Chronic Insomnia in Patients With Parkinson Disease: Which Associated Factors Are Relevant?

Background: Insomnia complaints are frequent in Parkinson disease (PD), affecting up to 55% of patients. Factors related to insomnia in PD are multifactorial and may be associated with the degenerative process of the disease, comorbidities related to aging, and medication use. The aim of this study is to determine the factors associated with the presence of chronic insomnia in patients with PD. Method: A cross-sectional study was performed involving 63 consecutive patients with PD from an outpatient clinic. Participants underwent clinical interviews with neurologists and a psychiatrist and were assessed with standardized scales (Epworth Sleepiness Scale, Parkinson's Disease Questionnaire, Pittsburgh Sleep Quality Index and, for individuals with a diagnosis of restless legs syndrome(RLS)/Willis-Ekbom disease (WED), the International RLS/WED grading scale) and video-polysomnography. Results: The main factors associated with chronic insomnia in PD were the habit of staying in bed without sleeping, large rapid eye movement (REM) sleep latency, high Pittsburgh Sleep Quality Index scores, and absence of obstructive sleep apnea (OSA). Conclusion: Insomnia in PD is related to specific factors including inadequate sleep habits, REM sleep latency, absence of OSA, and quality of sleep.