Clinicoradiological and prognostic features of COVID-19-associated acute disseminated encephalomyelitis

The Covid-19 pandemic has resulted in a spark in interest in the subject given the high exposure rate to viral antigens in the form of infections and vaccines. It is expected that acute disseminated encephalomyelitis (ADEM) cases see a rise in incidence during this period. Given the plethora of Covid-19-related central nervous system (CNS) involvement, it is important to be aware of the varied presentations of ADEM.

In this paper, we report 3 cases of ADEM following Covid-19 infection. Patients presented with polyfocal neurological symptoms 6 to 18 days after respiratory symptoms onset. The diagnosis of Covid-19 was made based on nasal swab reverse transcriptase-polymerase chain reaction (RT-PCR) and chest computerized tomography (CT).

These cases illustrate both classic and atypical presentations requiring exclusion of a spectrum of CNS conditions to be able to retain the diagnosis of ADEM. Consequently, we stress the importance of context, clinical examination and MRI findings in the differentials. In addition, we discuss workup, and particularly, the indication of brain biopsy. Also, the paper discusses options in therapy and the prognosis. The prognosis of covid-associated ADEM is dependent on the extent of pathology intrinsic to ADEM and the intrication of the prognosis of Covid-19 infection.

The key message in these 3 cases is that clinicians should have a low threshold of suspicion of ADEM in the Covid-19 context, adopt appropriate workup strategies, and initiate adequate treatment for better outcomes.