top of page

COVID-19 linked to brain abnormalities and size reduction

It’s long been reported that COVID-19 can have lasting effects on the lungs, but could it also be affecting the brain?

 

A recent study, published by Oxford University’s Wellcome Centre for Integrative Neuroimaging, compared the brain scans of individuals before and after being infected by COVID-19. The study found that participants who had mild to moderate COVID-19 infections had more gray matter loss and tissue abnormalities. These abnormalities were found mainly in areas of the brain associated with smell, a direct connection with the common COVID-19 symptom of losing the sense of smell.

 

 

 

 

 

 

 

 

 

 

 

 

The study consisted of 785 volunteers ranging between the age of 51 and 81; 401 participants had been infected by COVID-19, labeled the experimental group, while 384 participants were not, labeled the control group. For those infected with the virus, a time of 141 days separated their diagnosis and their second brain scan. Researchers first estimated brain changes over time in each group and then looked for differences in these changes between the groups. 

 

After comparing brain scans and cognitive scores, researchers noted that change occurred with participants in the experimental group compared to the control group. These changes included:

 

  • greater reduction in grey matter thickness and tissue-contrast in the orbitofrontal cortex and parahippocampal gyrus, areas associated with the sense of smell

  • greater tissue damage in regions functionally connected to the primary olfactory cortex, another area associated with smell

  • greater reduction in global brain size

 

Compared to the control group, the experimental group's grey matter thickness had a difference of 1.3% to 1.8%. Greater differences were noted among older volunteers and volunteers who had been hospitalized with the virus.

​

​

​

​

​

​

​

​

​

​

 

 

 

 

 

 

Currently, COVID-19 is still a virus that requires a lot of research. Scientist, as well as the public, are eager to learn more about the side effects of COVID-19. This study is important since it is one of the first to look at structural changes in the brain before and after a COVID-19 infection. The results of this research have been able to explain the symptom of smell loss after initially being infected with the virus, the grey matter within that part of the brain is diminished. However, the study still comes with its own set of limitations.

​

For one, participants were within the age range of 51 and 81. While older people are the ones to be most affected by the virus, research must also be done on how the brains of younger people are affected. Furthermore, there must also be research done on the long term effects of COVID-19 and the brain. The brain is a complex organ and one that can self-repair. Observations must be done to determine if the brain could fix its grey matter loss over time, or if the change could be permanent. 

 

It's best to figure this out sooner rather than later, since the discovery of brain abnormalities there have been many alarmist posts claiming the change to be permanent despite no scientific evidence claiming this yet.

031622_ls_brainshrink_inline1.jpg
gray.png

This image shows that the strongest, localized reduction of grey matter thickness in the 401 SARS-CoV-2 positive participants is found with areas associated with the sense of smell (red and yellow areas)

​

G. DOUAUD, IN COLLABORATION WITH ANDERSON WINKLER AND SAAD JBABDI, UNIVERSITY OF OXFORD AND NIH

This graph shows a difference of 1.3% to 1.8% in grey matter thickness between the control group and experimental group. 

​

G. DOUAUD, IN COLLABORATION WITH ANDERSON WINKLER AND SAAD JBABDI, UNIVERSITY OF OXFORD AND NIH

Further viewing
bottom of page