Myelin-oligodendrocyte glycoprotein antibody-positive encephalitis in a patient with Sturge–Weber syndrome

Sturge-Weber syndrome (SWS) is a rare congenital disorder associated with systemic vascular malformations characterized by port-wine stains, epilepsy, and glaucoma. Patients with SWS can develop stroke-like symptoms such as hemiparesis. We report a case of a 63-year old woman with SWS who developed left-sided hemiparesis and was finally diagnosed with myelin-oligodendrocyte glycoprotein (MOG) antibody-positive encephalitis. Brain magnetic resonance imaging (MRI) revealed right-dominant bilateral leptomeningeal enhancement, thickened dura mater, and a cerebellar lesion. Cerebrospinal fluid (CSF) examination showed pleocytosis. Both serum and CSF proved positive for MOG antibodies. The patient recovered immediately after intravenous methylprednisolone administration. SWS and MOG antibody-positive encephalitis share similar clinical findings of stroke-like symptoms and leptomeningeal enhancement on MRI. However, MOG antibody-positive encephalitis is highly steroid-responsive in most cases. If a patient with SWS develops stroke-like symptoms accompanied by abnormal CSF findings or subtentorial lesions, testing for MOG antibodies should be considered.