Longitudinal change in dopamine transporter availability in idiopathic REM sleep behavior disorder
Shin, Jung Hwan (2021), Longitudinal change in dopamine transporter availability in idiopathic REM sleep behavior disorder, Dryad, Dataset, https://doi.org/10.5061/dryad.3bk3j9kg9
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 biomarker significantly associated with this change. Baseline PD-pattern of DAT predicted 58% of disease converters (Hazard Ratio=4.95 [1.16~21.08]). The combination of hyposmia and baseline PD pattern of DAT predicted 67% of the conversion (Hazard Ratio=7.89 [1.85~33.69]). The estimated sample size required for a simulated neuroprotective clinical trial was 63 per group when the annual change of DAT pattern was used as an outcome in the subgroup with baseline DAT PD-pattern and hyposmia, which is the smallest number reported so far.
Conclusion: Baseline and longitudinal monitoring of the DAT pattern can be a useful biomarker in identifying individuals with a high risk of disease conversion and in selecting the potential population for clinical trials in iRBD.