Melatonin therapy for REM sleep behavior disorder

Causal associations between modifiable risk factors and isolated REM sleep behavior disorder: a mendelian randomization study

Objectives

This Mendelian randomization (MR) study identified modifiable risk factors for isolated rapid eye movement sleep behavior disorder (iRBD).

Methods

Genome-wide association study (GWAS) datasets for 29 modifiable risk factors for iRBD in discovery and replication stages were used. GWAS data for iRBD cases were obtained from the International RBD Study Group. The inverse variance weighted (IVW) method was primarily employed to explore causality, with supplementary analyses used to verify the robustness of IVW findings. Co-localization analysis further substantiated causal associations identified via MR. Genetic correlations between mental illness and iRBD were identified using trait covariance, linkage disequilibrium score regression, and co-localization analyses.

Results

Our study revealed causal associations between sun exposure-related factors and iRBD. Utilizing sun protection (odds ratio [OR] = 0.31 [0.14, 0.69], p = 0.004), ease of sunburn (OR = 0.70 [0.57, 0.87], p = 0.001), childhood sunburn occasions (OR = 0.58 [0.39, 0.87], p = 0.008), and phototoxic dermatitis (OR = 0.78 [0.66, 0.92], p = 0.003) decreased iRBD risk. Conversely, a deep skin color increased risk (OR = 1.42 [1.04, 1.93], p = 0.026). Smoking, alcohol consumption, low education levels, and mental illness were not risk factors for iRBD. Anxiety disorders and iRBD were genetically correlated.

Conclusion

Our study does not corroborate previous findings that identified smoking, alcohol use, low education, and mental illness as risk factors for iRBD. Moreover, we found that excessive sun exposure elevates iRBD risk. These findings offer new insights for screening high-risk populations and devising preventive measures.

A case report of atypical sleep in an ischemic stroke patient with psychiatric symptoms caused by olanzapine

Antipsychotics, tricyclic and 5-hydroxytryptamine reuptake inhibitors (SSRI) and 5-hydroxytryptamine and norepinephrine reuptake inhibitor (SNRI) antidepressants, and monoamine oxidase inhibitors can produce dream-rendering behaviors and/or dystonic deregulation during REM sleep. Acute episodes are also seen with withdrawal from alcohol or sedative-hypnotics, and the use of tricyclic and SSRI antidepressants. In this article, we present a case of olanzapine treatment of a patient with cerebrovascular disease with psychobehavioural symptoms. The patient was an elderly patient who developed psychobehavioural symptoms after a sudden cerebral infarction. Initially, his symptoms improved when he took olanzapine (5 mg orally once/night). However, the patient subsequently developed symptoms of hypersomnia when he continued to take olanzapine, and the symptoms of hypersomnia gradually worsened as the dose of olanzapine was gradually increased. Benzodiazepines are often used to treat anomalous sleep, and clonazepam is one of the commonly prescribed drugs. In this case, the patient's abnormal sleep behavior was alleviated after treatment with clonazepam. As an atypical antipsychotic drug, olanzapine has been reported to cause abnormal sleep behavior during clinical use, and only one case has been reported in China. Clinicians should be aware that heteromorphic sleep can occur in patients treated with olanzapine.

Melatonin enhances the restoration of neurological impairments and cognitive deficits during drug withdrawal in methamphetamine-induced toxicity and endoplasmic reticulum stress in rats

Methamphetamine (METH) is a psychostimulant with a very high addiction rate. Prolonged use of METH has been observed as one of the root causes of neurotoxicity. Melatonin (Mel) has been found to have a significant role in METH-induced neurotoxicity. This study aimed to investigate the restorative effect of Mel on behavioral flexibility in METH-induced cognitive deficits. Male Sprague-Dawley rats were randomly assigned to be intraperitoneally injected with saline (control) or Meth at 5 mg/kg for 7 consecutive days. Then, METH injection was withdrawn and rats in each group were subcutaneously injected with saline or Mel at 10 mg/kg for 14 consecutive days. The stereotypic behavioral test and attentional set-shifting task (ASST) were used to evaluate neurological functions and cognitive flexibility, respectively. Rats developed abnormal features of stereotyped behaviors and deficits in cognitive flexibility after 7 days of METH administration. However, post-treatment with Mel for 14 days after METH withdrawal dramatically ameliorated the neurological and cognitive deficits in METH-treated rats. Blood biomarkers indicated METH-induced systemic low-grade inflammation. Moreover, METH-induced endoplasmic reticulum (ER) stress in the prefrontal cortex was diminished by melatonin supplementation. These findings might reveal the therapeutic potential of Mel in METH toxicity-induced neurological and cognitive deficits.

Significant potential of melatonin therapy in Parkinson's disease - a meta-analysis of randomized controlled trials

Objective

Since its discovery as an antioxidant, melatonin has been increasingly recognized for its therapeutic potential beyond sleep disturbances in neurodegenerative disorders. This study aims to evaluate efficacy of various melatonin doses, treatment durations, and formulations, in alleviating motor symptoms and sleep disturbances in Parkinson's disease, the second most common neurodegenerative disorder worldwide.

Methods

PubMed, Cochrane Library, ClinicalTrials.gov and other databases were systematically searched to retrieve randomized controlled trials (RCTs) administrating melatonin to Parkinson's disease patients until June 10th, 2023. Outcomes including Unified Parkinson Disease Rating Scale (UPDRS) scores and Pittsburgh Sleep Quality Index (PSQI) scores, were pooled and reported as mean differences (MD) with 95% confidence intervals (CIs). Meta-analysis was performed using an inverse variance random-effects model in Review Manager 5.4 software. Trial Sequential Analysis was performed to avoid false-positive results from random errors.

