and bilateral vestibulopathy [2]. Our hypothesis for the mechanism of neurological involvement was polycranial neuritis, given that there was no evidence of orbital inflammation on MRI and there was significant improvement with corticosteroids. Neurologists should consider the diagnosis of VEXAS (and other autoinflammatory syndromes of innate immunity) in patients with neurological problems who have (i) unexplained fever and elevated acute phase reactants, especially when there is a remitting and relapsing course, (ii) unexplained multisystem disease, and (iii) no evidence of infection, malignancy or autoimmune (i.e., antibody-mediated) disease.
References:
[1] Bert-Marcaz C, Briantais A, Faucher B, Corazza G, Ebbo M, Attarian S, Delmont E, Fortanier E. Expanding the spectrum of VEXAS syndrome: association with acute-onset CIDP. J Neurol Neurosurg Psychiat...
We read with interest the letter by Bert-Marcaz et al., reporting on a 74-year-old man with vacuole, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome and chronic inflammatory demyelinating polyneuropathy [1]. We agree with the authors’ postulation that the simultaneous onset of the two diseases suggests a potentially causal link between VEXAS and the demyelinating abnormalities they observed on nerve conduction studies and nerve biopsy. We have previously reported a case of a 68-year-old man with VEXAS associated with neurological features, including ophthalmoplegia, sensorineural hearing loss and bilateral vestibulopathy [2]. Our hypothesis for the mechanism of neurological involvement was polycranial neuritis, given that there was no evidence of orbital inflammation on MRI and there was significant improvement with corticosteroids. Neurologists should consider the diagnosis of VEXAS (and other autoinflammatory syndromes of innate immunity) in patients with neurological problems who have (i) unexplained fever and elevated acute phase reactants, especially when there is a remitting and relapsing course, (ii) unexplained multisystem disease, and (iii) no evidence of infection, malignancy or autoimmune (i.e., antibody-mediated) disease.
References:
[1] Bert-Marcaz C, Briantais A, Faucher B, Corazza G, Ebbo M, Attarian S, Delmont E, Fortanier E. Expanding the spectrum of VEXAS syndrome: association with acute-onset CIDP. J Neurol Neurosurg Psychiatry. 2021 Dec 6:jnnp-2021-327949. doi: 10.1136/jnnp-2021-327949
[2] Diprose WK, Jordan A, Anderson NE. Autoinflammatory syndromes in neurology: when our first line of defence misbehaves. Pract Neurol. 2021 Oct 1:practneurol-2021-003031. doi: 10.1136/practneurol-2021-003031
There have been some studies investigating blood neurofilament light chain (NfL) levels as predictors of cognitive functions decline in neurological disorders. I want to discuss here the association between blood NfL levels and neuroaxonal damage in patients with brain damages including Alzheimer's disease and stroke by considering the underlying mechanisms.
First, Egle et al. reported that baseline increased serum NfL levels could predict cognitive decline and the risk of converting to dementia in a cerebral small vessel disease (SVD), but there was no change in serum NfL levels over a 5-year follow-up period [1]. The lack of dynamic changes of NfL in stroke stand in contrast to neurodegenerative disease, and serum NfL levels may not be used as a surrogate marker for monitoring cognitive impairment in patients with SVD. In contrast, Stokowskaet et al. examined plasma NfL levels for the prediction of functional improvement in the late phase after stroke [2]. The odds ratios (ORs) (95% confidence intervals [CIs]) of elevated plasma NfL levels for the improvement in balance and gait improvement were 2.34 (1.35-4.27) and 2.27 (1.25-4.32), respectively. In addition, OR (95% CI) of elevated plasma NfL levels for cognitive improvement was 7.54 (1.52-45.66), which was also verified by intervention trial. This study presented the usefulness of plasma NfL levels as a biomarker of physical and psychological function after stroke events. As there is a wide range of 95% CI...
There have been some studies investigating blood neurofilament light chain (NfL) levels as predictors of cognitive functions decline in neurological disorders. I want to discuss here the association between blood NfL levels and neuroaxonal damage in patients with brain damages including Alzheimer's disease and stroke by considering the underlying mechanisms.
First, Egle et al. reported that baseline increased serum NfL levels could predict cognitive decline and the risk of converting to dementia in a cerebral small vessel disease (SVD), but there was no change in serum NfL levels over a 5-year follow-up period [1]. The lack of dynamic changes of NfL in stroke stand in contrast to neurodegenerative disease, and serum NfL levels may not be used as a surrogate marker for monitoring cognitive impairment in patients with SVD. In contrast, Stokowskaet et al. examined plasma NfL levels for the prediction of functional improvement in the late phase after stroke [2]. The odds ratios (ORs) (95% confidence intervals [CIs]) of elevated plasma NfL levels for the improvement in balance and gait improvement were 2.34 (1.35-4.27) and 2.27 (1.25-4.32), respectively. In addition, OR (95% CI) of elevated plasma NfL levels for cognitive improvement was 7.54 (1.52-45.66), which was also verified by intervention trial. This study presented the usefulness of plasma NfL levels as a biomarker of physical and psychological function after stroke events. As there is a wide range of 95% CI of OR for cognitive improvement, unstable risk estimation may be updated by summing-up the events. Anyway, discrepancy in the results from two reports should be specified by further studies.
