Background There is increasing evidence that SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) not only affects the respiratory tract but also influence the central nervous system (CNS), resulting in neurological symptoms such as loss of smell and taste. Growing literature indicates largely distributed brain alterations encompassing subcortical micro- and macro-bleeds, cerebral swelling and haemorrhage in gray and white matter tissue. A systematic review was performed to synthesise the potential evidence of the brain correlates of SARS-CoV-2. Methods A literature search was conducted using electronic databases for studies reporting neuroimaging abnormalities in SARS-CoV-2 infected individuals. Identified case series, cohort studies, and case control studies on SARS-CoV-2 effects on the brain were critically appraised for methodological quality. A narrative synthesis of the findings from the included studies is presented. Results Twenty-seven studies were included in the review, including 5 case series, 8 cohort studies and 14 case control studies. The findings revealed predominant involvement of the olfactory system with disruptions across four olfactory structures. Abnormalities also extended to the corpus callosum, cingulate cortex, and insula, jointly implicating the olfactory brain network. Conclusion Alterations in olfactory areas, along with neighbouring brain regions, including prefrontal and limbic regions were associated to contraction of SARS-CoV-2. Viral infection could either trigger systemic reactions, or use the olfactory’s unique anatomical organisation as an environmental entry zone to directly impact on the CNS. Highlights • A spectrum of brain changes particularly at advanced stage relates to SARS-CoV-2 • Across severity phases SARS-CoV-2 affects olfactory structures • Emerging abnormalities in COVID-19 is associated with the olfactory brain network
【저자키워드】 COVID-19, SARS-CoV-2, Neuroimaging, CNS, Brain abnormalities, 【초록키워드】 Structure, coronavirus, severity, Infection, systematic review, Cohort studies, database, Brain, cohort study, Case series, Region, Central nervous system, respiratory tract, change, Evidence, Methodological quality, structures, olfactory, systemic reactions, case control study, Loss of Smell, acute respiratory syndrome, tissue, SARS-CoV-2 infected individuals, alteration, zone, abnormality, brain regions, corpus, Effect, Affect, Neurological symptom, case control studies, Result, resulting, conducted, was performed, anatomical, indicate, unique, predominant, Identified, callosum, cerebral swelling, olfactory brain, subcortical, 【제목키워드】 systematic review, Patient, Brain imaging,