Factors associated with injury in REM sleep behavior disorder

The impact of REM-sleep behavior disorder on people with Parkinson's disease and their partners

REM-sleep behavior disorder (RBD) may affect health-related quality of life (HRQoL) of people with Parkinson's disease (PwP) and partners. We aimed to determine how RBD affects HRQoL using a mixed-methods approach. Quantitatively, we analyzed data from the PRIME-NL Parkinson Evaluation study, including 829 PwP and 452 partners, using multivariable regression models to examine the association between screen-positive RBD and HRQoL. Qualitatively, we conducted interviews with 14 dyads of PwP with self-reported RBD and their partners. RBD was negatively associated with HRQoL in both groups, primarily due to short-term effects on daily life, co-existing symptoms like impaired cognition and autonomic issues, and sleep disturbances. Impact of RBD was already felt before or during the diagnostic process, with the main challenges being sleep-related complaints, anxiety and impact on relationships. PwP and partners employed both medical and non-medical coping strategies. These findings will help to optimize care for PwP with RBD and their partners.

Sleep and Prodromal Synucleinopathies

α-synucleinopathies are a complex group of progressive neurodegenerative disorders with an increasingly recognized long prodromal period, during which sleep dysfunction is a hallmark. Sleep disorders during the prodromal synucleinopathy period, primarily isolated rapid eye movement (REM) sleep behavior disorder (iRBD) and daytime hypersomnolence correlate best with the recently proposed "body-first" Lewy body disease progression. iRBD is the most widely recognized form of prodromal α-synucleinopathy, and patients with iRBD show abnormal α-synuclein in tissues and biofluids even in the absence of cognitive or motor symptoms. More importantly, individuals with iRBD have an elevated risk for near-term development of a clinically diagnosable symptomatic synucleinopathy. Other sleep disorders such as hypersomnia and circadian rhythm dysfunction also occur across the synucleinopathy spectrum, although their prognostic significance is less well understood than iRBD. Finally, isolated REM sleep without atonia may represent an even earlier stage of prodromal synucleinopathy, but further studies are needed.

From mechanisms to future therapy: a synopsis of isolated REM sleep behavior disorder as early synuclein-related disease

Parkinson disease (PD), dementia with Lewy bodies (DLB) and multiple system atrophy are synucleinopathies, characterized by neuronal loss, gliosis and the abnormal deposition of α-synuclein in vulnerable areas of the nervous system. Neurodegeneration begins however several years before clinical onset of motor, cognitive or autonomic symptoms. The isolated form of REM sleep behavior disorder (RBD), a parasomnia with dream enactment behaviors and excessive muscle activity during REM sleep, is an early stage synucleinopathy. The neurophysiological hallmark of RBD is REM sleep without atonia (RWSA), i.e. the loss of physiological muscle atonia during REM sleep. RBD pathophysiology is not fully clarified yet, but clinical and basic science suggest that ɑ-syn pathology begins in the lower brainstem where REM atonia circuits are located, including the sublaterodorsal tegmental/subcoeruleus nucleus and the ventral medulla, then propagates rostrally to brain regions such as the substantia nigra, limbic system, cortex. Genetically, there is only a partial overlap between RBD, PD and DLB, and individuals with iRBD may represent a specific subpopulation. A genome-wide association study identified five loci, which all seem to revolve around the GBA1 pathway. iRBD patients often show subtle motor, cognitive, autonomic and/or sensory signs, neuroimaging alterations as well as biofluid and tissue markers of neurodegeneration (in particular pathologic α-synuclein aggregates), which can be useful for risk stratification. Patients with iRBD represent thus the ideal population for neuroprotective/neuromodulating trials. This review provides insights into these aspects, highlighting and substantiating the central role of iRBD in treatment development strategies for synucleinopathies.

Sleep related injury and its correlates in isolated rapid eye movement sleep behavior disorder

OBJECTIVES

To evaluate factors associated with sleep related injury (SRI) and persistent SRI (pSRI) in patients with isolated rapid eye movement sleep behavior disorder (iRBD).

METHODS

This is a retrospective cohort study. A total of 388 patients with iRBD were involved for a comprehensive review of sleep related injuries. SRI is defined as a lifetime history of injurious behaviors to self and/or bed partner, and pSRI is considered if injurious symptoms continued to occur frequently (≥1/month). Correlations of SRI/pSRI with clinical, lifestyle and polysomnographic characteristics were analyzed.

RESULTS

Lifetime SRI was reported in 322 (83 %) patients (66.3 ± 8.5 years old, male 77.0 %), with 19.3 % having severe injuries, including fractures (2.5 %) and subdural hemorrhage (1.2 %), while 7.5 % required medical attendance. SRI was related to more severe depressive features (Padj = 0.017), current alcohol drinking (Padj = 0.014) and higher mentalis phasic and tonic EMG activity (Padj = 0.042 and 0.048). After a mean follow-up of 5.1 years, 18.2 % of SRI patients (38/209) had pSRI despite intense treatment. Frequent nightmare at baseline (OR [95 % CI] = 1.43 [1.01, 2.03]), restless leg syndrome (OR [95 % CI] = 5.68 [1.42, 22.64]) and adult-onset sleepwalking (OR [95 % CI] = 2.52 [1.10, 5.76]) were associated with an increased risk of pSRI.

CONCLUSIONS

SRI is common in patients with iRBD and 18 % had pSRI despite intensive treatment, emphasizing the importance of bedside safety. The identification of risk factors for SRI and pSRI underscores the need for systematic clinical screening and targeted interventions for at-risk patients.

