Imaging Markers of Neurologic Damage in COVID-19: A Systematic Review

Abstract
Background and objective: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection commonly leads to neurologic manifestations. In the present review, we aimed to investigate potential neuroimaging markers of early diagnosis and prognosis of neurologic manifestations in COVID-19. Methods: Our study was registered in the Prospective Register of Systematic Reviews (PROSPERO) under the protocol CDR42021265443. Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we selected 51 studies for whole-manuscript analysis. Results: Magnetic resonance imaging (MRI) was the most common imaging method. The pattern, sites of lesion, signs, and symptoms of neurologic injury varied. Such manifestations possibly resulted from a direct viral infection or, most likely, from indirect mechanisms including coagulation disturbances, hypoxemia, and immunological responses. Conclusion: The heterogeneity of the studies precludes any generalization of the findings. Brain MRI is the most informative imaging exam. Population studies including the entire spectrum of COVID-19 are missing. There is still a need for future population studies evaluating neurologic manifestations of all COVID-19 severities acutely and chronically.