Treatment of insomnia in Parkinson's disease: a controlled trial of eszopiclone and placebo.

Parkinson's disease (PD) is a common neurodegenerative disease affecting up to 1 million individuals in the United States. Sleep disturbances, typically in sleep maintenance, are found in up to 88% of these individuals and are associated with a variety of poor outcomes. Despite being common and important, there are few data to guide clinical care. We conducted a 6-week, randomized, controlled trial of eszopiclone and placebo in 30 patients with PD and insomnia. Patients with other primary sleep disorders (PSG defined) were excluded. The primary outcome was total sleep time (TST), and secondary measures included wake after sleep onset (WASO), number of awakenings, and quality of sleep, among others. The groups did not significantly differ on TST, but significant differences, favoring eszopiclone, did emerge in number of awakenings (P = 0.035), quality of sleep (P = 0.018), and in physician-rated CGI improvement (P = 0.035). There was also a trend toward significance in WASO (P = 0.071). There were no significant differences between groups in measures of daytime functioning. The drug was well tolerated, with 33% of patients on eszopiclone and 27% of patients on placebo reporting adverse events. Although modest in size, this is the first controlled study of the treatment of insomnia in patients with PD. Eszopiclone did not increase TST significantly but was superior to placebo in improving quality of sleep and some measures of sleep maintenance, which is the most common sleep difficulty experienced by patients with PD. Definitive trials of the treatment of sleep disorders in this population are warranted.