High-density EEG sleep correlates of cognitive and affective impairment at 12-month follow-up after acute COVID-19: A pilot study.

Objective: To disentangle the pathophysiology of cognitive/affective impairment in Coronavirus Disease- 2019 (COVID-19), we studied long-term cognitive and affective sequelae and sleep high-density elec- troencephalography (EEG) at 12-month follow-up in people with a previous hospital admission for acute COVID-19. Methods: People discharged from an intensive care unit (ICU) and a sub-intensive ward (nonICU) between March and May 2020 were contacted between March and June 2021. Participants underwent cognitive, psychological, and sleep assessment. High-density EEG recording was acquired during a nap. Slow and fast spindles density/amplitude/frequency and source reconstruction in brain gray matter were extracted. The relationship between psychological and cognitive findings was explored with Pearson cor- relation. Results: We enrolled 33 participants ( 17 nonICU) and 12 controls. We observed a lower Physical Quality of Life index, higher post-traumatic stress disorder (PTSD) score, and a worse executive function perfor- mance in nonICU participants. Higher PTSD and Beck Depression Inventory scores correlated with lower executive performance. The same group showed a reorganization of spindle cortical generators. Conclusions: Our results show executive and psycho-affective deficits and spindle alterations in COVID- 19 survivors – especially in nonICU participants – after 12 months from discharge. Significance: These findings may be suggestive of a crucial contribution of stress experienced during hos- pital admission on long-term cognitive functioning.