Clinical characteristics and phenoconversion in isolated REM sleep behavior disorder: a prospective single-center study in Korea, compared with Montreal cohort

STUDY OBJECTIVES

Isolated rapid eye movement sleep behavior disorder is a prodromal synucleinopathy, but its conversion rate and subtypes can vary among different cohorts. We report the clinical characteristics and phenoconversion rate of the large single-center isolated rapid eye movement sleep behavior disorder cohort in Korea and compared it to the Montreal cohort.

METHODS

This prospective cohort study examined 238 patients with polysomnography confirmed isolated rapid eye movement sleep behavior disorder from Seoul National University Hospital (SNUH) who completed at least 1 follow-up evaluation. We compared the baseline and phenoconversion data of the SNUH cohort to those of 242 isolated rapid eye movement sleep behavior disorder patients in the Montreal cohort.

RESULTS

In the SNUH cohort, age at rapid eye movement sleep behavior disorder diagnosis was similar (66.4 ± 7.8 vs 65.6 ± 8.4, P = .265), but the proportion of men was lower (63.0% vs 74.0%, P = .01), and the duration of follow-up was shorter than that in the Montreal cohort (3.7 ± 2.0 vs 4.8 ± 3.6 years, P < .001). During follow-up, 34 (11.8%) patients in the SNUH cohort converted to neurodegenerative disease: 18 (52.9%) to Parkinson's disease, 9 (26.5%) to dementia with Lewy bodies, and 7 (20.6%) to multiple system atrophy. The conversion rate in the SNUH cohort was 15% after 3 years, 22% after 5 years, and 32% after 7 years, which was significantly lower than that of the Montreal cohort (log-rank test, P = .002). Among phenoconversion subtype, fewer patients in the SNUH group than in the Montreal group converted to dementia with Lewy bodies (Gray's test P = .001).

CONCLUSIONS

Through a comparative analysis between the SNUH and Montreal cohorts, we identified a significant difference in phenoconversion rates, particularly for dementia with Lewy bodies patients. These findings underscore the importance of further research into the underlying factors, such as racial and geographical factors contributing to such disparities.

CITATION

Byun J-I, Sunwoo J-S, Shin YW, et al. Clinical characteristics and phenoconversion in isolated REM sleep behavior disorder: a prospective single-center study in Korea, compared with Montreal cohort. J Clin Sleep Med. 2025;21(1):81-88.

Network structure of REM sleep behavior disorder symptoms in iRBD patients

OBJECTIVE

Employing the REM Sleep Behavior Disorder Questionnaire-Hong Kong (RBDQ-HK) to investigate symptoms and their severity in rapid eye movement (REM) sleep behavior disorder (RBD) patients, this study delves into the construct of RBD through the RBDQ-HK and its links to depression and sleep quality.

METHODS

Data from the RBDQ-HK, the Geriatric Depression Scale (GDS), and the Pittsburgh Sleep Quality Index (PSQI) were compiled from individuals with isolated RBD (iRBD) confirmed by polysomnography. We constructed a network analysis of the RBDQ-HK, measured the centrality of each symptom (node), conducted Exploratory Graph Analysis (EGA) to unveil the dimension structure of the questionnaire, and calculated bridge expected influence (BEI) to identifying critical bridge. Multivariate linear regression was also employed to discover relationships between RBDQ-HK dimensions and variables such as PSQI and GDS.

RESULTS

In our cohort of 455 iRBD patients (299 males), the items in the RBDQ-HK were divided into three dimensions: dream, movement, and SRI/violence. The symptoms identified as most central to RBD were 'shouting or yelling in sleep', 'dream-enacting movements', and 'talking during sleep'. The highest (BEI) was 'violent and aggressive dreams', which has the potential to bridge three dimensions within the symptom network. Depression was significantly correlated with the movement and dream dimensions of RBD, and sleep quality was predominantly related to the dream dimension score.

CONCLUSION

Our findings verify that the principal symptoms of the RBDQ-HK align with the established diagnostic criteria and reveal a three-dimensional structure within RBD symptoms. The relationships between the RBD symptoms, depression, and sleep quality need to be identified for the effective management of RBD patients.

Rapid Eye Movement Sleep Behavior Disorder: Clinical Presentation and Diagnostic Criteria

Rapid eye movement (REM) sleep behavior disorder (RBD) classically presents with repetitive complex motor behavior during sleep with associated dream mentation. The diagnosis requires a history of repetitive complex motor behaviors and polysomnographic demonstration of REM sleep without atonia (RSWA) or capturing dream enactment behaviors. RSWA is best evaluated in the chin or flexor digitorum superficialis muscles. The anterior tibialis muscle is insufficiently accurate to be relied upon solely for RBD diagnosis. RBD may present with parkinsonism or cognitive impairment or may present in isolation. Patients should be monitored for parkinsonism, autonomic failure, or cognitive impairment.

Validation of the RBD Symptom Severity Scale in the North American Prodromal Synucleinopathy Consortium

BACKGROUND AND OBJECTIVES

REM sleep behavior disorder (RBD) is a parasomnia characterized by dream enactment. The International RBD Study Group developed the RBD Symptom Severity Scale (RBDSSS) to assess symptom severity for clinical or research use. We assessed the psychometric and clinimetric properties of the RBDSSS in participants enrolled in the North American Prodromal Synucleinopathy (NAPS) Consortium for RBD.

