Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease Presenting as Recurrent and Migrating Focal Cortical Encephalitis.

Although pediatric myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease is increasingly well-recognized, its full clinical spectrum is still being defined. Cortical encephalitis is emerging as a distinct clinico-radiologic syndrome of adult MOG antibody-associated disease. We describe a 12-year-old girl who presented with new onset seizures and left-sided hemiparesis. Brain MRI showed edema of the right temporal-parietal-occipital cortex with associated focal leptomeningeal enhancement. Patient received high-dose corticosteroids and 21 days of acyclovir despite negative infectious work-up due to the focal nature of encephalitis. Patient remained seizure-free for 20 months before presenting with new right hemiclonic seizures with right-sided hemiparesis and edema of the left temporal-parietal cortex with associated leptomeningeal enhancement. Patient's MOG antibody titer was 1:40. She completed high-dose corticosteroids and intravenous immunoglobulin. Our patient highlights the importance of MOG antibody testing in pediatric focal cortical encephalitis to avoid unnecessary anti-viral agents and provide more appropriate immunotherapy and a more informed prognosis.