Brain changes seen after 'mild' covid

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.

Lead author Prof Gwenaelle Douaud, from the Wellcome Centre for Integrative Neuroimaging, at the University of Oxford, said: "We were looking at essentially mild infection, so to see that we could really see some differences in their brain and how much their brain had changed compared with those who had not been infected was quite a surprise."

But the researchers do not know whether the changes are reversible or truly matter for health and wellbeing.

"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 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.

UK Biobank chief scientist Prof Naomi Allen said: "It opens up all sorts of questions that other researchers can follow up about the effect of coronavirus infection on cognitive function, on brain fog and on other areas of the brain - and to really focus research on how best to mitigate that."

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Source: BBC News, 8 March 2022