No brain MRI abnormalities after mild-to-moderate COVID-19: an observational study

To assess COVID-19-related morphological brain changes in individuals who recovered from mild-to-moderate COVID-19.

This prospective cohort study enrolled 112 consecutive individuals who recovered from mild-to-moderate COVID-19 and underwent an MRI of the brain between September 2020 and March 2022. MR exams were consistently obtained on a clinical 3T MR scanner in all study participants and 50 age-matched matched controls. The following clinical neuroradiological MR imaging findings were analyzed: post- and acute ischemic lesions, cortical signal alterations, microbleeds, perfusion abnormalities, cytotoxic lesions of the corpus callosum, and vascular abnormalities. Additionally, we manually quantified white matter lesion loads and the number of perivascular spaces and performed an automated brain volumetric analysis.

In 112 consecutive individuals the mean age was 45 years, female: male = 70:42, mean days at MRI after SARS CoV-2 infection: 228 (sd: 140), and hospitalized: non-hospitalized ratio = 30:82. Using general linear regression models, adjusting for age and gender, the frequency of white matter hyperintensities was not significantly different between subjects who recovered from COVID-19 and matched controls: 9.8 (sd: 17.3) vs. 7.6 (sd: 12.7), p = 0.590. Similarly, the number of enlarged perivascular spaces was not significantly different between the two groups: 62.7 (sd: 43.5) vs. 61.3 (sd: 47.2), p = 0.902. A subgroup analysis between those who were hospitalized in the course of the disease, in which no one required intensive care, and those who remained outpatients, also did not reveal any differences in MRI measures. We did not find evidence for perfusion-/diffusion abnormalities, (micro-)hemorrhages, or cortical abnormalities.

In the present cohort, there was currently no evidence of COVID-19-related morphological brain changes in individuals who recovered from mild-to-moderate COVID-19.