Global

Covid-19 may cause greater loss of gray matter and tissue damage in the brain than naturally occurs in people who have not been infected with the virus, a large new study found.

The study, published Monday in the journal Nature, is believed to be the first involving people who underwent brain scans both before they contracted Covid and months after.

Neurological experts who were not involved in the research said it was valuable and unique, but they cautioned that the implications of the changes were unclear and did not necessarily suggest that people might have lasting damage or that the changes might profoundly affect thinking, memory or other functions.