METHODS

NAPS participants, who have polysomnogram-confirmed RBD, and their bedpartners completed the RBDSSS (participant and bedpartner versions). The RBDSSS contains 8 questions to assess the frequency and severity/impact of (1) dream content, (2) vocalizations, (3) movements, and (4) injuries associated with RBD. Total scores for participant (maximum score = 54) and bedpartner (maximum score = 38) questionnaires were derived by multiplying frequency and severity scores for each question. The Clinical Global Impression Scale of Severity (CGI-S) and RBD symptom frequency were assessed by a physician during a semistructured clinical interview with participants and, if available, bedpartners. Descriptive analyses, correlations between overall scores, and subitems were assessed, and item response analysis was performed to determine the scale's validity.

RESULTS

Among 261 study participants, the median (interquartile range) score for the RBDSSS-PT (participant) was 10 (4-18) and that for the RBDSSS-BP (bedpartner) was 8 (4-15). The median CGI-S was 3 (3-4), indicating moderate severity. RBDSSS-BP scores were significantly lower in women with RBD (6 vs 9, p = 0.02), while there were no sex differences in RBDSSS-PT scores (8 vs 10.5, p = 0.615). Positive correlations were found between RBDSSS-PT vs RBDSSS-BP (Spearman rs = 0.561), RBDSSS-PT vs CGI-S (rs = 0.556), and RBDSSS-BP vs CGI-S (rs = 0.491, all p < 0.0001). Item response analysis showed a high discriminatory value (range 1.40-2.12) for the RBDSSS-PT and RBDSSS-BP (1.29-3.47).

DISCUSSION

We describe the RBDSSS with adequate psychometric and clinimetric properties to quantify RBD symptom severity and good concordance between participant and bedpartner questionnaires and between RBDSSS scores and clinician-assessed global severity.

Gender Difference in REM Sleep Behavior Disorder in Japanese Population: Polysomnography and Sleep Questionnaire Study

Rapid eye movement (REM) sleep behavior disorder (RBD) is generally common among males and is an established risk factor for neurodegenerative diseases. As the population ages, the prevalence of α-synucleinopathy (such as Parkinson's disease) is increasing. Additionally, the number of female patients is increasing in Japan. Therefore, we aimed to clarify the clinical characteristics of RBD from the perspective of gender differences in the Japanese population. The proportion of male RBD patients (65.2%) was significantly higher than that of female patients (34.8%). Additionally, female patients (70.5 ± 8.2 years) were significantly older than male patients (67.9 ± 8.0 years, p < 0.05). The mean score on the RBD Screening Questionnaire was significantly higher in male patients than in female (8.6 ± 2.9 vs. 7.7 ± 3.1, p < 0.05), while the mean score on the Pittsburgh Sleep Quality Index was significantly higher in males (5.9 ± 3.8 vs. 7.2 ± 3.600, p < 0.001). The Self-rating Depression Scale in females was 41.7 ± 8.5, and they were more likely to show depressive tendencies than males. In polysomnography, higher rates of obstructive sleep apnea and longer duration of stage N1 sleep were detected in males. After adjusting for age, BMI, and polysomnographic parameters, we found that female RBD patients had significantly worse sleep quality and rates of depression compared to male patients.

REM Behavior Disorder: Implications for PD Therapeutics

PURPOSE

Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia that occurs during REM sleep, characterized by REM sleep without atonia (RSWA) and dream enactment behavior (DEB). RBD is associated with several diseases and medications but most notably is a prodromal feature of synucleinopathies, including Parkinson's disease (PD). This article reviews RBD, its treatments, and implications for PD therapeutics.

RECENT FINDINGS

Recent research recognizes RBD as a prodromal marker of PD, resulting in expansion of basic science and clinical investigations of RBD. Current basic science research investigates the pathophysiology of RBD and explores animal models to allow therapeutic development. Clinical research has focused on natural history observation, as well as potential RBD treatments and their impact on sleep and phenoconversion to neurodegenerative disease. RBD serves as a fresh access point to develop both neuroprotective and symptomatic therapies in PD. These types of investigations are novel and will benefit from the more established basic science infrastructure to develop new interventions.

Sex differences in rapid eye movement sleep behavior disorder: A systematic review and meta-analysis

Although rapid eye movement (REM) sleep behavior disorder (RBD) has been widely considered as a male-predominant parasomnia, the existing evidence for the sex difference in the risk of RBD in the general population was conflicting. The present study conducted a systematic review to explore the sex differences in the prevalence, comorbidities, clinical characteristics, and phenoconversion of RBD. One hundred thirty-five eligible studies were identified for the systematic review, and 133 were finally included in the meta-analysis. Males in the general population showed a trend for a higher risk of probable/possible RBD (pRBD), especially among the male older adults (aged ≥60). In the clinical populations, males showed a significantly higher risk of confirmed RBD, but not of pRBD. Among idiopathic RBD (iRBD) patients, males had a significantly earlier age onset of RBD compared with females. Male patients with Parkinson's disease (PD) had a higher risk of comorbid RBD. There was no significant sex difference in the risk of developing neurodegenerative diseases in iRBD patients. Large scale and prospective studies utilizing stringent diagnostic criteria for RBD are recommended to further verify the sex differences in RBD and to investigate the mechanism underlying the sex difference.

