Sleep symptoms and polysomnographic architecture in advanced Parkinson's disease after chronic bilateral subthalamic stimulation.

OBJECTIVE To evaluate the sleep symptoms and polysomnographic architecture in advanced Parkinson's disease after chronic bilateral subthalamic stimulation (STN-DBS). METHODS Sleep was studied in 11 patients (six women and five men; mean (SD) age 63.6 (7.8) years) who underwent STN-DBS. Subjective sleep evaluation was assessed by clinical sleep interview and the Pittsburgh sleep quality index (PSQI) questionnaire, and sleep architecture by polysomnography with audiovisual recording. Nocturnal mobility was evaluated. RESULTS Before surgery, eight patients rated their sleep quality as unsatisfactory; seven of these had a marked improvement after surgery, and the PSQI questionnaire showed significantly improved sleep quality. After surgery, polysomnography showed an increase in the longest period of uninterrupted sleep and a decrease in the arousal index. There was an increase in nocturnal mobility after surgery, but no change in REM sleep behaviour disorder. CONCLUSIONS In advanced Parkinson's disease, chronic STN-DBS is associated with subjective improvement in sleep quality, probably through increased nocturnal mobility and reduction of sleep fragmentation.