Rapid eye movement sleep behaviour disorder: demographic, clinical and laboratory findings in 93 cases

Predictors of rapid eye movement sleep behavior disorder in patients with Parkinson’s disease based on random forest and decision tree

Background and objectives

Sleep disorders related to Parkinson’s disease (PD) have recently attracted increasing attention, but there are few clinical reports on the correlation of Parkinson’s disease patients with rapid eye movement (REM) sleep behavior disorder (RBD). Therefore, this study conducted a cognitive function examination for Parkinson’s disease patients and discussed the application effect of three algorithms in the screening of influencing factors and risk prediction effects.

Methods

Three algorithms (logistic regression, machine learning-based regression trees and random forest) were used to establish a prediction model for PD-RBD patients, and the application effects of the three algorithms in the screening of influencing factors and the risk prediction of PD-RBD were discussed.

Results

The subjects included 169 patients with Parkinson’s disease (Parkinson’s disease with RBD [PD-RBD] = 69 subjects; Parkinson’s disease without RBD [PD-nRBD] = 100 subjects). This study compared the predictive performance of RF, decision tree and logistic regression, selected a final model with the best model performance and proposed the importance of variables in the final model. After the analysis, the accuracy of RF (83.05%) was better than that of the other models (decision tree = 75.10%, logistic regression = 71.62%). PQSI, Scopa-AUT score, MoCA score, MMSE score, AGE, LEDD, PD-course, UPDRS total score, ESS score, NMSQ, disease type, RLSRS, HAMD, UPDRS III and PDOnsetage are the main variables for predicting RBD, along with increased weight. Among them, PQSI is the most important factor. The prediction model of Parkinson’s disease RBD that was established in this study will help in screening out predictive factors and in providing a reference for the prognosis and preventive treatment of PD-RBD patients.

Conclusions

The random forest model had good performance in the prediction and evaluation of PD-RBD influencing factors and was superior to decision tree and traditional logistic regression models in many aspects, which can provide a reference for the prognosis and preventive treatment of PD-RBD patients.

Current Therapies and Drug Development Pipeline in Lewy Body Dementia: An Update

The term Lewy body dementia refers to either of two related diagnoses: dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD). Clinical management of Lewy body dementia is challenging. The current treatment options focus on relieving symptoms; no disease-modifying therapies are available. There are currently no US Food and Drug Administration (FDA) approved drugs for the treatment of DLB, and there are only a few for PDD. Cholinesterase inhibitors are shown to be beneficial in improving cognitive symptoms in Lewy body dementia. Rivastigmine was approved by the FDA to treat PDD. Donepezil was approved in Japan as a treatment for DLB. Levodopa may provide modest benefit in treating motor symptoms and zonisamide in adjunct to low-dose levodopa helps with parkinsonism. Treatment of autonomic symptoms are based on symptomatic treatment with off-label agents. Our main objective in this article is to present an overview of the current pharmacological options available to treat the clinical features of DLB and PDD. When evaluating the existing management options for Lewy body dementia, it is difficult to fully separate PDD from DLB. However, we have attempted to identify whether the cited studies include patients with PDD and/or DLB. Moreover, we have provided an overview of the current drug pipeline in Lewy body dementia. All currently active trials are in phase I or II and most are focused on disease modification rather than symptomatic treatment. Phase II trial results for neflamapimod show promising results. Due to heterogeneity of symptoms and underlying pathophysiology, there is a need for new biomarker strategies and improved definitions of outcome measures for Lewy body dementia drug trials.

Relevance of sleep and associated structural changes in GBA1 mouse to human rapid eye movement behavior disorder

Rapid eye movement (REM) sleep behaviour disorder (RBD) is a REM parasomnia that often predicts the later occurrence of alpha-synucleinopathies. Variants in the gene encoding for the lysosomal enzyme glucocerebrosidase, GBA, strongly increase the risk of RBD. In a GBA1-mouse model recently shown to mimic prodromal stages of α-synucleinopathy, we now demonstrate striking REM and NREM electroencephalographic sleep abnormalities accompanied by distinct structural changes in the more widespread sleep neurocircuitry.

To the Gut Microbiome and Beyond: The Brain-First or Body-First Hypothesis in Parkinson's Disease

There is continued debate regarding Parkinson’s disease etiology and whether it originates in the brain or begins in the gut. Recently, evidence has been provided for both, with Parkinson’s disease onset presenting as either a “body-first” or “brain-first” progression. Most research indicates those with Parkinson’s disease have an altered gut microbiome compared to controls. However, some studies do not report gut microbiome differences, potentially due to the brain or body-first progression type. Based on the etiology of each proposed progression, individuals with the body-first progression may exhibit altered gut microbiomes, i.e., where short-chain fatty acid producing bacteria are reduced, while the brain-first progression may not. Future microbiome research should consider this hypothesis and investigate whether gut microbiome differences exist between each type of progression. This may further elucidate the impact of the gut microbiome in Parkinson’s disease and show how it may not be homogenous across individuals with Parkinson’s disease.

Magnetic Resonance Parkinsonism Index Is Associated with REM Sleep Behavior Disorder in Parkinson’s Disease

We investigated the association between the Magnetic Resonance Parkinsonism Index (MRPI) and REM sleep behavior disorder (RBD). We included 226 de novo PD patients (82 PD-RBD and 144 PD-noRBD) and 19 idiopathic RBD patients. Furthermore, 3T T1-weighted MR images were used for automated brainstem calculations. MRPI values were higher in the PD-RBD (p = 0.004) compared to PD-noRBD patients. Moreover, MRPI proved to be a significant predictor of REM Behavior Disorder Screening Questionnaire scores in PD (β = 0.195, p = 0.007) and iRBD patients (β = 0.582, p = 0.003). MRPI can be used as an imaging marker of RBD in patients with de novo PD and iRBD.

Emotional and Environmental Factors Aggravating Dream Enactment Behaviors in Patients with Isolated REM Sleep Behavior Disorder

OBJECTIVE

To identify emotional and environmental factors that aggravate dream enactment behaviors (DEBs) in isolated rapid eye movement (REM) sleep behavior disorder (iRBD).

METHODS

In this cross-sectional study, a total of 96 polysomnography-confirmed iRBD patients (mean age, 68.5 years; men, 68%) and their caregivers completed questionnaires regarding potential aggravating factors related to DEBs, including emotion/feelings (stress, anger, anxiety, depressive mood, fatigue, pain), food (alcohol, caffeine, overeating in the evening, fasting/hunger), activities and sleep patterns (strenuous exercise, sex before bed, conflict/fighting, sleep deprivation, oversleeping, sleeping away from home, watching TV before bed), weather/environmental factors (cloudy or rainy weather, heat, cold, noise) and medication (skipping medication, taking hypnotics).

RESULTS

The patients reported that stress (61%) was the most aggravating factor for DEBs, followed by anxiety (56%), anger (51%), fatigue (49%), and watching TV before bed (46%). Similarly, the caregivers reported that these factors were most relevant to the aggravation of DEBs in the patients, although some factors were ranked differently. In the subgroup analyses, aggravating factors for DEBs did not differ by RBD symptom severity. Interestingly, the proportion of patients experiencing DEB aggravation by stress, anxiety and depressive mood was significantly higher in women than in men. Furthermore, depressed patients reported that stress and cloudy or rainy weather made DEBs worse than nondepressed patients.