A systematic review of dreams and nightmares recall in patients with rapid eye movement sleep behaviour disorder

Rapid eye movement (REM) sleep behaviour disorder is a REM sleep parasomnia characterised by the loss of the physiological muscle atonia during REM sleep, resulting in dream enactment behaviours that may cause injuries to patients or their bed partners. The nocturnal motor episodes seem to respond to the dream contents, which are often vivid and violent. These behavioural and oneiric features make the REM sleep behaviour disorder a potential model to study dreams. This review aims to unify the literature about dream recall in REM sleep behaviour disorder as a privileged approach to study dreams, systematically reviewing studies that applied retrospective and prospective experimental designs to provide a comprehensive overview of qualitative and quantitative aspects of dream recall in this REM sleep parasomnia. The present work highlights that the study of dreaming in REM sleep behaviour disorder is useful to understand unique aspects of this pathology and to explore neurobiological, electrophysiological, and cognitive mechanisms of REM sleep and dreaming.

Comparative efficacy of prolonged-release melatonin versus clonazepam for isolated rapid eye movement sleep behavior disorder

PURPOSE

Clonazepam and melatonin are recommended as first-line treatments for isolated rapid eye movement (REM) sleep behavior disorder (iRBD). This study aimed to compare their efficacy and safety in REM sleep without atonia (RWA) and RBD-related symptoms.

METHODS

This prospective, open-label, randomized trial included patients with video-polysomnography-confirmed iRBD. The patients were randomly assigned to receive either clonazepam 0.5 mg or prolonged-release (PR) melatonin 2 mg 30 min before bedtime for 4 weeks. The primary outcome was changes in RWA on follow-up polysomnography (PSG). Secondary endpoints were changes in other PSG parameters, clinical global improvement-impression scale (CGI-I) scores, and sleep questionnaire scores. The safety endpoint was adverse events.

RESULTS

Of 40 patients with probable RBD considered, 34 were enrolled in the study and randomized. Visual scoring parameters of RWA indices were reduced, and automatic scoring parameters tended to be improved after clonazepam treatment but not after PR melatonin treatment. The proportion of N2 sleep was increased, and N3 and REM sleep were decreased only in the clonazepam group. The clonazepam group tended to answer "much or very much improvement" on the CGI-I more frequently than the PR melatonin group (p = 0.068). Daytime sleepiness and insomnia symptoms were reduced after PR melatonin but not after clonazepam. Depressive symptoms increased after clonazepam. Four of the patients (13.3%) reported mild to moderate adverse events, which were similar between the two groups.

CONCLUSION

Four weeks of clonazepam, but not PR melatonin, improved RWA. RBD symptom improvement tended to be better after clonazepam than PR melatonin in exchange for increased depressive symptoms and daytime sleepiness.

CLINICALTRIALS

gov identifier: NCT03255642 (first submitted August 21, 2017).

Clonazepam for the management of sleep disorders

BACKGROUND

The objectives of this review and meta-analysis of polysomnographic data are those to focus on the clinical use of clonazepam for the management of sleep disorders by re-analyzing clinical trials and randomized clinical trials which have been published in peer-reviewed journals.

METHODS

A review of the literature including clinical trials and randomized controlled trials was performed in PubMed®, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement protocol. A random effects model meta-analysis was then carried out for the four more frequently reported polysomnographic measures: total sleep time, sleep latency, sleep efficiency, and periodic leg movement during sleep (PLMS) index.

RESULTS

A total of 33 articles were retrieved and screened in full text, of which 18 met the criteria for review; among the latter, nine met the criteria for meta-analysis. The studies included in the review involved patients with insomnia, REM sleep behavior disorder, sleep bruxism, and restless leg syndrome or PLMS which reported, most often, an increase in total sleep time with clonazepam. A clear sleep-promoting effect of clonazepam was found also by meta-analysis.

DISCUSSION AND CONCLUSIONS

Our results indicate that the pharmacological treatment of sleep disorders with clonazepam must always be personalized according to the type of patient, the risk of addiction and the concomitant presence of respiratory disorders are key factors to take into account. However, in light of the clinical evidence of the few studies in the literature on the different types of disorders, more studies on the use of clonazepam (also in association with first choice treatments) are definitely needed.

Treatment with the novel TAAR1 agonist ulotaront is associated with reductions in quantitative polysomnographic REM sleep without atonia in healthy human subjects: Results of a post-hoc analysis

BACKGROUND

Isolated REM sleep behavior disorder (RBD) is a potentially injurious parasomnia lacking an established treatment. Ulotaront is a trace amine-associated receptor 1 (TAAR1) agonist with 5-HT_1A receptor agonist activity that has demonstrated efficacy in patients with schizophrenia. In a single dose challenge study in humans, ulotaront 50 mg demonstrated significant REM suppressant effects. We now report post-hoc exploratory analyses designed to evaluate the effect of ulotaront on quantitative REM sleep without atonia (RSWA).

METHODS

Young healthy adult men (ages 19-35) were randomized to double-blind, cross-over treatment (after 7-day wash-out) with single doses of ulotaront (50 mg or 10 mg) versus placebo followed by polysomnography (PSG) on each of the nights following treatment. Quantitative RSWA was analyzed in a blinded fashion using established visual and automated methods.

RESULTS

Subjects received 50 mg (n = 11) or 10 mg (n = 9) of ulotaront. Treatment with ulotaront 50 mg was associated with lower RSWA (p < 0.05), with greatest RSWA reduction (vs. placebo) observed in subjects with RSWA levels above the mean on the baseline night. RSWA levels were similar between treatment with ulotaront 10 mg and placebo.