Results

Five RCTs with a total of 155 patients were included. Statistically significant reductions in UPDRS total scores were observed in groups receiving Melatonin ≥10 mg/day (MD = -11.35, 95% CI: -22.35 to -0.35, I2 = 0%, p = 0.04) and immediate release formulations (MD = -11.35, 95% CI: -22.35 to -0.35, I2 = 0%, p = 0.04). No significant effects on individual UPDRS II, III, and IV scores were observed, regardless of melatonin dosage and treatment duration. Moreover, significant improvements in PSQI scores were observed with only immediate-release melatonin formulations (MD = -2.86, 95% CI: -4.74 to -0.97, I2 = 0%, p = 0.003).

Conclusion

Melatonin ≥10 mg/day for a minimum duration of ≥12 weeks in immediate-release formulations consistently demonstrated significant therapeutic potential in improving motor symptom and sleep disturbances in Parkinson disease. However, further trials are warranted to investigate its impact when initiated early in the disease course to fully explore its true therapeutic potential.

Systematic review registration

Unique identifier: CRD42023427491 (PROSPERO).

Targeting neuroendocrine abnormalities in Parkinson's disease with exercise

Parkinson's Disease (PD) is a prevalent and complex age-related neurodegenerative condition for which there are no disease-modifying treatments currently available. The pathophysiological process underlying PD remains incompletely understood but increasing evidence points to multiple system dysfunction. Interestingly, the past decade has produced evidence that exercise not only reduces signs and symptoms of PD but is also potentially neuroprotective. Characterizing the mechanistic pathways that are triggered by exercise and lead to positive outcomes will improve understanding of how to counter disease progression and symptomatology. In this review, we highlight how exercise regulates the neuroendocrine system, whose primary role is to respond to stress, maintain homeostasis and improve resilience to aging. We focus on a group of hormones - cortisol, melatonin, insulin, klotho, and vitamin D - that have been shown to associate with various non-motor symptoms of PD, such as mood, cognition, and sleep/circadian rhythm disorder. These hormones may represent important biomarkers to track in clinical trials evaluating effects of exercise in PD with the aim of providing evidence that patients can exert some behavioral-induced control over their disease.

Pharmacological interventions targeting α-synuclein aggregation triggered REM sleep behavior disorder and early development of Parkinson's disease

Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by elevated motor behaviors and dream enactments in REM sleep, often preceding the diagnosis of Parkinson's disease (PD). As RBD could serve as a biomarker for early PD developments, pharmacological interventions targeting α-synuclein aggregation triggered RBD could be applied toward early PD progression. However, robust therapeutic guidelines toward PD-induced RBD are lacking, owing in part to a historical paucity of effective treatments and trials. We reviewed the bidirectional links between α-synuclein neurodegeneration, progressive sleep disorders, and RBD. We highlighted the correlation between RBD development, α-synuclein aggregation, and neuronal apoptosis in key brainstem regions involved in REM sleep atonia maintenance. The current pharmacological intervention strategies targeting RBD and their effects on progressive PD are discussed, as well as current treatments for progressive neurodegeneration and their effects on RBD. We also evaluated emerging and potential pharmacological solutions to sleep disorders and developing synucleinopathies. This review provides insights into the mechanisms and therapeutic targets underlying RBD and PD, and explores bidirectional treatment effects for both diseases, underscoring the need for further research in this area.

Parkinson's Disease: A Narrative Review on Potential Molecular Mechanisms of Sleep Disturbances, REM Behavior Disorder, and Melatonin

Parkinson's disease (PD) is one of the most common neurodegenerative diseases. There is a wide range of sleep disturbances in patients with PD, such as insomnia and rapid eye movement (REM) sleep behavior disorder (or REM behavior disorder (RBD)). RBD is a sleep disorder in which a patient acts out his/her dreams and includes abnormal behaviors during the REM phase of sleep. On the other hand, melatonin is the principal hormone that is secreted by the pineal gland and significantly modulates the circadian clock and mood state. Furthermore, melatonin has a wide range of regulatory effects and is a safe treatment for sleep disturbances such as RBD in PD. However, the molecular mechanisms of melatonin involved in the treatment or control of RBD are unknown. In this study, we reviewed the pathophysiology of PD and sleep disturbances, including RBD. We also discussed the potential molecular mechanisms of melatonin involved in its therapeutic effect. It was concluded that disruption of crucial neurotransmitter systems that mediate sleep, including norepinephrine, serotonin, dopamine, and GABA, and important neurotransmitter systems that mediate the REM phase, including acetylcholine, serotonin, and norepinephrine, are significantly involved in the induction of sleep disturbances, including RBD in PD. It was also concluded that accumulation of α-synuclein in sleep-related brain regions can disrupt sleep processes and the circadian rhythm. We suggested that new treatment strategies for sleep disturbances in PD may focus on the modulation of α-synuclein aggregation or expression.

Melatonin as a Chronobiotic/Cytoprotective Agent in REM Sleep Behavior Disorder

Dream-enactment behavior that emerges during episodes of rapid eye movement (REM) sleep without muscle atonia is a parasomnia known as REM sleep behavior disorder (RBD). RBD constitutes a prodromal marker of α-synucleinopathies and serves as one of the best biomarkers available to predict diseases such as Parkinson disease, multiple system atrophy and dementia with Lewy bodies. Most patients showing RBD will convert to an α-synucleinopathy about 10 years after diagnosis. The diagnostic advantage of RBD relies on the prolonged prodromal time, its predictive power and the absence of disease-related treatments that could act as confounders. Therefore, patients with RBD are candidates for neuroprotection trials that delay or prevent conversion to a pathology with abnormal α-synuclein metabolism. The administration of melatonin in doses exhibiting a chronobiotic/hypnotic effect (less than 10 mg daily) is commonly used as a first line treatment (together with clonazepam) of RBD. At a higher dose, melatonin may also be an effective cytoprotector to halt α-synucleinopathy progression. However, allometric conversion doses derived from animal studies (in the 100 mg/day range) are rarely employed clinically regardless of the demonstrated absence of toxicity of melatonin in phase 1 pharmacological studies with doses up to 100 mg in normal volunteers. This review discusses the application of melatonin in RBD: (a) as a symptomatic treatment in RBD; (b) as a possible disease-modifying treatment in α-synucleinopathies. To what degree melatonin has therapeutic efficacy in the prevention of α-synucleinopathies awaits further investigation, in particular multicenter double-blind trials.