Second, Santangelo et al. examined predictors of cognitive decline rate to assess the risk of fast Alzheimer's disease (AD) progression [3]. Higher plasma NfL levels, worse scores at semantic verbal fluency and clock drawing test were significant predictors of fast progression in AD. Their regression model could predict 81.2% of patients' progression correctly, if all the three predictors were judged abnormal. Patients with AD present cognitive decline as a major neurological symptom and neuroaxonal damages are progressive. As conclusive results have been made whether blood NfL levels could substitute for information from neuroimaging and NfL levels in cerebrospinal fluids, further studies by using blood samples are needed to verify the association.
Regarding the second query, Lin et al. reported that high plasma NfL correlated with poor cognition in AD, and plasma NfL represented a biomarker of cognitive decline in AD [4]. Although the majority of studies found that blood NfL levels were inversely correlated with cognition, there are also positive relationships in some specific status of the neurological disorders, and individual differences and methodological procedures should be considered for the analysis [5]. Indeed, patients with AD have shown that intra-individual NfL changes were sensitive to detect the disease onset of neurodegenerative diseases [6].
In any case, the association between blood NfL levels and neuroaxonal damage in the brain during neurodegeneration may be mediated by disease-specific factors and fundamental biological factors such as sex and age.
We read with great interest the paper by Yaghi S. et al on the lacunar stroke mechanisms and their therapeutic implications. We would like to highlight that the deficiency of ADA2 (DADA2) is the most common cause of monogenic vasculitis and is also responsible for causing lacunar strokes, but is commonly overlooked [1]. It has an autosomal recessive inheritance and has multi-system involvement: skin, nervous, gastrointestinal and hematological systems being most commonly involved [1]. Children and young adults are most commonly affected with a “polyarteritis nodosa-type” picture with cutaneous involvement, abdominal pains and renal involvement, and mild strokes. The lacunar infarcts are more common in the posterior circulation [2]. Most cases are diagnosed late or go undiagnosed because of lack of knowledge about this disorder [3, 4].
Patients are treated by immunosuppressants with anti-tumour necrosis factor (TNF) agents and usually adalimumab is the first line agent. Early diagnosis and treatment lead to favorable treatment response.
References:
1. Meyts I, Aksentijevich I. Deficiency of Adenosine Deaminase 2 (DADA2): Updates on the Phenotype, Genetics, Pathogenesis, and Treatment. Journal of Clinical Immunology (2018) 38: 569-578
2. Geraldo AF, Carosi R, Tortora D et al. Widening the Neuroimaging features of Adenosine Deaminase 2 Deficiency. American Journal of Neuroradiology. February 2021
3. Sharma A, Agarwal A, Srivastava MVP, et al. Hy...
We read with great interest the paper by Yaghi S. et al on the lacunar stroke mechanisms and their therapeutic implications. We would like to highlight that the deficiency of ADA2 (DADA2) is the most common cause of monogenic vasculitis and is also responsible for causing lacunar strokes, but is commonly overlooked [1]. It has an autosomal recessive inheritance and has multi-system involvement: skin, nervous, gastrointestinal and hematological systems being most commonly involved [1]. Children and young adults are most commonly affected with a “polyarteritis nodosa-type” picture with cutaneous involvement, abdominal pains and renal involvement, and mild strokes. The lacunar infarcts are more common in the posterior circulation [2]. Most cases are diagnosed late or go undiagnosed because of lack of knowledge about this disorder [3, 4].
Patients are treated by immunosuppressants with anti-tumour necrosis factor (TNF) agents and usually adalimumab is the first line agent. Early diagnosis and treatment lead to favorable treatment response.
References:
1. Meyts I, Aksentijevich I. Deficiency of Adenosine Deaminase 2 (DADA2): Updates on the Phenotype, Genetics, Pathogenesis, and Treatment. Journal of Clinical Immunology (2018) 38: 569-578
2. Geraldo AF, Carosi R, Tortora D et al. Widening the Neuroimaging features of Adenosine Deaminase 2 Deficiency. American Journal of Neuroradiology. February 2021
3. Sharma A, Agarwal A, Srivastava MVP, et al. Hypertension with recurrent focal deficits. Pract Neurol 2021;0:1-5
4. Babtiwale S, Vishnu VY, Garg A, et al. Young stroke and systemic manifestations: Deficiency of Adenosine Deaminase-2 (DADA-2). Annals of Indian Academy of Neurology 2020. DOI: 10.4103/aian.AIAN_657_20
We recently published our preliminary case-control study showing that a medical history of hypothyroidism was more prevalent among COVID-19 patients with persistent olfactory dysfunction compared to controls (50% vs 8%; p=0.009) and that hypothyroidism was independently (p=0.021) associated with higher likelihood of persistent hyposmia/anosmia among patients with COVID-19 (OR: 21.1; 95%CI: 2.0 to 219.4) after adjusting for age and sex (1). As previously stated, our results are not -by any means- confirmatory of an etiologic association between hypothyroidism (or preferably chronic autoimmune thyroiditis, CAT, as aptly suggested by Rotondi et al.) and the development of persistent anosmia in COVID-19 patients (1). However, the suggetsed mechanism by Rotondi et al. strengthens our observations by proposing a possible biomolecular explanation behind our clinical observations. Indeed, chemokines that are induced by SARS-CoV-2 infection, and especially CXCL10, could act as effectors of demyelination of the central nervous system (CNS) - including the olfactory apparatus - through attraction and recruitment of T-lymphocytes (2,3). Although the proposed pathogenetic mechanism by Rotondi et al. needs further investigation and laboratory confirmation through experimental studies in COVID-19 patients with persistent olfactory dysfunction, it certainly invigorates our preliminary clinical results and sets the grounds for further research in a clinically significant post-COVID-9 seque...
