Factors related to excessive sleepiness in patients with Parkinson's disease

Introduction: Excessive sleepiness (ES) can affect up to 60% of Parkinson's disease (PD) patients, and it has a multifactorial etiology. It is related to the neurodegenerative processes affecting brain regions responsible for the sleep-wake cycle, the effects of drugs acting on the central nervous system, and the excessive sleep fragmentation of this population. Objectives: To identify the factors associated with the presence of ES in patients with PD. Methods: A cross-sectional study was performed involving 88 consecutive patients with PD from an outpatient clinic. Participants underwent clinical interviews with neurologists and psychiatrist, assessment using standardized scales (Epworth Sleepiness Scale, Parkinson's disease Questionnaire, Pittsburgh Sleep Quality Index and, for individuals with a diagnosis of RLS/WED, International RLS/WED grading scale), and video-polysomnography. Results: The complaint of ES was observed in 55.6% of the participants. The main related factors were: the presence of psychotic disorder, the presence of anxiety disorder, and the use of dopaminergic agonists. No higher prevalence of obstructive sleep apnea and any other sleep disorder was observed in PD group with ES in comparison with the group without ES. Conclusion: PD patients present a high prevalence of ES, and some factors, different from those observed in the general population, seem to have a greater impact in this group of patients.