Parkinson’s Disease and the COVID-19 Pandemic: A Review Article on the Association between SARS-CoV-2 and α-Synucleinopathy

There is an extensive debate on the neurological consequences of 2019 novel coronavirus disease (COVID-19) and its impact on Parkinson’s disease (PD) patients, which seems to puzzle neurologists. Links between viral infections and PD have long been suspected and studied, but the exact relationship remains elusive. Since severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters the brain through multiple routes and has a direct impact on the brain, cumulative damage occurs due to the activation of proinflammatory cytokines and chemokines. SARS-CoV-2 seems to aggravate PD due to its effects on α-synuclein, mitochondrial dysfunction, and dopamine depletion. A few studies have even highlighted the higher vulnerability of PD patients to COVID-19. The sudden dramatic change in lifestyle caused by the pandemic and the widespread lockdowns that were implemented have added to the hidden sorrows of PD patients, as they already have a compromised mechanism for coping with stress. This review summarizes insights from basic science and the clinical effect of SARS-CoV-2 infection on the human brain, with a specific focus on PD.