A new study led by Oxford scientists and published in the journal. Nature suggests that even mild COVID infections can cause brain shrinkage.
The first author of the study was Professor Gwenaëlle Douaud and Professor Stephen Smith was the senior author of the study.
Earlier this year, researchers at the University of Oxford, Oxford, London, performed a study using data from the UK Biobank, which is a large-scale biomedical database and research resource containing in-depth genetic and health information.
Scientists investigated 785 UK Biobank participants aged between 51-81 years. The participants were scanned twice throughout the spam of this study, out of which nearly 401 subjects tested positive for the SARS-CoV-2 infection in-between the two scans, and of which 15 had to be hospitalized.
All the participants had similar health conditions such as obesity, blood pressure, and diabetes, along with similar socioeconomic status. The study was done over a period of 4.5 months.
The findings, published in Nature, show tissue damage and shrinkage in brain areas associated with smell. This new understanding of COVID-19’s harmful effects will help us.
Better understand how the disease spreads through the central nervous system. More research is needed to determine whether these effects persist in the long run or are partially reversed.
Prior research has revealed that COVID might be a possible root of brain abnormalities, but these studies were focused on patients with severe infection and were done in the period following the disease.
The study conducted by the Wellcome Centre for Integrative Neuroimaging at the University of Oxford investigated and identified various effects in the subjects.
One of which was the reduction in the thickness of grey matter in the brain in the region related to smell (the orbitofrontal cortex and parahippocampal gyrus).
Other ramifications of the SARS CoV-2 virus that came to light during the study were that the participants had more tissue damage in areas associated with the primary olfactory cortex, an area associated with smell, as well as a reduction in overall brain size.
These effects ranged from 0.2 to 2% more change when compared to participants who had not been infected.
Alongside, the participants also displayed greater cognitive decline, that is, worsening or more frequent confusion or memory loss, in between two scans
On average, the participants who were infected with SARS-CoV-2 also showed a greater cognitive decline between their two scans, which was correlated to the deterioration of a specific part of the cerebellum (a brain structure that regulates muscular activity) linked to cognition.
Separately, the authors studied people who had pneumonia unrelated to COVID-19, demonstrating that the changes were specific to COVID-19 and not due to the general effects of catching a cold.
According to the lead author, Professor Gwenaëlle Douaud, from the Wellcome Centre for Integrative Neuroimaging, they were in a notable position
As they were able to look at the changes that took place in the brains of patients having mild SARS-CoV-2 infection, in contradiction to the other studies done in more severe cases of the virus.
Professor Douaud stressed the fact that despite the infection being mild in about 96% of the subjects, a greater loss of grey matter volume and greater tissue damage were observed. This mental deterioration was caused in part by these brain abnormalities.
All of these negative effects were more pronounced as people got older. The long-term resolution of this brain tissue damage is a key question for future brain imaging studies.
‘ The senior author, Professor Stephen Smith’s remarks on the study were that they had been lucky to be able to get their hands on the pre-infection scans as those helped them to not mix brain changes caused by the infection with the ones pre-existing.
Published By : Ankit Singh
Edited By :Khushi Thakur
