Systematic review and meta-analysis of brain neuroimaging abnormalities in COVID-19 patients and survivors

Accumulating evidence indicates that COVID-19 may cause neurological complications detectable on brain imaging. Yet, the overall prevalence, modality-specific characteristics, and clinical implications of these neuroimaging abnormalities have not been systematically summarized through comprehensive quantitative synthesis.

We searched the PubMed, Web of Science, Scopus, Embase, Cochrane Library, and China National Knowledge Infrastructure (CNKI) databases, and Wanfang for original articles published up to August 5, 2025. The pooled proportions of brain-imaging findings on computed tomography (CT), magnetic resonance imaging (MRI), and electroencephalography (EEG), including hemorrhage, microbleeds, ischemia, stroke, encephalitis, background activity abnormality, periodic or rhythmic activity, and epileptiform discharge, were estimated using a random-effects model. This study was conducted according to PRISMA guidelines.

Eighty-three eligible studies that included 9466 COVID-19 patients were included in the meta-analysis. Pooled results from 27 studies, including 3081 patients, showed that more than two-fifths (42.60%) of patients who underwent CT/MRI had objective brain abnormalities. The most frequently reported abnormalities on CT/MRI were changes in white matter and non-specific stroke. Twenty-five EEG studies, including 1273 patients, reported epileptiform discharges in one-fifth (20.54%) of cases. The systematic review of long-term brain imaging manifestations in COVID-19 survivors also found common changes in brain microstructure and function.

While these findings offer insights into the potential pathological mechanisms of neuroimaging abnormalities in COVID-19 patients, the high heterogeneity and variability across studies highlight the need for cautious interpretation. It will be necessary to conduct large-scale longitudinal studies with extended follow-up periods in order to validate these neuroimaging findings and clarify the long-term neuropsychiatric consequences of COVID-19.