Cross-sectional and longitudinal associations between probable rapid eye movement sleep behavior disorder and impulse control disorders in Parkinson's disease

Background and purpose The aim was to investigate whether probable rapid eye movement sleep behavior disorder (pRBD) is associated with impulse control disorders (ICDs) in drug-naive patients with Parkinson's disease (PD) and whether baseline pRBD is associated with a higher incidence of ICDs during follow-up. Methods The Parkinson's Progression Markers Initiative is an international, multicenter, prospective cohort study to identify biomarkers of PD progression. In all, 423 drug-naive patients with early-stage PD were included in the cross-sectional analysis, and 320 patients who screened negative for any ICDs or related behaviors at baseline were included in the longitudinal analysis. Results In the cross-sectional analysis, a significant correlation was found between pRBD and ICDs in drug-naive patients whilst controlling for potential confounders [odds ratio 2.56, 95% confidence interval (CI) 1.38-4.76, P = 0.003]. In the longitudinal analysis, baseline pRBD was an independent predictor of ICD development over time [hazard ratio (HR) 1.648, 95% CI 1.054-2.576; P = 0.028]. Other significant predictors of ICDs included younger age of onset (HR = 0.973, 95% CI = 0.950-0.997; P = 0.026) and greater State-Trait Anxiety Inventory score (HR = 1.040, 95% CI = 1.020-1.061; P < 0.001). Conclusion Our data suggest that identifying baseline pRBD in early-stage PD may help clinicians to choose a better therapeutic strategy so as to prevent or limit neuropsychiatric complications.