We recently published our preliminary case-control study showing that a medical history of hypothyroidism was more prevalent among COVID-19 patients with persistent olfactory dysfunction compared to controls (50% vs 8%; p=0.009) and that hypothyroidism was independently (p=0.021) associated with higher likelihood of persistent hyposmia/anosmia among patients with COVID-19 (OR: 21.1; 95%CI: 2.0 to 219.4) after adjusting for age and sex (1). As previously stated, our results are not -by any means- confirmatory of an etiologic association between hypothyroidism (or preferably chronic autoimmune thyroiditis, CAT, as aptly suggested by Rotondi et al.) and the development of persistent anosmia in COVID-19 patients (1). However, the suggetsed mechanism by Rotondi et al. strengthens our observations by proposing a possible biomolecular explanation behind our clinical observations. Indeed, chemokines that are induced by SARS-CoV-2 infection, and especially CXCL10, could act as effectors of demyelination of the central nervous system (CNS) - including the olfactory apparatus - through attraction and recruitment of T-lymphocytes (2,3). Although the proposed pathogenetic mechanism by Rotondi et al. needs further investigation and laboratory confirmation through experimental studies in COVID-19 patients with persistent olfactory dysfunction, it certainly invigorates our preliminary clinical results and sets the grounds for further research in a clinically significant post-COVID-9 sequela. Therefore, we are highly grateful to Rotondi and colleagues for their insightful and constructive comments in our study.
References
1. Tsivgoulis G, Fragkou PC, Karofylakis E, Paneta M, Papathanasiou K, Palaiodimou L, Psarros C, Papathanasiou M, Lachanis S, Sfikakis PP, Tsiodras S. Hypothyroidism is associated with prolonged COVID-19-induced anosmia: a case-control study. J Neurol Neurosurg Psychiatry. 2021.
2. Oliviero A, de Castro F, Coperchini F, Chiovato L, Rotondi M. COVID-19 Pulmonary and Olfactory Dysfunctions: Is the Chemokine CXCL10 the Common Denominator? Neuroscientist. 2020:1073858420939033.
3. Rotondi M, Chiovato L, Romagnani S, Serio M, Romagnani P. Role of chemokines in endocrine autoimmune diseases. Endocr Rev. 2007;28(5):492-520.
Thyroid hormones play a role in the development and function of virtually all human cells, including maturation of olfactory neurons. The clinical observation that patients with hypothyroidism can experience disturbances in their sense of smell was first reported more than 60 years ago, and it was subsequently confirmed in both humans and animal models. In vivo animal studies clearly demonstrated that hypothyroidism induced by anti-thyroid drugs administration in mice was associated to variable degrees of anosmia, which however promptly reverted following restoration of euthyroidism by levothyroxine replacement therapy (1).
This latter finding was regarded as the proof that thyroxine, besides its role for correct development of the nervous system would also be involved in the genesis of new olfactory receptor neurons, a process demonstrated to be maintained also in adulthood.
Since the early phase of the ongoing Sars-CoV-2 pandemic, anosmia was identified as a peculiar clinical symptom of COVID-19 being experienced by nearly 80% of the affected patients (2). It is now known that, at least in some cases, COVID-19 course may encompass protracted olfactory dysfunction and development of olphactory bulb atrophy (3). Thus, attention was paid to potential risk factors predicting this long-term sequela. Interestingly, Tsivgoulis et al., recently performed a prospective case–control study aimed at evaluating whether hypothyroidism could be associated to prolonged COVID...
Thyroid hormones play a role in the development and function of virtually all human cells, including maturation of olfactory neurons. The clinical observation that patients with hypothyroidism can experience disturbances in their sense of smell was first reported more than 60 years ago, and it was subsequently confirmed in both humans and animal models. In vivo animal studies clearly demonstrated that hypothyroidism induced by anti-thyroid drugs administration in mice was associated to variable degrees of anosmia, which however promptly reverted following restoration of euthyroidism by levothyroxine replacement therapy (1).
This latter finding was regarded as the proof that thyroxine, besides its role for correct development of the nervous system would also be involved in the genesis of new olfactory receptor neurons, a process demonstrated to be maintained also in adulthood.
Since the early phase of the ongoing Sars-CoV-2 pandemic, anosmia was identified as a peculiar clinical symptom of COVID-19 being experienced by nearly 80% of the affected patients (2). It is now known that, at least in some cases, COVID-19 course may encompass protracted olfactory dysfunction and development of olphactory bulb atrophy (3). Thus, attention was paid to potential risk factors predicting this long-term sequela. Interestingly, Tsivgoulis et al., recently performed a prospective case–control study aimed at evaluating whether hypothyroidism could be associated to prolonged COVID19-induced hyposmia/anosmia(3). Olfactory function and anosmia were objectively evaluated by the validated Quick Smell Identification Test. Briefly, among patients with a >40days duration of anosmia in the presence of a negative PCR for Sars-CoV-2, a strikingly higher prevalence of hypothyroidism (50% vs 8%; p=0.009) was observed in cases as compared to controls.
