Mar 8, 2022 - Health

COVID linked to brain damage in scent areas

Illustration of a brain surrounded by medical crosses and lines

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. 

Go deeper