CONCLUSION

Our results suggest that DEBs in iRBD patients may be mainly aggravated by emotional factors. These negative effects appeared to be more prominent in female and depressed patients.

Is There a Place for Medicinal Cannabis in Treating Patients with Sleep Disorders? What We Know so Far

The legalization of cannabis for medicinal, and in some countries, recreational, purposes in addition to growth in the cannabis industry has meant that cannabis use and interest in the area has increased rapidly over the past 20 years. Treatment of poor sleep and sleep disorders are two of the most common reasons for the current use of medicinal cannabis. However, evidence for the role of medical cannabis in the treatment of sleep disorders has not been clearly established, thus making it challenging for clinicians to make evidence-based decisions regarding efficacy and safety. This narrative review summarizes the highest quality clinical evidence currently available in relation to the use of medicinal cannabis for the treatment of sleep disorders including insomnia, obstructive sleep apnea, restless legs syndrome, rapid eye movement sleep behavior disorder, nightmare disorder and narcolepsy. A summary of the effect of cannabis on sleep quality and architecture is also presented. Currently, there is insufficient evidence to support the routine use of medicinal cannabis as an effective and safe treatment option for any sleep disorder. Nevertheless, emerging evidence is promising and warrants further investigation using standardized cannabinoid products and validated quantitative measurement techniques.

Efficacy and safety of treatments for REM sleep behaviour disorder in Parkinson's disease: a systematic review and Bayesian network meta-analysis protocol

INTRODUCTION

Sleep disorders are the main non-motor characteristics of Parkinson's disease (PD). The quality of life is significantly impacted by rapid eye movement sleep behaviour disorder (RBD). It is not clearly evidenced in the literature that some medications can reduce the dream activities of patients with PD and RBD and improve sleep quality. And, they have side effects that may increase the severity of this disease. To further understand which medication has better efficacy and fewer adverse effects for patients with PD and RBD, it is necessary to perform a network meta-analysis.

METHODS AND ANALYSIS

This protocol is performed accordingly to the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols and the Cochrane Collaboration Handbook.A thorough literature selection will be conducted up to September 2021 using PubMed, Cochrane Library (The Cochrane Database of Systematic Reviews) and Embase. We will not only include randomised controlled trials, but prospective, retrospective cohort, case-control, nested case-control, case-cohort, cross-sectional and case series. We will use the Cochrane Collaboration tool to assess the risk of bias. Pairwise and network meta-analyses will be conducted using the R netmeta package and Stata V.14.0. The relative ranking probability of the best intervention will be estimated using the surface under the cumulative ranking curve. Additionally, sensitivity analysis, subgroup analysis, quality assessment and publication bias analysis will be performed.

ETHICS AND DISSEMINATION

No research ethics approval is required for this systematic review, as no confidential patient data will be used. We will disseminate our findings through publication in a peer-reviewed journal and conference presentations, and our review will support development of a BMJ Rapid Recommendations providing contextualised clinical guidance based on this body of evidence.

PROSPERO REGISTRATION NUMBER

CRD42020206958.

Can Corticomuscular Coherence Differentiate between REM Sleep Behavior Disorder with or without Parkinsonism?

REM sleep behavior disorder (RBD) could be a predictor of Parkinsonism even before development of typical motor symptoms. This study aims to characterize clinical features and corticomuscular and corticocortical coherence (CMC and CCC, respectively) during sleep in RBD patients with or without Parkinsonism. We enrolled a total of 105 subjects, including 20 controls, 54 iRBD, and 31 RBD+P patients, patients who were diagnosed as idiopathic RBD (iRBD) and RBD with Parkinsonism (RBD+P) in our neurology department. We analyzed muscle atonia index (MAI) and CMC between EEG and chin/limb muscle electromyography (EMG) and CCC during different sleep stages. Although differences in the CMC of iRBD group were observed only during REM sleep, MAI differences between groups were noted during both REM and NREM N2 stage sleep. During REM sleep, CMC was higher and MAI was reduced in iRBD patients compared to controls (p = 0.001, p < 0.001, respectively). Interestingly, MAI was more reduced in RBD+P compared to iRBD patients. In comparison, CCC was higher in iRBD patients compared to controls whereas CCC was lower in RBD+P groups compared to control and iRBD groups in various frequency bands during both NREM N2 and REM sleep stages. Among them, increased CMC during REM sleep revealed correlation between clinical severities of RBD symptoms. Our findings indicate that MAI, CMC, and CCC showed distinctive features in iRBD and RBD+P patients compared to controls, suggesting potential usefulness to understand possible links between these diseases.

Current Treatment Options for REM Sleep Behaviour Disorder

The symptomatic treatment of REM sleep behaviour disorder (RBD) is very important to prevent sleep-related falls and/or injuries. Though clonazepam and melatonin are usually considered the first-line symptomatic therapy for RBD, their efficiency has not been proven by randomized clinical trials. The role of dopamine agonists in improving RBD symptoms is controversial, and rivastigmine, memantine, 5-hydroxytryptophan, and the herbal medicine yokukansan have shown some degree of efficacy in short- and medium-term randomized clinical trials involving a low number of patients. The development of potential preventive therapies against the phenoconversion of isolated RBD to synucleinopathies should be another important aim of RBD therapy. The design of long-term, multicentre, randomized, placebo-controlled clinical trials involving a large number of patients diagnosed with isolated RBD with polysomnographic confirmation, directed towards both symptomatic and preventive therapy for RBD, is warranted.

Sleep Disturbances and Phenoconversion in Patients with REM Sleep Behavior Disorder

Objective: We aimed to investigate relationships between sleep disturbances and phenoconversion to neurodegenerative diseases in patients with REM sleep behavior disorder (RBD). Method: Using a comprehensive sleep database in a university-affiliated hospital between December 2014 and March 2021, we reviewed the data of 226 patients with RBD (182 patients with idiopathic RBD (iRBD) and 44 patients with symptomatic RBD (sRBD) with a neurodegenerative disease). Results: Among 226 patients with RBD (male, 61.5%), the mean age at RBD onset and mean disease duration were 59.4 ± 10.5 and 5.9 ± 5.6 years, respectively. Further, 111 (49.1%) patients had periodic limb movements during sleep (PLMS, PLM index ≥ 15/h), while 110 patients (48.7%) had comorbid obstructive sleep apnea (OSA, respiratory disturbance index ≥ 15/h). There was a positive correlation between age at RBD onset and the apnea-hypopnea index and Pittsburgh Sleep Quality Index. Compared to patients with iRBD, patients with sRBD showed a lower N3 sleep (3.3 ± 5.0 vs. 1.6 ± 3.1%, p = 0.004) and higher periodic limb movement index (36.3 ± 31.8 vs. 56.9 ± 47.5/h, p = 0.021) at the baseline. Among the 186 patients with iRBD, 18 (8.0%) developed neurodegenerative diseases (converters, mean follow-up duration: 2.5 ± 1.6 years) and 164 did not (non-converters, mean follow-up 2.4 ± 2.2 years). There was no significant between-group difference in the demographics and baseline clinical features. Continuous positive airway pressure (CPAP) therapy was prescribed in 101 patients with OSA; among them, 71 (70%) patients agreed to use it. CPAP improved dream enactment behaviors. Conclusion: In our study, 8.0% of patients with iRBD showed phenoconversion within a mean follow-up duration of 2.5 years. Polysomnographic parameters could not predict phenoconversion to neurodegenerative disease. However, approximately half of the patients with RBD presented with significant sleep disorders, including OSA or PLMS. CPAP therapy may alleviate RBD symptoms in patients with RBD-OSA.

