Comparing Essential Tremor with and without Soft Dystonic Signs and Tremor Combined with Dystonia: The TITAN Study.

BACKGROUND: Tremor disorders remain as clinical diagnoses and the rate of misdiagnosis between the commonest non-parkinsonian tremors is relatively high. OBJECTIVES: To compare the clinical features of Essential Tremor without other features (pure ET), ET plus soft dystonic signs (ET + DS), and tremor combined with dystonia (TwD). METHODS: We compared the clinical features of patients with pure ET, ET + DS, and TwD enrolled in The ITAlian tremor Network (TITAN). Linear regression models were performed to determine factors associated with health status and quality of life. RESULTS: Three-hundred-eighty-three patients were included. Sex distribution was significantly different between the groups with males being more represented in pure ET and females in TwD. The initial site of tremor was different between the groups with about 40% of TwD having head tremor and ET + DS unilateral upper limb tremor at onset. This pattern mirrored the distribution of overt dystonia and soft dystonic signs at examination. Sensory trick, task-specificity, and position-dependence were more common, but not exclusive, to TwD. Pure ET patients showed the lowest degree of alcohol responsiveness and ET + DS the highest. Midline tremor was more commonly encountered and more severe in TwD than in the other groups. Regression analyses demonstrated that tremor severity, sex, age, and to a lesser degree the variable "group", independently predicted health status and quality of life, suggesting the existence of other determinants beyond tremor. CONCLUSIONS: Pure ET and TwD manifest with a phenotypic overlap, which calls for the identification of diagnostic biomarkers. ET + DS shared features with both syndromes, suggesting intra-group heterogeneity.

Does sex influence the natural history of idiopathic adult-onset dystonia?

BACKGROUND: Several earlier studies showed a female predominance in idiopathic adult-onset dystonia (IAOD) affecting the craniocervical area and a male preponderance in limb dystonia. However, sex-related differences may result from bias inherent to study design. Moreover, information is lacking on whether sex-related differences exist in expressing other dystonia-associated features and dystonia spread. OBJECTIVE: To provide accurate information on the relationship between sex differences, motor phenomenology, dystonia-associated features and the natural history of IAOD. METHODS: Data of 1701 patients with IAOD from the Italian Dystonia Registry were analysed. RESULTS: Women predominated over men in blepharospasm, oromandibular, laryngeal and cervical dystonia; the sex ratio was reversed in task-specific upper limb dystonia; and no clear sex difference emerged in non-task-specific upper limb dystonia and lower limb dystonia. This pattern was present at disease onset and the last examination. Women and men did not significantly differ for several dystonia-associated features and tendency to spread. In women and men, the absolute number of individuals who developed dystonia tended to increase from 20 to 60 years and then declined. However, when we stratified by site of dystonia onset, different patterns of female-to-male ratio over time could be observed in the various forms of dystonia. CONCLUSIONS: Our findings provide novel evidence on sex as a key mediator of IAOD phenotype at disease onset. Age-related sexual dimorphism may result from the varying exposures to specific age-related and sex-related environmental risk factors interacting in a complex manner with biological factors such as hormonal sex factors.

Are Cognitive Symptoms Part of the Phenotypic Spectrum of Idiopathic Adult-Onset Dystonia? Summary of Evidence from Controlled Studies.

