REM sleep behaviour disorder

BACKGROUND: Patients with Multiple System Atrophy (MSA) frequently report non-motor symptoms, and several research groups have highlighted this. OBJECTIVE: We systematically searched for and reviewed papers assessing prevalence of non-motor symptoms (NMS) in MSA patients as reported in the scientific literature. METHODS: We performed a systematic review of studies of subjects with MSA (involving > 10 patients) who were assessed for NMS, published in the English literature in PUBMED and EMBASE databases from 1947-2022...

BACKGROUND: Mild cognitive impairment (MCI), an intermediate stage between normal aging and dementia, has emerged as a prominent research area in geriatric care due to its heightened propensity for progressing toward dementia. Sleep plays a pivotal role in cognitive function, with dyssomnias not only exacerbating cognitive and affective symptoms associated with neurodegenerative diseases but also contributing to disease progression. AIM: This bibliometric analysis investigates the global research on MCI with dyssomnias over the past two decades, aiming to discern key findings, research domains, and emerging trends in this field...

Retinal thickness is related to Parkinson's disease (PD), but its association with the severity of PD is still unclear. We conducted a Mendelian randomized (MR) study to explore the association between retinal thickness and PD. For the two-sample MR analysis, the summary statistics obtained from genome-wide association studies on the thickness of Retinal nerve fiber layer (RNFL) and ganglion cell inner plexiform layer (GCIPL) were employed as exposure, while the summary statistics associated with PD were used as the outcome...

Non-rapid eye movement parasomnia disorders, also called disorders of arousal, are characterized by abnormal nocturnal behaviours, such as confusional arousals or sleep walking. Their pathophysiology is not yet fully understood, and objective diagnostic criteria are lacking. It is known, however, that behavioural episodes occur mostly in the beginning of the night, after an increase in slow-wave activity during slow-wave sleep. A better understanding of the prospect of such episodes may lead to new insights in the underlying mechanisms and eventually facilitate objective diagnosis...

Isolated rapid eye movement (REM) sleep behaviour disorder (iRBD) is a sleep disorder that is characterised by dream enactment episodes during REM sleep. It is the strongest known predictor of α-synuclein-related neurodegenerative disease (αNDD), such that >80% of people with iRBD will eventually develop Parkinson's disease, dementia with Lewy bodies, or multiple system atrophy in later life. More research is needed to understand the trajectory of phenoconversion to each αNDD. Only five 'gold standard' prevalence studies of iRBD in older adults have been undertaken previously, with estimates ranging from 0...

Patients with Parkinson's disease (PD) show a broad heterogeneity in clinical presentation, and subtypes may already arise in prodromal disease stages. Isolated REM sleep behaviour disorder (iRBD) is the most specific marker of prodromal PD, but data on clinical subtyping of patients with iRBD remain scarce. Therefore, this study aimed to identify iRBD subtypes. We conducted comprehensive clinical assessments in 66 patients with polysomnography-proven iRBD, including motor and non-motor evaluations, and applied a two-step cluster analysis...

BACKGROUND AND PURPOSE: Neuropsychiatric symptoms including depression, apathy and psychosis occur frequently in patients with Parkinson's disease. A subgroup of patients develop cognitive impairment, which may increase the risk of falls due to reduced attention. The acetylcholinesterase inhibitor rivastigmine is beneficial in Parkinson's disease dementia, but whether the use of rivastigmine is effective earlier in the disease course is unclear. The aim of this systematic review was to assess the evidence for rivastigmine in the treatment of neuropsychiatric symptoms in Parkinson's disease without dementia...

OBJECTIVE: Impulse control behaviors (ICBs) frequently coexist with Parkinson's disease (PD). However, the predictors of ICBs in PD remain unclear, and there is limited data on the biological correlates of ICBs in PD. In this study, we examined clinical, imaging, and biological variables to identify factors associated with longitudinal changes in ICBs in early-stage PD. METHODS: The data for this study were obtained from the Parkinson's Progression Markers Initiative, an international prospective cohort study that evaluates markers of disease progression in PD...

Extinction of conditioned fear is considered a fundamental process in the recovery from posttraumatic stress disorder and anxiety disorders. Sleep, especially rapid-eye-movement (REM) sleep, has been implicated in promoting extinction memory. The orexin system contributes to the regulation of sleep and wakefulness and emotional behaviors. In rodents, administrations of an orexin receptor antagonist following fear extinction training enhanced consolidation of extinction memory. Although orexin antagonists increase sleep, including REM sleep, the possible contribution of sleep to the effects of orexin antagonists on extinction memory has not been examined...

Excessive fragmentary myoclonus (EFM) is a frequent finding during routine video-polysomnography (VPSG). We aimed to automatically measure the prevalence of EFM according to current American Academy of Sleep Medicine (AASM) criteria, and the fragmentary myoclonus index (FMI) in sleep stage N1, N2, N3, rapid eye movement (REM) sleep and wake in a large patient population. A total of 500 VPSG recordings of patients admitted to the Sleep Laboratory, Department of Neurology, Medical University of Innsbruck, Austria, between May 1, 2022 and February 28, 2023, were included...