Management of REM sleep behavior disorder: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment

This systematic review provides supporting evidence for a clinical practice guideline for the management of rapid eye movement (REM) sleep behavior disorder in adults and children. The American Academy of Sleep Medicine commissioned a task force of 7 experts in sleep medicine. A systematic review was conducted to identify randomized controlled trials and observational studies that addressed interventions for the management of REM sleep behavior disorder in adults and children. Statistical analyses were performed to determine the clinical significance of critical and important outcomes. Finally, the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) process was used to assess the evidence for making recommendations. The literature search identified 4,690 studies; 148 studies provided data suitable for statistical analyses; evidence for 45 interventions is presented. The task force provided a detailed summary of the evidence assessing the certainty of evidence, the balance of benefits and harms, patient values and preferences, and resource use considerations.

CITATION

Howell M, Avidan AY, Foldvary-Schaefer N, et al. Management of REM sleep behavior disorder: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment. J Clin Sleep Med. 2023;19(4):769-810.

A critical review of the pharmacological treatment of REM sleep behavior disorder in adults: time for more and larger randomized placebo-controlled trials

Rapid Eye Movement sleep behavior disorder (RBD) is a parasomnia causing sufferers to physically act out their dreams. These behaviors can disrupt sleep and sometimes lead to injuries in patients and their bed-partners. Clonazepam and melatonin are the first-line pharmacological treatment options for RBD based on direct uncontrolled clinical observations and very limited double-blind placebo-controlled trials. Given the risk for adverse outcomes, especially in older adults, it is of great importance to assess the existing level of evidence for the use of these treatments. In this update, we therefore critically review the clinical and scientific evidence on the pharmacological management of RBD in people aged over 50. We focus on the first-line treatments, and provide an overview of all other alternative pharmacological agents trialed for RBD we could locate as supplementary materials. By amalgamating all clinical observations, our update shows that 66.7% of 1,026 RBD patients reported improvements from clonazepam and 32.9% of 137 RBD patients reported improvements from melatonin treatment on various outcome measures in published accounts. Recently, however, three relatively small randomized placebo-controlled trials did not find these agents to be superior to placebo. Given clonazepam and melatonin are clinically assumed to majorly modify or eliminate RBD in nearly all patients-there is an urgent need to test whether this magnitude of treatment effect remains intact in larger placebo-controlled trials.

Management of Sleep Disturbances in Parkinson's Disease

Parkinson's disease (PD) is defined by its motor symptoms rigidity, tremor, and akinesia. However, non-motor symptoms, particularly autonomic disorders and sleep disturbances, occur frequently in PD causing equivalent or even greater discomfort than motor symptoms effectively decreasing quality of life in patients and caregivers. Most common sleep disturbances in PD are insomnia, sleep disordered breathing, excessive daytime sleepiness, REM sleep behavior disorder, and sleep-related movement disorders such as restless legs syndrome. Despite their high prevalence, therapeutic options in the in- and outpatient setting are limited, partly due to lack of scientific evidence. The importance of sleep disturbances in neurodegenerative diseases has been further emphasized by recent evidence indicating a bidirectional relationship between neurodegeneration and sleep. A more profound insight into the underlying pathophysiological mechanisms intertwining sleep and neurodegeneration might lead to unique and individually tailored disease modifying or even neuroprotective therapeutic options in the long run. Therefore, current evidence concerning the management of sleep disturbances in PD will be discussed with the aim of providing a substantiated scaffolding for clinical decisions in long-term PD therapy.

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 and Sleep Disturbance in Subjetcs with Dementia]

Treating sleep disorders is a challenge in individuals with dementia. A precondition for treatment success is thorough diagnostics of sleep disorders. Sleep diaries and observational questionnairs represent important diagnostic tools. In addition to general treatment strategies including optimal treatment of comorbidities, behavioral therapy is a main intervention. Drugs for the treatment of a sleep disorder should only be prescribed with a clear indication and prolongation of prescription should regularly be checked. The active search for and the treatment of sleep disorders should always be performed in individuals with dementia.

Melatonin as a Chronobiotic and Cytoprotective Agent in Parkinson's Disease

This article discusses the role that melatonin may have in the prevention and treatment of Parkinson’s disease (PD). In parkinsonian patients circulating melatonin levels are consistently disrupted and the potential therapeutic value of melatonin on sleep disorders in PD was examined in a limited number of clinical studies using 2–5 mg/day melatonin at bedtime. The low levels of melatonin MT1 and MT2 receptor density in substantia nigra and amygdala found in PD patients supported the hypothesis that the altered sleep/wake cycle seen in PD could be due to a disrupted melatonergic system. Motor symptomatology is seen in PD patients when about 75% of the dopaminergic cells in the substantia nigra pars compacta region degenerate. Nevertheless, symptoms like rapid eye movement (REM) sleep behavior disorder (RBD), hyposmia or depression may precede the onset of motor symptoms in PD for years and are index of worse prognosis. Indeed, RBD patients may evolve to an α-synucleinopathy within 10 years of RBD onset. Daily bedtime administration of 3–12 mg of melatonin has been demonstrated effective in RDB treatment and may halt neurodegeneration to PD. In studies on animal models of PD melatonin was effective to curtail symptomatology in doses that allometrically projected to humans were in the 40–100 mg/day range, rarely employed clinically. Therefore, double-blind, placebo-controlled clinical studies are urgently needed in this respect.

