# Examining neuroimaging biomarkers, plasma biomarkers and cognitive functions in patients with recovered COVID-19 infection: a multicentre study using 7T MRI

## TL;DR

This study found that hospitalized COVID-19 patients had lower hippocampal volume and worse memory compared to non-hospitalized individuals, but similar brain white matter changes.

## Contribution

The study is the first to use 7T MRI to examine neuroimaging and plasma biomarkers in recovered hospitalized and non-hospitalized COVID-19 patients.

## Key findings

- Hospitalized patients had lower hippocampal volume and poorer memory than non-hospitalized controls.
- Higher white matter hyperintensity burden was linked to worse cognition and higher plasma biomarker levels.
- Biomarker–cognition correlations were similar between hospitalized and non-hospitalized groups.

## Abstract

We examined the impact of COVID-19 hospitalization on neuroimaging biomarkers and the association of these neuroimaging biomarkers with cognitive measures and plasma biomarkers. A total of 179 dementia-free people, including 52 hospitalized COVID-19 patients, across four medical centres in the USA and UK underwent 7T brain MRI scans, cognitive tests and blood collection. We found that hospitalized patients exhibited a comparable white matter hyperintensity burden, lower total hippocampal volume and lower plasma glial fibrillary acidic protein concentration, along with poorer memory performance, compared to age-matched non-hospitalized participants. Higher white matter hyperintensity burden was associated with older age, worse cognitive scores and higher plasma biomarker levels; higher total hippocampal volume was associated with younger age, better cognitive scores and lower plasma phosphorylated tau levels. However, these correlation coefficients did not differ between the hospitalized and non-hospitalized groups. Longitudinal studies are needed to clarify the long-term impact of COVID-19-related hospitalization.

Liou et al. found hospitalized COVID-19 patients had lower hippocampal volume, reduced plasma glial fibrillary acidic protein and poorer memory than age-matched controls, despite similar white matter hyperintensity burden. Biomarker–cognition correlations aligned with age and did not differ by hospitalization status. Longitudinal studies need to clarify the long-term impacts of COVID-19-related hospitalization.

Graphical AbstractFor image description, please refer to the figure legend and surrounding text.