Widespread structural and functional brain alterations in COVID-19: a systematic review of MRI studies

The coronavirus disease 2019 (COVID-19) pandemic has not only challenged global public health but also generated interest in its neurological basis. A growing number of neuroimaging studies have used quantitative magnetic resonance imaging (MRI) to quantify brain alterations in COVID-19 patients. We conducted a comprehensive review to synthesize brain regions with abnormal MRI metrics of microstructure and function in COVID-19 patients compared to healthy controls. Drawing upon 49 studies sourced from PubMed, Embase, and Web of Science databases, our review showcases structural and functional brain abnormalities across many brain regions in COVID-19. Across multimodal MRI studies, alterations were predominantly in frontal regions, temporal regions, parietal regions, limbic system, and subcortical nuclei. Our findings may help understanding of the neurophysiological basis of acute neurological symptoms and long-term neurological sequelae associated with COVID-19.