[P1-123] Differing Clinical Courses after Retrobulbar Optic Neuritis with Myelin-oligodendrocyte glycoprotein Antibodies
【Background】Some patient with myelin-oligodendrocyte glycoprotein antibodies（MOG-Ab）develop neuromyelitis optica spectrum disorder (NMOSD). We present two MOG-Ab-positive patients who suffered from Retrobulbar Optic Neuritis (RON), but whose clinical courses quite differed.【Case Reports】Case 1: A 10-years-old boy suffering from visual loss for 13 days admitted to our hospital. His MRI revealed gadolinium positive high T2 signal in the optic nerves and serum MOG-Ab was positive. After 2 weeks of intravenous methylprednisolone (m-PSL) thrapy, his sight improved only a little. Then 4-cycle plasmapheresis was added and his sight recovered to its former condition. His MOG-Ab returned to normal after 18 months after the onset. Case 2: A 10-years-old girl suffering from eye pain for a week and visual impairment for 3 days admitted to our hospital. Her MRI revealed gadolinium positive high T2 signal in the optic nerves and serum MOG-Ab was positive. After 2 weeks of m-PSL therapy, her sight improved and recovered to its former condition at 30 days after the onset. However she suffered from limbic encephalitis 11 months later. MOG-Ab and anti-glutamate receptor (Glu-R) antibodies were both positive. After 3 weeks of m-PSL therapy, her condition recovered to its former condition.【Discussion】Both of the patients had MOG-Ab that caused RON. The MOG-Ab of one patient disappeared, but that of the other patient stayed at the same level (first to 13th dilution). Attentive and long term follow-up is necessary for MOG-Ab positive patients until the Ab disappears.