Aseptic Meningitis as an Initial Manifestation of Anti-Myelin Oligodendrocyte Glycoprotein Antibody-associated Disease

: Antibody against myelin oligodendrocyte glycoprotein (MOG-IgG) associated encephalitis is an important syndrome associated with MOG-IgG. However, there have been no reports of MOG-IgG-associated optic neuritis or demyelination following meningitis without encephalitic symptoms. A 55-year-old woman presented to our hospital with headache, nausea, fever, and nuchal rigidity that had persisted for more than a month. She was hospitalized due to aseptic meningitis and recovered with conservative therapy. However, she was re-admitted due to left optic neuritis and demyelinating lesions. We diagnosed MOG-IgG-associated neuromyelitis optica spectrum disorder (NMOSD). She responded to treatment with intravenous methylprednisolone and oral prednisolone. Aseptic meningitis may be an initial manifestation of MOG-IgG-positive NMOSD.