Potential hypothesis for the increased risk of Parkinson´s disease following COVID-19.

Patients with severe COVID-19 may be more likely to develop PD as a result of shared biological pathways including a great expansion of MDSCs and an imbalance in Th17/Tregs ratio. We think that these shared pathogenic features may mechanistically explain the COVID-19 - PD axis. Thus, we assume that patients who recovered from critical COVID-19 should be selected based upon a potential higher risk of developing PD. Further studies are needed to better define the possible relationship between COVID-19 and neuroinflammation and identify whether some people are more likely to develop PD after contracting COVID-19 than others with special emphasis to ascertain possible vulnerable genetic backgrounds or epigenetic factors acting on brain which may promote PD during SARS COV-2 infection. Finally, we think that regular physical activity should be performed and encouraged in patients with PD.