BACKGROUND: Cognitive dysfunction has been reported in idiopathic adult-onset dystonia (IAOD), but whether this is a primary or secondary component of the disorder remains uncertain. OBJECTIVE: Here, we aimed to analyze the key domains of abnormal cognitive performance in IAOD and whether this is associated with motor or mood changes. METHODS: Article selection for our critical review was guided by PRISMA guidelines (mesh terms "dystonia" and "cognitive," publication period: 2000-2022). Only peer-reviewed, English-language original case-control studies involving patients with IAOD who were not exposed to dopamine- or acetylcholine-modulating agents and validated cognitive assessments were included. RESULTS: Abstract screening ultimately yielded 22 articles for full-text review and data extraction. A greater proportion of studies (17 of 22, 82%) reported abnormal cognitive performance in IAOD. Most of these studies focused on blepharospasm (BSP) and cervical dystonia (10 and 14, respectively). Most studies reporting cognitive impairment (11 of 17) identified multidomain impairment in cognition. Executive functions were the domain most frequently explored (14 of 22 studies), 79% of which detected worse performance in people with dystonia. Results related to other domains were inconclusive. Cognitive abnormalities were independent of motor symptoms in most studies (7 of 12) that explored this relationship and independent of mood status in all 8 that investigated this. CONCLUSIONS: Within IAOD, cognitive dysfunction (in particular, executive dysfunction) has been documented mainly in BSP and cervical dystonia. More comprehensive testing is warranted to assess abnormalities in other domains and in other forms of IAOD, as well as to evaluate longitudinal progression of cognitive disturbances in this condition.

Clinical correlates of "pure" essential tremor: the TITAN study.

Background: To date, there are no large studies delineating the clinical correlates of "pure" essential tremor (ET) according to its new definition. Methods: From the ITAlian tremor Network (TITAN) database, we extracted data from patients with a diagnosis of "pure" ET and excluded those with other tremor classifications, including ET-plus, focal, and task-specific tremor, which were formerly considered parts of the ET spectrum. Results: Out of 653 subjects recruited in the TITAN study by January 2022, the data of 208 (31.8%) "pure" ET patients (86M/122F) were analyzed. The distribution of age at onset was found to be bimodal. The proportion of familial cases by the age-at-onset class of 20 years showed significant differences, with sporadic cases representing the large majority of the class with an age at onset above 60 years. Patients with a positive family history of tremor had a younger onset and were more likely to have leg involvement than sporadic patients despite a similar disease duration. Early-onset and late-onset cases were different in terms of tremor distribution at onset and tremor severity, likely as a function of longer disease duration, yet without differences in terms of quality of life, which suggests a relatively benign progression. Treatment patterns and outcomes revealed that up to 40% of the sample was unsatisfied with the current pharmacological options. Discussion: The findings reported in the study provide new insights, especially with regard to a possible inversed sex distribution, and to the genetic backgrounds of "pure" ET, given that familial cases were evenly distributed across age-at-onset classes of 20 years. Deep clinical profiling of "pure" ET, for instance, according to age at onset, might increase the clinical value of this syndrome in identifying pathogenetic hypotheses and therapeutic strategies.

Phenotypic Variability in Acquired and Idiopathic Dystonia.

Background: To date, a few studies have systematically investigated differences in the clinical spectrum between acquired and idiopathic dystonias. Objectives: To compare demographic data and clinical features in patients with adult-onset acquired and idiopathic dystonias. Methods: Patients were identified from among those included in the Italian Dystonia Registry, a multicenter Italian dataset of patients with adult-onset dystonia. Study population included 116 patients with adult-onset acquired dystonia and 651 patients with isolated adult-onset idiopathic dystonia. Results: Comparison of acquired and idiopathic dystonia revealed differences in the body distribution of dystonia, with oromandibular dystonia, limb and trunk dystonia being more frequent in patients with acquired dystonia. The acquired dystonia group was also characterized by lower age at dystonia onset, greater tendency to spread, lower frequency of head tremor, sensory trick and eye symptoms, and similar frequency of neck pain associated with CD and family history of dystonia/tremor. Conclusions: The clinical phenomenology of dystonia may differ between acquired and idiopathic dystonia, particularly with regard to the body localization of dystonia and the tendency to spread. This dissimilarity raises the possibility of pathophysiological differences between etiologic categories.

Increasing prevalence 2015-2019 of amyotrophic lateral sclerosis in Sardinia, Italy.

