Sleep Disorders in Patients with Parkinson's Disease during COVID-19 Pandemic: A Case–Control Study

OBJECTIVE: To assess the impact of coronavirus disease 2019 (COVID-19) pandemic on sleep disorders among Parkinson's disease (PD) patients using validated questionnaires. MATERIALS AND METHODS: This prospective study involved 50 PD patients and 50 age, gender, and body mass index-matched controls. All participants underwent assessment of cognition using Montreal Cognitive Assessment scale, sleep quality using Parkinson's disease sleep scale-2 (PDSS-2; for PD patients) and Pittsburgh Sleep Quality Index (PSQI; for PD patients and healthy controls), excessive daytime sleepiness (EDS) using Epworth sleepiness scale (ESS), insomnia symptoms and severity using insomnia severity index (ISI), restless legs syndrome (RLS) using International RLS Study Group criteria, rapid eye movement sleep behavior disorder (RBD) using RBD Single-Question Screen (RBD1Q), and depression using Patient Health Questionnaire-9 scale. RESULTS: Eighty-eight percent of PD patients reported one or more sleep disorders, compared to 28% controls. While 72% of PD patients reported poor sleep quality (PDSS-2 ≥15, PSQI >5), 60% had insomnia, 58% reported RBD, 50% had EDS, and 36% reported RLS. Depressive symptoms were reported by 70% patients. PD patients with and without poor sleep quality were comparable with regards to demographic and clinical variables, except for depressive symptoms (P < 0.001). Depressive symptoms showed a significant association with EDS (P = 0.008), RBD (P < 0.001), and insomnia (P = 0.001). CONCLUSION: Prevalence of sleep disorders increased in PD patients during the COVID-19 pandemic. Prevalence of EDS, RBD, and RLS in PD patients was higher compared to that reported in studies during the pre-COVID-19 times. Presence of depressive symptoms was a significant correlate of presence of sleep disorders in PD patients.