The Treatment of Sleep Dysfunction in Neurodegenerative Disorders

Sleep dysfunction is highly prevalent across the spectrum of neurodegenerative conditions and is a key determinant of quality of life for both patients and their families. Mounting recent evidence also suggests that such dysfunction exacerbates cognitive and affective clinical features of neurodegeneration, as well as disease progression through acceleration of pathogenic processes. Effective assessment and treatment of sleep dysfunction in neurodegeneration is therefore of paramount importance; yet robust therapeutic guidelines are lacking, owing in part to a historical paucity of effective treatments and trials. Here, we review the common sleep abnormalities evident in neurodegenerative disease states and evaluate the latest evidence for traditional and emerging interventions, both pharmacological and nonpharmacological. Interventions considered include conservative measures, targeted treatments of specific clinical sleep pathologies, established sedating and alerting agents, melatonin, and orexin antagonists, as well as bright light therapy, behavioral measures, and slow-wave sleep augmentation techniques. We conclude by providing a suggested framework for treatment based on contemporary evidence and highlight areas that may emerge as major therapeutic advances in the near future.

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.

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.

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.

Understanding the role of sleep and its disturbances in Autism spectrum disorder

BACKGROUND

Several studies have established a positive relationship between sleep difficulties and symptomatology in ASD children. The rationale for this review is to describe and discuss the sleep difficulties, which are one of the significant complications associated with autism spectrum disorder (ASD).

PURPOSE

Many types of sleep disorders have been reported in ASD individuals, but still lack a comprehensive study and in-depth analysis. Despite the contribution of sleep problems to the overall symptoms of ASD, the symptoms of disturbed sleep experienced by many affected patients have only recently started to receive attention from clinicians and family members.

MATERIALS AND METHODS

This narrative overview has been prepared based on searching standard research databases with specific keywords; b. Additional search was made using the bibliographies of the retrieved articles; and c. author's collection of relevant peer-reviewed articles. Once selected, manuscripts are then compared and summarized based on the author's perspective. Results are based on a qualitative rather than a quantitative level.

RESULTS

This article highlights the role of sleep in the brain and neural development of children and emphasizes that the intensity of sleep problems is associated with an increased occurrence of ASD symptoms. It also suggests the significance of treating sleep problems in ASD individuals.

CONCLUSIONS

The review provides broader perspectives and a better understanding of sleep problems in pathophysiology, mechanism, and management with respect to ASD individuals. Finally, the implications for clinical practice and future agendas have also been discussed.

Pineal gland volume is associated with prevalent and incident isolated rapid eye movement sleep behavior disorder

We aimed to investigate the association of pineal gland volume with the risk of isolated rapid eye movement (REM) sleep behavior disorder (RBD). We enrolled 245 community-dwelling cognitively normal elderly individuals without major psychiatric or neurological disorders at the baseline evaluation, of whom 146 completed the 2-year follow-up evaluation. We assessed RBD symptoms using the REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ) and defined probable RBD (pRBD) as an RBDSQ score of ≥ 5. We manually segmented the pineal gland on 3T T1-weighted brain magnetic resonance imaging and estimated its volume. The smaller the baseline pineal gland volume, the more severe the RBD symptoms at baseline. The individuals with isolated pRBD showed smaller pineal gland volumes than those without isolated pRBD. The larger the baseline pineal gland volume, the lower the risks of prevalent isolated pRBD at the baseline evaluation and incident isolated pRBD at the 2-year follow-up evaluation. Pineal gland volume showed good diagnostic accuracy for prevalent isolated pRBD and predictive accuracy for incident isolated pRBD in the receiver operator characteristic analysis. Our findings suggest that pineal gland volume may be associated with the severity of RBD symptoms and the risk of isolated RBD in cognitively normal elderly individuals.

Melatonin for rapid eye movement sleep behavior disorder in Parkinson's disease: A randomised controlled trial

BACKGROUND

Melatonin may reduce REM-sleep behavior disorder (RBD) symptoms in Parkinson's disease (PD), though robust clinical trials are lacking.

OBJECTIVE

To assess the efficacy of prolonged-release (PR) melatonin for RBD in PD.

METHODS

Randomized, double-blind, placebo-controlled, parallel-group trial with an 8-week intervention and 4-week observation pre- and postintervention (ACTRN12613000648729). Thirty PD patients with rapid eye movement sleep behavior disorder were randomized to 4 mg of prolonged-release melatonin (Circadin) or matched placebo, ingested orally once-daily before bedtime. Primary outcome was the aggregate of rapid eye movement sleep behavior disorder incidents averaged over weeks 5 to 8 of treatment captured by a weekly diary. Data were included in a mixed-model analysis of variance (n = 15 per group).

RESULTS

No differences between groups at the primary endpoint (3.4 events/week melatonin vs. 3.6 placebo; difference, 0.2; 95% confidence interval = -3.2 to 3.6; P = 0.92). Adverse events included mild headaches, fatigue, and morning sleepiness (n = 4 melatonin; n = 5 placebo).

CONCLUSION

Prolonged-release melatonin 4 mg did not reduce rapid eye movement sleep behavior disorder in PD. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

A Stage-Based Approach to Therapy in Parkinson's Disease

Parkinson’s disease (PD) is a neurodegenerative disorder that features progressive, disabling motor symptoms, such as bradykinesia, rigidity, and resting tremor. Nevertheless, some non-motor symptoms, including depression, REM sleep behavior disorder, and olfactive impairment, are even earlier features of PD. At later stages, apathy, impulse control disorder, neuropsychiatric disturbances, and cognitive impairment can present, and they often become a heavy burden for both patients and caregivers. Indeed, PD increasingly compromises activities of daily life, even though a high variability in clinical presentation can be observed among people affected. Nowadays, symptomatic drugs and non-pharmaceutical treatments represent the best therapeutic options to improve quality of life in PD patients. The aim of the present review is to provide a practical, stage-based guide to pharmacological management of both motor and non-motor symptoms of PD. Furthermore, warning about drug side effects, contraindications, as well as dosage and methods of administration, are highlighted here, to help the physician in yielding the best therapeutic strategies for each symptom and condition in patients with PD.

