# Cognitive functioning and brain MRI findings six months after acute COVID-19. A prospective observational study

## TL;DR

This study found that brain MRI findings like microbleeds and white matter changes are linked to cognitive decline in some post-COVID-19 patients, but not directly caused by the virus itself.

## Contribution

The study is one of the first to prospectively link brain MRI findings with cognitive outcomes in long-term COVID-19 survivors.

## Key findings

- Age and education level were the strongest predictors of cognitive functioning.
- Cerebral microbleeds and white matter hyperintensities were associated with lower cognitive scores in some patients.
- Cognitive decline was not directly caused by a history of COVID-19.

## Abstract

COVID-19 has been linked to many neurological complications, including cognitive impairment and findings in brain imaging. However, limited data exist regarding the link between magnetic resonance imaging (MRI) findings and cognitive functioning in COVID-19 patients.

In this observational prospective study, we investigated the association between brain MRI findings, particularly cerebral microbleeds (CMBs) and white matter hyperintensities (WMHs), and cognitive functioning in COVID-19 survivors.

Six months after acute COVID-19 diagnosed in 2020, 67 ICU-treated, 44 ward-treated, and 44 home-isolated patients, as well as 48 non-COVID-19 controls, underwent MRI and comprehensive neuropsychological evaluation. We applied multivariable linear regression models to investigate the independent associations of total cognitive score and domain scores separately with CMBs, WMHs and other factors.

Age (p < 0.001, β = −0.36) and educational level (p < 0.001, β = 0.42) predominantly explained the differences in cognitive functioning. A lower total cognitive score was associated with the number of CMBs (p = 0.0016), but not with COVID-19 (p = 0.714). Among COVID-19 patients, treatment in a regular ward (p = 0.007, β = −0.46), a high burden of WMHs (p = 0.004, β = −1.35), and having one to three CMBs (p = 0.01, β = −0.43) were associated with lower total cognitive scores.

We observed a significant association between the presence of CMBs and lower cognitive scores, regardless of COVID-19 history. However, our results do not support CMBs to be independently associated with cognitive functioning. Additionally, WMH burden was associated with lower cognitive scores.