Pre- and post-treatment PSG data were available for 29 participants (74.4%). Dream-related score was found to be significantly associated with periodic limb movement index (PLMI) (R=0.44, P<0.01), while significant associations were observed between behavioral sub-score and total REM-related EMG activities (REMREEA) (R= 0.42, P<0.01) and tonic REMREEA (R= 0.39, P<0.05). Behavioral sub-score was also nearly correlated with age of RBD onset (R= –0.30, P=0.06) and phasic REMREEA (R= 0.32, P=0.05).
Participants scored significantly lower on RBDQ-3M overall scale (P<0.001), dream-related subscale (P<0.001), behavioral subscale (P<0.001), and ESS (P<0.05) after treatment. There was a significant increase in stage 2 sleep (Mean (SD): 65.2% (7.7) vs 69.0% (8.4), P<0.05, Cohen’s d = ––0.37), total REMREEA (Median (IQR): 21.0 (6.6-53.5) vs 32.3 (11.0-61.3), P=0.03, Cohen’s d = –0.38), and tonic REMREEA (Median (IQR): 9.0 (0.7-39.6) vs 20.6 (3.3-40.2), P=0.048, Cohen’s d = –0.33) observed as well. No significant change in daytime sleepiness was observed, and CPAP usage did not appear to affect ESS score.
A significant decrease in the frequency of nightmares and dreams with violent or frightening content was observed after treatment. There was also a reduction in shouting and yelling, limb movements, falling out of bed, potentially injurious behaviors to self and/or bed partner, and actual sleep-related injuries. Treatment response was reported in 66.7% of participants, with 33.3% still reporting SRI or potentially injurious behaviors of varying frequency. Participants with younger age of RBD onset and those with comorbid OSA were less likely to respond to treatment. No association between treatment response, severity of RBD symptoms, comorbid psychiatric disorders, or development of neurodegenerative disorders was observed.
Ultimately, clonazepam improved RBD, however residual symptoms were common. The authors suggest that more effective or adjunctive interventions may be available and need to be explored in order to reach better clinical management of RBD.
Li SX, Lam SP, Zhang J, et al. A prospective, naturalistic follow-up study of treatment outcomes with clonazepam in rapid eye movement sleep behavior disorder. Sleep Med. 2016; doi: 10.1016/j.sleep.2015.12.020.