Prolonged-release melatonin in patients with idiopathic REM sleep behavior disorder

Objective

We investigated the effects of prolonged-release melatonin (PRM) on idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD).

Methods

In this 4-week, randomized, double-blind, placebo-controlled pilot study, 30 participants with polysomnography-confirmed iRBD were assigned to receive PRM 2 mg per day, PRM 6 mg per day, or placebo. Medication was administered orally 30 min before bedtime. Primary outcomes included scores from the Clinical Global Impression-Improvement (CGI-I) and the Korean version of the RBD questionnaire-Hong Kong (RBDQ-KR). The secondary outcomes included RBDQ-KR factor 1 and factor 2 subscores, the Pittsburgh Sleep Quality Index score, the Epworth Sleepiness Scale score, the Short Form Health Survey version 2 score, and the frequency of dream-enacting behaviors assessed using a sleep diary.

Results

After 4 weeks, there were no differences in the proportions of patients with a CGI-I score of much improved or very much improved among the study groups. In addition, RBDQ-KR scores and secondary outcomes were not improved in all groups at 4 weeks, and there were no differences between the groups.

Conclusion

Our findings suggest that PRM may not be effective in treating RBD-related symptoms within the dose range used in this study. Further studies using doses higher than 6 mg per day are warranted.

Sleep Disorders

Sleep disorders are frequent and can have serious consequences on patients' health and quality of life. While some sleep disorders are more challenging to treat, most can be easily managed with adequate interventions. We review the main diagnostic features of 6 major sleep disorders (insomnia, circadian rhythm disorders, sleep-disordered breathing, hypersomnia/narcolepsy, parasomnias, and restless legs syndrome/periodic limb movement disorder) to aid medical practitioners in screening and treating sleep disorders as part of clinical practice.

Melatonin: Clinical Perspectives in Neurodegeneration

Prevention of neurodegenerative diseases is presently a major goal for our Society and melatonin, an unusual phylogenetically conserved molecule present in all aerobic organisms, merits consideration in this respect. Melatonin combines both chronobiotic and cytoprotective properties. As a chronobiotic, melatonin can modify phase and amplitude of biological rhythms. As a cytoprotective molecule, melatonin reverses the low degree inflammatory damage seen in neurodegenerative disorders and aging. Low levels of melatonin in blood characterizes advancing age. In experimental models of Alzheimer's disease (AD) and Parkinson's disease (PD) the neurodegeneration observed is prevented by melatonin. Melatonin also increased removal of toxic proteins by the brain glymphatic system. A limited number of clinical trials endorse melatonin's potentiality in AD and PD, particularly at an early stage of disease. Calculations derived from animal studies indicate cytoprotective melatonin doses in the 40-100 mg/day range. Hence, controlled studies employing melatonin doses in this range are urgently needed. The off-label use of melatonin is discussed.

Twenty Years After: Another Case Report of Melatonin Effects on REM Sleep Behavior Disorder, Using Serial Dopamine Transporter Imaging

INTRODUCTION

REM sleep behavior disorder (RBD) is considered a prodromal phase of α-synucleinopathy like Parkinson disease (PD). PD is characterized by a progressive decline of dopamine (DA) in the striatum. Here we report the surprising increase in DA transporter density over successive years in an RBD patient treated with melatonin.

CASE PRESENTATION

A then 72-year-old man was clinically suspected to suffer from PD in 2011. DA transporter scintigraphy (DaTSCAN) revealed reduced DA transporter density, and the patient was diagnosed with developing PD. Because of outacting dreams every night (speaking, yelling, kicking, pushing) he was referred to our clinic. Video-assisted polysomnography (PSG) confirmed the diagnosis of RBD in 2012. Management and Outcome: Melatonin treatment (2 mg slow release/day; 30 min prior to habitual bedtime; always at the same clock time) was initiated after PSG and continued. After 6 months of gradual improvement, clinical signs of RBD were absent. Control PSG in 2014 confirmed normalized REM sleep with atonia. Furthermore, no clinical sign of neurodegeneration occurred ever since. Additional DaTSCANs were performed in 2013 and 2015. Whereas the 2011 scan prior to melatonin treatment bore clear signs of PD, the 2013 scan was considered borderline and the 2015 scan without any sign of PD.

DISCUSSION

To the best of our knowledge, DA transporter density increase over time has never been reported in a single subject, neither healthy aged individuals nor patients suffering from RBD or PD. We interpret these results as a possible neuroprotective role for melatonin in synucleinopathy.

Trauma-Associated Sleep Disturbances: a Distinct Sleep Disorder?

PURPOSE OF REVIEW

This paper describes a newly proposed sleep disorder, trauma-associated sleep disorder (TSD). Whether or not this represents a truly unique condition is controversial. In this paper, we describe the overlapping features and differences between TSD, post-traumatic stress disorder (PTSD) and Rapid Eye Movement (REM) sleep behavior disorder (RBD).

RECENT FINDINGS

While REM sleep without atonia (RWA) and dream enactment are part of the diagnostic criteria for both RBD and TSD, only TSD features nightmares that occur both in non-REM and REM. A key difference between TSD and PTSD is the presence of symptoms during wakefulness in the latter, though the relationship between the two disorders is, as of yet, unclear. It is unknown whether or not a relationship exists between TSD and neurodegeneration, thus this needs to be explored further.