Sleep Disorders and Aging in Women

What are the effects of sleep disturbance and changes of sleep on aging women in the short and long term? Most research that has been done in recent years evaluates how sleep disorders and sleep disturbance may change mortality and outcomes of this population. Many confounding factors may be playing a role, including comorbid conditions. This article reviews sleep disorders including insomnia, circadian sleep-wake rhythm disorders, restless legs syndrome, disorders of hypersomnia, and sleep-disordered breathing in women aged 65 and older; prevalence of these disorders; and recommended treatment options.

Pharmacological Interventions for REM Sleep Behavior Disorder in Parkinson's Disease: A Systematic Review

To review the therapeutic effects of drugs on REM sleep behavior disorder (RBD) in Parkinson's disease (PD) by searching the MEDLINE/PubMed, Embase, Cochrane, and CBM databases. According to the inclusion and exclusion criteria, studies were included after excluding duplicate data. We evaluated the safety and efficacy of pharmacological intervention to improve RBD in patients with Parkinson's disease (PD-RBD). This systematic review mainly describes the drugs that can be used to treat PD-RBD patients. The results have shown that melatonin can be used as the first-line drug for PD-RBD, and clonazepam provides significant improvement on PD-RBD, androtigotine can be used as an alternative drug. However, further large-scale clinical trial studies are still needed to provide the best guidelines for the pharmacological treatment of PD-RBD.

Neurochemical Features of Rem Sleep Behaviour Disorder

Dopaminergic deficiency, shown by many studies using functional neuroimaging with Single Photon Emission Computerized Tomography (SPECT) and Positron Emission Tomography (PET), is the most consistent neurochemical feature of rapid eye movement (REM) sleep behaviour disorder (RBD) and, together with transcranial ultrasonography, and determination of alpha-synuclein in certain tissues, should be considered as a reliable marker for the phenoconversion of idiopathic RBD (iRBD) to a synucleopathy (Parkinson’s disease –PD- or Lewy body dementia -LBD). The possible role in the pathogenesis of RBD of other neurotransmitters such as noradrenaline, acetylcholine, and excitatory and inhibitory neurotransmitters; hormones such as melatonin, and proinflammatory factors have also been suggested by recent reports. In general, brain perfusion and brain glucose metabolism studies have shown patterns resembling partially those of PD and LBD. Finally, the results of structural and functional MRI suggest the presence of structural changes in deep gray matter nuclei, cortical gray matter atrophy, and alterations in the functional connectivity within the basal ganglia, the cortico-striatal, and the cortico-cortical networks, but they should be considered as preliminary.

Periodic limb movements in patients with obstructive sleep apnea syndrome

The aim of the study was to assess the factors associated with periodic limb movements during sleep (PLMS) among obstructive sleep apnea syndrome (OSAS) patients and identify the role of PLMS in patients with OSAS. 303 adult patients with OSAS were included in the study. All patients completed physical examination, Epworth sleepiness scale (ESS), and polysomnography. Diagnosis of PLMS was made if the periodic leg movements index (PLMI) was ≥ 15. Chi-square test, ANOVA, univariate and multivariate logistic regression analyses were conducted to identify factors associated with PLMS among OSAS patients. Statistical analyses were performed with SPSS 26.0 for mac. Statistically significant difference was considered if P value < 0 .05. Among the 303 adult patients with OSAS, 98 patients had significant PLMS and the other 205 had no significant PLMS. Compared with OSAS patients without PLMS, OSAS patient with PLMS were older, had shorter REM duration and greater apnea–hypopnea index (AHI) (P < 0.05). The study suggests that PLMS is a matter of concern among patients with OSAS. A better understanding of the role of PLMS among OSAS patients could be useful in better recognition, intervention and treatment of OSAS.

The Neurophysiology of Sleep in Parkinson's Disease

Sleep disturbances are among the most common nonmotor complications of Parkinson's disease (PD), can present in prodromal stages, and progress with advancing disease. In addition to being a symptom of neurodegeneration, sleep disturbances may also contribute to disease progression. Currently, limited options exist to modulate sleep disturbances in PD. Studying the neurophysiological changes that affect sleep in PD at the cortical and subcortical level may yield new insights into mechanisms for reversal of sleep disruption. In this article, we review cortical and subcortical recording studies of sleep in PD with a particular focus on dissecting reported electrophysiological changes. These studies show that slow-wave sleep and rapid eye movement sleep are both notably disrupted in PD. We further explore the impact of these electrophysiological changes and discuss the potential for targeting sleep via stimulation therapy to modify PD-related motor and nonmotor symptoms. © 2021 International Parkinson and Movement Disorder Society.

Sleep in Older Adults and Its Possible Relations With COVID-19

Since the beginning of the COVID-19 pandemic, older adults have been found to be a highly vulnerable group, with a higher prevalence of severe cases and negative outcomes. Research has focused on the reasons why older adults are at greater risk; Sleep-related factors have been suggested as one possible explanation for this. An individual's sleep pattern undergoes significant changes over the course of their life. In older adults a specific sleep profile can be observed, one characterized by advanced sleep timing, a morningness preference, longer sleep-onset latency, shorter overall sleep duration, increased sleep fragmentation, reduced slow-wave sleep and, increased wake time after sleep onset. Additionally, an increased prevalence of sleep disorders can be observed, such as obstructive sleep apnea and insomnia. Previous research has already linked sleep disorders (especially sleep apnea) with COVID-19, but few studies have focused specifically on the older population. We believe that the intrinsic sleep patterns of older adults, and the prevalence of sleep disorders in this population, may be important factors that could explain why they are at a greater risk of negative COVID-19 outcomes. In this review, we discuss the relationship between sleep and COVID-19 among older adults, focusing on three different aspects: (1) Sleep-related issues that might increase the likelihood of getting infected by SARS-COV-2; (2) Sleep disturbances that might increase the predisposition to worse COVID-19 prognosis and outcomes; and (3) COVID-19-related aspects affecting community-dwelling older adults, such as social isolation, quarantine, and home confinement, among others, that might impact sleep.

Rapid Eye Movement Behavior Disorder and Other Parasomnias

Rapid eye movement (REM) behavior disorder (RBD) is characterized by loss of skeletal muscle atonia that can lead to dream enactment. This condition can cause harm to patients and their bed partners if appropriate safety measures are not ensured. This condition is often the initial presenting symptom in a group of complex neurodegenerative processes. Definitive diagnosis requires a thorough history and an in-laboratory polysomnogram to look for evidence of REM sleep without atonia. Treatment options are limited but consist of sleep safety measures and pharmacotherapy. Patients diagnosed with idiopathic RBD associated with alpha-synucleinopathy are likely to have progression of disease.

Is REM sleep behavior disorder a friend or foe of obstructive sleep apnea? Clinical and etiological implications for neurodegeneration

NONE

Rapid eye movement sleep behavior disorder (RBD) is a parasomnia characterized by loss of muscle atonia during rapid eye movement sleep, associated with complex motor enactment of dreams. Obstructive sleep apnea (OSA) is a relatively common sleep disorder characterized by repetitive episodes of upper airway obstruction while sleeping, which can result in hypoxemia and sleep fragmentation. Even though the nature of RBD and OSA is different, OSA may sometimes be accompanied by RBD symptoms. Accordingly, it is reasonable to distinguish these 2 sleep disorders in people with dream enactment behaviors. Although RBD and OSA share similar sleep phenomena, their association has yet to be elucidated. Herein we draw attention to various RBD-mimicking conditions, RBD combined with OSA, and the relationship between RBD and OSA. Furthermore, the clinical implications of OSA in neurodegeneration and the optimized management of RBD combined with OSA are also discussed in this review.

