外眼筋麻痺で発症した中頭蓋窩くも膜嚢胞の1手術例

Arachnoid cyst of the middle cranial fossa with extraocular muscle paresis:case report

I．はじめに

　中頭蓋窩くも膜嚢胞は，頭蓋変形，眼球突出，頭蓋内圧亢進症状，痙攣発作，巣症状，精神発達遅延などの症状を呈することが知られており，また無症状で偶然発見される例も多い．われわれは，外眼筋麻痺で発症した中頭蓋窩くも膜嚢胞の1例を経験し，本患者に対し嚢胞切除術を行い，良好な結果を得たので文献的考察を含め，報告する．

Arachnoid cysts in the middle cranial fossa usually present with skull deformity, intracranial hypertension, epilepsy, focal symptoms and delayed mental develop-ment. Some cases, however, have neither symptoms nor signs. We have encountered a patient with an arachnoid cyst of the middle cranial fossa with extraocular muscle paresis and who was treated with cyst wall fenestration with good results.

An 11-year-old boy presenting with double vision was diagnosed as having an arachnoid cyst in the mid-dle cranial fossa with extraocular muscle paresis. He had no signs of increased intracranial pressure. This pa-tient underwent a cyst membranectomy. Postopera-tively this symptom rapidly subsided. Double vision dis-appeared two months postoperatively.

To our knowledge, if those cases associated with in-creased intracranial pressure signs are excluded, this is the first case reported so far of a middle cranial fossa arachnoid cyst with extraocular muscle paresis. This re-port illustrates that extraocular muscle paresis can be caused by an arachnoid cyst in the middle cranial fossa and that knowledge of this could be helpful in its early diagnosis and treatment.