Familial Aggregation and Biomarkers in REM Sleep Behaviour Disorder.

• Conditions: REM Sleep Behavior Disorder

• Registration Number: NCT03660982
• Lead Sponsor: Chinese University of Hong Kong

Brief Summary

In this cohort study, the investigators aim to study the familial aggregation of REM sleep behavior disorder (RBD) and compare the differences in major biomarkers of neurodegeneration, including percentage of EMG activity during REM sleep, cognitive functions, autonomic dysfunction, and psychiatric disorders, between unaffected first degree relatives of RBD cases and non-RBD controls.

Detailed Description

REM sleep behavior disorder (RBD) is a parasomnia characterized by abnormal behavioral manifestations during REM sleep. Previous case-control studies and prospective studies have documented the progression of α-synucleinopathy neurodegeneration in relation to RBD and have identified some biomarkers of predicting neurodegeneration in patients with iRBD, such as olfactory dysfunction, color vision deficit, autonomic dysfunction, tonic EMG activity during REM sleep, and psychiatric disorder. However, these biomarkers might precede the onset of RBD, as a result, searching for biomarkers for the neurodegeneration before RBD onset is helpful to map the progression of neurodegeneration. In this regard, the investigators aim to study the familial aggregation of RBD and its core features, and compare the differences in major biomarkers of neurodegeneration, including percentage of EMG activity during REM sleep, cognitive functions, autonomic dysfunction, and psychiatric disorders, between unaffected first degree relatives of RBD cases and non-RBD controls.

Study Timeline

• Study Start: 2014-10-01
• Study First Submitted: 2018-08-30
• Study First Submitted QC: 2018-09-04
• Study First Posted: 2018-09-07
• Status Verified: 2021-08
• Last Update Submitted: 2021-08-05
• Last Update Posted: 2021-08-06
• Primary Completion: 2022-09-30
• Study Completion: 2022-09-30

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 400

Inclusion Criteria

1. Chinese aged 40 or above;
2. Being capable of giving informed consent for participation of the study;
3. Sex matched between relatives from probands and controls.

Exclusion Criteria

1. Aged 39 or below;
2. Not capable of giving informed consent for participation of the study

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
The weighted prevalence rate of confirmed RBD among first degree relatives of RBD probands.	one night (8 hours)	The weighted prevalence rate of first degree relatives meeting full ICSD-II2 diagnostic criteria for RBD confirmed by clinical history and vPSG.
The prevalence rate of probable RBD among first degree relatives of RBD probands	15 minutes	The prevalence rate of probable RBD based on the self-reported/proxy-reported RBD symptoms in RBDQ-HK among first degree relatives of RBD probands in comparison to that of first degree relatives of controls.

Secondary Outcome Measures

Name	Time	Method
Other biomarkers of RBD in the first degree relatives of RBD patients.	2 hours	Previous studies have also confirmed that RBD patients present with autonomic dysfunction, olfactory dysfunction, color vision deficit, neurocognitive function, and a higher rate of psychiatric disorders, these markers will also be considered as secondary biomarkers and will be compared in the first degree relatives of between patients and controls.
The percentage of REM-related EMG activity (REMREEA)	one night (8 hours)	The percentage of REM-related EMG activity (REMREEA) is the most reliable and valid marker in differentiating patients with RBD from normal controls. Basically, the REMREEA include two components, namely phasic EMG activity and tonic EMG activity, respectively. The phasic EMG events were defined as any burst of EMG activity lasting 0.1 to 5 sec with amplitude \> 4 times the background EMG activity and will be score on the basis of 3-second mini-epoch during REM sleep. Each 30-sec epoch during REM sleep was scored as tonic or atonic depending on whether tonic chin EMG activity was present for more or less than 50% of the epoch. The total EMG activity was presented as the percentage of REM related EMG activity (REMREEA) with the percentage of tonic EMG activity plus the percentage of phasic EMG activity.
Significant motor activity	one night (8 hours)	Significant motor activity were recorded by video-polysomnography. The motor analysis will be scored according to the previously established method. In view of the potential problem in inter-rater reliability in those mild motor activities, we will only include those complex activities and vocalizations in the analyses. It has been shown that there are large differences in the significant motor activities between patients with RBD and normal controls. In view of the relatively high night-to-night variability and low inter-rater reliability in scoring motor activity, it will be considered as secondary outcome.

Trial Locations

Locations (1)

Department of psychiatry, Faculty of Medicine, The Chinese University of Hong Kong; 🇭🇰 Hong Kong, Hong Kong