A report by UK Biobank (UKB) suggests that Covid-19 survivors may experience a loss of grey matter and some other brain tissues over a period.
Researchers primarily noticed the damage in parts of the brain involving the sense of touch and smell, memory formation, and cognitive functions. The data for the research comprised of pre- and post-COVID brain scans and was provided by UKB. UKB is a data centre that gathers and collates health and genetic information.
The report found significant proof for brain-related pathologies in COVID-19. Some of this could have been caused by viral neurotropism. Until now, most brain imaging studies have concentrated on the qualitative and gross pathology of moderate to severe cases with hospitalised patients. However, it is still unclear whether this kind of studies can be successfully carried out on milder cases in a quantitative and automated way. Whether this can reveal a probable mechanism for the disease's spread is also unclear. The research is yet to go through a robust peer review, according to ANI.
How was the research carried out?
Before the pandemic, the UKB had performed brain imaging on more than 40,000 participants. In 2021, these participants we invited for re-imaging. Out of the 782 participants finally selected for the study, 404 were tested Corona positive between the two tests, 394 of which had usable brain scans. Researchers used the functional and structural brain scans from before and after the infection. They studied the comparison of longitudinal brain changes between these 394 patients and 388 controls.
What did the research find out?
The results revealed strong evidence of a loss of grey matter in the left insula, left parahippocampal gyrus, and the left lateral orbitofrontal cortex of the brain.
Dr M V Padma Srivastava, Head of the Department of Neurology, All India Institute of Medical Sciences (AIIMS), commented, "It revealed the nervous system of the body is impacted in COVID. This study is another step forward in understanding post-COVID phenomena in the brain."
The study's authors also noted that the virus could enter the Central Nervous System through the olfactory mucosa (in the nasal cavity) and the olfactory bulb (in the forebrain). Hence, the results might be the in vivo hallmark of the spread of the disease or the virus via olfactory and gustatory (taste) pathways.
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