Covid patients. The results showed that four and a half months after a mild Covid infection, patients had lost (on average) between 0.2 and 2% of brain volume, as compared to healthy people.
In addition to this, they also took between 8 and 12% longer on the tests that measured attention, visual screening ability, and processing speed.
In the region of the brain linked to smell, the Covid-19 patients had 0.7% more tissue damage compared to healthy people. This is part of a growing body of research that suggests that people who have recovered from Covid-19, including patients with milder symptoms, may struggle with cognitive functions.
Recently, a study published in the journal eClinicalMedicine suggested that a severe Covid-19 infection may cause cognitive impairment similar to that sustained with 20 years of ageing, between 50 and 70 years of age.