Familial intracranial aneurysms.

We describe a 53-year-old mother and a her 34-year-old son who suffered from spontaneous subarachnoid hemorrhage (SAH) and/or intracerebral hemorrhage due to a ruptured intracranial aneurysm. Diagnosis of the intracranial aneurysm was made by CT scan of the brain, and cerebral angiography. These two cases received surgical intervention and returned to their previous social activity after discharge, even though the mother had arrived in a comatose condition. The literature is reviewed and the characteristic expressions of familial intracranial aneurysms are described. The etiology of cerebral aneurysms is still uncertain but it is likely multifactorial. For the 176 patients with intracranial aneurysm(s) treated at Kaohsiung Medical College Hospital, the mean age at diagnosis was 51.9 years and these aneurysms were distributed mainly at the internal carotid artery (43.8%) and the anterior communicating artery (33.5%). The familial aneurysms tend to rupture at a younger age, occur less often at the anterior communicating artery and more often at the internal carotid artery and the middle cerebral artery as compared with that of non-familial aneurysms. In siblings, aneurysms occur at identical sites or at mirror sites and rupture within the same decade of life twice as frequently as expected in non-familial aneurysm cases. The familial aggregation of intracranial aneurysms and the above characteristic expressions suggest that heredity may play a role in some familial aneurysms. The pattern of inheritance, however, has not been established. Screening examinations and the treatment of unruptured intracranial aneurysms in asymptomatic relatives of the familial cases are also discussed.