COVID-19 and neuroinflammation: a literature review of relevant neuroimaging and CSF markers in central nervous system inflammatory disorders from SARS-COV2.

BACKGROUND: The literature on neurological manifestations in COVID-19 patients has been rapidly increasing with the pandemic. However, data on CNS inflammatory disorders in COVID-19 are still evolving. We performed a literature review of CNS inflammatory disorders associated with coronavirus disease-2019 (COVID-19). METHODS: We screened all articles resulting from a search of PubMed, Google Scholar and Scopus, using the keywords; "SARS-CoV-2 and neurological complication", "SARS-CoV-2 and CNS Complication" looking for reports of transverse myelitis, longitudinally extensive transverse myelitis, neuromyelitis optica, myelitis, Myelin Oligodendrocyte Glycoprotein Antibody Disorder (MOGAD), Acute Disseminated Encephalomyelitis (ADEM), Acute Hemorrhagic Necrotizing Encephalitis/Acute Hemorrhagic Leukoencephalitis (AHNE/AHLE), Cytotoxic lesion of the Corpus Callosum/Mild Encephalopathy Reversible Splenium Lesion(CLOCC/MERS) and Optic neuritis published between December 01, 2019 and March 15, 2021. RESULTS: Our literature search revealed 43 patients meeting the diagnosis of myelitis, including Transverse Myelitis, ADEM, AHNE/AHLE or CLOCC/MERS and Optic neuritis. Acute myelitis was most commonly associated with non-severe COVID-19 and all reported cases of AHNE/AHLE had severe COVID-19 infection. Based on IDSA/ATS criteria of either requiring vasopressor for septic shock or mechanical ventilation, 49% (n = 18) patients were considered to have a severe COVID infection. There were 7 (n = 19%) fatalities. CONCLUSION: To our knowledge, this is among the first reviews that includes the clinical features, neuroimaging, CSF findings and outcomes in COVID-19-associated CNS inflammatory disorders. Our observational review study reveals that although rare, myelitis, ADEM, AHNE and CLOCC can be associated with COVID-19 infection. Further studies using MRI imaging and CSF analysis in early diagnosis and intervention of these disorders are warranted.