What is the impact of Covid19 on the brain
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Summary
There is strong evidence of brain-related abnormalities in COVID-19. However, it is still unknown whether the impact of SARS-CoV-2 infection can be detected in milder cases and whether this can reveal possible mechanisms contributing to brain pathology.
Here, we investigated brain changes in 785 UK Biobank participants (aged 51 to 81 years) who were imaged twice, including 401 cases who tested positive for SARS-CoV-2 infection between their two scans. , with 141 days on average between diagnosis and the second scan. and 384 controls.
The availability of preinfection imaging data reduces the likelihood that preexisting risk factors will be misinterpreted as effects of the disease.
We identified significant longitudinal effects when comparing the two groups, including:
- Greater reduction in gray matter thickness and tissue contrast in the orbitofrontal cortex and parahippocampal gyrus.
- Greater changes in markers of tissue damage in regions functionally connected to the primary olfactory cortex.
- Greater reduction in overall brain size.
Infected participants also showed, on average, greater cognitive decline between the two time points.
Importantly, these longitudinal cognitive and imaging effects were still observed after excluding the 15 cases who had been hospitalized.
These imaging findings of the primarily limbic brain may be in vivo hallmarks of degenerative disease spread through the olfactory pathways, of neuroinflammatory events, or of loss of sensory information due to anosmia.
Whether this harmful impact can be partially reversed or whether these effects will persist in the long term remains to be investigated with additional follow-up.
