{"id":4869,"date":"2022-03-07T16:20:05","date_gmt":"2022-03-07T16:20:05","guid":{"rendered":"https:\/\/tahrir2day.com\/news\/2022\/03\/07\/scans-reveal-how-covid-may-change-the-brain-2\/"},"modified":"2022-03-07T16:20:05","modified_gmt":"2022-03-07T16:20:05","slug":"scans-reveal-how-covid-may-change-the-brain-2","status":"publish","type":"post","link":"https:\/\/tahrir2day.com\/news\/2022\/03\/07\/scans-reveal-how-covid-may-change-the-brain-2\/","title":{"rendered":"Scans reveal how Covid may change the brain"},"content":{"rendered":"
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Catching Covid can cause changes in the brain, according to a study.<\/b><\/p>\n<\/div>\n

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Scientists found significant differences in MRI (magnetic resonance imaging) scans before and after infection.<\/p>\n<\/div>\n

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Even after a mild infection, the overall brain size had shrunk slightly, with less gray matter in areas related to smell and memory.<\/p>\n<\/div>\n

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Researchers don’t know if the changes are permanent, but the stressed brain could heal.<\/p>\n<\/div>\n

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The study was published in the journal Nature.<\/p>\n<\/div>\n

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Lead author Prof Gwenaelle Douaud, from the Wellcome Center for Integrative Neuroimaging at the University of Oxford, said: “We looked at what was essentially a mild infection to see if we could really see some differences in her brain and how much her brain had changed compared to those who were not infected was quite a surprise.”<\/p>\n<\/div>\n

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The UK biobank project has been tracking the health of 500,000 people for around 15 years and has a database of scans recorded before the pandemic, providing a unique opportunity to study the long-term health effects of the virus. <\/p>\n<\/div>\n

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The scientists scanned again:<\/p>\n<\/div>\n

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  • 401 participants an average of 4.5 months after their infection, 96% of whom had mild Covid <\/li>\n
  • 384 participants who did not have Covid<\/li>\n<\/ul>\n<\/div>\n<\/div>\n
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    They found:<\/p>\n<\/div>\n

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    • Whole brain size in infected participants had shrunk by 0.2 to 2%<\/li>\n
    • There were gray matter losses in the olfactory areas associated with smell and regions associated with memory<\/li>\n
    • Those who had recently recovered from Covid found it a bit harder to accomplish complex mental tasks<\/li>\n<\/ul>\n<\/div>\n<\/div>\n
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      But researchers don’t know if the changes are reversible or really important for health and well-being.<\/p>\n<\/div>\n

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      “We have to keep in mind that the brain is really plastic – by that we mean it can heal itself – so there’s a really good chance that the harmful effects of an infection will wear off over time,” said Prof Douaud.<\/p>\n<\/div>\n

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      The greatest loss of gray matter has been in the olfactory areas – but it’s unclear whether the virus attacks this region directly or cells simply die from underuse after people with Covid lose their sense of smell.<\/p>\n<\/div>\n

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      It is also unclear whether all variants of the virus cause this damage. <\/p>\n<\/div>\n

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      The scans were performed when the original virus and the alpha variant were widespread and loss of smell and taste was a primary symptom. <\/p>\n<\/div>\n

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      But the number of people infected with the newer Omicron variant reporting this symptom has fallen dramatically.<\/p>\n<\/div>\n

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      “Your Mind Will Be Trained”<\/b><\/p>\n<\/div>\n

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      Paula Totaro lost her sense of smell when she caught Covid in March 2020.<\/p>\n<\/div>\n

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      “Once it was gone it was like living in a bubble or a vacuum – I found it really isolating,” she told BBC News.<\/p>\n<\/div>\n

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      But after contacting the AbScent charity, which supports people who have lost their ability to smell and taste, she began smell training.<\/p>\n<\/div>\n

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      “What smell training does — especially if you do it twice a day regularly and religiously — is that it forces you to take the smell, allow it to go back up your nose, and then think about what you’re smelling, ” She said.<\/p>\n<\/div>\n

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      “And that connection between what’s in the outside world and what’s going into your brain and your mind is what’s being trained.”<\/p>\n<\/div>\n

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      Ms Totaro has now regained most of her sense of smell – although she still struggles to discern what different smells are.<\/p>\n<\/div>\n

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      “It’s a mix of joy that the feeling has returned but still a bit of fear that I’m not quite there yet,” she said.<\/p>\n<\/div>\n

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      The UK Biobank’s chief scientist, Prof Naomi Allen, said: “It raises all sorts of questions for other researchers to explore about the impact of coronavirus infection on cognitive function, on brain fog and on other areas of the brain – and um to really focus on research on how best to mitigate that.”<\/p>\n<\/div>\n

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      Prof David Werring, of the University College London Institute of Neurology, said other health-related behaviors may have contributed to the changes observed. <\/p>\n<\/div>\n

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      “The changes in cognitive function were also subtle and of unclear relevance to daily functioning,” he said.<\/p>\n<\/div>\n

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      “And these changes are not necessarily seen in every infected individual and may not be relevant to newer strains.”<\/p>\n<\/div>\n

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      Follow @BBCMorelle on Twitter<\/a>.<\/p>\n<\/div>\n