Myelin Oligodendrocyte Glycoprotein-Associated Disorders Post-ChAdOx1 Vaccination.

ChAdOx1 nCoV-19 vaccine (AstraZeneca) has been associated with rare adverse events following vaccination such as thrombosis with thrombocytopenia syndrome, inflammatory myositis, and autoimmune encephalitis. Para-infectious or post-infectious myelin oligodendrocyte glycoprotein-associated disorders (MOGAD) have been reported in association with coronavirus disease. However, post-vaccine MOGAD (PV-MOGAD) has not yet been reported. Here, we report three cases of PV-MOGAD who presented with a prolonged severe headache after the ChAdOx1 vaccination. Other features of MOGAD such as optic neuritis or tumefactive demyelination appeared much later. Aseptic meningitis can be a presenting feature of PV-MOGAD. When patients present with a severe headache after the ChAdOx1 vaccination, PV-MOGAD should be considered along with thrombosis with thrombocytopenia syndrome.