Parkinson Disease-Related Brain Metabolic Patterns and Neurodegeneration in Isolated REM Sleep Behavior Disorder

OBJECTIVE

To elucidate the role of Parkinson disease (PD)-related brain metabolic patterns as a biomarker in isolated REM sleep behavior disorder (iRBD) for future disease conversion.

METHODS

This is a prospective cohort study consisting of 30 patients with iRBD, 25 patients with de novo PD with a premorbid history of RBD, 21 patients with longstanding PD on stable treatment, and 24 healthy controls. The iRBD group was longitudinally followed up. All participants underwent ¹⁸F-fluorodeoxyglucose (FDG) PET and were evaluated with olfaction, cognition, and the Movement Disorders Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) at baseline. From FDG-PET scans, we derived metabolic patterns from the longstanding PD group (PD-RP) and de novo PD group with RBD (dnPDRBD-RP). Subsequently, we calculated the PD-RP and dnPDRBD-RP scores in patients with iRBD. We validated the metabolic patterns in each PD group and separate iRBD cohort (n = 14).

RESULTS

The 2 patterns significantly correlated with each other and were spatially overlapping yet distinct. The MDS-UPDRS motor scores significantly correlated with PD-RP (p = 0.013) but not with dnPDRBD-RP (p = 0.076). In contrast, dnPDRBD-RP correlated with olfaction in butanol threshold test (p = 0.018) in patients with iRBD, but PD-RP did not (p = 0.21). High dnPDRBD-RP in patients with iRBD predicted future phenoconversion with all cutoff ranges from 1.5 to 3 SD of the control value, whereas predictability of PD-RP was only significant in a partial range of cutoff.

CONCLUSION

The dnPDRBD-RP is an efficient neuroimaging biomarker that reflects prodromal features of PD and predicts phenoconversion in iRBD that can be applied individually.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that a de novo PD pattern on FDG-PET predicts future conversion to neurodegenerative disease in patients with iRBD.

Exploring Nonmotor Neuropsychiatric Manifestations of Parkinson Disease in a Comprehensive Care Setting

Parkinson disease (PD) is a debilitating neurological condition that includes both motor symptoms and nonmotor symptoms (NMS). Psychiatric complaints comprise NMS and are collectively referred to as neuropsychiatric manifestations. Common findings include atypical depressive symptoms, anxiety, psychosis, impulse control disorder, deterioration of cognition, and sleep disturbances. Quality of life (QoL) of patients suffering from NMS is greatly impacted and many times can be more debilitating than motor symptoms of PD. We expand on knowledge gained from treatment models within a comprehensive care model that incorporates multidisciplinary specialists working alongside psychiatrists to treat PD. Insight into background, clinical presentations, and treatment options for patients suffering from neuropsychiatric manifestations of PD are discussed. Identifying symptoms early can help improve QoL, provide early symptom relief, and can assist tailoring treatment plans that limit neuropsychiatric manifestations.

Systematic video-analysis of motor events during REM sleep in idiopathic REM sleep behavior disorder, follow-up and DAT-SPECT

Abnormal motor manifestations in REM sleep are the most visible feature of idiopathic REM sleep behavior disorder (iRBD), which precedes the overt alpha-synucleinopathy. The aim of this study was to perform a systematic visual analysis of the motor events (ME) captured during video-polysomnography, and clarify their relation to the disease severity. Thirty-four iRBD patients (5 women, 29 men; age 67.7 ± 7.2) with a mean follow-up duration 2.9 ± 1.1 years. and 33 controls (10 women, 23 men; age 61.5 ± 8.2) were examined. The ME captured during REM sleep were classified into four categories, previously defined by Frauscher et al. according to clinical severity: minor/simple jerks, major, complex and violent. An average frequency of 110.8 ± 75.2 ME per hour were identified in iRBD, 7.5 ± 11.6 in the controls (p < 0.001). Of these ME, 68.4% were classified as minor/simple jerks, 9.3% as major, 21.7% as complex and 0.7% as violent. The ME frequency was negatively associated with tracer binding on dopamine transporter single-photon emission computed tomography (DAT-SPECT); the association was stronger for caudate nucleus compared to putamen. During follow-up seven patients (24.1%) phenoconverted, yielding a yearly phenoconversion rate 8.3%. Violent ME were associated with increased hazard ratio for phenoconversion in frequency (p = 0.012) and total duration (p = 0.007). Patients with higher amounts of violent ME had a greater risk of phenoconversion; therefore, their role as a predictor should be considered. Additionally, ME were associated with nigrostriatal degeneration, according to DAT-SPECT. These findings indicate that the degree of the clinical severity of motor manifestations in iRBD reflects the severity of the disease.

Effect of TAAR1/5-HT1A agonist SEP-363856 on REM sleep in humans

SEP-363856 is a trace amine-associated receptor 1 (TAAR1) and 5-hydroxytryptamine type 1A (5-HT_1A) agonist, currently in Phase 3 clinical trials for the treatment of schizophrenia. Although SEP-363856 activates TAAR1 and 5-HT_1A receptors in vitro, an accessible marker of time- and concentration-dependent effects of SEP-363856 in humans is lacking. In rodents, SEP-363856 has been shown to suppress rapid eye movement (REM) sleep. The aim of the current study was to translate the REM sleep effects to humans and determine pharmacokinetic/pharmacodynamic (PK/PD) relationships of SEP-363856 on a measure of brain activity. The effects of SEP-363856 were evaluated in a randomized, double-blind, placebo-controlled, 2-way crossover study of single oral doses (50 and 10 mg) on REM sleep in healthy male subjects (N = 12 at each dose level). Drug concentrations were sampled during sleep to interpolate individual subject's pharmacokinetic trajectories. SEP-363856 suppressed REM sleep parameters with very large effect sizes (>3) following single doses of 50 mg and plasma concentrations ≥100 ng/mL. Below that effective concentration, the 10 mg dose elicited much smaller effects, increasing only the latency to REM sleep (effect size = 1). The PK/PD relationships demonstrated that REM sleep probability increased as drug concentrations declined below 100 ng/mL over the course of the night. SEP-363856 was generally safe and well tolerated at both doses. The REM sleep-suppressing effects of SEP-363856 provide an accessible marker of brain activity, which can aid in dose selection and help elucidate its therapeutic potential in further clinical trials.

Continuous Real-World Gait Monitoring in Idiopathic REM Sleep Behavior Disorder

BACKGROUND

Patients with REM sleep behavior disorder (RBD) have a high risk of developing PD, and thus can be used to study prodromal biomarkers. RBD has been associated with changes in gait; quantifying these changes using wearable technology is promising; however, most data are obtained in clinical settings precluding pragmatic application.

OBJECTIVE

We aimed to investigate if wearable-based, real-world gait monitoring can detect early gait changes and discriminate individuals with RBD from controls, and explore relationships between real-world gait and clinical characteristics.

