During at least the first few months following a coronavirus infection, even mild cases of Covid-19 are associated with subtle tissue damage and accelerated losses in brain regions tied to the sense of smell, as well as a small loss in the brain’s overall volume, a new British study finds. Having mild Covid is also associated with a cognitive function deficit.

These are the striking findings of the new study led by University of Oxford investigators, one that leading Covid researchers consider particularly important because it is the first study of the disease’s potential impact on the brain that is based on brain scans taken both before and after participants contracted the coronavirus.