Presynaptic Dopaminergic Imaging Characterizes Patients with REM Sleep Behavior Disorder Due to Synucleinopathy.

OBJECTIVE: To apply a machine learning analysis to clinical and presynaptic dopaminergic imaging data of patients with rapid eye movement (REM) sleep behavior disorder (RBD) to predict the development of Parkinson disease (PD) and dementia with Lewy bodies (DLB). METHODS: In this multicenter study of the International RBD study group, 173 patients (mean age 70.5 ± 6.3 years, 70.5% males) with polysomnography-confirmed RBD who eventually phenoconverted to overt alpha-synucleinopathy (RBD due to synucleinopathy) were enrolled, and underwent baseline presynaptic dopaminergic imaging and clinical assessment, including motor, cognitive, olfaction, and constipation evaluation. For comparison, 232 RBD non-phenoconvertor patients (67.6 ± 7.1 years, 78.4% males) and 160 controls (68.2 ± 7.2 years, 53.1% males) were enrolled. Imaging and clinical features were analyzed by machine learning to determine predictors of phenoconversion. RESULTS: Machine learning analysis showed that clinical data alone poorly predicted phenoconversion. Presynaptic dopaminergic imaging significantly improved the prediction, especially in combination with clinical data, with 77% sensitivity and 85% specificity in differentiating RBD due to synucleinopathy from non phenoconverted RBD patients, and 85% sensitivity and 86% specificity in discriminating PD-converters from DLB-converters. Quantification of presynaptic dopaminergic imaging showed that an empirical z-score cutoff of -1.0 at the most affected hemisphere putamen characterized RBD due to synucleinopathy patients, while a cutoff of -1.0 at the most affected hemisphere putamen/caudate ratio characterized PD-converters. INTERPRETATION: Clinical data alone poorly predicted phenoconversion in RBD due to synucleinopathy patients. Conversely, presynaptic dopaminergic imaging allows a good prediction of forthcoming phenoconversion diagnosis. This finding may be used in designing future disease-modifying trials. ANN NEUROL 2024;95:1178-1192.

Progression of clinical markers in prodromal Parkinson's disease and dementia with Lewy bodies: a multicentre study.

The neurodegenerative synucleinopathies, including Parkinson's disease and dementia with Lewy bodies, are characterized by a typically lengthy prodromal period of progressive subclinical motor and non-motor manifestations. Among these, idiopathic REM sleep behaviour disorder is a powerful early predictor of eventual phenoconversion, and therefore represents a critical opportunity to intervene with neuroprotective therapy. To inform the design of randomized trials, it is essential to study the natural progression of clinical markers during the prodromal stages of disease in order to establish optimal clinical end points. In this study, we combined prospective follow-up data from 28 centres of the International REM Sleep Behavior Disorder Study Group representing 12 countries. Polysomnogram-confirmed REM sleep behaviour disorder subjects were assessed for prodromal Parkinson's disease using the Movement Disorder Society criteria and underwent periodic structured sleep, motor, cognitive, autonomic and olfactory testing. We used linear mixed-effect modelling to estimate annual rates of clinical marker progression stratified by disease subtype, including prodromal Parkinson's disease and prodromal dementia with Lewy bodies. In addition, we calculated sample size requirements to demonstrate slowing of progression under different anticipated treatment effects. Overall, 1160 subjects were followed over an average of 3.3 ± 2.2 years. Among clinical variables assessed continuously, motor variables tended to progress faster and required the lowest sample sizes, ranging from 151 to 560 per group (at 50% drug efficacy and 2-year follow-up). By contrast, cognitive, olfactory and autonomic variables showed modest progression with higher variability, resulting in high sample sizes. The most efficient design was a time-to-event analysis using combined milestones of motor and cognitive decline, estimating 117 per group at 50% drug efficacy and 2-year trial duration. Finally, while phenoconverters showed overall greater progression than non-converters in motor, olfactory, cognitive and certain autonomic markers, the only robust difference in progression between Parkinson's disease and dementia with Lewy bodies phenoconverters was in cognitive testing. This large multicentre study demonstrates the evolution of motor and non-motor manifestations in prodromal synucleinopathy. These findings provide optimized clinical end points and sample size estimates to inform future neuroprotective trials.

Classifying Idiopathic Rapid Eye Movement Sleep Behavior Disorder, Controls, and Mild Parkinson's Disease Using Gait Parameters.

