Cognitive deficit in post-acute COVID-19: an opportunity for EEG evaluation?

Background and purpose Among the most common post-COVID symptoms, many patients experienced subjective cognitive deficit, commonly named brain fog, that might be present also in those individuals without severe acute COVID-19 respiratory involvement. Some studies have investigated some of the mechanisms that might be associated with the brain fog with objective techniques including transcranial magnetic stimulation and neuroimaging. Methods The aim of this study was to investigate the presence of electroencephalographic (EEG) alterations in people with post-COVID self-reported cognitive deficit. Results Out of the 90 patients attending the post-COVID neurology ambulatory service, twenty patients presenting brain fog at least 4 weeks after acute non-severe COVID-19 infection, and without previous history of epilepsy, were investigated with 19-channel EEG, Montreal Cognitive Assessment (MoCA), and magnetic resonance imaging (MRI). EEG was found altered in 65% of the sample, among which 69% presented a slowing activity and 31% were characterized by epileptic discharges principally in the frontal areas. None of the patients showed DWI MRI lesions. Conclusions These findings highlight the usefulness of EEG analysis to objectively describe possible neurophysiological abnormalities in post-COVID patients presenting subjective cognitive deficit.

Automated summary

This study aimed to investigate EEG alterations in individuals with self-reported cognitive deficit after COVID-19. Among 90 patients attending a post-COVID neurology service, 20 patients with brain fog 4 weeks after non-severe COVID-19 infection were studied. EEG analysis revealed abnormalities in 65% of the sample, with 69% showing slowing activity and 31% presenting epileptic discharges in frontal areas. None of the patients exhibited DWI MRI lesions.