Age of Diagnosis and Comorbid PLMD Predict Poor Response of REM Behavior Disorder to Clonazepam

Previous studies have shown the therapeutic effects of clonazepam for rapid eye movement sleep behavior disorder (RBD), but they had several limitations such as the lack of clear definition of treatment outcomes and little information about adjuvant therapy. The aims of this study were to evaluate the treatment outcomes with clonazepam and to explore possible determinants of treatment response. We performed a retrospective medical chart review of 171 patients with RBD. All the participants underwent overnight polysomnography and completed questionnaires. The positive treatment response was defined as the absence of disruptive behaviors causing sleep-related injuries during the last year of follow-up. Among the 171 patients presented with disruptive behaviors, 155 (90.6%) experienced positive treatment responses. Of the responders, 18 (11.6%) received adjunctive medication due to insufficient therapeutic effect of clonazepam monotherapy. After adjusted analysis, an earlier age of diagnosis (odds ratio [OR] = 0.74, 95% confidence interval [CI] = 0.64-0.86, P < .001) and comorbid periodic limb movement during sleep (OR = 4.96, 95% CI = 1.05-23.33, P = .043) were related to poor treatment response. Clinicians should recognize the predictors of poor treatment response and consider combination therapy for better prevention of sleep-related injuries in those who show unsatisfactory responses to clonazepam monotherapy.