SUMMARY

Additional research, such as application of TSD diagnostic criteria to more diverse population, would help to determine whether or not TSD is a distinct clinical entity, its relationships to PTSD, as well as the association of this condition with the development of neurodegeneration.

Treatment of Sleep Dysfunction in Parkinson's Disease

OPINION STATEMENT

Impaired sleep and alertness affect the majority of Parkinson's disease (PD) patients, negatively impacting safety and quality of life. The etiology of impaired sleep-wake cycle in PD is multifactorial and encompasses medication side effects, nocturnal PD motor symptoms, and presence of co-existent sleep and neuropsychiatric disorders. The primary neurodegenerative process of PD involves brain regions that regulate the sleep-wake cycle, such as brainstem and hypothalamic nuclei. Sleep disorders in PD include insomnia, REM sleep behavior disorder (RBD), sleep disordered breathing (SDB), restless legs syndrome (RLS), and circadian disruption. Despite its high prevalence in the PD population, there is a paucity of clinical studies that have investigated treatment of sleep dysfunction associated with PD. Therefore, we aim to review available evidence and outline treatment strategies for improvement of disorders of sleep and wakefulness in PD patients. Evidence supporting the efficacy of pharmacological and non-pharmacological treatment strategies in PD is limited. There is thus a great need but also opportunity for development of well-designed clinical trials for impaired sleep and alertness in PD. Providing education about sleep hygiene and strategies for its implementation represents the initial step in management. Prompt diagnosis and treatment of co-existent primary sleep and psychiatric disorders are critical, as this may significantly improve sleep and alertness. While the optimal treatment for insomnia in PD has not been established, available strategies include cognitive-behavioral therapy, medications with soporific properties, and light therapy. Safety measures, clonazepam, and melatonin are the mainstay of treatment for RBD. Continuous positive airway pressure is an effective treatment for SDB in PD. The treatment algorithm for RLS associated with PD mirrors that used for idiopathic RLS. Circadian disruption has emerged as an important etiology of impaired sleep-wake cycles in PD, and circadian-based interventions hold promise for novel treatment approaches.

Management of sleep disorders in Parkinson's disease and multiple system atrophy

Parkinson's disease (PD) and multiple system atrophy (MSA) are disorders associated with α synuclein-related neurodegeneration. Nonmotor symptoms are common hallmarks of these disorders, and disturbances of the sleep-wake cycle are among the most common nonmotor symptoms. It is only recently that sleep disturbances have received the attention of the medical and research community. Significant progress has been made in understanding the pathophysiology of sleep and wake disruption in alphasynucleinopathies during the past few decades. Despite these advancements, treatment options are limited and frequently associated with problematic side effects. Further studies that center on the development of novel treatment approaches are very much needed. In this article, the author discusses the current state of the management of disturbed sleep and alertness in PD and MSA. © 2017 International Parkinson and Movement Disorder Society.

Treatment of REM Sleep Behavior Disorder

OPINION STATEMENT

REM sleep behavior disorder (RBD) is a common parasomnia disorder affecting between 1 and 7 % of community-dwelling adults, most frequently older adults. RBD is characterized by nocturnal complex motor behavior and polysomnographic REM sleep without atonia. RBD is strongly associated with synucleinopathy neurodegeneration. The approach to RBD management is currently twofold: symptomatic treatment to prevent injury and prognostic counseling and longitudinal follow-up surveillance for phenoconversion toward overt neurodegenerative disorders. The focus of this review is symptomatic treatment for injury prevention. Injury occurs in up to 55 % of patients prior to treatment, even when most behaviors seem to be infrequent or minor, so patients with RBD should be treated promptly following diagnosis to prevent injury risk. A sound evidence basis for symptomatic treatment of RBD remains lacking, and randomized controlled treatment trials are needed. Traditional therapeutic mainstays with relatively robust retrospective case series level evidence include melatonin and clonazepam, which appear to be equally effective, although melatonin is more tolerable. Melatonin also has one small randomized controlled crossover trial supporting its use for RBD treatment. Melatonin dosed 3-12 mg at bedtime should be considered as the first-line therapy, followed by clonazepam 0.25-2.0 mg at bedtime if initial melatonin is judged ineffective or intolerable. However, neither agent is likely to completely stop dream enactment behaviors, so choosing a moderate target dosage of melatonin 6 mg or clonazepam 0.5 mg, or the highest tolerable dosage that reduces attack frequency and avoids adverse effects from overtreatment, is currently the most reasonable strategy. Alternative second- and third-line therapies with anecdotal efficacy include temazepam, lorazepam, zolpidem, zopiclone, pramipexole, donepezil, ramelteon, agomelatine, cannabinoids, and sodium oxybate. A novel non-pharmacological approach is a bed alarm system, although this may be most useful in patients who also report sleep walking or a history of leaving their bed during dream enactment episodes. The benefit of hypnosis, especially in those with psychiatric RBD, also requires further study. RBD is an attractive target for future neuroprotective treatment trials to prevent evolution of overt parkinsonism or memory decline, but currently, there are no known effective treatments and future trials will be necessary to determine if RBD is an actionable time point in the evolution of overt synucleinopathy.

Sleep Disorders in Neurologic Practice: A Case-based Approach

Sleep disorders are common in neurology practice, but are often undiagnosed and untreated. Specific patient cohorts, such as older adults, patients residing in nursing homes, and patients with underlying chronic neurologic and psychiatric disorders, are at particular risk. If these sleep problems are not properly evaluated and managed the patient may experience exacerbation of the underlying neurologic disorder. This article highlights some of the key sleep disorders relevant to practicing neurologists, emphasizing hypersomnolence, insomnia, and sleep-related movement disorders in the setting of neurologic disorders to enhance the tools available for evaluation, and discusses management strategies.

