Prevalence and Impact of Probable REM Sleep Behavior Disorder in Essential Tremor: A Multicenter Cross‐Sectional Study

OBJECTIVES: To investigate the prevalence of probable REM sleep behavior disorder (pRBD) in essential tremor (ET), identify associated risk factors, and evaluate its effects on motor and non-motor symptoms. METHODS: Clinical data were collected from 1297 ET patients across multicenter. pRBD was assessed using the RBD Questionnaire-Hong Kong (RBDQ-HK). Risk factors associated with pRBD were identified through multivariable logistic regression. Furthermore, a meta-analysis was conducted to synthesize existing estimates of pRBD/RBD prevalence in ET. RESULTS: In this study, pRBD was identified in 11.6% of ET patients. Meta-analysis yielded pooled prevalence estimates of 16% for pRBD (ES = 0.16, 95% CI [0.10-0.21]) and 14% for RBD (ES = 0.14, 95% CI [0.07-0.21]). ET patients with pRBD were older (59.89 ± 13.99 vs. 54.63 ± 16.59 years, p < 0.001) and had a later tremor onset (47.55 ± 15.98 vs. 43.15 ± 17.62 years, p = 0.007) compared with those without pRBD. ET-pRBD patients also exhibited a higher frequency of midline tremor (54.67% vs. 43.93%, p = 0.003), rest tremor (27.33% vs. 16.04%, p = 0.001), and elevated Non-Motor Symptom Scale (NMSS) scores (20.30 ± 18.50 vs. 10.43 ± 12.42, p < 0.001). Multivariable logistic regression identified lower educational attainment (OR = 0.93, p = 0.002) and higher NMSS scores (OR = 1.03, p < 0.001) as independent risk factors. CONCLUSIONS: pRBD is prevalent in ET and independently associated with lower education and increased non-motor symptom burden. Recognition of pRBD may help identify an ET subgroup with distinctive clinical features.