Cerebral aneurysms in the perforating artery manifesting intracerebral andsubarachnoid haemorrhage - Report of two cases

Background. An arteriosclerotic aneurysm in the perforating artery has been focused on as a causative factor for hypertensive intracerebral haemorrhag e. However. its pathogenesis remains unknown, and its existence is still a controversy. Case Description. A 62-year-old female and a 70-year-old male with a histor y of hypertension suffered from intracerebral haemorrhage accompanied by su barachnoid haemorrhage. Cerebral angiograms demonstrated an aneurysm arisin g from the perforating artery at the central location of the haematoma in b oth cases. The aneurysms were confirmed as the cause of bleeding during mic rosurgery, and were resected. Histological examination of the surgical spec imens revealed that the walls of the aneurysms lacked internal elastic lami na and consisted only of the adventitia. Conclusion. These findings demonstrate that the aneurysm in the perforating artery can be a causative factor for hypertensive intracerebral haemorrhag e, and indicate that the loss of internal elastic lamina induced by hyperte nsion may contribute to the formation of the aneurysm of the perforating ar tery.