Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Researchers from the University of Oxford have used data from UK Biobank participants to look at changes to the brain on average 4.5 months after mild SARS-CoV-2 infection.

3D rendering of coronavirus

The findings, published in Nature, reveal tissue damage and greater shrinkage in brain areas related to smell. This new insight into the damaging effects of COVID-19 will contribute to our overall understanding of how the disease spreads through the central nervous system. Whether these effects persist in the long term, or are partially reversed, requires further investigation.

Research has already shown that COVID-19 may cause brain-related abnormalities, but most studies have focused on hospitalized patients with severe disease, and have been limited to post-infection data. The effects of SARS-CoV-2 on the brain in milder (and more common) cases were unknown until now, and investigating these cases could reveal possible mechanisms that contribute to brain disease or damage.

Professor Gwenaëlle Douaud and colleagues investigated changes in the brains of 785 participants in UK Biobank, a large-scale biomedical database and research resource. Participants were aged 51–81 and underwent two brain scans, on average 38 months apart, as well as cognitive tests. A total of 401 participants tested positive for infection with SARS-CoV-2 between their two scans, of whom 15 were hospitalised. The remaining 384 individuals, who did not get infected, were similar to the infected group in age, sex, and many risk factors, including blood pressure, obesity, smoking, socio-economic status and diabetes.

The study, led by the Wellcome Centre for Integrative Neuroimaging at the University of Oxford, identified a number of effects, on average 4.5 months following infection, including a greater reduction in grey matter thickness in the regions of the brain associated with smell (the orbitofrontal cortex and parahippocampal gyrus). UK Biobank participants who had COVID-19 also displayed evidence of greater tissue damage in regions connected with the primary olfactory cortex, an area linked to smell, and a reduction in whole brain size. These effects ranged from 0.2 to 2% additional change compared with the participants who had not been infected.

Read the full story on the University of Oxford website

Similar stories

Long COVID: vaccination could reduce symptoms, new research suggests

While evidence suggests that people who are vaccinated before they get COVID are less likely to develop long COVID than unvaccinated people, the effectiveness of vaccination on existing long COVID has been less clear.

Com-COV vaccine study to research third dose booster options for 12-to-15-year-olds

Researchers running the University of Oxford-led Com-COV programme have launched a further study of COVID-19 vaccination schedules in young people aged 12 to 15 – with a focus on assessing different options for a third dose booster vaccination.

Population-scale study highlights ongoing risk of COVID-19 in some cancer patients despite vaccination

COVID-19 vaccination is effective in most cancer patients, but the level of protection against COVID-19 infection, hospitalisation and death offered by the vaccine is less than in the general population and vaccine effectiveness wanes more quickly.

New reporting guidelines developed to improve AI in healthcare settings

New reporting guidelines, jointly published in Nature Medicine and the BMJ by Oxford researchers, will ensure that early studies on using Artificial Intelligence (AI) to treat real patients will give researchers the information needed to develop AI systems safely and effectively.

Major boost for Oxford’s mission to counter future pandemic threats

The Moh Family Foundation has given a substantial gift to support the work of Oxford University’s Pandemic Sciences Institute, greatly strengthening its ability to identify and counter future pandemic threats and ensure equitable access to treatments and vaccines around the world.