METHODS

63 individuals with RBD (66±10 years) and 34 controls recruited in the Oxford Parkinson's Disease Centre Discovery Study were assessed. Data were collected using a wearable device positioned on the lower back for 7 days. Real-world gait was quantified in terms of its Macrostructure (volume, pattern and variability (S2)) and Microstructure (14 characteristics). The value of Macro and Micro gait in discriminating RBD from controls was explored using ANCOVA and ROC analysis, and correlation analysis was performed between gait and clinical characteristics.

RESULTS

Significant differences were found in discrete Micro characteristics in RBD with reduced gait velocity, variability and rhythm (p≤0.023). These characteristics significantly discriminated RBD (AUC≥0.620), with swing time as the single strongest discriminator (AUC=0.652). Longer walking bouts discriminated best between the groups for Macro and Micro outcomes (p≤0.036).

CONCLUSIONS

Our results suggest that real-world gait monitoring may have utility as "risk" clinical marker in RBD participants. Real-world gait assessment is low-cost and could serve as a pragmatic screening tool to identify gait impairment in RBD.

Age of Diagnosis and Comorbid PLMD Predict Poor Response of REM Behavior Disorder to Clonazepam

Previous studies have shown the therapeutic effects of clonazepam for rapid eye movement sleep behavior disorder (RBD), but they had several limitations such as the lack of clear definition of treatment outcomes and little information about adjuvant therapy. The aims of this study were to evaluate the treatment outcomes with clonazepam and to explore possible determinants of treatment response. We performed a retrospective medical chart review of 171 patients with RBD. All the participants underwent overnight polysomnography and completed questionnaires. The positive treatment response was defined as the absence of disruptive behaviors causing sleep-related injuries during the last year of follow-up. Among the 171 patients presented with disruptive behaviors, 155 (90.6%) experienced positive treatment responses. Of the responders, 18 (11.6%) received adjunctive medication due to insufficient therapeutic effect of clonazepam monotherapy. After adjusted analysis, an earlier age of diagnosis (odds ratio [OR] = 0.74, 95% confidence interval [CI] = 0.64-0.86, P < .001) and comorbid periodic limb movement during sleep (OR = 4.96, 95% CI = 1.05-23.33, P = .043) were related to poor treatment response. Clinicians should recognize the predictors of poor treatment response and consider combination therapy for better prevention of sleep-related injuries in those who show unsatisfactory responses to clonazepam monotherapy.

Current Concepts and Controversies in the Management of REM Sleep Behavior Disorder

Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by dream enactment and the loss of muscle atonia during REM sleep, known as REM sleep without atonia (RSWA). RBD can result in significant injuries, prompting patients to seek medical attention. However, in others, it may present only as non-violent behaviors noted as an incidental finding during polysomnography (PSG). RBD typically occurs in the context of synuclein-based neurodegenerative disorders but can also be seen accompanying brain lesions and be exacerbated by medications, particularly antidepressants. There is also an increasing appreciation regarding isolated or idiopathic RBD (iRBD). Symptomatic treatment of RBD is a priority to prevent injurious complications, with usual choices being melatonin or clonazepam. The discovery that iRBD represents a prodromal stage of incurable synucleinopathies has galvanized the research community into delineating the pathophysiology of RBD and defining biomarkers of neurodegeneration that will facilitate future disease-modifying trials in iRBD. Despite many advances, there has been no progress in available symptomatic or neuroprotective therapies for RBD, with recent negative trials highlighting several challenges that need to be addressed to prepare for definitive therapeutic trials for patients with this disorder. These challenges relate to i) the diagnostic and screening strategies applied to RBD, ii) the limited evidence base for symptomatic therapies, (iii) the existence of possible subtypes of RBD, (iv) the relevance of triggering medications, (v) the absence of objective markers of severity, (vi) the optimal design of disease-modifying trials, and vii) the implications around disclosing the risk of future neurodegeneration in otherwise healthy individuals. Here, we review the current concepts in the therapeutics of RBD as it relates to the above challenges and identify pertinent research questions to be addressed by future work.

Timeline of Rapid Eye Movement Sleep Behavior Disorder in Overt Alpha-Synucleinopathies

OBJECTIVE

The aim was to analyze the timeline, prevalence, and survival of rapid eye movement (REM) sleep behavior disorder (RBD) in patients who developed alpha-synucleinopathies (Parkinson disease, dementia with Lewy bodies, and Parkinson disease dementia) compared with age- and sex-matched controls in a population-based incident-cohort study.

METHODS

We used a population-based, 1991 to 2010 incident-cohort study of alpha-synucleinopathies. A movement-disorder specialist reviewed medical records to confirm diagnoses. RBD was diagnosed by reported dream-enactment symptoms or polysomnography. Probable RBD and polysomnographically confirmed RBD were analyzed separately and combined.

RESULTS

Among the 444 incident cases of alpha-synucleinopathy, 86 were clinically diagnosed with RBD (19.8%), including 30 (35%) by polysomnography and 56 (65%) as probable. The prevalence of idiopathic RBD at alpha-synucleinopathy diagnosis was 3.4%, increasing to 23.8% after 15 years. Cumulative lifetime incidence was 53 times greater in alpha-synucleinopathy patients than in controls (odds ratio [OR] = 53.1, 95% confidence interval [CI]: 13.0-217.2, p < 0.0001), higher in dementia with Lewy bodies than in Parkinson disease (OR = 2.57, 95% CI: 1.50-4.40, p = 0.0004), and higher in men than in women with Parkinson disease, dementia with Lewy bodies, or Parkinson disease dementia (OR = 3.70, 95% CI: 2.07-6.62, p < 0.0001), but did not increase mortality risk.

INTERPRETATION

Our cohort had RBD incidence of 3.4%. Overall RBD increased to 23.8% after 15 years, with an overall incidence of 2.5 cases per 100 person-years. With 53 times greater lifetime incidence in alpha-synucleinopathy patients than in controls, RBD was more likely to develop in dementia with Lewy bodies than in Parkinson disease or Parkinson disease dementia, and in men than in women, but did not increase mortality risk within our cohort. ANN NEUROL 2021;89:293-303.

Dream enactment behavior: review for the clinician

NONE

Dream enactment behavior commonly occurs on occasion in normal children and adults. Disruptive and frequent dream enactment behavior may come to the attention of the clinician either as the primary reason for consultation or as a prominent characteristic of a patient with other sleep disorders. Questioning patients with chronic neurologic and psychiatric disorders may also reveal previously unrecognized behavior. In the absence of sleep pathology, process of dream enactment likely begins with active, often emotionally charged dream content that may occasionally break through the normal REM sleep motor suppressive activity. Disrupted sleep resulting from many possible causes, such as circadian disruption, sleep apnea, or medications, may also disrupt at least temporarily the motor-suppressive activity in REM sleep, allowing dream enactment to occur. Finally, pathological neurological damage in the context of degenerative, autoimmune, and infectious neurological disorders may lead to chronic recurrent and severe dream enactment behavior. Evaluating the context, frequency, and severity of dream enactment behavior is guided first and foremost by a structured approach to the sleep history. Physical exam and selected testing support the clinical diagnosis. Understanding the context and the likely cause is essential to effective therapy.

A quantitative analysis of the effect of bilateral subthalamic nucleus-deep brain stimulation on subjective and objective sleep parameters in Parkinson's disease

OBJECTIVE

To explore how subjective and objective sleep parameters respond to bilateral subthalamic nucleus-deep brain stimulation (STN-DBS) in patients with Parkinson's disease (PD).