An Open-Labeled Trial of Ramelteon in Idiopathic Rapid Eye Movement Sleep Behavior Disorder

STUDY OBJECTIVES

Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by REM sleep without atonia and elaborate motor activity in association with dream mentation. The melatonin receptor agonist ramelteon has been documented as being effective in two patients with secondary RBD. However, there are no reports on ramelteon treatment for idiopathic RBD.

METHODS

In an open-labeled trial, we treated 12 consecutive patients with idiopathic RBD for at least 4 w with 8 mg ramelteon given within 30 min before bedtime.

RESULTS

Ramelteon treatment did not have a clear effect on REM sleep without atonia or an RBD severity scale measured by video-supported polysomnography. However, clinical assessment using a visual analog scale showed a trend toward significance and there were also definitely positive changes in some individual cases. Ramelteon was well tolerated in most patients, with minor side effects.

CONCLUSIONS

Considering that ramelteon is associated with few side effects, further study may ascertain whether patients with RBD could be effectively treated by ramelteon, especially when clonazepam may not be suitable due to its side effects.

COMMENTARY

A commentary on this article appears in this issue on page 643.

Beneficial Effects of Ramelteon on Rapid Eye Movement Sleep Behavior Disorder Associated with Parkinson's Disease - Results of a Multicenter Open Trial

Objective Melatonin is effective for treating patients with rapid eye movement sleep behavior disorder (RBD). Ramelteon, a novel hypnotic, acts as a melatonin receptor agonist. In the current study, we investigated the effects of ramelteon on sleep disorders, including RBD, in patients with Parkinson's disease (PD). Methods We evaluated 35 patients from multiple centers with idiopathic PD accompanied by sleep disturbances (age: 69.1±11.1 years; 17 men, 18 women; PD morbidity: 6.9±5.7 years; Hoehn & Yahr stage: 2.5±0.8; levodopa dose equivalent: 561±401 mg/day). The patients received 8 mg of ramelteon before sleep once daily for 12 weeks. Motor and sleep symptoms were evaluated both before and after ramelteon administration. Results Of the 35 patients enrolled in this study, 24 (68.6%) were diagnosed with probable RBD (pRBD) using the Japanese version of the RBD screening questionnaire. Ramelteon administration reduced the severity of sleep disturbances in patients with PD. It also lowered scores on the Japanese version of the RBD questionnaire in patients with PD and pRBD. Conclusion Ramelteon may have beneficial effects on sleep disturbances, especially on RBD in patients with PD.

Sleep, Cognition and Dementia

The older patient population is growing rapidly around the world and in the USA. Almost half of seniors over age 65 who live at home are dissatisfied with their sleep, and nearly two-thirds of those residing in nursing home facilities suffer from sleep disorders. Chronic and pervasive sleep complaints and disturbances are frequently associated with excessive daytime sleepiness and may result in impaired cognition, diminished intellect, poor memory, confusion, and psychomotor retardation all of which may be misinterpreted as dementia. The key sleep disorders impacting patients with dementia include insomnia, hypersomnolence, circadian rhythm misalignment, sleep disordered breathing, motor disturbances of sleep such as periodic leg movement disorder of sleep and restless leg syndrome, and parasomnias, mostly in the form of rapid eye movement (REM) sleep behavior disorder (RBD). RBD is a pre-clinical marker for a class of neurodegenerative diseases, the "synucleinopathies", and requires formal polysomnographic evaluation. Untreated sleep disorders may exacerbate cognitive and behavioral symptoms in patients with dementia and are a source of considerable stress for bed partners and family members. When left untreated, sleep disturbances may also increase the risk of injury at night, compromise health-related quality of life, and precipitate and accelerate social and economic burdens for caregivers.

Can Avoiding Light at Night Reduce the Risk of Breast Cancer?

Excessive exposure to artificial light at night (ALAN) suppresses nocturnal melatonin (MLT) production in the pineal gland and is, therefore, associated with an increased risk of breast cancer (BC). We examined indoor and outdoor light habits of 278 women, BC patients (n = 93), and controls (n = 185; 2010-2014). Cases and controls were age and residential area matched. Data regarding behavior in the sleeping habitat in a 5-year period, 10 to 15 years prior to disease diagnosis, were collected using a questionnaire. Sleep quality, bedtime, sleep duration, TV watching habits, presleeping reading habits, subjective illumination intensity, and type of illumination were collected. Binary logistic regression models were used to calculate odds ratios with 95% confidence intervals (ORs with 95% CIs) for BC patients in relation to those habits. OR results revealed that women who had slept longer (controls), 10 to 15 years before the time of the study, in a period of 5 years, had a significant (OR = 0.74; 95% CI = 0.57-0.97; P < .03) reduced BC risk. Likewise, women who had been moderately exposed to ALAN as a result of reading using bed light (reading lamp) illumination and women who had slept with closed shutters reduced their BC risk: OR = 0.81, 95% CI = 0.67-0.97, P < .02, and OR = 0.82, 95% CI = 0.68-0.99, P < .04, respectively. However, women who had been exposed to ALAN as a result of living near strong illumination sources were at a significantly higher BC risk (OR = 1.52; 95% CI = 1.10-2.12; P < .01). These data support the hypothesis that diminishing nighttime light exposure will diminish BC risk and incidence. This hypothesis needs to be tested directly using available testing strategies and technologies that continuously measure an individual's light exposure, its timing, and sleep length longitudinally and feed this information back to the individual, so that BC risk can be distinguished prospectively.

Effect of melatonin on sleep disorders in a monkey model of Parkinson's disease

OBJECTIVES

To evaluate and compare the effects of melatonin and levodopa (L-dopa) on sleep disorders in a monkey model of Parkinson's disease.

MATERIALS AND METHODS

The daytime and nighttime sleep patterns of four macaques that were rendered parkinsonian by administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were recorded using polysomnography in four conditions: at baseline, during the parkinsonian condition; after administration of L-dopa, and after administration of a combination of melatonin with L-dopa.

