Verified on 08/03/2022 by Florine Dergelet, Editor
Covid-19 is a respiratory disease but it would also have effects on the brain. Already studied before, a more substantial study has just confirmed the neurological effects of an infection on the brain, even in patients with a mild form.
Study confirms brain damage from Covid-19
We already knew that Covid-19 caused brain damage in patients with the virus. But, previous studies focused mainly on a small number of patients, most of the time with severe forms. This new study carried out by the team from the University of Oxford in the United Kingdom, is therefore the first to have compared the brains of a hundred patients before and following their infections in order to study the effects of Covid-19. long term on the brain. While most of the patients had a mild form, the study clearly demonstrates that Covid-19 can have consequences on the brain, in particular at the level of ” gray matter ».
To carry out their research, the scientists collected the brain scans of 785 people between the ages of 51 and 81. After undergoing brain imaging regarding 3 years ago in an operation performed by Biobank, the patients had new MRI scans. Among the 785 individuals, 401 have been infected with Covid-19 in the meantime. This allowed the researchers to compare the results and learn more regarding the consequences of the pathological process of Covid-19.
Loss or damage of brain tissue
According to the results published this Monday, March 7 in the journal Nature, people who had been infected showed ” a greater decline in their mental faculties, especially in their response times and executive functions ».
On average, infection with the virus resulted in a loss or lesion of 0.2% to 2% of brain tissue several months later in patients with Covid-19 compared to uninfected who themselves had less marked changes. A finding that affects even patients with mild forms since the infection was relatively mild in 96% of study participants. As Gwenaëlle Douaud, lead author of the study, explains, ” to get an idea of the magnitude of these effects, we can compare them to what happens during normal aging: we know that people lose between 0.2% and 0.3% of gray matter each year in memory-related regions ».
In addition, the researcher also mentions “ greater loss and deterioration of gray matter, primarily in areas of the brain related to smell in infected patients. According to her, the lasting loss of sense of smell ” causes a decrease in gray matter in areas of the brain related to olfaction “. But this effect might be reversible, as the researcher concludes: “ We can think that with the return of the sense of smell, these cerebral abnormalities will become less marked over time. ».