BACKGROUND: Subtle gait changes associated with idiopathic rapid eye movement sleep behavior disorder (iRBD) could allow early detection of subjects with future synucleinopathies. OBJECTIVE: The aim of this study was to create a multiclass model, using statistical learning from probability distribution of gait parameters, to distinguish between patients with iRBD, healthy control subjects (HCs), and patients with Parkinson's disease (PD). METHODS: Gait parameters were collected in 21 participants with iRBD, 21 with PD, and 21 HCs, matched for age, sex, and education level. Lasso sparse linear regression explored gait features able to classify the three groups. RESULTS: The final model classified iRBD from HCs and from patients with PD equally well, with 95% accuracy, 100% sensitivity, and 90% specificity. CONCLUSIONS: Gait parameters and a pretrained statistical model can robustly distinguish participants with iRBD from HCs and patients with PD. This could be used to screen subjects with future synucleinopathies in the general population and to identify a conversion threshold to PD. © 2022 International Parkinson and Movement Disorder Society.

Fine-Mapping of SNCA in Rapid Eye Movement Sleep Behavior Disorder and Overt Synucleinopathies.

OBJECTIVE: Rapid eye movement sleep behavior disorder (RBD) is a prodromal synucleinopathy, as >80% will eventually convert to overt synucleinopathy. We performed an in-depth analysis of the SNCA locus to identify RBD-specific risk variants. METHODS: Full sequencing and genotyping of SNCA was performed in isolated/idiopathic RBD (iRBD, n = 1,076), Parkinson disease (PD, n = 1,013), dementia with Lewy bodies (DLB, n = 415), and control subjects (n = 6,155). The iRBD cases were diagnosed with RBD prior to neurodegeneration, although some have since converted. A replication cohort from 23andMe of PD patients with probable RBD (pRBD) was also analyzed (n = 1,782 cases; n = 131,250 controls). Adjusted logistic regression models and meta-analyses were performed. Effects on conversion rate were analyzed in 432 RBD patients with available data using Kaplan-Meier survival analysis. RESULTS: A 5'-region SNCA variant (rs10005233) was associated with iRBD (odds ratio [OR] = 1.43, p = 1.1E-08), which was replicated in pRBD. This variant is in linkage disequilibrium (LD) with other 5' risk variants across the different synucleinopathies. An independent iRBD-specific suggestive association (rs11732740) was detected at the 3' of SNCA (OR = 1.32, p = 4.7E-04, not statistically significant after Bonferroni correction). Homozygous carriers of both iRBD-specific SNPs were at highly increased risk for iRBD (OR = 5.74, p = 2E-06). The known top PD-associated variant (3' variant rs356182) had an opposite direction of effect in iRBD compared to PD. INTERPRETATION: There is a distinct pattern of association at the SNCA locus in RBD as compared to PD, with an opposite direction of effect at the 3' of SNCA. Several 5' SNCA variants are associated with iRBD and with pRBD in overt synucleinopathies. ANN NEUROL 2020;87:584-598.

Genetic, Structural, and Functional Evidence Link TMEM175 to Synucleinopathies.

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.

Fluoxetine for the Symptomatic Treatment of Multiple System Atrophy: The MSA-FLUO Trial.

BACKGROUND: There are no effective treatments for multiple system atrophy (MSA). OBJECTIVE: The objective of this study was to assess the efficacy and safety of the serotonin reuptake inhibitor fluoxetine (40 mg/d) for the symptomatic treatment of MSA. METHODS: This was a double-blind, parallel-group, placebo-controlled, randomized trial in patients with "probable" MSA. The primary outcome was the change from baseline to week 12 in the mean total score of the Unified MSA Rating Scale (UMSARS Parts I + II). Secondary outcomes included change from baseline to week 6 in total UMSARS, and change from baseline to week 12 in the Scales for Outcomes in Parkinson Disease-Autonomic Dysfunction, Beck Depression Inventory, and different domains of the MSA-Quality of Life Questionnaire. Exploratory outcomes included change from baseline to week 12 in the UMSARS Parts I and II separately and change from baseline to week 24 in the total UMSARS score. RESULTS: A total of 81 patients were randomly assigned, with no significant difference in the primary outcome (-2.13 units [95% confidence interval, CI, -4.55 to 0.29]; P = 0.08). There was a greater reduction on fluoxetine in the change from baseline to 12-week in UMSARS Part II (exploratory outcome: -1.41 units [95% CI, -2.84; 0.03]; p = 0.05) and in MSA-QoL emotional/social dimension (secondary outcome: -6.99 units [95% CI, -13.40; -0.56]; p < 0.03). A total of 5 deaths occurred (3 on fluoxetine and 2 on placebo). CONCLUSION: The MSA-FLUO failed to demonstrate fluoxetine superiority over placebo on the total UMSARS score, whereas trends in motor and emotional secondary/exploratory outcomes deserve further investigation. © 2021 International Parkinson and Movement Disorder Society.

