A Comparison of Regional Brain Volumes in Older Adults With and Without History of COVID-19

Abstract

BACKGROUND: Recent studies have shown that SARS-CoV-2 can have neuropsychiatric consequences and has the ability to penetrate the blood-brain barrier. If SARS-CoV-2 has a specific route of entry into the brain, it may leave imprints in the form of specific changes in brain morphology. Older individuals are most vulnerable to the neuropsychiatric COVID-19 complications. This study aims to compare regional brain volumes in older adults individuals with and without COVID-19 history (COVID+ and COVID-, respectively).
 METHODS: Individuals over 65 years old who applied for treatment to the Memory Clinic (Mental-Health Clinic No. 1 named after N.A. Alexeev, Moscow, Russia) were assessed between October 2020 and April 2021. Their COVID-19 history was determined by the self-report and COVID-19 certificate. Individuals with severe neuropsychiatric or acute or severe chronic somatic or infectious disease and those taking medications potentially affecting cognitive functioning were excluded. All participants underwent MRI examinations followed by image segmentation and morphometric quantitative analysis. Regional brain volumes were compared in COVID+ and COVID- people.
 RESULTS: 207 participants were included in the study. The COVID+ group consisted of 24 participants. The comparison between groups revealed statistically significant differences in left amygdala area (median 1199.3 mm3 in COVID+ vs. 1263.7 mm3 in COVID-) and right postcentral gyrus volumes (median 8055.5 mm3 in COVID+ vs. 8434.0 mm3 in COVID-). Then case-control analysis was performed in individuals matched for gender, age and common somatic causes of structural brain changes (hypertension and/or diabetes mellitus type 2) for 22 subjects in each group. Statistically significant differences in regional brain volumes between groups were absent.
 CONCLUSION: We did not find strong evidence for any regional brain volumes changes in people older than 65 years with a history of COVID-19 in comparison to those without history of COVID-19. Though, given study limitations, these results cannot be generalized to other people who recovered from COVID-19.