New‑onset non‑motor symptoms in patients with Parkinson's disease and post‑COVID‑19 syndrome: A prospective cross‑sectional study.

The clinical range of post-coronavirus disease 2019 (COVID-19) symptoms in patients with Parkinson's disease (PD) has not yet been thoroughly characterized, with the exception of a few small case studies. The aim of the present study was to investigate the motor and non-motor progression of patients with PD (PWP) and post-COVID-19 syndrome (PCS) at baseline and at 6 months after infection with COVID-19. A cross-sectional prospective study of 38 PWP+/PCS+ and 20 PWP+/PCS- matched for age, sex and disease duration was conducted. All patients were assessed at baseline and at 6 months using a structured clinicodemographic questionnaire, the Unified Parkinson's Disease Rating Scale Part III (the UPDRS III), the Montreal Cognitive Assessment, the Hoehn and Yahr scale, the Geriatric Depression Scale and the levodopa equivalent daily dose (LEDD). There was a statistically significant difference in the LEDD (P=0.039) and UPDRS III (P=0.001) at baseline and at 6 months after infection with COVID-19 between the PWP with PCS groups. The most common non-motor PCS symptoms were anosmia/hyposmia, sore throat, dysgeusia and skin rashes. There was no statistically significant difference in demographics or specific scores between the two groups, indicating that no prognostic factor for PCS in PWP could be identified. The novelty of the present study is that it suggests the new onset of non-motor PCS symptoms of PWP with a mild to moderate stage.