視神経減圧術が著効した慢性肥厚性脳硬膜炎の1例

A successful case of hypertrophic cranial pachymeningitis treated by optic nerve decompression

I．はじめに

　肥厚性脳硬膜炎（HCP）は，頭蓋底に好発する硬膜の慢性炎症性肥厚を特徴とする疾患であり，多発脳神経障害をはじめ多彩な神経症状を呈することが知られている^{1-3,5-21,23-25,27）}．われわれは，視力障害にて発症しステロイドの効果が一過性であったため直達手術を施行し，視力を著明に改善し得た，眼窩内と連続性を持った蝶形骨縁HCPの1例を経験したので文献的考察を加え報告する．

A successful direct operation in a case of hyper-trophic cranial pachymeningitis (HCP) is described. A 51-year-old male was admitted with right visual disturb-ance. CT scanning revealed a mass lesion in the right middle cranial fossa extending into the right orbita. From MRI it was ascertained that this mass lesion con-sisted of thickening of the skull base dura.

The effect of steroids was transient and his visual disturbance was rapidly increasing. A direct operation was performed consisting of partial dissection of the thickening dura and decompression of the right optic nerve. Histological diagnosis showed HCP. After surgery his symptoms dramatically improved.

The etiology, natural course and treatment of HCP are well reported in the literature. In the present case the etiology was not clear, but there was a possible re-lationship with intraorbital pseudotumor or multifocal fibrosclerosis. The reported occasional transitory effect of steroids on HCP and a poor prognosis for visual acuity are common traits in these patients. The authors thus feel that a direct operation should be immediately carried out when the effect of steroids on visual dis-turbances associated with HCP is judged transient.