Fig. 6

Central mechanisms of post-COVID-19 fatigue. Healthcare workers suffered from fatigue, sleep disorders, and poor physical capacity after COVID-19 infection. The cerebral cortex exhibited reduced activation and excitability in the PFC and M1 at 1 m. Multiple linear regression analysis revealed that the increase in DH-LICI and the decrease in NDH-latency were associated with the more significant improvement in fatigue symptoms. Abbreviations: PFC, prefrontal cortex; M1, primary motor cortex; LICI, long-interval intracortical inhibition; HBO, oxygenated hemoglobin; DH, dominant hemisphere; NDH, non-dominant hemisphere