抗MOG抗体高力価陽性脳脊髄炎後に発症した視神経炎の1例

A case of optic neuritis following encephalomyelitis with high-titer anti-myelin oligodendrocyte glycoprotein（MOG）antibodies

要約　目的：抗ミエリンオリゴデンドロサイト糖蛋白（MOG）抗体が高値の脳脊髄炎後に視神経炎が発症した1症例の報告。

症例：6歳女児。発熱，頸部の疼痛，歩行障害を発症し，当院小児科へ入院。その際，視力は左右とも1.2であった。MRIで大脳と視床，脊髄に高信号域があり，脳脊髄炎と診断された。メチルプレドニゾロンによるステロイドパルス治療1クール施行後，症状は軽快した。髄液の抗MOG抗体は強陽性であった。退院7日後，両眼の視力障害で再受診。

所見と経過：視力は左右眼とも光覚弁で，両眼に強い乳頭浮腫があった。両眼の視神経にMRIで高信号があり，視神経炎と診断した。ステロイドのパルス療法で，3クール後に視力は左右眼とも1.2に回復した。3か月後の抗MOG抗体は大きく低下した。以後13か月間，視神経炎の再発はない。

結論：抗MOG抗体が高値の脳脊髄炎の治療後に視神経炎が発症し，ステロイドパルス療法で寛解した。

Abstract　Purpose：To report a case of acute optic neuritis following encephalomyelitis with high-titer anti-myelin oligodendrocyte glycoprotein（MOG）antibodies in the cerebrospinal fluid.

Case：A 6-year-old girl had developed fever, pain in the neck, and difficulty in walking. Visual acuity was reportedly 1.2 in either eye. Magnetic resonance imaging（MRI）showed high signal in the brain and the spinal cord, leading to the diagnosis of acute encephalomyelitis. High-titer anti-MOG antibodies were detected in the cerebrospinal fluid. After pulse therapy with methylprednisolone, clinical manifestations were improved. However, she had visual impairment in both eyes one week after leaving the hospital.

Findings and Clinical Course：Visual acuity was light perception in either eye. Both eyes showed severe optic disc edema. MRI showed high signal in both optic nerves, leading to the diagnosis of acute optic neuritis. Three courses of pulse therapy with methylprednisolone was followed by improved visual acuity of 1.2 in either eye. Serum anti-MOG level showed normalization when measured 3 months later. Shehas been doing well for 13 months until present.

Conclusion：Acute optic neuritis developed following encephalomyelitis with high-titer anti-MOG antibodies. Optic neuritis subsided after pulse therapy with methylprednisolone.