Prodromal Markers in Recurrent Dream Enactment Behaviors Without REM Sleep Without Atonia

This proposed study is a case-control study, which aims to determine whether recurrent DEBs but without sufficient RSWA represents an early stage of α-synucleinopathy. The investigators will recruit 62 participants with recurrent DEBs but without sufficient RSWA and their age-, sex- matched controls from the community and on-going projects. All participants will undergo clinical interview, comprehensive measures of prodromal markers of neurodegeneration (including excessive daytime sleepiness, olfactory functioning, constipation, erectile dysfunction, urinary dysfunction, symptomatic hypotension, depression, and clinical motor markers) as suggested by the International Parkinson and Movement Disorder Society (MDS) research criteria. In addition, a subset of the sample (n = 26 in each group) will undergo the triple-tracer positron emission tomography/computed tomography (PET/CT) imaging protocol of 18F-DOPA, to determine dopamine functions in putamen. This proposed study will help to disentangle the core features of RBD and validate the concept of prodromal RBD with reference to prodromal markers related to α-synucleinopathy neurodegeneration.