More interestingly, hypothyroidism was identified to be significantly and independently associated with higher risk for persistent olfactory dysfunction among patients with COVID-19, even after adjusting for potential confounders such as age and sex. This latter is a relevant point in that it is known that autoimmune thyroid diseases display a strong female gender prevalence, thus the correction for sex further strengthen the findings.
Although the above results were obtained in a rather limited study group, their potential clinical significance should not be neglected in view of their potential utility in the clinical care of the so called “post-COVID-19” syndrome”. However, some considerations should be drawn. Indeed, all of the patients studied by Tsivgoulis et al. were affected by chronic autoimmune thyroiditis (CAT) and were receiving levothyroxine replacement therapy with restoration of euthyroidism as assessed by normal thyroid function tests at study entry.
Thus, a direct role for thyroid hormones on the persistency of olfactory dysfunction would be difficult to be envisaged in these patients. On the other hand, the observation by Tsivgoulis et al. appears to be worth to be further investigated in view of the following aspects.
CAT is the most prevalent human autoimmune disease being the major cause of primary hypothyroidism. Interestingly, among several immune-active molecules, CXCL10 a Th1-oriented chemokine, was identified to play a crucial role in the recruitment and maintenance of lymphocytes sustaining chronic autoimmune inflammation (4). More specifically, patients with CAT either in the hypothyroid phase and in the euthyroid patients under LT4 phase display significantly higher circulating levels of CXCL10 as compared to both healthy controls and non-autoimmune hypothyroid patients (4). As far as COVID-19 is concerned, CXCL10 is currently regarded as a main actor in the so called “immune signature” of COVID-19, which is characterized by increased levels of soluble biomarkers (cytokine and chemokines) involved in the recruitment and activation of several immune cell types (5). Of note, we have previously reported how CXCL10 would play a crucial role in the genesis of olfactory dysfunction in COVID-19 infections. Briefly, following Sars-CoV-2 entrance in the upper respiratory tract, it enters nerve cells, promoting the secretion of CXCL10, which, in turn, recruits immune cells expressing the CXCL10-receptor CXCR3 (2). CXCL10-dependent attraction of T lymphocytes within the CNS would ultimately contribute to the demyelination of the olfactory pathway. Indeed, CXCL10 is a strongly involved chemokine in T cells recruitment within the CNS and T-lymphocytes are crucial effectors in the demyelination process (2). Taking together the above evidences, while highlighting the interesting findings reported by Tsivgoulis et al., we would strongly support the concept that the elevated circulating concentrations of CXCL10 observed in several human autoimmune condition and in particular CAT, rather than hypothyroidism (unless when left untreated) would be the cause of a more prolonged anosmia in COVID-19 patients.
REFERENCES
1. Beard MD, Mackay-Sim A. Loss of sense of smell in adult, hypothyroid mice. Brain Res. 1987;433(2):181-189.
2. Oliviero A, de Castro F, Coperchini F, Chiovato L, Rotondi M. COVID-19 Pulmonary and Olfactory Dysfunctions: Is the Chemokine CXCL10 the Common Denominator? Neuroscientist. 2020:1073858420939033.
3. Tsivgoulis G, Fragkou PC, Karofylakis E, Paneta M, Papathanasiou K, Palaiodimou L, Psarros C, Papathanasiou M, Lachanis S, Sfikakis PP, Tsiodras S. Hypothyroidism is associated with prolonged COVID-19-induced anosmia: a case-control study. J Neurol Neurosurg Psychiatry. 2021.
4. Rotondi M, Chiovato L, Romagnani S, Serio M, Romagnani P. Role of chemokines in endocrine autoimmune diseases. Endocr Rev. 2007;28(5):492-520.
5. Coperchini F, Chiovato L, Ricci G, Croce L, Magri F, Rotondi M. The cytokine storm in COVID-19: Further advances in our understanding the role of specific chemokines involved. Cytokine Growth Factor Rev. 2021.
Dear Editor,
We have read with interest a recent paper by Seiffge and his colleagues published in your journal (1). In their study entitled as “Small vessel disease burden and intracerebral haemorrhage in patients taking oral anticoagulants”, the authors have investigated the role of small vessel disease on intracerebral hemorrhages (ICH) associated with the use of oral anticoagulation therapy. The authors showed that the small vessel disease with medium-to-high severity, detected by either computed tomography (CT) or magnetic resonance imaging (MRI), was significantly more prevalent in patients with ICH taking oral anticoagulants in compared to those without prior anticoagulation therapy (56.1% vs 43.5% on CT, and 78.7% vs 64.5% on MRI, respectively; p<0.001). Leukoaraiosis and atrophy were also reported to be more frequent and severe in patients with ICH related to anticoagulation therapy. We think that the results of the study are considerable emphasizing the importance of small vessel disease for ICH, which should therefore be implemented among the criteria of the risk stratification scores of bleeding.
The use of the scoring systems for the risk stratification of the intracranial bleeding is practically important in patients who are the candidates for the anticoagulation therapy. A recent study investigating the risk factors predicting ICH in patients with atrial fibrillation under anticoagulation therapy demonstrated that the presence of white matter...