CONCLUSION

Treatment with ulotaront 50 mg (but not 10 mg) was associated with reductions in RSWA levels in healthy subjects, especially in subjects with higher baseline RSWA levels, providing proof-of-concept for ulotaront efficacy in reducing RSWA levels. However, whether ulotaront might have efficacy as a treatment for human RBD awaits double-blind trials with ulotaront in clinical RBD populations.

Tonic REM sleep muscle activity is the strongest predictor of phenoconversion risk to neurodegenerative disease in isolated REM sleep behaviour disorder

Previous studies have shown that rapid eye movement sleep without atonia during polysomnography can predict the risk of phenoconversion to neurodegenerative disease in patients with isolated rapid eye movement sleep behaviour disorder. Discrepancy remains with regards to the morphology of rapid eye movement sleep without atonia that best predicts phenoconversion risk. This study aimed to ascertain the predictive value of tonic, phasic and mixed rapid eye movement sleep without atonia in patients with isolated rapid eye movement sleep behaviour disorder, at time of diagnosis. Sixty-four patients with polysomnography-confirmed isolated rapid eye movement sleep behaviour disorder, including 19 who phenoconverted during follow-up, were identified from an existing database. Tonic, phasic, mixed and "any" rapid eye movement sleep without atonia activity from the mentalis, tibialis anterior and flexor digitorum superficialis muscles was analysed blind to status using the diagnostic polysomnography. Rapid eye movement sleep without atonia variables were compared between converters and non-converters. Rapid eye movement sleep without atonia cut-offs predicting phenoconversion were established using receiver-operating characteristic analysis. The mean follow-up duration was 5.50 ± 4.73 years. Phenoconverters (n = 19) had significantly higher amounts of tonic (22.2 ± 19.1%, p = 0.0014), mixed (18.1 ± 14.1%, p = 0.0074) and "any" (mentalis muscle; 58.7 ± 28.0%, p = 0.0009) and all muscles (68.0 ± 20.8%, p = 0.0049) rapid eye movement sleep without atonia at diagnosis than non-converters. Optimal rapid eye movement sleep without atonia cut-off values predicting phenoconversion were 5.8% for tonic (73.7% sensitivity; 75.6% specificity), 7.3% for mixed (68.4% sensitivity; 73.3% specificity) and 43.6% for "any" (mentalis muscle; 68.4% sensitivity; 80.0% specificity) activity. "Any" (mentalis muscle) rapid eye movement sleep without atonia had the highest area under the curve (0.809) followed by tonic (0.799). The percentage of tonic rapid eye movement sleep without atonia was the strongest biomarker of phenoconversion in this cohort of patients with isolated rapid eye movement sleep behaviour disorder.

Dreaming in Parasomnias: REM Sleep Behavior Disorder as a Model

Sleep parasomnias have drawn the interest of sleep experts because they represent a valuable window to directly monitor dream activity and sleep mentation associated with nocturnal events. Indeed, parasomnias and their manifestations are helpful in investigating dream activity and features, overcoming methodological limits that affect dream study. Specifically, REM sleep Behavior Disorder (RBD) is a parasomnia characterized by enacted dream episodes during Rapid Eye Movements (REM) sleep, caused by the loss of physiological atonia. Patients suffering from RBD report a peculiar oneiric activity associated with motor episodes characterized by high Dream Recall Frequency (DRF) and vivid dreams. Additionally, isolated RBD (iRBD) represents a prodromal stage of neurodegeneration preceding the development of α-synucleinopathies. This narrative review aims to combine evidence describing dream activity in RBD and similarities and differences with other NREM parasomnias. Moreover, a special focus has been reserved for those conditions in which RBD is associated with α-synucleinopathies to clarify the potential role of dreams in neurodegenerative processes.

Drugs Used in Parasomnia

Parasomnias, especially disorders of arousal during childhood, are often relatively benign and transitory and do not usually require a pharmacologic therapy. A relevant aspect in both nonrapid eye movement and rapid eye movement parasomnia treatment is to prevent sleep-related injuries by maintaining a safe environment. Physicians should always evaluate the possible presence of favoring and precipitating factors (sleep disorders and drugs). A pharmacologic treatment may be indicated in case of frequent, troublesome, or particularly dangerous events. The aim of this article is to review current available evidence on pharmacologic treatment of different forms of parasomnia.

Isolated REM sleep behaviour disorder: current diagnostic procedures and emerging new technologies

Isolated REM sleep behaviour disorder (iRBD) is characterised by dream enactment behaviours, such as kicking and punching while asleep, and vivid/violent dreams. It is now acknowledged as a prodromal phase of neurodegenerative disease-approximately 80% of people with iRBD will develop dementia with Lewy Bodies, Parkinson's disease or another degenerative brain disease within 10 years. It is important that neurologists and other clinicians understand how to make an early accurate diagnosis of iRBD so that affected people can have the opportunity to take part in clinical trials. However, making a diagnosis can be clinically challenging due to a variety of reasons, including delayed referral, symptom overlap with other disorders, and uncertainty about how to confirm a diagnosis. Several methods of assessment are available, such as clinical interview, screening questionnaires and video polysomnography or 'sleep study'. This review aims to support clinical neurologists in assessing people who present with symptoms suggestive of iRBD. We describe the usefulness and limitations of each diagnostic method currently available in clinical practice, and present recent research on the utility of new wearable technologies to assist with iRBD diagnosis, which may offer a more practical assessment method for clinicians. This review highlights the importance of thorough clinical investigation when patients present with suspected iRBD and emphasises the need for easier access to diagnostic procedures for accurate and early diagnosis.

