A prospective, naturalistic follow-up study of treatment outcomes with clonazepam in rapid eye movement sleep behavior disorder

Background: Rapid eye movement sleep behavior disorder (RBD) is characterized by prominent dreamenacting behaviors, often resulting in sleep-related injuries. Objectives: This study aimed to prospectively examine the treatment response of people with RBD treated with clonazepam, by quantitatively delineating the characteristic changes in the clinical and polysomnographic features, and to explore the factors associated with this response. Methods: Patients diagnosed with idiopathic RBD (iRBD) were consecutively recruited and invited to complete clinical and polysomnographic (PSG) assessments and self-administered questionnaires (including the modified REM Sleep Behavior Questionnaire, RBDQ-3M) before and after the initiation of treatment with clonazepam. Results: Thirty-nine iRBD patients (male: 74.4%, mean age at diagnosis: 68.3 +/- 7.8 years) were recruited with a follow-up duration of 28.8 +/- 13.3 months. Clonazepam was offered as the first-line treatment (starting dose: 0.43 +/- 0.16 mg, range: 0.125-1.00; dose at follow-up: 0.98 +/- 0.63 mg, range: 0.125-3). Treatment response, as defined by a complete elimination of sleep-related injuries and potentially injurious behaviors to self and/or to bed partner, at follow-up was reported in 66.7% of the overall study subjects. Frequency of disturbing dreams with violent and frightening content and vigorous behavioral RBD symptoms was significantly reduced, while residual nocturnal symptoms and an increase in REM-related EMG activities were observed at follow-up. Less optimal treatment outcomes were found to be associated with the presence of comorbid obstructive sleep apnea and earlier onset of RBD. Conclusions: Clonazepam differentially changes dream affect and content, as well as reduces vigorous verbal and motor behaviors. Residual RBD symptoms are common, despite treatment. Other more effective alternative or adjunctive interventions are needed for better clinical management of RBD. (C) 2016 Elsevier B.V. All rights reserved.