BACKGROUND: While amyotrophic lateral sclerosis (ALS) incidence has increased during the last decades, structured evidence on increased prevalence is lacking. After reporting a significant yearly increase of ALS incidence over a 10-year period, we checked for increased prevalence in Southern Sardinia over a quinquennium. METHODS: ALS patients (El Escorial Criteria) recruited from the study area and followed at ALS Centre, University of Cagliari, were included. Prevalence was computed for January 1, 2015 and January 1, 2019 and was calculated for the overall ALS population as well as for tracheostomized and non-tracheostomized patients. RESULTS: We observed a non-significant trend for greater ALS prevalence in 2019 than in 2015 (18.31 per 100,000 vs. 15.26 per 100,000; rate ratio: 1.83, p = 0.01). By contrast, a significantly raising 2015 to 2019 ALS prevalence was observed in tracheostomized patients. No significant difference could be detected in non-tracheostomized. CONCLUSIONS: We provided the highest prevalence rate to date reported in the worldwide literature, and also showed a non-significant raising ALS prevalence in the Sardinian population over a quinquennium. The trend in raising ALS prevalence was likely due to extended survival due to invasive interventions.

Validation of a guideline to reduce variability in diagnosing cervical dystonia.

BACKGROUND: Cervical dystonia is characterized by a variable pattern of neck muscle involvement. Due to the lack of a diagnostic test, cervical dystonia diagnosis is based on clinical examination and is therefore subjective. The present work was designed to provide practical guidance for clinicians in confirming or refuting suspected cervical dystonia. METHODS: Participants were video recorded according to a standardized protocol to assess 6 main clinical features possibly contributing to cervical dystonia diagnosis: presence of repetitive, patterned head/neck movements/postures inducing head/neck deviation from neutral position (item 1); sensory trick (item 2); and red flags related to conditions mimicking dystonia that should be absent in dystonia (items 3-6). Inter-/intra-rater agreement among three independent raters was assessed by k statistics. To estimate sensitivity and specificity, the gold standard was cervical dystonia diagnosis reviewed at each site by independent senior neurologists. RESULTS: The validation sample included 43 idiopathic cervical dystonia patients and 41 control subjects (12 normal subjects, 6 patients with isolated head tremor, 4 with chorea, 6 with tics, 4 with head ptosis due to myasthenia or amyotrophic lateral sclerosis, 7 with orthopedic/rheumatologic neck diseases, and 2 with ocular torticollis). The best combination of sensitivity and specificity was observed considering all the items except for an item related to capability to voluntarily suppress spasms (sensitivity: 96.1%; specificity: 81%). CONCLUSIONS: An accurate diagnosis of cervical dystonia can be achieved if, in addition to the core motor features, we also consider some clinical features related to dystonia mimics that should be absent in dystonia.

Impact of occupational categories on the incidence of amyotrophic lateral sclerosis in Sardinia Island, Italy.

OBJECTIVE: Occupation is one of the potential risk factors for amyotrophic lateral sclerosis (ALS) for which previous controlled studies produced inconsistent results. The aim of this study is to assess the impact of several groups of occupational categories on ALS incidence. METHODS: ALS patients from the southern part of Sardinia who had onset during 2012-2021 and fulfilled El Escorial revised diagnostic criteria were included. The risk of ALS was estimated in relation to the occupation held in 2011, as obtained from the 2011 Census that classified working activities in ten groups. Each occupational group was compared with a reference category represented by all other occupations, and rate ratio were calculated. Additive interaction between activity at work and age at ALS onset/sex on ALS incidence was calculated. RESULTS: Employment in agriculture/breeding and in the armed forces were significantly associated with increasing ALS risk. None of the other assessed occupation groups was associated with change in the risk of ALS. Geographic analysis indicated that the effect of agriculture/breeding was particularly evident in the areas of higher risk for the general population. By contrast, an inverse pattern of spatial risk was associated with armed forces activity at work. The increased risk of ALS associated to agriculture/breeding was more evident in older people. No significant interaction was detected between working in the armed forces and older age/sex. CONCLUSIONS: The significant interaction between agriculture/breeding and age suggests that the mechanisms leading to ALS are complex and involve several factors.

AChR+ Ocular Myasthenia and Facial Hemispasm: A Case Report of Unusual Association and Botulinum Toxic Type A Safety and Efficacy.

