Excessive daytime sleepiness in Parkinson's disease

Much has been written about sleep issues associated with Parkinson's disease (PD), including excessive daytime sleepiness (EDS). This chapter enumerates these issues related to the disease itself, whether directly or indirectly. Secondary causes of EDS, as well as recognition and management of EDS, will be addressed. We also examine some of the possible mechanisms involved and highlight some unique aspects The term, EDS, refers to the inappropriate propensity for, as well as the actual inappropriate occurrence of, sleep during normal waking hours. EDS is a real and serious component of PD. Since the recognition of EDS years ago there have been a plethora of articles, research, and observations on sleep in patients with PD and sleep issues have been incorporated into the rubric of what constitutes PD. In the last decade, new scales have been developed (e.g., the SCOPA scale, the Pittsburgh Sleepiness Quality Index, and the Parkinson's Disease Sleep Scales 1 and 2). More telling perhaps, the revised Unified Parkinson's Disease Rating Scale (MDS-UPDRS) includes questions regarding nocturnal and daytime sleep.