Dear Editor,
We have read with interest a recent paper by Seiffge and his colleagues published in your journal (1). In their study entitled as “Small vessel disease burden and intracerebral haemorrhage in patients taking oral anticoagulants”, the authors have investigated the role of small vessel disease on intracerebral hemorrhages (ICH) associated with the use of oral anticoagulation therapy. The authors showed that the small vessel disease with medium-to-high severity, detected by either computed tomography (CT) or magnetic resonance imaging (MRI), was significantly more prevalent in patients with ICH taking oral anticoagulants in compared to those without prior anticoagulation therapy (56.1% vs 43.5% on CT, and 78.7% vs 64.5% on MRI, respectively; p<0.001). Leukoaraiosis and atrophy were also reported to be more frequent and severe in patients with ICH related to anticoagulation therapy. We think that the results of the study are considerable emphasizing the importance of small vessel disease for ICH, which should therefore be implemented among the criteria of the risk stratification scores of bleeding.
The use of the scoring systems for the risk stratification of the intracranial bleeding is practically important in patients who are the candidates for the anticoagulation therapy. A recent study investigating the risk factors predicting ICH in patients with atrial fibrillation under anticoagulation therapy demonstrated that the presence of white matter changes was one of the risk factors being significantly higher in patients having ICH than controls (66.6% versus 32.5% respectively, p=0.0001) (2). On the other hand, the authors concluded that although the presence of white matter changes was one of the risk factors predicting ICH in patients with atrial fibrillation under anticoagulation therapy, it failed to show a significant association with CHA2DS2-VASc or HAS-BLED scores. While the use of validated scoring systems was encouraged in prediction of the ‘risk’ versus ‘benefit’ reasoning when deciding whether or not to start/resume oral anticoagulation therapy in patients with atrial fibrillation, this discrepancy tells us that these scoring systems may benefit from some revisions. Indeed, we have previously discussed the need for the revisions in HAS-BLED, and suggested the incorporation of the presence of white matter abnormalities and leukoaraiosis into the scoring system, in addition with the type of stroke (whether ischemic or hemorrhagic of type), and the localization of previous hemorrhages (whether deep versus lobar in location) (3,4). The latest guideline of the European Society of Cardiology (ESC) for the diagnosis and the management of atrial fibrillation have also emphasized that there is a prominent increase in the occurrence of ICH in parallel with the increase in the numbers of cerebral micro bleeds (5). On the other hand, the effects of cerebral micro bleeds on the treatment strategies were reported to be proven.
In the light of these data, it seems that some revisions are being required for the scoring systems, as supported by the recent study by Seiffge and his colleagues (1), demonstrating the importance of small vessel disease in patients with anticoagulation-associated ICH. The failure to demonstrate a significant association with the risk factors of ICH, including small vessel disease, and the CHA2DS2-VASc or HAS-BLED scores in the study by Paciaroni and his colleagues (2) may be explained, at least to some extent, by the shortcomings of the scoring systems to cover important risk factors of ICH in this group of patients, mainly the white matter abnormalities, leukoaraiosis, the type and the localization of previous strokes and the micro bleeds. In this era, the neuroimaging techniques are easily reachable in the detection of white matter abnormalities or cerebral micro bleeds, and the use of these data should be encouraged before a decision was made for the anticoagulation therapy. On these bases, we would like to emphasize the importance and the need for the revision in scoring systems to better cover the risk factors of ICH, which, we believe, will more adequately aid the (re)institution of the oral anticoagulation treatment.
References
1. Seiffge DJ, Wilson D, Ambler G, Banerjee G, Hostettler IC, Houlden H, et al. Small vessel disease burden and intracerebral haemorrhage in patients taking oral anticoagulants. J Neurol Neurosurg Psychiatry. 2021; jnnp-2020-325299.
2. Paciaroni M, Agnelli G, Giustozzi M, Caso V, Toso E, Angelini F, et al. Risk Factors for Intracerebral Hemorrhage in Patients With Atrial Fibrillation on Non-Vitamin K Antagonist Oral Anticoagulants for Stroke Prevention. Stroke. 2021;52(4):1450-1454.
3. Ince B, Benbir G, Gozubatik-Celik G. Should HAS-BLED scoring be revised for better risk estimation in patients with intracerebral hemorrhage? Expert Rev Cardiovasc Ther. 2014;12(8):929-931.
4. Ince B, Senel G. Deep versus lobar intracerebral hemorrhage on HAS-BLED scoring system. Chest. 2016;149(6):1589-1590.
5. Hindricks G, Potpara T, Dagres N, Arbelo E, Bax JJ, Blomström-Lundqvist C, et al; ESC Scientific Document Group. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS): The Task Force for the diagnosis and management of atrial fibrillation of the European Society of Cardiology (ESC) Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC. European Heart J. 2021;42(5):373–498.
Malpetti et al. examined neuroinflammation in subcortical regions for predicting clinical progression in patients with progressive supranuclear palsy (PSP) (1). Principal component analysis (PCA) was applied for the analysis, and neuroinflammation and tau burden in the brainstem and cerebellum significantly correlated with the subsequent annual rate of change in the score of Progressive Supranuclear Palsy Rating Scale. Namely, PCA-derived [11C]PK11195 positron emission tomography (PET) markers of neuroinflammation and tau pathology significantly correlated with regional brain volume, but MRI volumes alone did not predict the clinical progression. I present some information with special reference to treatment strategies.
