See Morris and Weil (doi: ) for a scientific commentary on this article. In a prospective multicentre study involving 1280 patients with idiopathic RBD, Postuma et al. show that approximately 6% of patients each year (>73.5% over 12 years) convert to full neurodegenerative disease. They test the predictive power of 21 prodromal markers of neurodegeneration, providing a template for planning neuroprotective trials.

Objective: To report the presentation, main syndromes, human leukocyte antigen (HLA) association, and immunoglobulin G (IgG) subclass in the anti-IgLON5 disease: a disorder with parasomnias, sleep apnea, and IgLON5 antibodies.Methods: This was a retrospective clinical analysis of 22 patients. The IgG subclass was determined using reported techniques.

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Video-polysomnography (v-PSG) is essential for diagnosing rapid eye movement (REM) sleep behavior disorder (RBD). Although there are current American Academy of Sleep Medicine standards to diagnose RBD, several aspects need to be addressed to achieve harmonization across sleep centers. Prodromal RBD is a stage in which symptoms and signs of evolving RBD are present, but do not yet meet established diagnostic criteria for RBD. However, the boundary between prodromal and definite RBD is still unclear. As a common effort of the Neurophysiology Working Group of the International RBD Study Group, this manuscript addresses the need for comprehensive and unambiguous v-PSG recommendations to diagnose RBD and identify prodromal RBD. These include: (1) standardized v-PSG technical settings; (2) specific considerations for REM sleep scoring; (3) harmonized methods for scoring REM sleep without atonia; (4) consistent methods to analyze video and audio recorded during v-PSGs and to classify movements and vocalizations; (5) clear v-PSG guidelines to diagnose RBD and identify prodromal RBD. Each section follows a common template: The current recommendations and methods are presented, their limitations are outlined, and new recommendations are described. Finally, future directions are presented. These v-PSG recommendations are intended for both practicing clinicians and researchers. Classification and quantification of motor events, RBD episodes and vocalizations are however intended for research purposes only. These v-PSG guidelines will allow collection of homogeneous data, providing objective v-PSG measures and making future harmonized multicentric studies and clinical trials possible.

Background and Purpose: Cervical artery dissection (CAD) is a common cause of ischemic stroke in younger aged subjects. Retrospective studies suggest cervical manipulative therapy (CMT) and preceding infections as extrinsic risk factors for CAD. In a case-control study, we assessed a questionnaire with 7 mild mechanical traumas as potential trigger factors for CAD, including CMT and recent infections. Patients and Methods: Forty-seven consecutive patients with CAD were compared with 47 consecutive patients of similar age with ischemic stroke due to etiologies other than CAD. Patients underwent a standardized face-to-face interview. We assessed head or neck pain and recent infection <7 days before symptom onset, as well as the following mechanical trigger factors <24 h and <7 days prior to symptom onset: (1) heavy lifting, (2) sexual intercourse, (3) mild direct or (4) indirect neck trauma, (5) jerky head movements, (6) sports activity, and (7) CMT. Results:We found no association between any single one of the above risk factors and CAD. CMT (CAD, n = 10; non-CAD, n = 5) and recent infections (CAD, n = 18; non-CAD, n = 10) were more frequent in the CAD group but failed to reach significance. However, the cumulative analysis of all mechanical trigger factors revealed a significant association of mechanical risk factors as a whole in CAD <24 h prior to symptom onset (p = 0.01). Conclusion: Mild mechanical stress, including CMT, plays a role as possible trigger factor in the pathogenesis of CAD. CMT and recent infections alone failed to reach significance during the present investigation, presumably due to the relatively small sample size of the study cohort.

Objective The TMEM175/GAK/DGKQ locus is the 3rd strongest risk locus in genome‐wide association studies of Parkinson disease (PD). We aimed to identify the specific disease‐associated variants in this locus, and their potential implications. Methods Full sequencing of TMEM175/GAK/DGKQ followed by genotyping of specific associated variants was performed in PD (n = 1,575) and rapid eye movement sleep behavior disorder (RBD) patients (n = 533) and in controls (n = 1,583). Adjusted regression models and a meta‐analysis were performed. Association between variants and glucocerebrosidase (GCase) activity was analyzed in 715 individuals with available data. Homology modeling, molecular dynamics simulations, and lysosomal localization experiments were performed on TMEM175 variants to determine their potential effects on structure and function. Results Two coding variants, TMEM175 p.M393T (odds ratio [OR] = 1.37, p = 0.0003) and p.Q65P (OR = 0.72, p = 0.005), were associated with PD, and p.M393T was also associated with RBD (OR = 1.59, p = 0.001). TMEM175 p.M393T was associated with reduced GCase activity. Homology modeling and normal mode analysis demonstrated that TMEM175 p.M393T creates a polar side‐chain in the hydrophobic core of the transmembrane, which could destabilize the domain and thus impair either its assembly, maturation, or trafficking. Molecular dynamics simulations demonstrated that the p.Q65P variant may increase stability and ion conductance of the transmembrane protein, and lysosomal localization was not affected by these variants. Interpretation Coding variants in TMEM175 are likely to be responsible for the association in the TMEM175/GAK/DGKQ locus, which could be mediated by affecting GCase activity. ANN NEUROL 2020;87:139–153

