Excessive daytime somnolence associated with Parkinson’s disease

Excessive daytime sleepiness (EDS) occurs in up to 50 % of patients with Parkinson’s disease (PD) and is characterized by an inability to maintain full alertness in the daytime and undesirable lapses into sleep. Often overshadowed by the motor symptoms of PD, EDS can contribute to home and automobile accidents and have a negative impact on mood and overall quality of life. Sleep disturbances and EDS can result from the medications used to treat PD, degeneration of neuronal systems involved in the control of the sleep–wake system that occurs as part of the PD disease process, and comorbid conditions including specific sleep disorders and depression. The treatment of EDS in the PD patient requires careful evaluation of the multiple contributing causes and instituting recommendations that can consist of sleep hygiene and behavioral changes, alterations in the dosing and timing of PD medications, treatment of comorbid disorders, and the use of medications that affect nocturnal sleep quality and daytime alertness.