METHODS

Thirty DBS sleep studies were included by searching PubMed, Embase, and the Cochrane Library, and only 21 prospectively designed studies, including 541 patients, were eligible for the main analysis. We evaluated sleep disturbance using 1 objective measurement, polysomnography (PSG), and 4 subjective scales, including PD Sleep Scale (PDSS), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and restless legs syndrome (RLS). We pooled data using the standard mean difference (SMD). The primary outcome was a change in sleep parameters 6 months postoperatively. Outcomes from <12 months to ≥12 months follow-up were compared in the subgroup analysis. Meta-regression was further conducted.

RESULTS

STN-DBS significantly improved all 4 subjective sleep scales in the 6-month follow-up: ESS (SMD = 0.234), PDSS (SMD = 0.724), PSQI (SMD = 1.374) and RLS (SMD = 1.086), while most PSG parameters remained unchanged, except for shortened rapid eye movement sleep latency (RSL) (SMD = 0.520). In the over-12-month follow-up, improvement persisted in PDSS but not in ESS. Dopamine drug reduction (p = 0.009) and motor improvement (p = 0.036) were correlated with ESS improvement and PDSS improvement, respectively.

CONCLUSIONS

Bilateral STN-DBS continuously improved subjective nocturnal sleep, while its effect on ESS lasted for only 1 year. Medication reduction and motor improvement may contribute to improved daytime sleepiness and better subjective nocturnal sleep, respectively. Except for a shortened RSL, STN-DBS did not change PSG parameters, including sleep efficiency and sleep architecture.

REGISTRATION

Open Science Framework: DOI 10.17605/OSF.IO/3EGRC.

Effect of Yokukansan for the Treatment of Idiopathic Rapid Eye Movement Sleep Behavior Disorder: A Retrospective Analysis of Consecutive Patients

STUDY OBJECTIVES

The herbal medicine Yokukansan (YKS; Yi-Gan San in Chinese) is reported to be effective for treating rapid eye movement sleep behavior disorder (RBD). However, the effectiveness and safety of YKS treatment have not been confirmed in a large sample. Thus, we retrospectively analyzed the outcomes of YKS treatment on patients with RBD using clinical records.

METHODS

Treatment outcomes were evaluated using the Clinical Global Impression of Illness Severity (CGI-S) and Improvement (CGI-I) scales. Patients with scores of 1 (very much improved) and 2 (much improved) on the CGI-I were classified as responders. After excluding patients with very mild RBD symptoms and those without detailed clinical information, 36 patients with idiopathic RBD including 17 receiving YKS monotherapy and 19 receiving YKS add-on therapy in addition to other medication were analyzed.

RESULTS

The patients' mean age [standard deviation, SD] was 69.3 [6.8] years, and the mean duration of RBD morbidity [SD] was 5.7 [3.5] years at the start of YKS treatment. Importantly, 12 of 17 patients (70.6%) receiving YKS monotherapy were responders. However, among patients receiving YKS add-on therapy, the proportion of responders was substantially lower (4 of 19 patients; 21.1%). No adverse events were reported, other than mild gastric distress in one case.

CONCLUSIONS

Considering the effectiveness of YKS and the low likelihood of adverse events, YKS should be considered as a potential treatment for patients with RBD.

CITATION

Matsui K, Sasai-Sakuma T, Ishigooka J, Nishimura K, Inoue Y. Effect of yokukansan for the treatment of idiopathic rapid eye movement sleep behavior disorder: a retrospective analysis of consecutive patients. J Clin Sleep Med. 2019;15(8):1173-1178.

Shedding Light on Nocturnal Movements in Parkinson's Disease: Evidence from Wearable Technologies

In Parkinson’s disease (PD), abnormal movements consisting of hypokinetic and hyperkinetic manifestations commonly lead to nocturnal distress and sleep impairment, which significantly impact quality of life. In PD patients, these nocturnal disturbances can reflect disease-related complications (e.g., nocturnal akinesia), primary sleep disorders (e.g., rapid eye movement behaviour disorder), or both, thus requiring different therapeutic approaches. Wearable technologies based on actigraphy and innovative sensors have been proposed as feasible solutions to identify and monitor the various types of abnormal nocturnal movements in PD. This narrative review addresses the topic of abnormal nocturnal movements in PD and discusses how wearable technologies could help identify and assess these disturbances. We first examine the pathophysiology of abnormal nocturnal movements and the main clinical and instrumental tools for the evaluation of these disturbances in PD. We then report and discuss findings from previous studies assessing nocturnal movements in PD using actigraphy and innovative wearable sensors. Finally, we discuss clinical and technical prospects supporting the use of wearable technologies for the evaluation of nocturnal movements.

REM sleep behavior disorder (RBD)

Since its first description in 1986 by Dr. Carlos Schenck, and his group's subsequent report of the delayed emergence of a Parkinsonian disorder in idiopathic RBD patients one decade later, RBD has emerged in recent years as one of the most promising markers of prodromal Parkinson's (References 2, 3). RBD is present in 25-58% of patients with Parkinson's disease and up to 90% of those with Dementia with Lewy Bodies (DLB) or Multiple System Atrophy (MSA). In a substantial proportion of these patients RBD onset occurs before motor symptoms. Critically, when seen in isolation, RBD is a highly specific marker of future synucleinopathy: long-term cohort studies indicate that more than 80% of people who develop isolated RBD will go on to develop an alpha-synuclein related neurodegenerative disorder. Recently, the largest ever study of 1280 polysomnographically-diagnosed RBD subjects from 24 International RBD Study Group sleep centres by a single author group, found an overall conversion rate from iRBD to an overt neurodegenerative syndrome of 6.3% per year. RBD is therefore common, representative of a large proportion of sporadic disease, and provides a unique window for the study of prodromal neurodegeneration, whether it be Parkinson's or Dementia.

A Preliminary Trial in the Efficacy of Yokukansankachimpihange on REM Sleep Behavior Disorder in Dementia With Lewy Bodies

Background: Clonazepam (CNZP) is effective in ~90% of patients with rapid eye movement sleep behavior disorder (RBD) but has risks of oversedation, muscular relaxation, and adverse effects on cognitive function when used to treat RBD associated with dementia with Lewy bodies (DLB). Yokukansankachimpihange (YKSCH), a traditional herbal medicine, decreases sleep latency and increases sleep stage 2, like benzodiazepines (BZPs), but does not cause adverse events such as oversedation, muscular relaxation, and adverse effects on cognitive function. Given these pharmacological properties, YKSCH was studied as a potential alternative to CNZP.

Methods: Of patients who were diagnosed with DLB according to the criteria for the clinical diagnosis of DLB established by the Consortium on Dementia with Lewy Bodies (CDLB) in 2017, 13 consecutive patients with the cutoff score (5 points) or more in a REM sleep behavior disorder screening questionnaire and polysomnographic evidence of REM without atonia were observed using the Neuropsychiatric Inventory (NPI) night-time behavior disturbance, visual analog scale (VAS) frequency, and VAS severity as the co-primary endpoints. Data from 11 patients who completed the study were statistically analyzed.

Results: Statistically significant improvements were observed in the NPI night-time behavior disturbance, VAS frequency, and VAS severity. No notable adverse events were reported.

Conclusion: The results indicated that YKSCH, which does not cause oversedation, muscular relaxation, or adverse effects on cognitive function, may provide a new therapeutic option for RBD associated with DLB as an alternative to CNZP.

