Optic neuritis, encephalitis and leptomeningeal enhancement in a patient with anti-MOG antibodies: A case study.

A subset of patients with neuromyelitis optica spectrum disorders are positive for myelin-oligodendrocyte glycoprotein (MOG) antibodies. These patients present with distinct clinical demyelinating syndrome often confused for multiple sclerosis. We describe the case of a patient who initially presented with 10-day history of right-sided retro-orbital headache worse with lateral gaze, photophobia, and subjective decreased visual acuity. After successful treatment on a steroid regimen, this patient represented two weeks following discharge with seizure and was found to have unilateral meningeal T2-FLAIR MRI hyperintensity with associated cortical swelling, a rare finding. CSF studies showed negative anti-AQP4 antibodies and positive anti-MOG antibodies. This case demonstrates that patients presenting with symptoms concerning for NMOSD who are AQP4-Ab-negative should be tested for anti-MOG antibodies for optimized disease management and important prognostic implications.