Comprehensive Analysis of Familial Parkinsonism Genes in Rapid-Eye-Movement Sleep Behavior Disorder.

BACKGROUND: There is only partial overlap in the genetic background of isolated rapid-eye-movement sleep behavior disorder (iRBD) and Parkinson's disease (PD). OBJECTIVE: To examine the role of autosomal dominant and recessive PD or atypical parkinsonism genes in the risk of iRBD. METHODS: Ten genes, comprising the recessive genes PRKN, DJ-1 (PARK7), PINK1, VPS13C, ATP13A2, FBXO7, and PLA2G6 and the dominant genes LRRK2, GCH1, and VPS35, were fully sequenced in 1039 iRBD patients and 1852 controls of European ancestry, followed by association tests. RESULTS: We found no association between rare heterozygous variants in the tested genes and risk of iRBD. Several homozygous and compound heterozygous carriers were identified, yet there was no overrepresentation in iRBD patients versus controls. CONCLUSION: Our results do not support a major role for variants in these genes in the risk of iRBD. © 2020 International Parkinson and Movement Disorder Society.

Awakening to sleep disorders in Europe: Survey on education, knowledge and treatment competence of European residents and neurologists.

OBJECTIVES: Sleep-wake disorders are common in the general population and in most neurological disorders but are often poorly recognized. With the hypothesis that neurologists do not get sufficient training during their residency, the Young European Sleep Neurologist Association (YESNA) of the European Academy of Neurology (EAN) performed a survey on postgraduate sleep education. METHODS: A 16-item questionnaire was developed and distributed among neurologists and residents across European countries. Questions assessed demographic, training and learning preferences in sleep disorders, as well as a self-evaluation of knowledge based on five basic multiple-choice questions (MCQs) on sleep-wake disorders. RESULTS: The questionnaire was completed by 568 participants from 20 European countries. The mean age of participants was 31.9 years (SD 7.4 years) and was composed mostly of residents (73%). Three-quarters of the participants reported undergraduate training in sleep medicine, while fewer than 60% did not receive any training on sleep disorders during their residencies. Almost half of the participants (45%) did not feel prepared to treat neurological patients with sleep problems. Only one-third of the participants correctly answered at least three MCQs. Notably, 80% of participants favoured more education on sleep-wake disorders during the neurology residency. CONCLUSIONS: Education and knowledge on disorders in European neurological residents is generally insufficient, despite a strong interest in the topic. The results of our study may be useful for improving the European neurology curriculum and other postgraduate educational programmes.

Clinical trials in REM sleep behavioural disorder: challenges and opportunities.

The rapid eye movement sleep behavioural disorder (RBD) population is an ideal study population for testing disease-modifying treatments for synucleinopathies, since RBD represents an early prodromal stage of synucleinopathy when neuropathology may be more responsive to treatment. While clonazepam and melatonin are most commonly used as symptomatic treatments for RBD, clinical trials of symptomatic treatments are also needed to identify evidence-based treatments. A comprehensive framework for both disease-modifying and symptomatic treatment trials in RBD is described, including potential treatments in the pipeline, cost-effective participant recruitment and selection, study design, outcomes and dissemination of results. For disease-modifying treatment clinical trials, the recommended primary outcome is phenoconversion to an overt synucleinopathy, and stratification features should be used to select a study population at high risk of phenoconversion, to enable more rapid clinical trials. For symptomatic treatment clinical trials, objective polysomnogram-based measurement of RBD-related movements and vocalisations should be the primary outcome measure, rather than subjective scales or diaries. Mobile technology to enable objective measurement of RBD episodes in the ambulatory setting, and advances in imaging, biofluid, tissue, and neurophysiological biomarkers of synucleinopathies, will enable more efficient clinical trials but are still in development. Increasing awareness of RBD among the general public and medical community coupled with timely diagnosis of these diseases will facilitate progress in the development of therapeutics for RBD and associated neurodegenerative disorders.

