The Impact of COVID-19 on Parkinson's Disease: A Case-Controlled Registry and Questionnaire Study on Clinical Markers and Patients' Perceptions

Introduction. Parkinson's disease (PD) is a neurodegenerative disease with motor and nonmotor symptoms. Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Objectives. To explore how COVID-19 affects motor, nonmotor, and general health aspects of PD and to map how PD patients perceive their change in symptoms since falling ill with COVID-19. Method. The study was descriptive, case-controlled, and based on both registry and questionnaire data. At baseline, the controls were matched on age, sex, and disease severity. Information on the severity of the disease, nonmotor symptoms, motor symptoms, and general health was retrieved from the Swedish Registry for PD. Registry data from a COVID-19 group (n=45) and a control group (n=73), as well as questionnaires from a COVID-19 group (n=24) and a control group (n=42), were compared. Results. We did not find that SARS-CoV-2 infection affects any major aspect of nonmotor symptoms, motor symptoms, general health, and perception of change in PD patients' post-COVID-19. Compared to controls, the COVID-19 group reported a more positive subjective experience of pain and quality of life and a perception of change post-COVID-19 regarding general motor function, sleep quality, and mood (all p<0.05). Conclusion. Although SARS-CoV-2 infection does not seem to affect PD symptoms in any major respect, the subjective experience of several aspects of life in PD patients might be slightly improved post-COVID-19 compared to a control group. The findings warrant further investigations due to the small sample size and possible survivorship bias.