Predictors of dream enactment behavior among medical students: The case of the University of Gondar, Ethiopia

INTRODUCTION

Dream enactment behavior is one of the features of rapid eye movement sleep behavior disorder. It might be a manifestation of neurodegenerative diseases and can lead to fall associated injuries. There is no evidence of dream enactment behavior and its associated factors in Ethiopia. Hence, this study targeted to pinpoint the predictors of dream enactment behavior among Medical students at the University of Gondar.

METHODS

The cross-sectional survey was carried out at the University of Gondar among Medical students selected by simple random sampling technique from Dec 2020 to Feb 2021. We used a structured pretested questionnaire to collect the data and dream enactment behavior was evaluated using rapid eye movement sleep behavior disorder single question. Descriptive statistics were computed, and determinant factors were identified using binary logistic regression model. In the final model, explanatory variables with a p<0.05 were considered as predictors (statistically significant) of the dream enactment behavior. The strength of association was determined using adjusted odds ratio (AOR) with its 95% CI.

RESULTS

Four-hundred and twelve students took part in the study with 97.4% response rate. The mean age of participants was 20.82(±1.88) years and 291(70.63%) were males. The prevalence of dream enactment was 34.47% (95% CI: 30.02-39.20). Daytime sleepiness score (AOR = 1.104; 95% CI: 1.053-1.160), age (AOR = 1.15; 95% CI: 1.019-1.290), monthly pocket money (AOR = 0.9991; 95% CI: 0.9985-0.9997), alcohol drink (AOR = 2.71; 95% CI: 1.076-6.846), and perceived stress (AOR = 3.854; 95% CI: 1.802-8.242) were statistically significant factors of dream enactment behavior.

CONCLUSIONS

In this study, the magnitude of dream enactment behavior was high which was significantly associated with daytime sleepiness score, age, monthly pocket money, alcohol drink, and perceived stress all of which are modifiable except age. The University of Gondar has to plan a strategy to avert the condition via the prevention of the determinant factors. Students need to reduce stress and avoid alcohol drink. We strongly urge forthcoming scholars to ascertain association of dream enactment and academic performance of university students.

A series of 8 cases of sleep-related psychogenic dissociative disorders and proposed updated diagnostic criteria

STUDY OBJECTIVES

To identify the most relevant clinical and video-polysomnographic characteristics of patients with sleep-related dissociative disorders (SRDDs) and to propose a framework for new diagnostic criteria.

METHODS

We searched potential SRDD cases from the scientific literature and from a database of patients referred for clinical and video-polysomnographic assessment in a single sleep disorders center for disruptive nocturnal behaviors (n = 731). The most relevant clinical and neurophysiological characteristics of the cases were extracted and a descriptive analysis was performed.

RESULTS

Twenty-six SRDD cases (8 new and 18 previously published cases) were reviewed. Almost all cases of SRDDs occurred in a context of past traumatic events or abuse and were associated with at least 1 comorbid psychiatric disorder. We highlighted 4 relevant clinical characteristics of SRDD useful for the differential diagnosis with parasomnias: episodes of long duration of more than 1 hour (90.9%), self-inflicted injuries (83.3%), occurrence while awake close to bedtime (35.7%), and the presence of daytime dissociative symptoms (72.7%). The video-polysomnography documented typical episodes of SRDD with prolonged wakefulness before, during, and after the event in 11/26 cases. New diagnostic criteria for SRDD were proposed, with 3 levels of certainty for the diagnosis based on clinical, video-polysomnographic, and homemade video findings.

CONCLUSIONS

More than 30 years after its formal identification, SRDD is not currently recognized as an official diagnostic entity. We better delineate the clinical and neurophysiological features of SRDD and propose a framework for its reinstatement in the next revisions of the sleep and psychiatric disorders classifications.

CITATION

Lopez R, Lefevre L, Barateau L, Micoulaud-Franchi J-A, Dauvilliers Y, Schenck CH. A series of 8 cases of sleep-related psychogenic dissociative disorders and proposed updated diagnostic criteria. J Clin Sleep Med. 2022;18(2):563-573.

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.

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 Disturbance, Sleep Disorders and Co-Morbidities in the Care of the Older Person

Sleep complaints can be both common and complex in the older patient. Their consideration is an important aspect of holistic care, and may have an impact on quality of life, mortality, falls and disease risk. Sleep assessment should form part of the comprehensive geriatric assessment. If sleep disturbance is brought to light, consideration of sleep disorders, co-morbidity and medication management should form part of a multifaceted approach. Appreciation of the bi-directional relationship and complex interplay between co-morbidity and sleep in older patients is an important element of patient care. This article provides a brief overview of sleep disturbance and sleep disorders in older patients, in addition to their association with specific co-morbidities including depression, heart failure, respiratory disorders, gastro-oesophageal reflux disease, nocturia, pain, Parkinson's disease, dementia, polypharmacy and falls. A potential systematic multidomain approach to assessment and management is outlined, with an emphasis on non-pharmacological treatment where possible.

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.

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.

Dream enactment behavior: review for the clinician

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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.

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.

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.

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.

