118 Acute disseminated encephalomyelitis associated with SARS-CoV-2 vaccine in multiple sclerosis: a case report

We present a case of acute disseminated encephalomyelitis (ADEM) occurring 3 weeks following the AstraZeneca SARS-CoV-2 vaccine, in a patient previously diagnosed with multiple sclerosis.Case: This 55-year-old lady had a background of multiple sclerosis (MS), but never required disease-modi- fying therapies owing to a mild disease course. She received the first dose of the AstraZeneca SARS-CoV-2 vaccine, and then was admitted with word-finding difficulties and collapse 25 days later. She deteriorated rapidly and became obtunded on day 2, requiring intubation and intensive care admission. CSF analysis revealed mildly high protein (0.76g/L) with 5 white cells/mm3, and magnetic resonance imaging (MRI) showed multifocal demyelination in keeping with acute disseminated encephalomyelitis (ADEM). She received high-dose intravenous methylprednisolone, followed by plasma exchange and tocilizumab. Despite a mild radiological and clinical improvement the patient remained fully dependent for care needs, unable to speak or mobilise.ConclusionsA number of SARS-CoV-2 vaccines have now been associated with ADEM, but this risk still appears very low in comparison with risks of SARS-CoV-2 infection. This is the first reported case of ADEM in a patient with multiple sclerosis after SARS-CoV-2 vaccination. Literature suggests increased risk of multiple sclerosis exacerbations commonly after SARS-CoV-2 infection.