Sleep and Mental Health

REM sleep behavior disorder is a novel and distinct parasomnia characterized by recurrent dream enactment behaviors (DEBs) and polysomnographic features of REM sleep without atonia (RSWA), with typical onset age at early 60’s. Idiopathic RBD (iRBD) has been suggested as the most specific precursor of α-synucleinopathy-related neurodegeneration (e.g. Parkinson’s disease (PD)). There are increasing reports of positive familial cases in both iRBD and PD. In the past few years, we have established the baseline data of a case-control family cohort of iRBD (250 first-degree relatives (FDR) of patients with iRBD and 230 FDRs of controls). Not only did we confirm the familial aggregation of iRBD with neurodegeneration and iRBD cases but also found that the FDRs harbored a spectrum of isolated RBD features (including DEBs, REM-sleep behavioral events, and RSWA). Besides, when compared with control-FDRs, iRBD-FDRs patients showed more prodromal markers of neurodegeneration (including possible/probable RBD, excessive daytime sleepiness, constipation, and subclinical parkinsonism) as suggested by the International Parkinson and Movement Disorder Society (MDS) research criteria. This current proposed study is a prospective study with a mean of 7-year follow-up interval to monitor the progression of α-synucleinopathy neurodegeneration and related markers. A series of prodromal markers related to neurodegeneration including clinical and sleep assessment (e.g. autonomic symptoms, motor signs, neurocognitive function, sleep parameters, and one-week actigraphy) that were measured at baseline will be reassessed. Specifically, home PSG with a body-movement monitoring system will be additionally implemented in the proposed study to empower the identification of RBD features, especially during the COVID pandemic period at which hospital accessibility is restricted. In addition, the development of clinical neurodegenerative diseases will be ascertained. This proposed study, by recruiting FDRs of iRBD patients (and controls) with prospective study design, will provide novel and important information on the progression of prodromal makers of α-synucleinopathy neurodegenerative diseases in a high-risk population and facilitate further genetic/omics and future neuroprotective intervention study of the familial iRBD.

The participants in this proposed study will be recruited from our established family cohort of iRBD. So far, around 500 subjects have been recruited at baseline, and we expected that more than 80% of them could be followed up in this study.

We hope to invite you to Shatin Hospital or other related research sites for this study If the visit is inconvenient to you, we may also arrange home visits alternatively.