Daytime Sleepiness in Parkinson's Disease: Perception, Influence of Drugs, and Mood Disorder

Parkinson's disease (PD) is associated with sleep complaints as excessive daytime sleepiness (EDS) and several factors have been implicated in the genesis of these complaints. Objective. To correlate the subjective perception of EDS with variables as the severity of the motor symptoms, medications, and the presence of depressive symptoms. Materials and Methods. A cross-sectional study, using specific scales as Epworth sleepiness scale (ESS), Beck depression inventory (iBeck) and Hoehn and Yahr (HY), in 42 patients with PD. Results. The patients had a mean age of 61.2 ± 11.3 years and mean disease duration of 4.96 ± 3.3 years. The mean ESS was 7.5 ± 4.7 and 28.6% of patients reached a score of abnormally high value (>10). There was no association with gender, disease duration, and dopamine agonists. Patients with EDS used larger amounts of levodopa (366.7 ± 228.0 versus 460.4 ± 332.25 mg, P = 0.038), but those who had an iBeck >20 reached lower values of ESS than the others (5.9 ± 4.1 versus 9.3 ± 4.8, P = 0.03). Conclusions. EDS was common in PD patients, being related to levodopa intake. Presence of depressed mood may influence the final results of self-assessment scales for sleep disorders.