Clonazepam may not be the best available treatment for REM sleep behavior disorder (RBD), according to a study published in Sleep Medicine.
Although regarded as the first-line treatment for RBD due to its ability to reduce injurious behaviors, there is a lack of quantitative measures evaluating treatment response for both dream-related and behavioral symptoms.
To better delineate treatment response, researchers from The Chinese University of Hong Kong, The University of Hong Kong, and the Sleep Medicine Center at West China Hospital conducted a prospective study to examine characteristic changes in the clinical and polysomnographic features of RBD in patients treated with clonazepam.
Thirty-nine patients with confirmed idiopathic RBD (male: 74.4%, mean age at diagnosis: 68.3 ± 7.8 years) were recruited between 2008 and 2011. Enrolled patients were not receiving pharmacological treatment for RBD prior to the study, and were not diagnosed with any concurrent neurological disorder. Clonazepam was offered as first-line treatment to all participants, with a follow-up duration of 28.8 ± 13.3 months. All participants underwent at least 1 night of video polysomnography with audiovisual recording at baseline prior to treatment, and completed a follow-up video polysomnographic (PSG) study, which included electroencephalogram (EEG) (F4/M1, C4/M1, O2/M1); bilateral electrooculogram (EOG); electrocardiogram (ECG); electromyogram (EMG) of mentalis, bilateral extensor digitorum, and bilateral anterior tibialis muscle; airflow; respiratory effort; oxygen saturation (SaO2); breathing sound; and body position.
Of the 39 participants, 8 (20.5%) developed a neurodegenerative disorder during follow-up, and 17 (43.6%) were diagnosed with obstructive sleep apnea (OSA), 10 (58.8%) of whom reported regular CPAP usage. Initial average dose of clonazepam was 0.43 mg, with 27 (69.2) participants remaining on clonazepam at follow-up. Ten participants changed their prescription due to side effects, including daytime somnolence (n=6) and persistent RBD symptoms (n=4), and 2 participants were not on any treatment.