Challenging diagnosis of myelin oligodendrocyte glycoprotein (MOG) antibody: positive optic neuritis

Case presentation: Ten year-old female presented whit visual loss and ocular pain with extraocular movements in the left eye papilledema. After 15 days, it progressed to right eye. No other neurological symptoms were observed. The case was investigated optical nerve magnetic resonance imaging (MRI), which evidenced enhancement of perineural involvement, brain spinal cord MRI without demyelination. Cerebrospinal fluid demonstrated pleocytosis (31 cells) gammaglobulin increase (19%), oligoclonal immunoglobulin G bands elevation. Anti-aquaporin-4 (AQP4) IgG, by Cell Based Assay, negative. Treatment methylprednisolone initiaded, adequate response. 1 3 years, there relapses, similar neuritis. Imaging (brain, optic cord) maintained, no alterations last attack, testing for MOG-IgG became available, positive results. steroids azathioprine sustained, new acute attack until this moment.