RESULTS

It was confirmed that MPTP intoxication induces sleep disorders, with sleep episodes during daytime and sleep fragmentation at nighttime. L-dopa treatment significantly reduced the awake time during the night and tended to improve all other sleep parameters, albeit not significantly. In comparison to the parkinsonian condition, combined treatment with melatonin and L-dopa significantly increased total sleep time and sleep efficiency, and reduced the time spent awake during the night in all animals. A significant decrease in sleep latencies was also observed in three out of four animals. Compared with L-dopa alone, combined treatment with melatonin and L-dopa significantly improved all these sleep parameters in two animals. On the other hand, combined treatment had no effect on sleep architecture and daytime sleep.

CONCLUSION

These data demonstrated, for the first time, objective improvement on sleep parameters of melatonin treatment in MPTP-intoxicated monkeys, showing that melatonin treatment has a real therapeutic potential to treat sleep disturbances in people with Parkinson's disease.

Management of REM sleep behavior disorder: An evidence based review

Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by dream enactment behavior resulting from a loss of REM skeletal muscle atonia. The neurobiology of REM sleep and the characteristic features of REM atonia have an important basis for understanding the aggravating etiologies the proposed pharmacological interventions in its management. This review outlines the evidence for behavioral and therapeutic measures along with evidence-based guidelines for their implementation, impact on falls, and effect on polysomnography (PSG) while highlighting the non-motor, autonomic, and cognitive impact of this entity. PubMed databases were reviewed upto May 2013 in peer-reviewed scientific literature regarding the pathophysiology and management of RBD in adults. The literature was graded according to the Oxford centre of evidence-based Medicine Levels. An early intervention that helps prevent consequences such as falls and provides a base for intervention with neuroprotective mechanisms and allocates a unique platform that RBD portrays with its high risk of disease conversion with a sufficiently long latency. RBD provides a unique platform with its high risk of disease conversion with a sufficiently long latency, providing an opportunity for early intervention both to prevent consequences such as falls and provide a base for intervention with neuroprotective mechanisms.

Melatonin therapy for REM sleep behavior disorder: a critical review of evidence

Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia associated with dream enactment often involving violent or potentially injurious behaviors during REM sleep that is strongly associated with synucleinopathy neurodegeneration. Clonazepam has long been suggested as the first-line treatment option for RBD. However, evidence supporting melatonin therapy is expanding. Melatonin appears to be beneficial for the management of RBD with reductions in clinical behavioral outcomes and decrease in muscle tonicity during REM sleep. Melatonin also has a favorable safety and tolerability profile over clonazepam with limited potential for drug-drug interactions, an important consideration especially in elderly individuals with RBD receiving polypharmacy. Prospective clinical trials are necessary to establish the evidence basis for melatonin and clonazepam as RBD therapies.

Treatment of the sleep disorders associated with Parkinson's disease

Sleep disorders are common in patients with Parkinson's disease (PD), and preliminary work has suggested viable treatment options for many of these disorders. For rapid eye movement sleep behavior disorder, melatonin and clonazepam are most commonly used, while rivastigmine might be a useful option in patients whose behaviors are refractory to the former. Optimal treatments for insomnia in PD have yet to be determined, but preliminary evidence suggests that cognitive-behavioral therapy, light therapy, eszopiclone, donepezil, and melatonin might be beneficial. Use of the wake-promoting agent modafinil results in significant improvement in subjective measures of excessive daytime sleepiness, but not of fatigue. Optimal treatment of restless legs syndrome and obstructive sleep apnea in PD are not yet established, although a trial of continuous positive airway pressure for sleep apnea was recently completed in PD patients. In those patients with early morning motor dysfunction and disrupted sleep, the rotigotine patch provides significant benefit.

The relationship between thermoregulation and REM sleep behaviour disorder in Parkinson's disease

BACKGROUND

This study explored the relationship between symptoms of rapid eye movement sleep behaviour disorder, thermoregulation and sleep in Parkinson's Disease.

METHODS

The study group comprised 12 patients with Parkinson's Disease and 11 healthy age-matched controls. We investigated markers of thermoregulation (core-body temperature profile), circadian rhythm (locomotor actigraphy) and sleep (polysomnography).

RESULTS

The mesor (the mean value around which the core temperature rhythm oscillates) of the core-body temperature in patients with Parkinson's Disease was significantly lower than that of controls. In addition, the nocturnal fall in CBT (the difference between the mesor and the nadir temperature) was also significantly reduced in PD patients relative to controls. Furthermore, in patients the reduction in the amplitude of their core-body temperature profile was strongly correlated with the severity of self-reported rapid eye movement sleep behaviour disorder symptom, reduction in the percentage of REM sleep and prolonged sleep latency. By contrast, these disturbances of thermoregulation and sleep architecture were not found in controls and were not related to other markers of circadian rhythm or times of sleep onset and offset.

CONCLUSIONS

These findings suggest that the brainstem pathology associated with disruption of thermoregulation in Parkinson's disease may also contribute to rapid eye movement sleep behavioural disorder. It is possible that detailed analysis of the core-body temperature profile in at risk populations such as those patients with idiopathic rapid eye movement sleep behaviour disorder might help identify those who are at high risk of transitioning to Parkinson's Disease.

Dementia and sleep

Sleep evaluation can be essential in the treatment of dementia because sleep-related issues are common in dementia, often treatable, affect patient function, and are a major cause of caregiver distress. This article provides a practical approach to treatment of sleep in patients with dementia. Certain specific sleep disorders can be associated with certain underlying disorders and greater knowledge of these relationships is leading to more refined treatment approaches. Whether a sleep-related disorder such as obstructive sleep apnea, or limited sleep time, predisposes to the development of dementia is an active area of research.