脳底動脈解離によるくも膜下出血の1例

Subarachnoid Hemorrhage Caused by Dissection of the Basilar Artery: A Case Report

Ⅰ．はじめに

　脳動脈解離は近年の画像診断の進歩に伴い，従来よりも高い頻度で生じていることが明らかになってきている¹⁵⁾．しかしながら脳底動脈解離は比較的稀な疾患であり，われわれはその1例を経験したので報告する^1,2)．

　We report a case of subarachnoid hemorrhage, which was caused by dissection of the basilar artery during treatment for diabetes mellitus. The patient was a 60-year-old male who consulted our hospital complaining of sudden-onset of a severe headache. Head CT scan showed subarachnoid hemorrhage around the basilar artery, but 3D-CT angiography revealed no abnormality. The basilar artery was shown to be normal during cerebral angiography on Day 1. However, in retrospect pseudolumen of the basilar artery was suspected in the proximal portion of the branching point of the anterior inferior cerebellar artery.

　During a second cerebral angiography on Day 17, blood pressure elevated to 185/83mmHg and 30 minutes later this patient's consciousness deteriorated to 10 points of the GCS（E4, V2, M4). The double lumen in the basilar artery was identified around the branching point of the anterior inferior cerebellar artery. Head MRI on the same day showed intramural hemorrhage of the basilar artery as a high intensity lesion. Head MRI on Day 18 revealed multiple cerebellar infarctions in the region of the bilateral anterior inferior cerebellar arteries.

　His consciousness recovered to almost normal by reducing the blood pressure. Transient gait disturbance also recovered thereafter. Head MRI on Day 90 indicated disappearance of the intramural hemorrhage in the basilar artery. It was important to reduce the blood pressure to prevent recurrence of the arterial dissection.