Acute disseminated encephalomielite and Covid-19 - a literature review

Background: The infection caused by SARS-CoV-2 is associated with several neurological manifestations. Among these, acute disseminated encephalomyelitis (ADEM), an immune-mediated disease, has a reasonable incidence. In this context, the absence of direct viral infection of the CNS and late presentation of the condition corroborate to the hypothesis of an immune relationship. Objectives: Describe the relation between acute disseminated encephalomyelitis and COVID-19 infection. Design and setting: Literature review, held at the University Center of João Pessoa, located in the city of João Pessoa, Paraíba, Brazil. Methods: Through the PubMed database, using descriptors as follows: “acute disseminated encephalomyelitis” AND “COVID-19”, associated with time filter of the years 2020-2021. Results: The pathogenesis of ADEM in COVID-19 occurs through several mechanisms. One is a cross reaction between immune cells and nerve cells, which causes damage by activating the immune response and releasing protease enzymes. Another perspective is that the state of hyperinflammation activates like glial cells. In addition, an infection can trigger the production of autoantibodies against glial components, generating demyelinating lesions. In a series of cases that included 43 patients, nine had manifestations of ADEM, with a variety of clinical and radiological forms. Of these nine, on neuroimaging, all had multifocal, supratentorial white matter, four had hemorrhagic changes and two had myelitis. Conclusions: The coexistence between ADEM and COVID-19, although well established in some cases, still shows the need for studies that better clarify the relation between viral infection and brain lesions present in these clinical conditions.