Covid gradually deteriorates grey matter in brain: Study

New York: A study has analysed brain scans of people infected by Covid-19 and showed a consistent pattern in loss of grey matter over time. The University of Oxford affiliated team conducted the study and posted their findings ahead of peer review to medRix, drawing on UK Biobank's data.

The team wrote that the loss of grey matter is at the limbic cortical areas directly linked to the primary, olfactory and gustatory system, precisely areas related to the perception of smell and taste. Three regions showed a significant loss in thickness and volume of grey matter among covid patients. They were the parahippocampal gyrus, the lateral orbitofrontal cortex and the superior insula. Also, the pandemic affected the left hemisphere of the brain the most.

Those hospitalised were also found with comparatively similar brain conditions, plus a more significant loss of grey matter in the cingulate cortex, central nucleus of the amygdala and hippocampal cornu ammonia.

The team compared pre-pandemic brain scans of subjects to scans taken three years later among 394 Covid-19 patients and 388 matched controls. The comparison showed that they could differentiate the effects of Covid-19 disease from patients' pre-existing health conditions.

They also analysed 15 hospitalised covid patients compared with 379 people who had not been hospitalised.

The team said that they used automated, objective and quantitative methods to uncover the consistent spatial pattern. But more investigation is needed to understand whether these abnormal changes are the hallmark of the disease in the brain, would it be a future vulnerability of the limbic system, including memory etc., for these patients.