RESTING‐STATE ELECTROENCEPHALOGRAPHIC RHYTHMS UNDERPINNING VIGILANCE ARE ABNORMAL IN POST COVID‐19 PATIENTS EXPERIENCING FATIGUE.

Background: Previous evidence showed that persons experiencing post‐COVID‐19 with "brain fog" were characterized by abnormal resting‐state electroencephalographic (rsEEG) rhythms reflecting vigilance dysfunctions. In the present exploratory study, we tested the hypothesis that in post‐COVID persons with normal cognitive status, abnormalities in those rhythms (and vigilance function) may be related to fatigue. Method: We enrolled post‐COVID participants about one year after their infection, which claimed "brain fog." They underwent clinical/neuropsychological assessment and 61‐channel‐EEG recordings. Matched controls (never COVID‐19 affected) were included. Using eLORETA freeware, regional neural current densities were estimated in the rsEEG cortical sources at individual delta, theta, and alpha bands and at beta and gamma fixed bands. Clinical and instrumental data were evaluated in the long COVID‐19 patients as a function of fatigue symptoms over the controls. Result: The post‐COVID patients had no cognitive deficits at the group level. Those patients showed lower posterior rsEEG alpha source activities than the controls. Notably, this effect was more significant with the long COVID‐19 patients experiencing fatigue symptoms than those without (Fig. 1). Conclusion: In post‐COVID patients with normal cognition, abnormal rsEEG alpha source activation may indicate a significant relationship between vigilance dysfunction and fatigue. [ABSTRACT FROM AUTHOR]