Risk factors for the formation of multiple intracranial aneurysms

Object. Several factors are known to increase the risk of subarachnoid hemo rrhage (SAH) and spontaneous intracerebral hematoma. However, information o n the roles of these same factors in the formation of multiple aneurysms is less well defined. The purpose of this study was to examine factors associ ated with an increased risk of multiple aneurysm formation. Methods. A retrospective review of the medical records of all patients with a diagnosis of SAH and intracranial aneurysms who were admitted to a singl e institution between 1985 and 1997 was undertaken. The authors examined as sociations between risk factors (patient age and sex, menopausal state of f emale patients, hypertension, cigarette smoking, alcohol consumption, histo ry of cardiovascular disease or diabetes mellitus, and family history of ce rebrovascular disease) and the presence of multiple aneurysms by using the Fisher exact test and logistic regression analysis. Of 400 patients admitte d with a diagnosis of cerebral aneurysms, 392 were included in the study (2 87 women and 105 men). Two hundred eighty-four patients harbored a single a neurysm and 108 harbored multiple aneurysms (2 aneurysms in 68 patients, th ree aneurysms in 22 patients, four aneurysms in 13 patients, and five aneur ysms in five patients). Conclusions. Statistical analysis revealed that, as opposed to the occurren ce of a single aneurysm, there was a significant association between the pr esence of multiple aneurysms and hypertension (p < 0.001), cigarette smokin g (p < 0.001), family history of cerebrovascular disease (p < 0.001), femal e sex (p < 0.001), and postmenopausal state in female patients (p < 0.001).