Familial intracranial aneurysms: An autopsy study

OBJECTIVE: Familial intracranial aneurysms are more common than has been appreciated, but systematic autopsy studies of affected individuals have not been reported. We reviewed the autopsy findings of a group of patients with familial aneurysms to elucidate the nature of the putative underlying arteriopathy. METHODS: Using a computerized diagnostic index, we identified all patients with intracranial aneurysms in whom postmortem examination had been performed at the Mayo Clinic between January 1, 1992, and December 31, 1994. The medical records, radiographic studies, and autopsy findings of these patients were reviewed. RESULTS: Among the 28 patients with intracranial aneurysms, 3 (11%) had one or more first-degree relatives with documented intracranial aneurysms. The mean age of the three patients (two women and one man) was 54 years. Microscopic examination of the vascular system revealed medial changes, consisting of degeneration of elastic fibers and increased ground substance, in the systemic arteries of 2 of the 3 patients with familial aneurysms but in none of the 25 patients with sporadic aneurysms. These nonspecific medial changes involved both common and extracranial internal carotid arteries in one patient and the entire aorta as well as intracranial and common carotid arteries in the other patient. CONCLUSION: These observations suggest that an underlying arteriopathy in patients with familial intracranial aneurysms involves the tunica media and commonly may affect systemic (extracranial) arteries.