REM sleep atonia loss distinguishes synucleinopathy in older adults with cognitive impairment

OBJECTIVE

To determine whether quantitative polysomnographic REM sleep without atonia (RSWA) distinguishes between cognitive impairment phenotypes.

BACKGROUND

Neurodegenerative cognitive impairment in older adults predominantly correlates with tauopathy or synucleinopathy. Accurate antemortem phenotypic diagnosis has important prognostic and treatment implications; additional clinical tools might distinguish between dementia syndromes.

METHODS

We quantitatively analyzed RSWA in 61 older adults who underwent polysomnography including 46 with cognitive impairment (20 probable synucleinopathy), 26 probable non-synucleinopathy (15 probable Alzheimer disease, 11 frontotemporal lobar dementia), and 15 age- and sex-matched controls. Submentalis and anterior tibialis RSWA metrics and automated REM atonia index were calculated. Group statistical comparisons and regression were performed, and receiver operating characteristic curves determined diagnostic RSWA thresholds that best distinguished synucleinopathy phenotype.

RESULTS

Submentalis-but not anterior tibialis RSWA-was greater in synucleinopathy than nonsynucleinopathy; several RSWA diagnostic thresholds distinguished synucleinopathy with excellent specificity including submentalis tonic, 5.6% (area under the curve [AUC] 0.791); submentalis any, 15.0% (AUC 0.871); submentalis phasic, 10.8% (AUC 0.863); and anterior tibialis phasic, 31.4% (AUC 0.694). In the subset of patients without dream enactment behaviors, submentalis RSWA was also greater in patients with synucleinopathy than in those without synucleinopathy. RSWA was detected more frequently by quantitative than qualitative methods (p = 0.0001).

CONCLUSION

Elevated submentalis RSWA distinguishes probable synucleinopathy from probable nonsynucleinopathy in cognitively impaired older adults, even in the absence of clinical dream enactment symptoms.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that quantitative RSWA analysis is useful for distinguishing cognitive impairment phenotypes. Further studies with pathologic confirmation of dementia diagnoses are needed to confirm the diagnostic utility of RSWA in dementia.

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.

REM sleep muscle activity in idiopathic REM sleep behavior disorder predicts phenoconversion

OBJECTIVE

To determine whether REM sleep without atonia (RSWA) during polysomnography (PSG) predicts phenoconversion in patients with idiopathic REM sleep behavior disorder (iRBD), a prodromal feature of a neurodegenerative disease.

METHODS

We analyzed RSWA in 60 patients with iRBD, including manual phasic, tonic, and any muscle activity in the submentalis and anterior tibialis muscles and the automated REM atonia index in the submentals. We identified patients who developed parkinsonism or mild cognitive impairment (MCI) during at least 3 years of follow-up after PSG. Kaplan-Meier analysis was performed and receiver operator curves were calculated to determine RSWA cutoffs predicting faster phenoconversion.

RESULTS

Twenty-six (43%) patients developed parkinsonism (n = 17) or MCI (n = 9). Phenoconverters were older at iRBD diagnosis (p = 0.02). Median time to phenoconversion was 3.9 ± 2.5 years. iRBD phenoconverters had significantly more RSWA at diagnosis. Phenoconversion risk from iRBD diagnosis was 20% and 35% at 3 and 5 years, respectively, with greater risk in patients with iRBD with >46.4% any combined RSWA, which increased further to 30% and 55% at 3 and 5 years for patients >65 years of age at diagnosis.

CONCLUSIONS

Patients with iRBD with higher amounts of polysomnographic RSWA had a greater risk of developing Parkinson disease or MCI. Patients with older age and higher RSWA amounts had more rapid phenoconversion than younger patients with RBD. Our study suggests that RSWA is a potential biomarker for risk stratification of iRBD phenoconversion that could facilitate prognostication for patients with iRBD.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that for patients with iRBD, increased RSWA correlates with increased risk for developing parkinsonism or MCI.

Physician and patient determinants of prognostic counseling in idiopathic REM sleep-behavior disorder

OBJECTIVES/BACKGROUND

Prognostic counseling about the risk for developing overt neurodegenerative disorders for patients with idiopathic REM sleep-behavior disorder (iRBD) and isolated REM sleep without atonia (iRSWA) is difficult, given lack of disease-modifying interventions and uncertainty in accurate prognostication for individuals. We aimed to analyze patient and physician characteristics associated with documented prognostic discussions for patients with iRBD and iRSWA.

PATIENTS/METHODS

We retrospectively reviewed the medical records for 138 (112 iRBD and 26 iRSWA) patients seen at the Mayo Clinic between 2012 and 2015. We analyzed physician and patient demographics, initial complaint, and other information discussed during office visits. We then comparatively analyzed the impact of physician and patient characteristics on documented prognostic discussions using Chi Square or Fischer's exact test.

RESULTS

Mean iRBD patient age was 65.0 ± 13.0, and mean iRSWA age was 58 ± 15 years. Seventy-eight (69.6%) iRBD and 22 (84.6%) iRSWA patients were men. Sixty-two (55%) iRBD and three (12%) iRSWA patients received prognostic counseling about phenoconversion risk. iRBD was a secondary complaint in 67 (59.8%). Patients over age 60 years and those having iRBD as a chief complaint more frequently received prognostic discussions than those with opposite characteristics (all p < 0.05). Patient sex and antidepressant use were not associated with counseling. Sleep neurologists disclosed prognostic information most frequently, with male more likely than female clinicians to disclose prognoses.

