A型インフルエンザ罹患後に視神経炎症状のみを呈した急性散在性脳脊髄炎の1例

Optic neuritis as the sole manifestation in a case of acute disseminated encephalomyelitis after influenza A

要約　目的：A型インフルエンザ罹患後に視神経炎のみを呈した急性散在性脳脊髄炎の症例の報告。症例：8歳女児が10日前からの両眼視力障害で受診した。40日前にA型インフルエンザに罹患していた。所見と経過：視力は両眼とも眼前指数弁で，両眼に乳頭の発赤腫脹があった。磁気共鳴画像検査（MRI）で両側の非対称性の散在性脱髄性病変があった。他には神経学的異常はなく，インフルエンザA抗体価が上昇していた。急性散在性脳脊髄炎と診断し，ステロイドのパルス療法を開始した。20日後に左右眼とも視力は1.2に改善し，乳頭の腫脹と脱髄性病変も軽快した。以後11か月後の現在まで再発はない。結論：本症例は視神経炎のみを症状とする急性散在性脳脊髄炎と考えられる。

Abstract.　Purpose：To report a case of acute disseminated encephalomyelitis after influenza A with optic neuritis as the sole clinical manifestation. Case：An 8-year-old girl presented with impaired visual acuity in both eyes since 10 days before. She had suffered from influenza A 40 days before. Findings：Visual acuity was counting fingers in either eye. Both eyes showed hyperemia and swelling of optic disc. Magnetic resonance imaging（MRI）showed scattered asymmetric demyelinating lesions. No other neurological abnormalities were present. The serum showed elevated titer for influenza A. She was diagnosed with acute disseminated encephalomyelitis with optic neuritis and was treated with pulsed corticosteroid. Visual acuity improved to 1.2 20 days later with improvement of demyelinating lesions. There has been no recurrence for 11 months until present. Conclusion：The present case appears to be an unusual instance of acute disseminated encephalomyelitis with optic neuritis as the sole clinical manifestation.