As there are no modifiable lifestyle factors to suppress progression of PSP (2), keeping quality of life by symptom-controlling medications has been recommended. Morgan et al. reported that symptomatic medications, most often for parkinsonism and depression, were prescribed for 87% of patients with PSP, whose satisfaction was poor in most cases (3). Although there have been no effective neuroprotective therapies and/or disease-modifying agents for patients with tauopathies and synucleinopathies, Jabbari et al. recently identified that genetic variation at the leucine-rich repeat kinase 2 (LRRK2) locus was significantly associated with survival in PSP, which might be based on the effect of long noncoding RNA on LRRK2 expression (4). As LRRK2 is associ...
Malpetti et al. examined neuroinflammation in subcortical regions for predicting clinical progression in patients with progressive supranuclear palsy (PSP) (1). Principal component analysis (PCA) was applied for the analysis, and neuroinflammation and tau burden in the brainstem and cerebellum significantly correlated with the subsequent annual rate of change in the score of Progressive Supranuclear Palsy Rating Scale. Namely, PCA-derived [11C]PK11195 positron emission tomography (PET) markers of neuroinflammation and tau pathology significantly correlated with regional brain volume, but MRI volumes alone did not predict the clinical progression. I present some information with special reference to treatment strategies.
As there are no modifiable lifestyle factors to suppress progression of PSP (2), keeping quality of life by symptom-controlling medications has been recommended. Morgan et al. reported that symptomatic medications, most often for parkinsonism and depression, were prescribed for 87% of patients with PSP, whose satisfaction was poor in most cases (3). Although there have been no effective neuroprotective therapies and/or disease-modifying agents for patients with tauopathies and synucleinopathies, Jabbari et al. recently identified that genetic variation at the leucine-rich repeat kinase 2 (LRRK2) locus was significantly associated with survival in PSP, which might be based on the effect of long noncoding RNA on LRRK2 expression (4). As LRRK2 is associated with some forms of Parkinson's disease (PD), the potential effect of LRRK2 modulation should be examined as a disease-modifying therapy for PSP and other related tauopathies, including PD.
VandeVrede et al. reviewed tau-targeted therapies in clinical trials (5), and also presented the history and future directions of disease-modifying therapy (6). Although an effective disease-modifying therapy has not been developed yet, information on some genetic variations might lead to the development of new medications in the future (4).
References
1. Malpetti M, Passamonti L, Jones PS, et al. Neuroinflammation predicts disease progression in progressive supranuclear palsy. J Neurol Neurosurg Psychiatry 2021 Mar 17. doi: 10.1136/jnnp-2020-325549. [Epub ahead of print]
2. Glasmacher SA, Leigh PN, Saha RA. Predictors of survival in progressive supranuclear palsy and multiple system atrophy: a systematic review and meta-analysis. J Neurol Neurosurg Psychiatry 2017;88:402-411.
3. Morgan JC, Ye X, Mellor JA, et al. Disease course and treatment patterns in progressive supranuclear palsy: A real-world study. J Neurol Sci 2021;421:117293.
4. Jabbari E, Koga S, Valentino RR, et al. Genetic determinants of survival in progressive supranuclear palsy: a genome-wide association study. Lancet Neurol 2021;20:107-116.
5. VandeVrede L, Boxer AL, Polydoro M. Targeting tau: Clinical trials and novel therapeutic approaches. Neurosci Lett 2020;731:134919.
6. VandeVrede L, Ljubenkov PA, Rojas JC, et al. Four-Repeat Tauopathies: Current Management and Future Treatments. Neurotherapeutics 2020;17:1563-1581.
The research study conducted by Ward et al., [1] has effectively marked an understandable association between frailty, lifestyle and genetics as factors of dementia in adults aged 60 and above. The findings of this study could potentially have major implications in the field of neuropsychiatric research in the field of geriatric studies.
One of the concerns regarding the methodology of classification of a healthy lifestyle score was that participants who were currently non-smokers were identified as a valid classification in the healthy subgroup. This is questionable due to the fact that, for this classification, no reference was cited to accept non current smokers as a valid factor in the healthy lifestyle score. According to several studies, smoking was indicated as one of the major risk factors for dementia among the elderly. [2] A 2019 Lancet commission identified that smoking was the third among nine modifiable risk factors for dementia. Furthermore a review of 37 studies in the field of association of smoking as a risk factor for dementia identified that compared to never smokers, smokers had a 30% higher chance of developing dementia in general along with a 40% higher chance of developing Alzheimers. [3] So to associate non-current smokers into a healthy lifestyle category is concerning but instead, the classification should have been rather as never-smokers and smokers (both current and non-current). An appropriate classification of smokers and non-smokers...
Show MoreWard et al.'s recent study on frailty, lifestyle, genetics and dementia risk (1) is a major contribution to the growing multimorbidity approach towards dementia. But it is not clear why the authors exclusively frame their discussion on practical steps to reduce dementia risk around healthy lifestyle. They paradoxically argue that "adherence to national guidelines for healthy lifestyle behaviours is central to dementia risk reduction recommendations," while also recognising that multi-domain lifestyle interventions have a weak evidence base in favour of them. An exclusive focus on lifestyle to achieve reduction of frailty and dementia overlooks social gradients of health, particularly the unequal distribution of access to the kind of safe and stimulating living and working environments in which risk reduction can take place through high-quality stimulation and the absence of stressors like noise and air pollution (2). The authors make no mention of social determinants. People with higher income are more likely to part in lifestyle interventions (3), and focusing exclusively on conscious behavioural change to achieve dementia risk reduction may therefore worsen inequalities in dementia risk (4). Therefore, to address not only dementia risk reduction but also the reduction of health inequities, as well as promoting lifestyle changes, the research community ought to stress the need for action against the social determinants of frailty and dementia (5).
