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 highrisk group should be periodically screened and treated with appropriate surgical or other forms of therapy when necessary.