Prevalence of and risk factors for probable rapid eye movement sleep behavior disorder in Chinese patients with essential tremor.

OBJECTIVES

To investigate the prevalence and risk factors for probable rapid eye movement (REM) sleep behavior disorder (pRBD) in Chinese patients with essential tremor (ET).

METHODS

In this cross-sectional study, 391 ET patients underwent assessments of sociodemographics, lifestyles, environmental exposures, medical histories, and motor/nonmotor symptoms. pRBD status was evaluated using the RBD screening questionnaire (RBDSQ). Risk factors for pRBD in ET patients were identified via multivariable logistic regression.

RESULTS

Fifty-six patients (14.3 %) met the criteria for pRBD, with a male predominance (60.7 %). Patients with pRBD were significantly older (mean age: 61.43 vs. 51.99 years) and had late tremor onset (49.34 vs. 42.21 years) than those without pRBD (both Padjusted < 0.05). They also showed higher prevalence of jaw tremor (32.1 % vs. 9.3 %), depressive symptoms (67.9 % vs. 43.3 %), antidepressant use (10.7 % vs. 1.8 %), elevated anxiety scores (Hamilton Anxiety Rating Scale: 12.38 ± 7.47 vs. 9.05 ± 6.09), and depression scores (Hamilton Depression Rating Scale-24: 11.25 ± 7.81 vs. 7.91 ± 6.20) (all Padjusted < 0.05). Multivariate analysis identified male sex (OR = 3.038, P = 0.001), older age (OR = 1.045, P < 0.001), jaw tremor (OR = 3.734, P = 0.001), at least mild depression (OR = 2.484, P = 0.006), and antidepressant use (OR = 6.069, P = 0.009) were independent predictors.

CONCLUSIONS

pRBD affects approximately 1/7 of ET patients. Identified risk factors overlap with α-synucleinopathy-associated features (male predominance, jaw tremor, depressive symptoms), suggesting ET-pRBD patients may constitute a phenoconversion-prone subgroup requiring long-term monitoring. Antidepressants known to exacerbate RBD symptoms should be prescribed judiciously in this population.