Parkinson's disease and sleep.

Sleep disorders are common in PD and many factors can contribute to disturbed nocturnal sleep and daytime sleepiness. Factors contributing to sleep disturbance include the presence of insomnia, mood or anxiety disorders, dementia, specific sleep disorders, PD motor disorders, and the effects of PD or medications. Patients who have PD should be interrogated about sleep disturbance and daytime sleepiness and preferably, because of underestimation of the severity of sleepiness or lack of awareness, patients should be interviewed in the presence of a close friend or relative. The ability to drive, if sleepiness is present, should be assessed and appropriate recommendations made. Treatment of sleepiness involves treating any underlying sleep disturbance and may involve the use of stimulant or alerting medications in the daytime.