Actigraphic evidence for night-time hyperkinesia in Parkinson's disease.

Parkinson's disease is a common motor disorder that not only leads to motor symptoms but also autonomic dysregulation, mental changes, sensory disturbances, and sleep disorders such as increased daytime sleepiness and sleep fragmentation. The aim of this study was to find out how the daytime and night-time motor activity levels in individuals without motor disorders differ from patients with Parkinson's disease. Daytime and night-time motor activity levels in 17 PD patients and 69 controls were measured for three consecutive days and nights via actigraphy, a method of continuous long-term assessment of activity levels. A ratio between night-time and daytime motor activity was calculated. PD patients had a 1.5-2-fold lower daytime motor activity but also showed 1.5-2-fold higher motor activity at night time. Older controls showed a lower daytime but similar night-time motor activity when compared to younger controls. A ratio of night-time to daytime motor activity could clearly distinguish controls and patients. The possibility to distinguish patients and controls by the ratio of night-time to daytime motor activity is worth further investigation.