Residual Injurious Symptoms and Its Association With Neurodegenerative Outcomes in Idiopathic Rapid Eye Movement Sleep Behavior Disorder: A Retrospective, Longitudinal Follow-up Study

BACKGROUND

The risk of neurodegenerative disorders in idiopathic rapid eye movement sleep behavior disorder (iRBD) patients with residual injurious symptoms (RIS) after symptomatic treatment with clonazepam and/or melatonin is unclear.

OBJECTIVE

The objective of this study was to determine the rate and correlates of RIS and its association with the risk of neurodegenerative diseases in patients with iRBD.

METHODS

This was a retrospective cohort study. RIS was defined by the RBD Questionnaire-Hong Kong (RBDQ-HK) as the presence of residual sleep-related injuries or potential injurious behaviors for at least once a month after at least 1 year of treatment.

RESULTS

A total of 15 out of 133 (11.3%) patients with iRBD (age at diagnosis = 66.5 ± 7.3 years, 77.4% male) had RIS after 2.7 years of treatment. Patients with RIS were younger at both onset and polysomnography-confirmed diagnosis of iRBD (years, mean ± standard deviation, 56.3 ± 6.9 vs. 61.8 ± 7.6, P = 0.01; 61.2 ± 4.2 vs. 67.2 ± 7.4, P < 0.001, respectively), had more severe behavioral symptoms at diagnosis (both RBDQ-HK total score and behavioral subscore, P = 0.01), and used a higher maximum dose of clonazepam (mg; median [interquartile range], 1.5 [1.0] vs. 1.0 [1.0], P = 0.01). RIS was probably associated with a higher risk of developing dementia with Lewy bodies (adjusted hazard ratio [95% confidence interval], 5.47 [1.71-17.46], adjusted for onset age of RBD), but not Parkinsons's disease in the follow-up.

CONCLUSION

RIS is not uncommon in patients with iRBD despite long-term medication treatment. An earlier onset and more severe clinical profile are associated with RIS. The prediction of RIS toward dementia with Lewy bodies but not PD suggests that RIS may probably help to identify the specific risk of different subtypes of α-synucleinopathy. © 2020 International Parkinson and Movement Disorder Society.

Clinical Perspectives of Parkinson's Disease for Ophthalmologists, Otorhinolaryngologists, Cardiologists, Dentists, Gastroenterologists, Urologists, Physiatrists, and Psychiatrists

Parkinson's disease (PD) is a multisystemic disorder characterized by various non-motor symptoms (NMS) in addition to motor dysfunction. NMS include sleep, ocular, olfactory, throat, cardiovascular, gastrointestinal, genitourinary, or musculoskeletal disorders. A range of NMS, particularly hyposmia, sleep disturbances, constipation, and depression, can even appear prior to the motor symptoms of PD. Because NMS can affect multiple organs and result in major disabilities, the recognition and multidisciplinary and collaborative management of NMS by physicians is essential for patients with PD. Therefore, the aim of this review article is to provide an overview of the organs that are affected by NMS in PD together with a brief review of pathophysiology and treatment options.

A Neurologist's Guide to REM Sleep Behavior Disorder

REM Sleep Behavior Disorder (RBD) is a chronic sleep condition characterized by dream enactment and loss of REM atonia. Individuals often present to clinic with complaints of injury to themselves or their bed-partner due to violent movements during sleep. RBD patients have a high risk of developing one of the neurodegenerative α-synucleinopathy diseases: over 70% will develop parkinsonism or dementia within 12 years of their diagnosis. RBD patients also exhibit accelerated disease progression and a more severe phenotype than α-synucleinopathy sufferers without RBD. The disease's low prevalence and the relatively limited awareness of the condition amongst medical professionals makes the diagnosis and treatment of RBD challenging. Uncertainty in patient management is further exacerbated by a lack of clinical guidelines for RBD patient care. There are no binary prognostic markers for RBD disease course and there are no clinical guidelines for neurodegeneration scaling or tracking in these patients. Both clinicians and patients are therefore forced to deal with uncertain outcomes. In this review, we summarize RBD pathology and differential diagnoses, diagnostic, and treatment guidelines as well as prognostic recommendations with a look to current research in the scientific field. We aim to raise awareness and develop a framework for best practice for RBD patient management.

Muscle Activity Detection during Sleep by Ear-EEG

Muscle activation during sleep is an important biomarker in the diagnosis of several sleep disorders and neurodegenerative diseases. Muscle activity is typically assessed manually based on the EMG channels from polysomnography recordings. Ear-EEG provides a mobile and comfortable alternative for sleep assessment. In this study, ear-EEG was used to automatically detect muscle activities during sleep. The study was based on a dataset comprising four full night recordings from 20 healthy subjects with concurrent polysomnography and ear-EEG. A binary label, active or relax, extracted from the chin EMG was assigned to selected 30 s epoch of the sleep recordings in order to train a classifier to predict muscle activation. We found that the ear-EEG based classifier detected muscle activity with an accuracy of 88% and a Cohen's kappa value of 0.71 relative to the labels derived from the chin EMG channels. The analysis also showed a significant difference in the distribution of muscle activity between REM and non-REM sleep.

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.

Lewy Body Degenerations as Neuropsychiatric Disorders

Parkinson disease has historically been conceptualized as a movement disorder. In recent decades, nonmotor and neuropsychiatric symptoms have become increasingly recognized as being of paramount importance for patients with Parkinson disease. Neuropsychiatric phenomena dominate the course of the other major Lewy body disease, dementia with Lewy bodies. In this review, we survey the clinical relevance of nonmotor and neuropsychiatric symptoms to the heterogeneous presentations of Lewy body disease and their significance to ongoing research in this area. We consider how the nature of Lewy body neuropathology may help explicate the basis of nonmotor and neuropsychiatric symptoms in these two disorders.

Drugs Used in Parasomnia

Patient education and behavioral management represent the first treatment approaches to the patient with parasomnia, especially in case of disorders of arousal (DOA). A pharmacologic treatment of DOA may be useful when episodes are frequent and persist despite resolution of predisposing factors, are associated with a high risk of injury, or cause significant impairment, such as excessive sleepiness. Approved drugs for DOA are still lacking. The most commonly used medications are benzodiazepines and antidepressants. The pharmacologic treatment of rapid eye movement sleep behavior disorder is symptomatic, and the most commonly used drugs are clonazepam and melatonin.

Exploring the Predictors of Rapid Eye Movement Sleep Behavior Disorder for Parkinson's Disease Patients Using Classifier Ensemble

The rapid eye movement sleep behavior disorder (RBD) of Parkinson's disease (PD) patients can be improved with medications such as donepezil as long as it is diagnosed with a thorough medical examination, since identifying a high-risk group of RBD is a critical issue to treat PD. This study develops a model for predicting the high-risk groups of RBD using random forest (RF) and provides baseline information for selecting subjects for polysomnography. Subjects consisted of 350 PD patients (Parkinson's disease with normal cognition (PD-NC) = 48; Parkinson's disease with mild cognitive impairment (PD-MCI) = 199; Parkinson's disease dementia (PDD) = 103) aged 60 years and older. This study compares the prediction performance of RF, discriminant analysis, classification and regression tree (CART), radial basis function (RBF) neural network, and logistic regression model to select a final model with the best model performance and presents the variable importance of the final model's variable. As a result of analysis, the sensitivity of RF (79%) was superior to other models (discriminant analysis = 14%, CART = 32%, RBF neural network = 25%, and logistic regression = 51%). It was confirmed that age, the motor score of Untitled Parkinson's Disease Rating (UPDRS), the total score of UPDRS, the age when a subject was diagnosed with PD first time, the Korean Mini Mental State Examination, and Korean Instrumental Activities of Daily Living, were major variables with high weight for predicting RBD. Among them, age was the most important factor. The model for predicting Parkinson's disease RBD developed in this study will contribute to the screening of patients who should receive a video-polysomnography.