INTRODUCTION: Hemifacial spasm represents segmental myoclonus of muscles innervated by the facial nerve, which is usually and successfully treated with botulinum toxin. Botulinum toxin (BTX) acts as an acetylcholine release inhibitor at presynaptic cholinergic junctions and therefore is considered contraindicated (or administrable with caution) in patients with neuromuscular disorders like Myasthenia Gravis (MG). Moreover, to date, the association of hemifacial spasm and ocular MG is extremely rare and only a few cases have been described. CASE PRESENTATION: We report the case of a 73 years old man with a 3-year history of ocular MG who developed a left hemifacial spasm. The patient underwent hemispasm, treatment with BTX type A (abobotulinum toxin-A, total dose of 50 IU) that resulted in safe and successful 6 months re-evaluation. CONCLUSION: Our results suggest that in selected cases with concomitant MG and conditions characterized by orbicularis oculi spasms or hemispasm, BTX therapy may not be contraindicated and could be given at longer intervals due to prolonged effects.

Measurement Properties of Clinical Scales Rating the Severity of Blepharospasm: A Multicenter Observational Study.

Background: Several scales have been proposed to clinically evaluate the Motor Severity of Blepharospasm (BSP) but information about their measurement properties as a multicenter instrument is limited. Objective: To compare the measurement properties of four clinical scales in rating the severity of BSP in a large sample of patients from multiple sites. Methods: The Burke-Fahn-Marsden Scale (BFMS), the Global Dystonia Severity Rating Scale (GDRS), the Jankovic Rating Scale (JRS), and the Blepharospasm Severity Rating Scale (BSRS) were administered to 211 patients across 10 sites who were also requested to self-complete the Blepharospasm Disability Index (BDI). Measurement properties to be assessed included inter-/intra-observer agreement, item-to-total correlation, internal consistency, floor and ceiling effect, convergent/discriminant validity, and adherence to the distribution of BDI. Results: The BFMS had unsatisfactory measurement properties, the GDRS had acceptable reliability but other properties could not be completely testable; the JRS had satisfactory measurement properties but the scale did not accurately reflect the distribution of disability parameter (BDI) in the sample, and the BSRS had satisfactory measurement properties and also showed the best adherence to the distribution of BDI in the assessed sample. Conclusion: The comparison of the measurement properties of four rating scales to assess the motor state of the BSP in a large sample of patients from multiple sites showed that the GDRS should be used to simultaneously assess BSP and dystonia in other body parts, while the JRS (easier to use) and BSRS (better to discriminate severity) should be used to assess BSP alone.

Motor and psychiatric features in idiopathic blepharospasm: A data-driven cluster analysis.

INTRODUCTION: Idiopathic blepharospasm is a clinically heterogeneous dystonia also characterized by non motor symptoms. METHODS: We used a k-means cluster analysis to assess 188 patients with idiopathic blepharospasm in order to identify relatively homogeneous subpopulations of patients, using a set of motor and psychiatric variables to generate the cluster solution. RESULTS: Blepharospasm patients reached higher scores on scales assessing depressive- and anxiety-related disorders than healthy/disease controls. Cluster analysis suggested the existence of three groups of patients that differed by type of spasms, overall motor severity, and presence/severity of psychiatric problems. The greater severity of motor symptoms was observed in Group 1, the least severity in Group 3, while the severity of blepharospasm in Group 2 was between that observed in Groups 1 and 3. The three motor subtypes also differed by psychiatric features: the lowest severity of psychiatric symptoms was observed in the group with least severe motor symptoms (group 3), while the highest psychiatric severity scores were observed in group 2 that carried intermediate motor severity rather than in the group with more severe motor symptoms (group 1). The three groups did not differ by disease duration, age of onset, sex or other clinical features. CONCLUSIONS: The present study suggests that blepharospasm patients may be classified in different subtypes according to the type of spasms, overall motor severity and presence/severity of depressive symptoms and anxiety.

