モヤモヤ様血管を伴った特発性中大脳動脈閉塞症に反対側の中大脳動脈瘤を合併した1例

Spontaneous Middle Cerebral Artery Occlusion with Moyamoya-like Vessels Associated with Contralateral Middle Cerebral Artery Aneurysm; A case report

I．はじめに

　モヤモヤ血管はウイルス動脈輪閉塞症（モヤモヤ病）をはじめ，脳動脈硬化症，脳腫瘍など種々の疾患に合併して認められることがある．しかし，一側中大脳動脈起始部の原因不明の閉塞部周囲にモヤモヤ様面管を伴う症例は，過去には意外に報告例が少ない．この所見は，いわゆる厚生省の定めるウイルス動脈輪閉塞症の診断基準を満たさないことから，モヤモヤ病とは本質的に異なった疾患であろうと考えられている^1）．最近われわれは，左中大脳動脈瘤破裂において，その反対側の右中大脳動脈の起始部が閉塞し，その周囲にモヤモヤ様血管を認めた症例を経験したので，若干の文献的検討を加えて報告する．

A case of spontaneous middle cerebral artery occlu-sion with moyamoya-like vessels associated with con-tralateral middle cerebral artery aneurysm is reported. A 23-year-old male was admitted to our hospital with complaints of severe headache and vomiting. On admis-sion CT scan demonstrated subarachnoid hemorrhage with high density in the left Sylvian fissure and sug-gested a ruptured left middle cerebral artery aneurysm.Carotid angiograms demonstrated a left middle cerebral artery aneurysm and an occlusion of the right middle cerebral artery at its origin with moyamoya-like vessels. There was no occlusion or stenosis in the bilateral in-tracranial internal carotid arteries. Furthermore, bilater-al vertebral angiograms were also normal. The aneurysm was successfully clipped. The postoperative course was uneventful and the patient was discharged with no neurological deficit.

So far as we could ascertain, there have been only 21 cases reported previously of spontaneous middle cere-bral artery stenosis or occlusion with moyamoya-like vessels. According to angiographic studies and trans-cranial Doppler ultrasound findings, we are more in-clined to believe that hemodynamic changes secondary to arterial occlusion lead to the formation and growth of aneurysms of the contralateral middle cerebral artery.