Risk and predictors of dementia and parkinsonism in idiopathic REM sleep behaviour disorder: a multicentre study.

Idiopathic REM sleep behaviour disorder (iRBD) is a powerful early sign of Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. This provides an unprecedented opportunity to directly observe prodromal neurodegenerative states, and potentially intervene with neuroprotective therapy. For future neuroprotective trials, it is essential to accurately estimate phenoconversion rate and identify potential predictors of phenoconversion. This study assessed the neurodegenerative disease risk and predictors of neurodegeneration in a large multicentre cohort of iRBD. We combined prospective follow-up data from 24 centres of the International RBD Study Group. At baseline, patients with polysomnographically-confirmed iRBD without parkinsonism or dementia underwent sleep, motor, cognitive, autonomic and special sensory testing. Patients were then prospectively followed, during which risk of dementia and parkinsonsim were assessed. The risk of dementia and parkinsonism was estimated with Kaplan-Meier analysis. Predictors of phenoconversion were assessed with Cox proportional hazards analysis, adjusting for age, sex, and centre. Sample size estimates for disease-modifying trials were calculated using a time-to-event analysis. Overall, 1280 patients were recruited. The average age was 66.3 ± 8.4 and 82.5% were male. Average follow-up was 4.6 years (range = 1-19 years). The overall conversion rate from iRBD to an overt neurodegenerative syndrome was 6.3% per year, with 73.5% converting after 12-year follow-up. The rate of phenoconversion was significantly increased with abnormal quantitative motor testing [hazard ratio (HR) = 3.16], objective motor examination (HR = 3.03), olfactory deficit (HR = 2.62), mild cognitive impairment (HR = 1.91-2.37), erectile dysfunction (HR = 2.13), motor symptoms (HR = 2.11), an abnormal DAT scan (HR = 1.98), colour vision abnormalities (HR = 1.69), constipation (HR = 1.67), REM atonia loss (HR = 1.54), and age (HR = 1.54). There was no significant predictive value of sex, daytime somnolence, insomnia, restless legs syndrome, sleep apnoea, urinary dysfunction, orthostatic symptoms, depression, anxiety, or hyperechogenicity on substantia nigra ultrasound. Among predictive markers, only cognitive variables were different at baseline between those converting to primary dementia versus parkinsonism. Sample size estimates for definitive neuroprotective trials ranged from 142 to 366 patients per arm. This large multicentre study documents the high phenoconversion rate from iRBD to an overt neurodegenerative syndrome. Our findings provide estimates of the relative predictive value of prodromal markers, which can be used to stratify patients for neuroprotective trials.

Sleep Disorders in Wilson's Disease.

PURPOSE OF REVIEW: We aimed to review the sleep disorders described in Wilson's disease (WD), focusing on their mechanisms and treatments. RECENT FINDINGS: REM sleep behavior disorder or sleepiness can be warning signs of future WD. These early symptoms may significantly reduce the time to WD diagnosis. Early anti-copper therapies (chelators or zinc salts), reducing copper accumulation in the brain and though saving brain tissue, can allow the complete disappearance of these sleep disorders and of course improve the other symptoms of WD. Insomnia, restless legs syndrome (RLS), daytime sleepiness, cataplexy, and REM sleep behavior disorder (RBD) are present in WD and should be explored with video polysomnography and multiple sleep latency test. Suggested immobilization test could be useful in the diagnosis of RLS in WD. Motor and non-motor symptoms, dysautonomic dysfunctions, drugs, and lesions of the circuits regulating wake and sleep may be involved in the mechanisms of these sleep abnormalities. Adapted treatments should be proposed.

Full sequencing and haplotype analysis of MAPT in Parkinson's disease and rapid eye movement sleep behavior disorder.