A Bayesian approach to Essential Tremor plus: A preliminary analysis of the TITAN cohort.

BACKGROUND: The construct of Essential Tremor plus (ET-plus) refers to patients who also have rest tremor and/or mild neurologic signs of unknown significance. It is unclear whether soft signs represent confounding factors or are useful in suspecting an alternative condition. METHODS: Using a Bayesian approach to ET-plus patients recruited in The ITAlian tremor Network (TITAN), we analyzed the probability that these patients do not have ET. RESULTS: The data of 274 ET-plus patients were extracted from the TITAN database. The majority of patients (240/274; 87.5%) had a single soft sign. The post-test probability of not having ET was different according to the specific soft sign: namely, 0.64 (rest tremor); 0.46 (questionable dystonia); 0.85 (questionable bradykinesia); 0.19 (soft gait impairment); and 0.09 (questionable cognitive issues). In patients with multiple soft signs, the post-test probability of not having ET was higher than 50% for 7 out of 11 combinations, accounting for 44.1% of subjects. Overall, the post-test probability of not having ET was higher than 50% in up to 71.5% of ET-plus patients. DISCUSSION: We have here shown that: 1) the soft signs differently contribute in modulating the probability that a patient does not have ET; and 2) the effect of multiple soft signs are not always addictive. Future studies are needed to collect prevalence figures of soft signs in different neurological disorders as well as in the elderly and to calculate their value in predicting the development of an alternative tremor syndrome.

Does Olfactory Dysfunction Correlate with Disease Progression in Parkinson's Disease? A Systematic Review of the Current Literature.

BACKGROUND: Loss of olfaction is a well-established early feature of Parkinson's disease (PD). Although olfactory dysfunction has been widely described as a prodromal feature of PD in the literature, whether it can be considered a biomarker of PD progression is still a matter of debate. OBJECTIVE: The aim of this work is to define the possible relationship between the progression of olfactory dysfunction and other putative clinical hallmarks of PD over time, through a systematic review of the current literature. METHODS: We conducted a systematic review of the literature on PubMed from inception to March 2022. We included only longitudinal studies conducted on patients with diagnosis of idiopathic PD who underwent olfactory function testing at baseline and repeated it at least once during follow-up. RESULTS: Among 5740 records identified through database searching, nine longitudinal studies met full criteria and underwent data extraction. CONCLUSIONS: Olfaction seemed to decrease over time, albeit with a degree of fluctuation. Moreover, smell detection ability seems to deteriorate more rapidly in the early phase of disease, indicating a possible association with disease progression. More studies are needed to better understand the role of olfaction as a biomarker of PD progression over time.

The Italian tremor Network (TITAN): rationale, design and preliminary findings.

INTRODUCTION: The recently released classification has revised the nosology of tremor, defining essential tremor (ET) as a syndrome and fueling an enlightened debate about some newly conceptualized entities such as ET-plus. As a result, precise information of demographics, clinical features, and about the natural history of these conditions are lacking. METHODS: The ITAlian tremor Network (TITAN) is a multicenter data collection platform, the aim of which is to prospectively assess, according to a standardized protocol, the phenomenology and natural history of tremor syndromes. RESULTS: In the first year of activity, 679 patients have been recruited. The frequency of tremor syndromes varied from 32% of ET and 41% of ET-plus to less than 3% of rare forms, including focal tremors (2.30%), task-specific tremors (1.38%), isolated rest tremor (0.61%), and orthostatic tremor (0.61%). Patients with ET-plus were older and had a higher age at onset than ET, but a shorter disease duration, which might suggest that ET-plus is not a disease stage of ET. Familial aggregation of tremor and movement disorders was present in up to 60% of ET cases and in about 40% of patients with tremor combined with dystonia. The body site of tremor onset was different between tremor syndromes, with head tremor being most commonly, but not uniquely, associated with dystonia. CONCLUSIONS: The TITAN study is anticipated to provide clinically relevant prospective information about the clinical correlates of different tremor syndromes and their specific outcomes and might serve as a basis for future etiological, pathophysiological, and therapeutic research.

