Familial cerebral aneurysms.

Familial cerebral aneurysms are currently the subject of burgeoning interest. We review the pertinent, recent reports on this topic in the light of our study of 17 families with familial cerebral aneurysms. The prevalence of familial cerebral aneurysms ranges from 5-28%. The sex distribution displays a female bias. Mothers are more often affected than fathers and daughters more than sons. There is no site predilection for familial cerebral aneurysms but they tend to occur at the same (or mirror) site within families. The age at rupture of familial cerebral aneurysms is younger, especially in females, than for sporadic aneurysms. They tend to rupture within the same decade in families, and within five years of each other in identical twins. The size of ruptured familial cerebral aneurysms appears to be smaller, especially in women, than sporadic aneurysms. The pattern of inheritance is unknown. A poor outcome of rupture is more frequent in familial cerebral aneurysms cases than in sporadic ones. Angiographic screening of family members at risk, especially first degree relatives, appears justified.