外因性か内因性か鑑別に苦慮した小児くも膜下出血の1例

A Child Case of Subarachnoid Hemorrhage Triggered by Head Injury : A Case Report

I．はじめに

　頭部外傷にて救急搬送され，脳底部くも膜下出血を認めた場合，外傷性か病的くも膜下出血か鑑別に苦慮することがある．特に，病的くも膜下出血の稀な小児例では，その原因を特定することは，さらに困難である．

　今回われわれは，傷害事件による頭部外傷をきっかけにくも膜下出血を発症した小児例を経験したので報告する．

We report a case of basal subarachnoid hemorrhage in a child. The etiology of this lesion was difficultto diagnose. The patient was a 9-year-old boy. He sustained minor head injury followed by loss of con-sciousness and cardiopulmonary arrest. He was brought to our emergency room by ambulance.

On arrival, he presented with cardiopulmonary arrest and deep comatose state. Basal subarachnoidhemorrhage was revealed on CAT scan. 3D-CTA documented two bulging portions : one was at the junc-tion between the left vertebral artery and the left posterior inferior cerebellar artery. The other one wasshown at the basilar artery. He died on the 7th hospital clay.

The autopsy revealed a laceration of the left vertebral artery. Microscopically, the wall around the lac-eration showed a defect in the internal elastic membrane and a decrease of smooth muscle cells with mod-erate fibrosis in the tunica media. These findings were compatible with the structure of a congenitalaneurysm.

Hence, the patient was strongly suspected to have had a congenital aneurysm whose rupture was trig-gered by minor head injury.