Parkinson’s disease and sleepiness

Abstract

Objective: To investigate the potential causes of excessive daytime sleepiness in patients with PD—poor sleep quality, abnormal sleep–wakefulness control, and treatment with dopaminergic agents. Methods: The authors performed night-time polysomnography and daytime multiple sleep latency tests in 54 consecutive levodopa-treated patients with PD referred for sleepiness, 27 of whom were also receiving dopaminergic agonists. Results: Sleep latency was 6.3 ± 0.6 minutes (normal >8 minutes), and the Epworth Sleepiness score was 14.3 ± 4.1 (normal 15/h; range 15.1 to 50.0). Severity of sleepiness was weakly correlated with Epworth Sleepiness score (r = −0.34) and daily dose of levodopa (r = 0.30) but not with dopamine-agonist treatment, age, disease duration, parkinsonian motor disability, total sleep time, periodic leg movement, apnea–hypopnea, or arousal indices. Conclusions: In patients with PD preselected for sleepiness, severity of sleepiness was not dependent on nocturnal sleep abnormalities, motor and cognitive impairment, or antiparkinsonian treatment. The results suggest that sleepiness—sudden onset of sleep—does not result from pharmacotherapy but is related to the pathology of PD.