Even Mild COVID-19 Can Lead to Substantial Brain Changes

Brain imaging studies in people with COVID-19 typically have been small, cases have not been matched carefully to controls, medical history has not been considered, and most importantly, no brain imaging from before COVID-19 diagnoses has been available for comparison.

A new study from the U.K. Biobank overcomes all these deficiencies. Two magnetic resonance imaging (MRI) scans and cognitive testing were performed on people as part of a longitudinal population study that predated the COVID-19 pandemic. In 401 people, positive tests for SARS-CoV-2 occurred between the two MRIs (during the first 18 months of the pandemic); second MRI scans were performed an average of 141 days after positive SARS-CoV-2 tests in this group. These 401 cases were…