Re...
Show MoreWard et al. reported the relationships between frailty index, healthy lifestyle and polygenic risk scores, and incident all-cause dementia (1). The adjusted hazard ratio (HR) (95% CI) of participants with high frailty for incident dementia was 3.68 (3.11 to 4.35). In addition, the adjusted HR (95% CI) of participants with high genetic risk and high frailty for incident dementia was 5.81 (4.01 to 8.42).The authors emphasized of controlling frailty for dementia prevention strategies, even among subjects at high genetic risk. I have two comments about their study.
First, Lourida et al. investigated the association between healthy lifestyles and risk of dementia by considering genetic risk (2). The adjusted HR (95% CI) of participants with high genetic risk and unfavorable lifestyle for incident dementia was 2.83 (2.09 to 3.83). In addition, a favorable lifestyle was associated with a lower dementia risk among participants with high genetic risk. There was no significant interaction between genetic risk and lifestyle factors, and I suppose that unfavorable lifestyles and genetic factors independently contribute to the risk of dementia. The level of frailty may be related to lifestyles and contribute to subsequent progression of cognitive impairment.
Second, Kojima et al. conducted a meta-analysis regarding the effect of frailty on the incident dementia among community-dwelling older people (3). Th pooled HRs (95% CIs) of frailty for the incident Alzheimer disease...
Show MoreWe read with interest the letter by Bert-Marcaz et al., reporting on a 74-year-old man with vacuole, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome and chronic inflammatory demyelinating polyneuropathy [1]. We agree with the authors’ postulation that the simultaneous onset of the two diseases suggests a potentially causal link between VEXAS and the demyelinating abnormalities they observed on nerve conduction studies and nerve biopsy. We have previously reported a case of a 68-year-old man with VEXAS associated with neurological features, including ophthalmoplegia, sensorineural hearing loss and bilateral vestibulopathy [2]. Our hypothesis for the mechanism of neurological involvement was polycranial neuritis, given that there was no evidence of orbital inflammation on MRI and there was significant improvement with corticosteroids. Neurologists should consider the diagnosis of VEXAS (and other autoinflammatory syndromes of innate immunity) in patients with neurological problems who have (i) unexplained fever and elevated acute phase reactants, especially when there is a remitting and relapsing course, (ii) unexplained multisystem disease, and (iii) no evidence of infection, malignancy or autoimmune (i.e., antibody-mediated) disease.
References:
Show More[1] Bert-Marcaz C, Briantais A, Faucher B, Corazza G, Ebbo M, Attarian S, Delmont E, Fortanier E. Expanding the spectrum of VEXAS syndrome: association with acute-onset CIDP. J Neurol Neurosurg Psychiat...
There have been some studies investigating blood neurofilament light chain (NfL) levels as predictors of cognitive functions decline in neurological disorders. I want to discuss here the association between blood NfL levels and neuroaxonal damage in patients with brain damages including Alzheimer's disease and stroke by considering the underlying mechanisms.
First, Egle et al. reported that baseline increased serum NfL levels could predict cognitive decline and the risk of converting to dementia in a cerebral small vessel disease (SVD), but there was no change in serum NfL levels over a 5-year follow-up period [1]. The lack of dynamic changes of NfL in stroke stand in contrast to neurodegenerative disease, and serum NfL levels may not be used as a surrogate marker for monitoring cognitive impairment in patients with SVD. In contrast, Stokowskaet et al. examined plasma NfL levels for the prediction of functional improvement in the late phase after stroke [2]. The odds ratios (ORs) (95% confidence intervals [CIs]) of elevated plasma NfL levels for the improvement in balance and gait improvement were 2.34 (1.35-4.27) and 2.27 (1.25-4.32), respectively. In addition, OR (95% CI) of elevated plasma NfL levels for cognitive improvement was 7.54 (1.52-45.66), which was also verified by intervention trial. This study presented the usefulness of plasma NfL levels as a biomarker of physical and psychological function after stroke events. As there is a wide range of 95% CI...
Show MoreWe read with great interest the paper by Yaghi S. et al on the lacunar stroke mechanisms and their therapeutic implications. We would like to highlight that the deficiency of ADA2 (DADA2) is the most common cause of monogenic vasculitis and is also responsible for causing lacunar strokes, but is commonly overlooked [1]. It has an autosomal recessive inheritance and has multi-system involvement: skin, nervous, gastrointestinal and hematological systems being most commonly involved [1]. Children and young adults are most commonly affected with a “polyarteritis nodosa-type” picture with cutaneous involvement, abdominal pains and renal involvement, and mild strokes. The lacunar infarcts are more common in the posterior circulation [2]. Most cases are diagnosed late or go undiagnosed because of lack of knowledge about this disorder [3, 4].
Patients are treated by immunosuppressants with anti-tumour necrosis factor (TNF) agents and usually adalimumab is the first line agent. Early diagnosis and treatment lead to favorable treatment response.