Insufficient sleep syndrome possibly represents the worldwide leading cause of daytime sleepiness, but remains poorly recognised and studied. The aim of this case series is to comprehensively describe a cohort of patients with insufficient sleep syndrome. Eighty-two patients were studied concerning demographic and socio-economic features, medical, psychiatric and sleep comorbidities, substance use, sleep symptoms, actigraphy, video-polysomnography, multiple sleep latency tests and treatment. The typical patient with insufficient sleep syndrome is a middle-aged adult (with no difference of gender), employed, who has a family, often carrying psychiatric and neurological comorbidities, in particular headache, anxiety and depression...

INTRODUCTION: The aim of our study was to find out the opinion of patients with Parkinson's Disease (PD) whose disease was preceded by REM sleep behaviour disorder (RBD) regarding early information about the high risk of phenoconversion in RBD. CLINICAL RATIONALE FOR THE STUDY: RBD is an early clinical manifestation of α-synucleinopathies with a more than 90% risk of phenoconversion to PD, dementia with Lewy bodies (DLB) or multiple system atrophy (MSA). It remains a subject for debate as to whether and how RBD patients should be informed about the high risk of phenoconversion...

Previous prospective studies examining associations of obstructive sleep apnea and sleep macroarchitecture with future cognitive function recruited older participants, many demonstrating baseline cognitive impairment. This study examined obstructive sleep apnea and sleep macroarchitecture predictors of visual attention, processing speed, and executive function after 8 years among younger community-dwelling men. Florey Adelaide Male Ageing Study participants (n = 477) underwent home-based polysomnography, with 157 completing Trail-Making Tests A and B and the Mini-Mental State Examination...

OBJECTIVE: To describe phenotypic, polysomnographic characteristics, impact, and treatment response in children with sleep related rhythmic movement disorder (SR-RMD). BACKGROUND: There is limited research on SR-RMD. We have developed a systematic clinical evaluation of children with SR-RMD to improve understanding and treatment. METHODS: A retrospective chart review of 66 children at a UK tertiary hospital. Baseline assessment included validated screening questionnaires to study autism spectrum characteristics, general behaviour and sensory profile...

Different mouse strains used in biomedical research show different phenotypes associated with their genotypes. Two mouse strains commonly used in biomedical sleep research are C57Bl/6 and C3H/He, the strains differ in numerous aspects, including their ability to secrete melatonin as well as the expression of several sleep-related genes. However, sleep regulation has only limitedly been compared between C3H/HeN and C57Bl/6 mice. We therefore compared sleep-wake behaviour and EEG-measured spectral brain activity for C57bl/6 and C3H/HeN mice during a 12:12 h light: dark baseline and during and after a 6 h sleep deprivation...

The loss of dopamine in the striatum underlies motor symptoms of Parkinson's disease (PD). Rapid eye movement sleep behaviour disorder (RBD) is considered prodromal PD and has shown similar neural changes in the striatum. Alterations in brain iron suggest neurodegeneration; however, the literature on striatal iron has been inconsistent in PD and scant in RBD. Toward clarifying pathophysiological changes in PD and RBD, and uncovering possible biomarkers, we imaged 26 early-stage PD patients, 16 RBD patients, and 39 age-matched healthy controls with 3 T MRI...

BACKGROUND: Recent consensus research criteria have identified a 'psychiatric onset' form of prodromal dementia with Lewy bodies (DLB) characterised by prominent late-onset psychiatric symptoms. Although recognised as important to raise the index of diagnostic suspicion, evidence regarding this cohort was deemed too limited to impose formal criteria. We reviewed the published literature on psychiatric-onset DLB to identify key clinical characteristics and evidence gaps to progress our understanding of this entity...

BACKGROUND: The sleep onset process is an ill-defined complex process of transition from wakefulness to sleep, characterized by progressive modifications at the subjective, behavioural, cognitive, and physiological levels. To this date, there is no international consensus which could aid a principled characterisation of this process for clinical research purposes. The current review aims to systemise the current knowledge about the underlying mechanisms of the natural heterogeneity of this process...

Nightmares are common among the general population and psychiatric patients and have been associated with signs of nocturnal arousal such as increased heart rate or increased high-frequency electroencephalographic (EEG) activity. However, it is still unclear, whether these characteristics are more of a trait occurring in people with frequent nightmares or rather indicators of the nightmare state. We compared participants with frequent nightmares (NM group; n = 30) and healthy controls (controls; n = 27) who spent 4 nights in the sleep laboratory over the course of 8 weeks...

Idiopathic hypersomnia (IH) and Kleine-Levin syndrome (KLS) are rare disorders of central hypersomnolence of unknown cause, affecting young people. However, increased sleep time and excessive daytime sleepiness (EDS) occur daily for years in IH, whereas they occur as relapsing/remitting episodes associated with cognitive and behavioural disturbances in KLS. Idiopathic hypersomnia is characterized by EDS, prolonged, unrefreshing sleep at night and during naps, and frequent morning sleep inertia, but rare sleep attacks, no cataplexy and sleep onset in REM periods as in narcolepsy...