To investigate the prevalence of fatigue, daytime sleepiness, reduced sleep quality, and restless legs syndrome (RLS) in a large cohort of patients with Charcot-Marie-Tooth disease (CMT) and their impact on health-related quality of life (HRQoL). Participants of a web-based survey answered the Epworth Sleepiness Scale, the Pittsburgh Sleep Quality Index, the Multidimensional Fatigue Inventory, and, if the diagnostic criteria of RLS were met, the International RLS Severity Scale. Diagnosis of RLS was affirmed in screen-positive patients by means of a standardized telephone interview. HRQoL was assessed by using the SF-36 questionnaire. Age- and sex-matched control subjects were recruited from waiting relatives of surgical outpatients. 227 adult self-reported CMT patients answered the above questionnaires, 42.9% were male, and 57.1% were female. Age ranged from 18 to 78 years. Compared to controls (n = 234), CMT patients reported significantly higher fatigue, a higher extent and prevalence of daytime sleepiness and worse sleep quality. Prevalence of RLS was 18.1% in CMT patients and 5.6% in controls (p = 0.001). RLS severity was correlated with worse sleep quality and reduced HRQoL. Women with CMT were affected more often and more severely by RLS than male patients. With regard to fatigue, sleep quality, daytime sleepiness, RLS prevalence, RLS severity, and HRQoL, we did not find significant differences between genetically distinct subtypes of CMT. HRQoL is reduced in CMT patients which may be due to fatigue, sleep-related symptoms, and RLS in particular. Since causative treatment for CMT is not available, sleep-related symptoms should be recognized and treated in order to improve quality of life.Electronic supplementary materialThe online version of this article (doi:10.1007/s00415-009-5390-1) contains supplementary material, which is available to authorized users.

Objective:Anti-IgLON5 disease is a recently described neurological disease that shares features of autoimmunity and neurodegeneration. Abnormal movements appear to be frequent and important but have not been characterized and are under-reported. Here we describe the frequency and types of movement disorders in a series of consecutive patients with this disease.Methods:In this retrospective, observational study, the presence and phenomenology of movement disorders were assessed with a standardized clinical questionnaire. Available videos were centrally reviewed by three experts in movement disorders.Results:Seventy two patients were included. In 41 (57%) the main reason for initial consultation was difficulty walking along with one or several concurrent movement disorders. At the time of anti-IgLON5 diagnosis, 63 (87%) patients had at least one movement disorder with a median of three per patient. The most frequent abnormal movements were gait and balance disturbances (52 patients, 72%), chorea (24, 33%), bradykinesia (20, 28%), dystonia (19, 26%), abnormal body postures or rigidity (18, 25%), and tremor (15, 21%). Other hyperkinetic movements (myoclonus, akathisia, myorhythmia, myokymia, or abdominal dyskinesias) occurred in 26 (36%) patients. The craniofacial region was one of the most frequently affected by multiple concurrent movement disorders (23 patients, 32%) including dystonia (13), myorhythmia (6), chorea (4) or myokymia (4). Considering any body region, the most frequent combination of multiple movement disorders consisted of gait instability or ataxia associated with craniofacial dyskinesias or generalized chorea observed in 31(43%) of patients. In addition to abnormal movements, 87% of patients had sleep alterations, 74% bulbar dysfunction, and 53% cognitive impairment. Fifty-five (76%) patients were treated with immunotherapy, resulting in important and sustained improvement of the movement disorders in only seven (13%) cases.Conclusions:Movement disorders are a frequent and leading cause of initial neurological consultation in patients with anti-IgLON5 disease. Although multiple types of abnormal movements can occur, the most prevalent are disorders of gait, generalized chorea, and dystonia and other dyskinesias that frequently affect craniofacial muscles. Overall, anti-IgLON5 disease should be considered in patients with multiple movement disorders, particularly if they occur in association with sleep alterations, bulbar dysfunction, or cognitive impairment.