title: Sleep disturbances in Parkinson disease and their potential role in heterogeneity.
abstract: Parkinson disease (PD) is commonly conceptualized as a movement disorder. Most previous attempts to define the heterogeneity of the condition have used prospective methods based on arbitrary features such as motor symptoms or age of disease onset. However, nonmotor symptoms including neuropsychological, neuropsychiatric, and behavioral impairments have received less attention. Sleep disturbances are extremely common in PD and appear to be associated with cognitive and psychiatric problems. Recent research has begun to elucidate the links between these variables, but the origin and extent of these relationships are not clearly understood. This review outlines the importance of sleep for healthy cognition and mood, highlighting the possible implications that disturbed sleep may have with regard to patients with PD. It also emphasizes the need for further studies that explore the heterogeneity of all disease features in PD.
authors.affiliation: Parkinson's Disease Research Clinic, Ageing Brain Centre, Brain & Mind Research Institute, University of Sydney, Camperdown, New South Wales, Australia.
authors.forename: David G
authors.initials: DG
authors.lastname: Gunn
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Naismith
authors.forename: Simon J G
authors.initials: SJ
authors.lastname: Lewis
mesh_terms: D000368:Aged; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000453:epidemiology*; D017286:Polysomnography; D012720:Severity of Illness Index; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000453:epidemiology*; D012895:Sleep, REM / Q000502:physiology