Rathke囊胞による小児視神経炎の1例

Optic neuritis in a child with Rathke cleft cyst

要約　目的：Rathke囊胞により片眼性視神経炎が発症した小児例の報告。症例：15歳男児が右眼の視力低下で受診した。4年前に片頭痛と0.3への右眼視力低下があり，プレドニゾロン内服で軽快した。所見：矯正視力は右指数弁，左1.2で，眼底は正常であった。蛍光眼底造影で造影後期に右眼乳頭に過蛍光があった。ステロイド内服などで視力は1.2に回復したが，再び悪化し，頭痛，視野障害，失神発作などが生じた。初診の14か月後に，CTで下垂体の右方にRathke囊胞が発見された。囊胞を摘出し，その2週間後に視力は1.2になり，視野も改善した。結論：Rathke囊胞による圧迫が小児の視神経炎の原因であった。

Abstract.　Purpose：To report a child with recurrent unilateral optic neuritis secondary to Rathke cleft cyst. Case：A 15-year-old boy presented with impaired vision in the right eye. He had had migaine and decreased vision to 0.3 in the right eye 4 years before. Peroal prednisolone was followed by recovery of vision. Findings：Corrected visual acuity was counting fingers right and 1.2 left. Funduscopy showed normal findings. Fluorescein angiography showed hyperfluorescence towards the late phase. Peroral prednisolone was followed by improvement of vision one month later. Right visual acuity gradually decreased to 0.1 during the following 5 months associated with migraine, visual field defect, and attacks of fainting. Fourteen months after his initial visit, computed tomography showed Rathke cleft cyst adjacent to the pituitary gland. Excision of the cyst was followed by improvement of vision to 1.2 and of visual field. Conclusion：This case illustrates that Rathke cleft cyst may induce symptoms simulating optic neuritis in childhood.