References:
Show More1. Meyts I, Aksentijevich I. Deficiency of Adenosine Deaminase 2 (DADA2): Updates on the Phenotype, Genetics, Pathogenesis, and Treatment. Journal of Clinical Immunology (2018) 38: 569-578
2. Geraldo AF, Carosi R, Tortora D et al. Widening the Neuroimaging features of Adenosine Deaminase 2 Deficiency. American Journal of Neuroradiology. February 2021
3. Sharma A, Agarwal A, Srivastava MVP, et al. Hy...
We recently published our preliminary case-control study showing that a medical history of hypothyroidism was more prevalent among COVID-19 patients with persistent olfactory dysfunction compared to controls (50% vs 8%; p=0.009) and that hypothyroidism was independently (p=0.021) associated with higher likelihood of persistent hyposmia/anosmia among patients with COVID-19 (OR: 21.1; 95%CI: 2.0 to 219.4) after adjusting for age and sex (1). As previously stated, our results are not -by any means- confirmatory of an etiologic association between hypothyroidism (or preferably chronic autoimmune thyroiditis, CAT, as aptly suggested by Rotondi et al.) and the development of persistent anosmia in COVID-19 patients (1). However, the suggetsed mechanism by Rotondi et al. strengthens our observations by proposing a possible biomolecular explanation behind our clinical observations. Indeed, chemokines that are induced by SARS-CoV-2 infection, and especially CXCL10, could act as effectors of demyelination of the central nervous system (CNS) - including the olfactory apparatus - through attraction and recruitment of T-lymphocytes (2,3). Although the proposed pathogenetic mechanism by Rotondi et al. needs further investigation and laboratory confirmation through experimental studies in COVID-19 patients with persistent olfactory dysfunction, it certainly invigorates our preliminary clinical results and sets the grounds for further research in a clinically significant post-COVID-9 seque...
Show MoreThyroid hormones play a role in the development and function of virtually all human cells, including maturation of olfactory neurons. The clinical observation that patients with hypothyroidism can experience disturbances in their sense of smell was first reported more than 60 years ago, and it was subsequently confirmed in both humans and animal models. In vivo animal studies clearly demonstrated that hypothyroidism induced by anti-thyroid drugs administration in mice was associated to variable degrees of anosmia, which however promptly reverted following restoration of euthyroidism by levothyroxine replacement therapy (1).
Show MoreThis latter finding was regarded as the proof that thyroxine, besides its role for correct development of the nervous system would also be involved in the genesis of new olfactory receptor neurons, a process demonstrated to be maintained also in adulthood.
Since the early phase of the ongoing Sars-CoV-2 pandemic, anosmia was identified as a peculiar clinical symptom of COVID-19 being experienced by nearly 80% of the affected patients (2). It is now known that, at least in some cases, COVID-19 course may encompass protracted olfactory dysfunction and development of olphactory bulb atrophy (3). Thus, attention was paid to potential risk factors predicting this long-term sequela. Interestingly, Tsivgoulis et al., recently performed a prospective case–control study aimed at evaluating whether hypothyroidism could be associated to prolonged COVID...
Dear Editor,
We have read with interest a recent paper by Seiffge and his colleagues published in your journal (1). In their study entitled as “Small vessel disease burden and intracerebral haemorrhage in patients taking oral anticoagulants”, the authors have investigated the role of small vessel disease on intracerebral hemorrhages (ICH) associated with the use of oral anticoagulation therapy. The authors showed that the small vessel disease with medium-to-high severity, detected by either computed tomography (CT) or magnetic resonance imaging (MRI), was significantly more prevalent in patients with ICH taking oral anticoagulants in compared to those without prior anticoagulation therapy (56.1% vs 43.5% on CT, and 78.7% vs 64.5% on MRI, respectively; p<0.001). Leukoaraiosis and atrophy were also reported to be more frequent and severe in patients with ICH related to anticoagulation therapy. We think that the results of the study are considerable emphasizing the importance of small vessel disease for ICH, which should therefore be implemented among the criteria of the risk stratification scores of bleeding.
The use of the scoring systems for the risk stratification of the intracranial bleeding is practically important in patients who are the candidates for the anticoagulation therapy. A recent study investigating the risk factors predicting ICH in patients with atrial fibrillation under anticoagulation therapy demonstrated that the presence of white matter...
Show MoreMalpetti et al. examined neuroinflammation in subcortical regions for predicting clinical progression in patients with progressive supranuclear palsy (PSP) (1). Principal component analysis (PCA) was applied for the analysis, and neuroinflammation and tau burden in the brainstem and cerebellum significantly correlated with the subsequent annual rate of change in the score of Progressive Supranuclear Palsy Rating Scale. Namely, PCA-derived [11C]PK11195 positron emission tomography (PET) markers of neuroinflammation and tau pathology significantly correlated with regional brain volume, but MRI volumes alone did not predict the clinical progression. I present some information with special reference to treatment strategies.
As there are no modifiable lifestyle factors to suppress progression of PSP (2), keeping quality of life by symptom-controlling medications has been recommended. Morgan et al. reported that symptomatic medications, most often for parkinsonism and depression, were prescribed for 87% of patients with PSP, whose satisfaction was poor in most cases (3). Although there have been no effective neuroprotective therapies and/or disease-modifying agents for patients with tauopathies and synucleinopathies, Jabbari et al. recently identified that genetic variation at the leucine-rich repeat kinase 2 (LRRK2) locus was significantly associated with survival in PSP, which might be based on the effect of long noncoding RNA on LRRK2 expression (4). As LRRK2 is associ...
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