中大脳動脈閉塞にともないleptomeningeal arteryに発生した脳動脈瘤の1例

A Case of Cerebral Aneurysm Located at the Leptomeningeal Artery Associated with Occlusion of the Middle Cerebral Artery

I．はじめに

　脳動脈瘤の発生に関して，動脈閉塞により血行動態が変化し動脈瘤が生じたという報告はこれまでも散見され，また動物実験において内頸動脈を閉塞し動脈瘤を生じさせた報告も見られる．一方，leptomeningeal arteryに脳動脈瘤が発生することは極めて稀である．われわれは，中大脳動脈前枝の閉塞により側副血行路として前大脳動脈末梢のleptomeningeal arteryが発達し，hemo—dynamic stressから同部位に動脈瘤が発生したと考えられる症例を経験したので，文献的考察を加え報告する．

A case is presented of a ruptured aneurysm located at a leptomeningeal artery associated with an occlusion of the anterior trunk of the middle cerebral artery.

A 60-year-old male had a sudden onset of severe headache and hemiplegia. CT showed a left frontal sub-cortical hematoma. Cerebral angiograms demonstrated an occlusion of the anterior trunk of the left middle cerebral artery with moyamoya phenomenon. In addi-tion, an aneurysm was found arising from the lep-tomeningeal artery. The parent artery was filled with contrast medium from the middle internal frontal artery.

We have reviewed literature and discussed the cause of an aneurysm located at the leptomeningeal artery. Hemodynamic factors were strongly suggested as the reason for the aneurysmal formation in this case.