COVID-19 survivors may suffer from a loss of grey matter and other brain tissue over time, suggests a new study.
As per the study conducted by the researchers from UK Biobank, the damage was seen in brain areas that involved smell, taste, cognitive function and memory formation.
The researchers studied pre- and post-COVID brain image tests.
"There is strong evidence for brain-related pathologies in COVID-19, some of which could be a consequence of viral neurotropism. The vast majority of brain imaging studies so far have focused on qualitative, gross pathology of moderate to severe cases, often carried out on hospitalised patients," say the researchers.
"It remains unknown however whether the impact of COVID-19 can be detected in milder cases, in a quantitative and automated manner, and whether this can reveal a possible mechanism for the spread of the disease," they say.
UK Biobank performed brain image tests on over 40,000 participants before the start of the COVID-19 pandemic.
UK Biobank performed brain image tests on over 40,000 participants before the start of the COVID-19 pandemic.They invited hundreds of these participants for a second imaging visit in 2021.
Researchers then studied the effects of the Covid-19 disease in the brain using data from 782 participants.
"Here, we studied the effects of the disease in the brain using multimodal data from 782 participants from the UK Biobank COVID-19 re-imaging study, with 394 participants having tested positive for SARS-CoV-2 infection between their two scans.
"We used structural and functional brain scans from before and after infection, to compare longitudinal brain changes between these 394 COVID-19 patients and 388 controls who were matched for age, sex, ethnicity and interval between scans.
"We identified significant effects of COVID-19 in the brain with a loss of grey matter in the left parahippocampal gyrus, the left lateral orbitofrontal cortex and the left insula," researchers mention.
UK Biobank, which is releasing data from the COVID-19 re-imaging study on a rolling basis, said 404 participants were identified as those who had tested positive for COVID-19. Of these, 394 had usable brain scans.