Almost 20% of people who were hospitalized for COVID-19 infections early in the pandemic still had signs of impairment with brain function 2 years after infection, finds a new study in Scientific Reports.

The study population came from Portugal, in a region hit hard by the first wave of the COVID-19 pandemic. Based on hospital admission episodes and SARS-CoV-2 infection status from March 2020 to February 2021, the authors identified four groups: group 1 (101) hospitalized for COVID-19 infections, group 2 (87) hospitalized but uninfected with COVID-19, group 3 (252) infected but not requiring hospitalization, and group 4 (258) uninfected and not hospitalized for any reason.

Cognitive assessments were conducted in two parts 2 years after infection, a general screening using the Montreal Cognitive Assessment and a subsequent neuropsychological assessment conducted by one of four psychologists if the score of the general screening was low. Overall, verbal memory, visual memory, executive functions, language, and information processing speed and attention were evaluated.