Family history of subarachnoid hemorrhage and the incidence of asymptomatic, unruptured cerebral aneurysms.

OBJECT: Previously the authors reported a significant correlation between a family history of subarachnoid hemorrhage (SAH) and the discovery of an unruptured aneurysm in a group of healthy volunteers. This study corroborates and extends previous findings regarding the relationship between genetic and acquired factors in the formation of cerebral aneurysms.
METHODS: The incidence of asymptomatic, unruptured cerebral aneurysms was studied among patients with a family history of SAH within the second degree of consanguinity. Forty-one unruptured cerebral aneurysms were found in 34 (13.9%) of 244 patients. This incidence was significantly higher than that found in a control group of healthy volunteers (6%). Furthermore, patients who had a family history of SAH combined with multiple systemic risk factors were found to have the highest incidence of unruptured aneurysms (32%; odds ratio 3.49, 95% confidence interval 1.37-8.9).
CONCLUSIONS: These findings suggest that patients with a family history of SAH with or without the presence of more than one systemic risk factor are at significantly higher risk of harboring cerebral aneurysms. This high-risk group should be periodically screened and treated with appropriate surgical or other forms of therapy when necessary.