軽微な臨床症状で終始した椎骨脳底動脈解離による脳底動脈閉塞症の1例

A Case of Basilar Artery Occlusion Caused by Vertebrobasilar Artery Dissection Presenting with Mild Clinical Symptoms

I．はじめに

　近年，椎骨脳底動脈解離性動脈瘤（VBA-DA）に対する認識が高まるにつれ，その報告は飛躍的に増加し，椎骨脳底動脈領域における脳血管障害において重要な位置を占めるようになってきた．しかし，解離が進行すれば当然至るはずの脳底動脈閉塞症（BAO）に注目した報告はほとんどなく，また，そのような症例の予後は極めて不良である^1,2,16）．われわれは，VBA-DAを原因としてBAOを来したにもかかわらず軽微な臨床症状で終始した1例を経験したので，若干の文献的考察を加えて報告する．

We reported a first case of basilar artery occlusion caused by vertebrobasilar artery dissection presenting with mild clinical symptoms. A 45-year-old female was admitted to our department due to the abrupt onset of pain in her posterior neck and occipital head, and numbness in the right upper and lower extremities. She had no other neurological complaints. Computerized tomography and magnetic resonance imaging (MRI) disclosed no abnormalities in parenchyma, but MRI re-vealed a linear high intensity structure in front of the medulla oblongata on T1 and T2 weighted images.Cerebral angiogram showed the pearl and string sign from the left vertebral artery to the proximal basilar artery, and showed the basilar artery occlusion, but the basilar artery distal to the occlusion site was perfused sufficiently by the carotid via posterior communicating arteries. We diagnosed it as basilar artery occlusion caused by vertebrobasilar artery dissection, which was confirmed during the operation to prevent a hemor-rhage from the aneurysmal dilatation. In this case, col-lateral good circubation was thought to have contri-buted to her good clinical course.