Catching Covid may cause changes to the brain, a study suggests.
Scientists found significant differences in MRI (magnetic resonance imaging) scans before and after infection.
Even after a mild infection, the overall size of the brain had shrunk slightly, with less grey matter in the parts related to smell and memory.
The researchers do not know whether the changes are permanent but stressed the brain could heal.
The study is published in the journal Nature.
“We need to bear in mind that the brain is really plastic – by that we mean it can heal itself – so there is a really good chance that, over time, the harmful effects of infection will ease,” Prof [Gwenaelle] Douaud said.
The most significant loss of grey matter was in the olfactory areas – but it is unclear whether the virus directly attacks this region or cells simply die off through lack of use after people with Covid lose their sense of smell.
It is also unclear whether all variants of the virus cause this damage.
The scans were performed when the original virus and alpha variant were prevalent and loss of smell and taste a primary symptom.
