Insomnia and sleepiness in Parkinson disease: associations with symptoms and comorbidities.
OBJECTIVE
Insomnia and daytime sleepiness are common complaints in Parkinson disease (PD), but the main causes remain unclear. We examined the potential impact of both motor and non-motor symptoms of PD on sleep problems.


METHODS
Patients with PD (n = 128) were assessed using the Insomnia Severity Index, Epworth Sleepiness Scale, Unified Parkinson Disease Rating Scale, Beck Depression Inventory, Fatigue Severity Scale, Survey of Autonomic Symptoms, and the 39-item Parkinson Disease Questionnaire. A subset of subjects (n = 38, 30%) also completed nocturnal polysomnography and a multiple sleep latency test (MSLT).


RESULTS
Multivariate stepwise logistic regression models revealed that subjective insomnia was independently associated with depressed mood (odds ratio [OR] = 1.79; 95% confidence interval (CI) [1.01-3.19]), autonomic symptoms (1.77 [1.08-2.90]), fatigue (1.19 [1.02-1.38]), and age (0.61 [0.39-0.96]). Subjective daytime sleepiness was associated with dosage of dopaminergic medication (1.74 [1.08-2.80]) and fatigue (1.14 [1.02-1.28]). On polysomnography, longer sleep latency correlated with autonomic symptoms (rho = 0.40, p = 0.01) and part I (non-motor symptoms) of the Unified PD Rating Scale (rho = 0.38, p = 0.02). Decreased sleep efficiency correlated with autonomic symptoms (rho = -0.42, p < 0.0001). However, no significant difference emerged on polysomnography and MSLTs between patients with or without insomnia or daytime sleepiness. Higher rates of apneic events did predict shorter sleep latencies on the MSLTs.


CONCLUSIONS
Non-motor symptoms appear to be associated with subjective insomnia, whereas fatigue and dopaminergic medication are associated with subjective daytime sleepiness. Objective sleep laboratory data provided little insight into complaints of insomnia and sleepiness, though obstructive sleep apnea predicted worsened sleepiness when measured objectively.
Sleep Disorders Center and Department of Neurology, University of Michigan, Ann Arbor, MI ; Department of Psychiatry, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
Seockhoon
S
Chung
Nicolaas I
NI
Bohnen
Roger L
RL
Albin
Kirk A
KA
Frey
Martijn L T M
ML
Müller
Ronald D
RD
Chervin
D000368:Aged; D000369:Aged, 80 and over; D015984:Causality; D015897:Comorbidity; D003863:Depression / Q000453:epidemiology / Q000503:physiopathology; D006970:Disorders of Excessive Somnolence / Q000453:epidemiology* / Q000503:physiopathology; D004569:Electroencephalography / Q000379:methods; D005221:Fatigue / Q000453:epidemiology / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D016017:Odds Ratio; D010300:Parkinson Disease / Q000453:epidemiology* / Q000503:physiopathology; D017286:Polysomnography / Q000379:methods; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012720:Severity of Illness Index; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology* / Q000503:physiopathology; D012894:Sleep Stages / Q000502:physiology; D011795:Surveys and Questionnaires
Parkinson disease; daytime sleepiness; depression; insomnia; non-motor symptoms