Incidence of amyotrophic lateral sclerosis in Sardinia, Italy: age-sex interaction and spatial-temporal variability.

Objective: This study assessed amyotrophic lateral sclerosis (ALS) incidence in Sardinia, Italy, and the combined contribution of age and gender to disease risk. We also checked disease incidence for spatial-temporal variability. Methods: ALS patients from all neurological centers of the study area who had onset during 2010-2019 and fulfilled El Escorial revised diagnostic criteria were included. Incidence was calculated for the overall study area and each province separately. Additive interaction between age and sex on ALS incidence was assessed. Results: The average crude annual incidence rate was 3.6/100,000 person-years (95% CI, 3.2-4.1), 3.1/100,000 person-years (95% CI, 2.7-3.5) when age-adjusted. Incidence was greater among people aged ≥65 years and men, with the two variables undergoing significant additive interaction. Incidence increased yearly over the study period, with annual incidence correlating with the increasing yearly frequency of people aged ≥65 years, but not with the proportion of incident cases carrying genetic mutations. Stratifying by province, the rates from Oristano and South Sardinia were higher than the rate from Cagliari. ALS patients from areas at different risk were comparable for frequency of clinical/genetic features. Conclusion: ALS incidence in Sardinia was in the upper part of the European range of variability. We also provided new information about age and sex as risk factors for ALS, showing male sex as a modifier of the effect of aging on ALS incidence. Spatial-temporal variations in ALS incidence correlated to changes in the proportion of the aging population rather than to the distribution of genetic factors.

The Relationships Between Ataxia and Cognition in Spinocerebellar Ataxia Type 2.

The clinical spectrum of spinocerebellar ataxia type 2 includes motor manifestations and cognitive disturbances in executive functions, memory, and visuoconstructive skills. The relationships between severity of motor disturbances and altered cognition are poorly known. In this study, we assessed patients with spinocerebellar ataxia type 2 and age- and sex-matched healthy control subjects by a test battery including the Mini-mental State Examination, the Wisconsin Card Sorting test, and the Wechsler Memory Scale-Revised. The correlation between severity of motor ataxia (as assessed by a validated and widely used severity scale, the SARA scale, and by an objective automated computerized system of gait analysis) and altered cognition was then evaluated by Spearman correlation analysis. Patients performed worse than healthy controls in almost all administered neuropsychological tests. Nevertheless, only global intellectual abilities and executive functions significantly correlated with the overall severity of ataxia as assessed by the SARA scale, and impaired executive functions alone correlated with performance on several spatio-temporal gait analysis parameters. Our findings would probably suggest a prominent influence of executive functions on motor abilities in patients with spinocerebellar ataxia type 2 and raise the possibility that cognitive pharmaceutical or rehabilitative interventions may be of benefit in the management of motor problems in these patients.

Sensory trick in upper limb dystonia.

INTRODUCTION: Sensory trick is a specific maneuver that temporarily improves dystonia that is usually observed in 44%-89% of patients with cranial-cervical dystonia and in 20% of patients with upper limb dystonia. This study aimed to assess the prevalence of sensory trick in a cohort of 37 patients with idiopathic adult-onset upper limb dystonia and to determine whether sensory trick can be a useful tool to distinguish dystonic and non-dystonic tremor. METHODS: Thirty-seven right-handed patients with idiopathic upper limb dystonia and disturbed handwriting and 19 patients with non-dystonic action tremor in the upper limb causing writing disturbances participated into the study. Patients were asked to write a standard sentence twice, before and after applying a standardized sensory trick (gently grabbing right wrist with his left hand). Readability of the two sentences was assessed by three observers blinded to diagnosis. RESULTS: Five/37 patients (13%) self-discovered ST over disease history, while performing the standardized trick maneuver improved handwriting in 14/37 patients (38%). Interobserver agreement on the effectiveness of sensory trick among the three observers yielded a kappa value of 0.86 (p < 0.0001). The standardized trick was effective in 8/19 patients with dystonic tremor (42%) and in 0/19 patients with non-dystonic tremor (p = 0.003). CONCLUSION: The results of applying a standardized non-spontaneous trick demonstrated that, in upper limb dystonia, ST may be more frequent than usually observed. Effective sensory trick, when present, may be a hallmark of idiopathic dystonia. The lack of effective sensory trick may help to identify non dystonic upper limb tremor.

