COVID and the brain
COVID-19 is primarily a respiratory disease, but it also appears to cause damage in other organs including the brain: characteristic symptoms include ‘brain fog’ and a loss of taste and smell. Understanding more about how the virus causes these symptoms – and how to intervene to prevent long-term damage – will be a key health policy challenge for the coming years.
Prof Gwenaëlle Douaud is one of a team of WIN researchers harnessing Big Data to investigate the effects of COVID-19 on the human brain. “Using the UK Biobank resource, we were in a unique position to look at changes that took place in the brain following mild—as opposed to more moderate or severe— infection,” says Gwen, who has previously shared science insights for policy and Big Data by partnering with Oxford East MP Anneliese Dodds through the Royal Society’s pairing scheme.
Using information from UK Biobank, a large-scale biomedical database that holds detailed clinical, genomic and brain imaging data from many thousands of people, Gwen and the team at WIN have completed the first and, so far, only longitudinal study investigating the impact of the virus on human brain structure.
The research team was able to access brain scans taken before the pandemic from individuals who went on to contract COVID-19. Over 400 people who had been infected by the virus were re-scanned: by comparing brain imaging before and after infection with changes seen over the same period of time in a control group, researchers identified brain areas that shrink in association with COVID-19.
“Our study was “longitudinal”, i.e., it looked at the same people at two different timepoints separated on average by 3 years. Despite the infection being mild for 96% of our participants, we found that the brains of the infected participants showed changes between their two scans that were different from changes seen in the non-infected participants: infected participants showed a greater loss of grey matter, as well as greater abnormalities in the brain tissue,” says Gwen. “The infected participants also showed a greater decline in their mental abilities to perform complex tasks. All these negative effects were greater for older infected participants.”
WIN leads the neuroimaging for UK Biobank, a free and open database that holds health information on more than half a million people. This work is led by the Big Data, Imaging Genetics and Statistics Group at WIN. The data is helping researchers discover new relationships between traits linked to the brain, genome variations and common human diseases, and to understand more about the biological and behavioural mechanisms underpinning these associations.
Gwen’s vision is to take her COVID-19 research further, and for her findings to help shape policy. “A key question is to see if this brain tissue damage resolves over the longer term. We hope to be able to invite back the participants of this study in two years’ time,” she says. “We believe our work on COVID-19 and the brain highlights the power of Big Data and makes a strong case for future investment in the area.”
Gwen's study is published in Nature: SARS-CoV-2 is associated with changes in brain structure in UK Biobank. Further information about the study can be found in these FAQs. The study was picked up by news outlets across the world including the BBC and CNN. Gwen also gave interviews to the BBC, which were aired on the News at Six and featured on the Inside Health podcast. For a selection of the key press coverage, please see this list of selected news stories.