BACKGROUND: MAPT haplotypes are associated with PD, but their association with rapid eye movement sleep behavior disorder is unclear. OBJECTIVE: To study the role of MAPT variants in rapid eye movement sleep behavior disorder. METHODS: Two cohorts were included: (A) PD (n = 600), rapid eye movement sleep behavior disorder (n = 613) patients, and controls (n = 981); (B) dementia with Lewy bodies patients with rapid eye movement sleep behavior disorder (n = 271) and controls (n = 950). MAPT-associated variants and the entire coding sequence of MAPT were analyzed. Age-, sex-, and ethnicity-adjusted analyses were performed to examine the association between MAPT, PD, and rapid eye movement sleep behavior disorder. RESULTS: MAPT-H2 variants were associated with PD (odds ratios: 0.62-0.65; P = 0.010-0.019), but not with rapid eye movement sleep behavior disorder. In PD, the H1 haplotype odds ratio was 1.60 (95% confidence interval: 1.12-2.28; P = 0.009), and the H2 odds ratio was 0.68 (95% confidence interval: 0.48-0.96; P = 0.03). The H2/H1 haplotypes were not associated with rapid eye movement sleep behavior disorder. CONCLUSIONS: Our results confirm the protective effect of the MAPT-H2 haplotype in PD, and define its components. Furthermore, our results suggest that MAPT does not play a major role in rapid eye movement sleep behavior disorder, emphasizing different genetic background than in PD in this locus. © 2018 International Parkinson and Movement Disorder Society.

C9orf72 repeat expansions in rapid eye movement sleep behaviour disorder.

BACKGROUND: A large hexanucleotide repeat expansion in C9orf72 has been identified as the most common genetic cause in familial amyotrophic lateral sclerosis and frontotemporal dementia. Rapid Eye Movement Sleep Behavior Disorder (RBD) is a sleep disorder that has been strongly linked to synuclein-mediated neurodegeneration. The aim of this study was to evaluate the role of the C9orf72 expansions in the pathogenesis of RBD. METHODS: We amplified the C9orf72 repeat expansion in 344 patients with RBD by a repeat-primed polymerase chain reaction assay. RESULTS: We identified two RBD patients carrying the C9orf72 repeat expansion. Most interestingly, these patients have the same C9orf72 associated-risk haplotype identified in 9p21-linked amyotrophic lateral sclerosis and frontotemporal dementia families. CONCLUSIONS: Our study enlarges the phenotypic spectrum associated with the C9orf72 hexanucleotide repeat expansions and suggests that, although rare, this expansion may play a role in the pathogenesis of RBD.

Sleep and sleep disorders in people with Parkinson's disease.

Sleep disorders are common in people with Parkinson's disease. These disorders, which increase in frequency throughout the course of the neurodegenerative disease and impair quality of life, include insomnia, excessive daytime sleepiness, circadian disorders, obstructive sleep apnoea, restless legs syndrome, and rapid eye movement (REM) sleep behaviour disorder. The causes of these sleep disorders are complex and multifactorial, including the degeneration of the neural structures that modulate sleep, the detrimental effect of some medications on sleep, the parkinsonian symptoms that interfere with mobility and comfort in bed, and comorbidities that disrupt sleep quality and quantity. The clinical evaluation of sleep disorders include both subjective (eg, questionnaires or diaries) and objective (eg, actigraphy or video polysomnography) assessments. The management of patients with Parkinson's disease and a sleep disorder is challenging and should be individualised. Treatment can include education aiming at changes in behaviour (ie, sleep hygiene), cognitive behavioural therapy, continuous dopaminergic stimulation at night, and specific medications. REM sleep behaviour disorder can occur several years before the onset of parkinsonism, suggesting that the implementation of trials of neuroprotective therapies should focus on people with this sleep disorder.

More sleep, more milk.

Breastfeeding is the best feeding method for infants, but this task is particularly challenging for mothers. Sleep time and quality are undeniably reduced in the postpartum period. No study has demonstrated the relationship between slow-wave sleep and lactation. Here, we discuss a unique experimental case during which the mother self-reported her sleep with a SUUNTO 9 watch and quantified her milk volume, blind to sleep parameters. This case report highlights an interesting strong correlation between stage N3 (slow-wave) sleep duration and milk production. It also demonstrates that this production is linked positively to self-reported sleepiness in the morning and breast tension and negatively to the number of awakenings. These results emphasize the need for preserving sleep, especially N3 sleep, during breastfeeding. Splitting nighttime infant care between parents, preserving the mother's sleep as much as possible during the first part of the night, could help improve lactation. CITATION: Aerts C, Janaqi S, Cochen de Cock V. More sleep, more milk. J Clin Sleep Med. 2023;19(8):1563-1565.

Coordination Rigidity in the Gait, Posture, and Speech of Persons with Parkinson's Disease.