Differences in psychopathology and behavioral characteristics of patients affected by conversion motor disorder and organic dystonia.

PURPOSE: Typically, the diagnosis of conversion motor disorder (CMD) is achieved by the exclusion of a wide range of organic illnesses rather than by applying positive criteria. New diagnostic criteria are highly needed in this scenario. The main aim of this study was to explore the use of behavioral features as an inclusion criterion for CMD, taking into account the relationship of the patients with physicians, and comparing the results with those from patients affected by organic dystonia (OD). PATIENTS AND METHODS: Patients from the outpatient Movement Disorder Service were assigned to either the CMD or the OD group based on Fahn and Williams criteria. Differences in sociodemographics, disease history, psychopathology, and degree of satisfaction about care received were assessed. Patient-neurologist agreement about the etiological nature of the disorder was also assessed using the k-statistic. A logistic regression analysis estimated the discordance status as a predictor to case/control status. RESULTS: In this study, 31 CMD and 31 OD patients were included. CMD patients showed a longer illness life span, involvement of more body regions, higher comorbidity with anxiety, depression, and borderline personality disorder, as well as higher negative opinions about physicians' delivering of proper care. Contrary to our expectations, CMD disagreement with neurologists about the etiological nature of the disorder was not statistically significant. Additional analysis showed that having at least one personality disorder was statistically associated with the discordance status. CONCLUSION: This study suggests that CMD patients show higher conflicting behavior toward physicians. Contrary to our expectations, they show awareness of their psychological needs, suggesting a possible lack of recognition of psychological distress in the neurological setting.

Whole-exome sequencing for variant discovery in blepharospasm.

BACKGROUND: Blepharospasm (BSP) is a type of focal dystonia characterized by involuntary orbicularis oculi spasms that are usually bilateral, synchronous, and symmetrical. Despite strong evidence for genetic contributions to BSP, progress in the field has been constrained by small cohorts, incomplete penetrance, and late age of onset. Although several genetic etiologies for dystonia have been identified through whole-exome sequencing (WES), none of these are characteristically associated with BSP as a singular or predominant manifestation. METHODS: We performed WES on 31 subjects from 21 independent pedigrees with BSP. The strongest candidate sequence variants derived from in silico analyses were confirmed with bidirectional Sanger sequencing and subjected to cosegregation analysis. RESULTS: Cosegregating deleterious variants (GRCH37/hg19) in CACNA1A (NM_001127222.1: c.7261_7262delinsGT, p.Pro2421Val), REEP4 (NM_025232.3: c.109C>T, p.Arg37Trp), TOR2A (NM_130459.3: c.568C>T, p.Arg190Cys), and ATP2A3 (NM_005173.3: c.1966C>T, p.Arg656Cys) were identified in four independent multigenerational pedigrees. Deleterious variants in HS1BP3 (NM_022460.3: c.94C>A, p.Gly32Cys) and GNA14 (NM_004297.3: c.989_990del, p.Thr330ArgfsTer67) were identified in a father and son with segmental cranio-cervical dystonia first manifest as BSP. Deleterious variants in DNAH17, TRPV4, CAPN11, VPS13C, UNC13B, SPTBN4, MYOD1, and MRPL15 were found in two or more independent pedigrees. To our knowledge, none of these genes have previously been associated with isolated BSP, although other CACNA1A mutations have been associated with both positive and negative motor disorders including ataxia, episodic ataxia, hemiplegic migraine, and dystonia. CONCLUSIONS: Our WES datasets provide a platform for future studies of BSP genetics which will demand careful consideration of incomplete penetrance, pleiotropy, population stratification, and oligogenic inheritance patterns.