Snoring and excessive daytime sleepiness in Parkinson's disease.

Recent recognition of daytime sleepiness in Parkinson's disease (PD) has prompted a search for its causes. Sleepy patients may be more susceptible to sleep attacks after the use of dopamine agonists and the recognition of sleep disturbances in PD may influence important therapeutic decisions. To identify clinical factors influencing excessive daytime sleepiness (EDS) and sleep complaints in PD, we studied 86 consecutive patients with clinical diagnosis of PD using a sleep questionnaire, the Epworth Sleepiness Scale, the Unified Parkinson's Disease Rating Scale and the Montgomery and Asberg Depression Rating Scale. Patients with cognitive dysfunction were not included in the study. We found that 49 patients (53.3%) had insomnia, 45 (49.9%) restless legs syndrome (RLS), 51 (55.4%) vivid dreams, 61 (71.8%) snoring and 29 (31.5%) had EDS. RLS was more frequent in patients with longer duration of illness. Snoring was the most important risk factor associated with EDS (OR=3.64, 95% CI=1.11-11.9, P=0.03) and a marginal association between motor dysfunction and EDS was observed (OR=1.06, 95% CI=1.00-1.12, P=0.05).