Circadian rest-activity rhythm is altered in Parkinson's disease patients with hallucinations

The sleep‐wake cycle in Parkinson's Disease (PD) is profoundly disrupted, but less is known about circadian rhythm in PD and its relationship to other important clinical features. This study compared rest‐activity rhythms in healthy older adults and PD patients with and without hallucinations. Twenty‐nine older adults and 50 PD patients (27 with hallucinations, 23 without) were assessed using wrist‐worn actigraphy for 5 days. Disease‐related and cognitive data were also collected. PD patients demonstrated reduced amplitude of activity (F = 12.719, P < 0.01) and increased intradaily variability (F = 22.005, P < 0.001), compared to healthy older adults, independently of age, and cognitive status. Hallucinators showed lower interdaily stability (F = 7.493, P < 0.01) significantly greater activity during “night‐time” (F = 6.080, P < 0.05) and significantly reduced relative amplitude of activity (F = 5.804, P < 0.05) compared to nonhallucinators, independently of clinical factors including motor fluctuations. PD patients with hallucinations display altered rest‐activity rhythm characterized by an unpredictable circadian pattern across days, likely arising from damage to brainstem and hypothalamic sleep centers. Treatment of sleep and rest‐activity rhythm disturbance is an important target in Parkinson's Disease. © 2008 Movement Disorder Society.