The depletion of ubiquilin in Drosophila melanogaster disturbs neurochemical regulation to drive activity and behavioral deficits

Drosophila melanogaster is a useful and highly tractable model organism for understanding the molecular mechanisms of human diseases. We previously characterized a new dUbqn knockdown model that induces learning-memory and locomotive deficits mediated by impaired proteostasis. Although proteinopathies are the main causes of neurodegenerative diseases, limited information is currently available on the relationship between proteostasis and neurodegenerative-related behavioral perturbations, such as locomotion, wakefulness, and sexual activities. Thus, the present study aimed to elucidate the mechanisms by which dUbqn depletion which is known to cause proteinopathies, affects neurodegenerative-related behavioral perturbations. Pan-neuronal dUbqn-depleted flies showed significantly reduced evening activity along with altered pre- and postsynaptic structural NMJ's proteins by attenuating signals of Bruchpilot puncta and GluRIIA clustering. In addition, the neurochemical profiles of GABA, glutamate, dopamine, and serotonin were disturbed and these changes also affected courtship behaviors in dUbqn-depleted flies. Collectively, these results extend our understanding on how dUbqn depletion affects neurochemical regulation to drive behavioral disturbances that are generally found in the early stage of neurodegenerative diseases. Moreover, the present study may contribute a novel finding to the design of new agents that prevent disease progression or even treat diseases related to neurodegeneration.

Smaller subcortical volume in Parkinson patients with rapid eye movement sleep behavior disorder

Parkinson disease (PD) patients with rapid eye movement (REM) sleep behavior disorder (RBD) have worse motor symptoms and non-motor symptoms than patients without RBD. The aim of this study was to examine underlying differences in brain structure from a network perspective. Baseline data were obtained from Parkinson's Progression Markers Initiative (PPMI) participants. We divided PD patients and healthy controls (HC) into RBD positive and RBD negative using a cutoff score of ≥5 on the RBD screening questionnaire. HC with probable RBD were excluded. We first carried out a region-of-interest analysis of structural MRIs using voxel-based morphometry to study volumetric differences for the putamen, thalamus and hippocampus in a cross-sectional design. Additionally, an exploratory whole-brain analysis was performed. To study group differences from a network perspective, we then performed a 'seed-based' analysis of structural covariance, using the bilateral dorsal-caudal putamen, mediodorsal thalamus and anterior hippocampus as seed regions. The volume of the right putamen was smaller in PD patients with RBD. RBD symptom severity correlated negatively with volume of the right putamen, left hippocampus and left thalamus. We did not find any differences in structural covariance between PD patients with and without RBD. Presence of RBD and severity of RBD symptoms in PD are associated with smaller volumes of the putamen, thalamus and hippocampus.

REM sleep behavior disorder in narcolepsy: A secondary form or an intrinsic feature?

Disrupted nighttime sleep is one of the pentad of symptoms defining Narcolepsy. REM sleep behavior disorder (RBD) largely contributes to night sleep disruption and narcolepsy is the most common cause of secondary RBD. However, RBD linked to narcolepsy (N-RBD) has been insufficiently characterized, leaving unsolved a number of issues. Indeed, it is still debated whether N-RBD is an intrinsic feature of narcolepsy, as indubitable for cataplexy, and therefore strictly linked to the cerebrospinal fluid hypocretin-1 (CSF hcrt-1) deficiency, or an associated feature, with a still unclear pathophysiology. The current review aims at rendering a comprehensive state-of-the-art of N-RBD, highlighting the open and unsettled topics. RBD reportedly affects 30-60% of patients with Narcolepsy type 1 (NT1), but it may be seen also in Narcolepsy type 2 (NT2). When compared to idiopathic/isolated RBD (iRBD), N-RBD has been reported to be characterized by less energetic and quieter episode, which however occur with the same probability in the first and the second part of the night and sometime even subcontinuously. N-RBD patients are generally younger than those with iRBD. N-RBD has been putatively linked to wake-sleep instability due to CSF hcrt-1 deficiency, but this latter by itself cannot explain completely the phenomenon as N-RBD has not been universally linked to low CSF hcrt-1 levels and it may be observed also in NT2. Therefore, other factors may probably play a role and further studies are needed to clarify this issue. In addition, therapeutic options have been poorly investigated.

Gender differences in clinical findings and α-synucleiopathy-related markers in patients with idiopathic REM sleep behavior disorder

BACKGROUND

Rapid eye movement (REM) sleep behavior disorder (RBD) is a male-predominant parasomnia. Earlier clinical RBD patient studies showed gender differences of clinical symptoms and polysomnographic (PSG) findings. However, no previous investigated this issue by means of validated severity scales or by neuropsychological examination related to alpha-synucleinopathy. This study elucidates gender differences in clinical, physiological, and neuropsychological findings in Japanese idiopathic RBD (iRBD) patients.

METHODS

From 220 patients with complaint of sleep-related vocalization or behaviors who visited Yoyogi Sleep Disorder Center from June 2003 through December 2016, 43 female (68.7 ± 7.3 yr) and 141 male patients (66.7 ± 6.7 yr) diagnosed as having iRBD by video-polysomnography (v-PSG) were selected. All subjects answered the RBD questionnaire (RBDQ-JP) and underwent olfactory function test (Sniffin' Sticks test) and cognitive function test (MoCA-J).

RESULTS

Female iRBD patients had later first symptom-witnessed age (sleep-talking 63.2 ± 10.5 yr, behaviors 60.9 ± 8.6 yr) than male patients (sleep-talking 59.1 ± 8.8 yr, behaviors 64.7 ± 8.9 yr). No gender difference was found in age at diagnosis, clinical severity (RBDQ-JP), or olfactory or cognitive function. Regarding electromyogram (EMG) findings during REM sleep, phasic EMG activity was higher in female patients (22.3 ± 17.8% vs. 16.5 ± 16.1%), although no difference was found in tonic EMG activity.

CONCLUSIONS

Although female iRBD patient symptoms were first recognized later than those of male patients, they showed elevated EMG activity during REM sleep and showed deteriorated olfactory and cognitive function similarly to male patients at the first medical consultation. Results suggest that disease progression in female RBD patients is equivalent to that in male patients.

Update on nonpharmacological interventions in parasomnias

Parasomnias are abnormal behaviors that occur during sleep and can be associated, in particular during adulthood, with impaired sleep quality, daytime dysfunction, and occasionally with violent and harmful nocturnal behaviors. In these cases, therapies are often considered. Longterm pharmacological treatments are not always well tolerated and often have limited efficacy. Therefore, behavioral approaches remain an important treatment option for several types of parasomnias. However, the evidence-based approaches are limited. In the current review, we highlight results from various nonpharmacological techniques on different types of parasomnias and provide a glimpse into the future of nonpharmacological treatments in this field.