Parkinson's disease (PD) is associated with reduced coordination abilities. These can result either in random or rigid patterns of movement. The latter, described here as coordination rigidity (CR), have been studied less often. We explored whether CR was present in gait, quiet stance, and speech-tasks involving coordination among multiple joints and muscles. Kinematic and voice recordings were used to compute measures describing the dynamics of systems with multiple degrees of freedom and nonlinear interactions. After clinical evaluation, patients with moderate stage PD were compared against matched healthy participants. In the PD group, gait dynamics was associated with decreased dynamic divergence-lower instability-in the vertical axis. Postural fluctuations were associated with increased regularity in the anterior-posterior axis, and voice dynamics with increased predictability, all consistent with CR. The clinical relevance of CR was confirmed by showing that some of those features contribute to disease classification with supervised machine learning (82/81/85% accuracy/sensitivity/specificity).

Partial endorsement of: "Video-polysomnography procedures for diagnosis of rapid eye movement sleep behavior disorder (RBD) and the identification of its prodromal stages: Guidelines from the International RBD Study Group" by the World Sleep Society.

Updated guidelines for the video-polysomnography (vPSG) procedures for diagnosing rapid eye movement sleep behavior disorder (RBD) and the identification of its prodromal stages have recently been proposed by the Neurophysiology Working Group of the International RBD Study Group (IRBDSG). These guidelines were selected for review by a World Sleep Society (WSS) Parasomnias Task Force and the WSS International Sleep Medicine Guidelines Committee. A survey was completed by sleep society leaders and prominent sleep clinicians and researchers in 31 WSS member countries across six continents, focused on sleep technologist training and certification; extent of public/private health insurance coverage for the vPSG evaluation of RBD; extent of hospital-based sleep-technologist-attended overnight vPSG studies; availability of video during PSG studies; and sufficient specification of PSG machines to record and analyze REM sleep without atonia. The findings from this survey indicated that most health systems and medical communities across WSS member countries would not be capable of implementing the proposed more stringent guidelines, which would then strongly interfere with the diagnosis of RBD in a large portion of patients who would not be able to receive the required (often repeated) vPSG evaluation. Therefore, the WSS can only partially endorse the updated guidelines and concludes that the current International Classification of Sleep Disorders-3rd edition diagnostic criteria for RBD should still be retained as the standard reference for the diagnosis of RBD, and that further discussion across all members of the IRBDSG should take place to ensure the feasibility of any future proposed changes.

Night-Time Apomorphine Infusion: Who Are the Best Candidates?

Background: We recently demonstrated in a randomized controlled trial (APOMORPHEE, NCT02940912) that night-time only subcutaneous apomorphine infusion improves sleep disturbances and insomnia in patients with advanced Parkinson's disease and moderate to severe insomnia. Objectives: To identify the best candidates for receiving night-time only subcutaneous apomorphine infusion in routine care. Methods: In this post-hoc analysis of APOMORPHEE, we compared the characteristics of patients according to whether they chose to continue night-time only subcutaneous apomorphine infusion at the end of the study period or not. Results: Half of the patients (22/42) chose to continue the treatment. Off duration (day or night), painful Off dystonia, and insomnia severity at baseline were associated with night-time only apomorphine continuation. Multivariate analysis retained only Off duration as an independent predictor of continuation. Conclusions: The best candidates for night-time only apomorphine are patients with severe and prolonged Off periods (day or night) and severe insomnia.

HLA in isolated REM sleep behavior disorder and Lewy body dementia.

Synucleinopathies-related disorders such as Lewy body dementia (LBD) and isolated/idiopathic REM sleep behavior disorder (iRBD) have been associated with neuroinflammation. In this study, we examined whether the human leukocyte antigen (HLA) locus plays a role in iRBD and LBD. In iRBD, HLA-DRB1*11:01 was the only allele passing FDR correction (OR = 1.57, 95% CI = 1.27-1.93, p = 2.70e-05). We also discovered associations between iRBD and HLA-DRB1 70D (OR = 1.26, 95%CI = 1.12-1.41, p = 8.76e-05), 70Q (OR = 0.81, 95%CI = 0.72-0.91, p = 3.65e-04) and 71R (OR = 1.21, 95%CI = 1.08-1.35, p = 1.35e-03). Position 71 (pomnibus = 0.00102) and 70 (pomnibus = 0.00125) were associated with iRBD. Our results suggest that the HLA locus may have different roles across synucleinopathies.