Disruption of sleep and alertness is one of the most disabling non-motor symptoms of
Parkinson's disease (PD). Mechanisms leading to impaired sleep and alertness in PD are not
well understood, and treatment options remain limited. The proposed research will examine
markers of the circadian system, sleepiness and sleep quality in PD patients. Further, the
project will examine effects of bright light exposure on circadin function, sleep and
alertness in PD.