[A case of the anterior choroidal artery aneurysm combined with the abnormal intracranial vascular network (author's transl)].

A case of the anterior choroidal artery aneurysm combined with the abnormal intracranial vascular net-work was reported. The patient was 43-year-old male who was attacked by subarachnoid hemorrhage in February 25th 1975. When he was admitted to our clinic 30 days after the ictus, his general status was good and the neurological examination showed no particular findings except only slightly accelerated deep tendon reflexes on the left side. Cerebrospinal fluid still remained xanthochromic although no nuchal rigidity was denoted. Based on the angiographic four vessel studies, the circulatory condition of the patient's brain was summarized as follows; the internal carotid arteries were stenosed or occluded between the C1 and C2 segment on both sides, and abundant collateral circulation was developed mainly around the circle of Willis making an angiographically peculiar vascular net-work in tha base of the brain. Another angiographic finding to be noticed was a berry aneurysm which originated from the distal part of the left anterior choirdal artery. No special treatment was performed on him. He was discharged without any neurological residuals. It would be difficult to find out any hemodynamic relationship between the occlusion of the internal carotid arteries and occurence of the aneurysm. But the abnormally dilated anterior choroidal artery might suggest that the vessel wall of this artery would be burdened in the abnormal distension stress due to the increased transaxial pressure in this artery. Unqder such a hemodynamically stressed state, it would be possible the aneurysm like outpouching of the vessel wall being developed in some fragile portion of the artery functioning as a prominent collateral circulation.