Cerebral aneurysms in the perforating artery manifesting intracerebral and subarachnoid haemorrhage--report of two cases.

Abstract

An arteriosclerotic aneurysm in the perforating artery has been focused on as a causative factor for hypertensive intracerebral haemorrhage. However, its pathogenesis remains unknown, and its existence is still a controversy. A 62-year-old female and a 70-year-old male with a history of hypertension suffered from intracerebral haemorrhage accompanied by subarachnoid haemorrhage. Cerebral angiograms demonstrated an aneurysm arising from the perforating artery at the central location of the haematoma in both cases. The aneurysms were confirmed as the cause of bleeding during microsurgery, and were resected. Histological examination of the surgical specimens revealed that the walls of the aneurysms lacked internal elastic lamina and consisted only of the adventitia. These findings demonstrate that the aneurysm in the perforating artery can be a causative factor for hypertensive intracerebral haemorrhage, and indicate that the loss of internal elastic lamina induced by hypertension may contribute to the formation of the aneurysm of the perforating artery.