Longitudinal change in dopamine transporter availability in idiopathic REM sleep behavior disorder

Objective: To elucidate longitudinal changes in the dopamine transporter (DAT) availability in association with the prodromal markers in idiopathic rapid-eye-movement sleep behavior disorder (iRBD), we analyzed a longitudinal prospective iRBD cohort data.

Method: The study cohort consisted of iRBD, Parkinson’s disease (PD) patients and healthy controls. All participants were evaluated for olfaction, neuropsychological tests, the Movement disorders society-Unified Parkinson’s disease Rating Scale and underwent 18F-FP-CIT PET scans every 2 years. We calculated the DAT pattern by performing the principal component analysis of tracer uptakes in 6 striatal regions.

Results: DAT patterns in iRBD patients with baseline hyposmia, constipation and mild parkinsonian signs distributed toward PD-pattern and clearly distinguished from the healthy control pattern. The DAT pattern moved toward PD-pattern over time in some iRBD patients during the follow-up and baseline hyposmia was the only biom...