CONCLUSIONS

Several patient and physician characteristics appear to influence documented prognostic counseling for iRBD/RSWA patients. Future studies of iRBD/RSWA patients' preferences are needed to clarify ethically appropriate physician-patient communication concerning prognosis.

REM sleep behaviour disorder

Rapid eye movement (REM) sleep behaviour disorder (RBD) is a parasomnia that is characterized by loss of muscle atonia during REM sleep (known as REM sleep without atonia, or RSWA) and abnormal behaviours occurring during REM sleep, often as dream enactments that can cause injury. RBD is categorized as either idiopathic RBD or symptomatic (also known as secondary) RBD; the latter is associated with antidepressant use or with neurological diseases, especially α-synucleinopathies (such as Parkinson disease, dementia with Lewy bodies and multiple system atrophy) but also narcolepsy type 1. A clinical history of dream enactment or complex motor behaviours together with the presence of muscle activity during REM sleep confirmed by video polysomnography are mandatory for a definite RBD diagnosis. Management involves clonazepam and/or melatonin and counselling and aims to suppress unpleasant dreams and behaviours and improve bedpartner quality of life. RSWA and RBD are now recognized as manifestations of an α-synucleinopathy; most older adults with idiopathic RBD will eventually develop an overt neurodegenerative syndrome. In the future, studies will likely evaluate neuroprotective therapies in patients with idiopathic RBD to prevent or delay α-synucleinopathy-related motor and cognitive decline.

Rapid eye movement sleep behavior disorder and the link to alpha-synucleinopathies

Rapid eye movement (REM) sleep behavior disorder (RBD) involves REM sleep without atonia in conjunction with a recurrent nocturnal dream enactment behavior, with vocalizations such as shouting and screaming, and motor behaviors such as punching and kicking. Secondary RBD is well described in association with neurological disorders including Parkinson's disease (PD), multiple system atrophy (MSA), and other conditions involving brainstem structures such as tumors. However, RBD alone is now considered to be a potential harbinger of later development of neurodegenerative disorders, in particular PD, MSA, dementia with Lewy bodies (DLB), and pure autonomic failure. These conditions are linked by their underpinning pathology of alpha-synuclein protein aggregation. In RBD, it is therefore important to recognize the potential risk for later development of an alpha-synucleinopathy, and to investigate for other potential causes such as medications. Other signs and symptoms have been described in RBD, such as orthostatic hypotension, or depression. While it is important to recognize these features to improve patient management, they may ultimately provide clinical clues that will lead to risk stratification for phenoconversion. A critical need is to improve our ability to counsel patients, particularly with regard to prognosis. The ability to identify who, of those with RBD, is at high risk for later neurodegenerative disorders will be paramount, and would in addition advance our understanding of the prodromal stages of the alpha-synucleinopathies. Moreover, recognition of at-risk individuals for neurodegenerative disorders may ultimately provide a platform for the testing of possible neuroprotective agents for these neurodegenerative disorders.

REM Sleep Behavior Disorder: Diagnosis, Clinical Implications, and Future Directions

Rapid eye movement sleep behavior disorder (RBD) is diagnosed by a clinical history of dream enactment accompanied by polysomnographic rapid eye movement sleep atonia loss (rapid eye movement sleep without atonia). Rapid eye movement sleep behavior disorder is strongly associated with neurodegenerative disease, especially synucleinopathies such as Parkinson disease, dementia with Lewy bodies, and multiple system atrophy. A history of RBD may begin several years to decades before onset of any clear daytime symptoms of motor, cognitive, or autonomic impairments, suggesting that RBD is the presenting manifestation of a neurodegenerative process. Evidence that RBD is a synlucleinopathy includes the frequent presence of subtle prodromal neurodegenerative abnormalities including hyposmia, constipation, and orthostatic hypotension, as well as abnormalities on various neuroimaging, neurophysiological, and autonomic tests. Up to 90.9% of patients with idiopathic RBD ultimately develop a defined neurodegenerative disease over longitudinal follow-up, although the prognosis for younger patients and antidepressant-associated RBD is less clear. Patients with RBD should be treated with either melatonin 3 to 12 mg or clonazepam 0.5 to 2.0 mg to reduce injury potential. Prospective outcome and treatment studies of RBD are necessary to enable accurate prognosis and better evidence for symptomatic therapy and future neuroprotective strategies.

Sleep Disturbances in Frontotemporal Dementia

Sleep disorders appear to be frequent comorbidities in patients with frontotemporal dementia (FTD). Insomnia and excessive daytime sleepiness commonly occur in patients with FTD and significantly contribute to caregiver burden and burnout. Sleep is severely fragmented in FTD patients, likely secondary to behavioral disturbances, other primary sleep disorders such as sleep disordered breathing and restless leg syndrome, and neurodegeneration of nuclei involved in sleep and wakefulness. Treatment of primary sleep disorders may improve excessive daytime sleepiness and sleep quality and may improve daytime cognitive functioning. Rapid eye movement (REM) sleep behavior disorder is rare in FTD and may be confused with excessive nocturnal activity due to disturbed circadian rhythm. The relationship between FTD, sleep quality, and sleep disorders requires further study to better understand the contribution of disturbed sleep to daytime neurocognitive functioning and quality of life in FTD. Further, future studies should focus on comparing sleep disturbances between different FTD syndromes, especially behavioral variant FTD and primary progressive aphasia. Comorbid sleep disorders should be promptly sought and treated in patients with FTD to improve patient and caregiver quality of life.