Brain Incidental MRI-Findings among COVID-19 Patients: A Systematic Review

Abstract

Introduction: Currently, case reports and case series are the main source of evidence regarding brain MRI findings in patients with COVID-19. Due to limited information of neurological findings of COVID-19 during MRI scanning, we conducted a systematic search with the aim to review and assess brain MRI findings linked to COVID-19.

Methods: Electronic search was conducted in  to a comprehensive approach in  major medical databases such as PubMed, Embase, and the Cochrane Library. Initially, for inclusion in this review, studies had to satisfy the following criteria: (1) Recruitment of patients diagnosed with COVID-19; (2) Examination of brain MRI findings; (3) Provision of adequate information to enable assessment of brain MRI outcomes; (4) Utilization of either observational or interventional study designs; (5) Publication of the study in the English language; and (6) Availability of the publication as an original research article within a peer-reviewed journal. Case reports and case series were excluded and only cohort and case-control studies were included in the review. A careful conduction of a systematic data extraction was performed, using excel sheets to perform data extraction by two independent reviewers. Finally, a narrative synthesis of the results were reported in the following section of the review.

Results: The electronic search yielded a comprehensive collection of 105 brain neuroimaging studies concerning individuals affected by COVID-19. Among these, 53 studies centered on assessing neurological symptoms devoid of detailed brain topography, thus excluding them from further consideration. Subsequently, a total of 23 studies, which focused on the examination of brain changes associated with SARS-CoV-2 infection, were finally selected for the conclusive review. This selection comprised 9 cohort studies and 14 case-control studies, each contributing unique insights. Furthermore, the assessment of the quality of included articles was conducted with precision, employing the Joanna Briggs Institute (JBI) Critical Appraisal Checklists designed for observational studies. This evaluation yielded results of commendable compliance, ranging from 67% to 100% across the evaluated studies.

Conclusions: The observed brain changes linked to SARS-CoV-2 infection in individuals affected by both acute and mild cases of COVID-19 predominantly centered around the olfactory brain network, encompassing limbic and prefrontal regions. The exact mechanisms behind these disruptions within these brain areas, whether they stem from direct viral involvement or indirect influences, still remain to be definitively established.