Illustration: Sarah Grillo/Axios
Patients with mild cases of COVID-19 suffered a loss of the brain's "gray matter" plus damage in areas associated with the sense of smell and a larger-than-average decline in cognitive function, according to research published Monday in the journal Nature.
Why it matters: The U.K. study is the first to compare brain scans before and after infection — and mostly deals with patients who had mild cases, which are the most common type arising from COVID infections.
Key takeaway: The loss of brain volume observed equals an extra year of normal aging, lead author Gwenaëlle Douaud at University of Oxford told NBC News.
The study: Researchers investigated brain changes in 785 participants in the UK Biobank, a repository containing genetic and health information from half a million participants. A total of 401 cases tested positive for infection between their two scans, with 141 days on average separating their diagnosis and second scan.
Yes, but: What's still unclear is whether the brain damage is reversible.
Our thought bubble: The overlapping smell and memory-related brain functions shown to be affected by COVID raise questions about whether the virus could contribute to Alzheimer's or other forms of dementia, the researchers wrote.