REM sleep behavior disorder was associated with Parkinson's disease: a community-based study

Background: Our study was aimed to validate a modified RBD (REM sleep behavior disorder) single question (RBD1Q-C), study the prevalence of probable RBD (pRBD) in a rural community based on RBD1Q-C and investigate the association between pRBD and Parkinson's disease (PD). Methods: The validation study of RBD1Q-C included 32 Chinese participants (14 idiopathic RBD patients and 18 controls). All participants underwent a polysomnogram (PSG). We then conducted a door-to-door survey to estimate the prevalence of pRBD assessed by RBD1Q-C, and its association with PD among 19614 residents who lived in Malu community of Shanghai, China. Results: RBD1Q-C demonstrated a high sensitivity of 100 %, a moderate specificity of 55.6 %. The agreement between RBD1Q-C and PSG-based RBD diagnosis was good (k = 0.552). PPV of the RBD1Q-C was 63.6 % and NPV was 100 %. The prevalence of pRBD in Malu community was 4.9 %. In people over 50 years old, presence of pRBD was significantly associated with increased risk of having PD (odds ratio = 2.61, 95 % CI: 1.56-4.39). Conclusion: RBD1Q-C was shown to be a useful screening tool. Based on the RBD1Q-C, we found that pRBD was not rare in Chinese rural population and associated with odds of PD, calling for more attention from patients, caregivers and physicians.