Risk Factors for Multiple Intracranial Aneurysms
The presence of multiple intracranial aneurysms may be a sign of significant risk factors for aneurysm formation that differ from those factors that increase risk for aneurysm rupture. Only 2 studies concern independent risk factors for multiple aneurysms
Methods: Of 266 patients with aneurysmal subarachnoid hemorrhage (139 men and 127 women, aged 15 to 60 years), 80 (30%) had multiple intracranial aneurysms. The prevalence of several health-related habits, previous diseases, and medications of these patients were compared by multiple logistic regression between those with single and those with multiple aneurysms.
Results: On the basis of multivariate statistics, only regular cigarette smoking at any time was a significant risk factor for the presence of multiple aneurysms. The odds ratio (OR) of smoking for multiple aneurysms was 2.10 (95% CI, 1.06 to 4.13) after adjustment for age and sex. After additional adjustment for hypertension, the risk was 2.06 (95% CI, 1.04 to 4.07). Of other variables, only age (OR, 1.02 per year; 95% CI, 1.00 to 1.05; P=0.09) and female sex (OR, 1.60; 95% CI, 0.90 to 2.85; P=0.11) showed a tendency to increase the risk for multiple aneurysms after adjustment for smoking. On the other hand, patients with hypertension had significantly (P=0.029) more aneurysms (1.61Â±1.04) than did those without (1.37Â±0.68), although they did not more frequently have multiple aneurysms.
Conclusions: Cigarette smoking and possibly also age and female sex seem to be risk factors for multiple intracranial aneurysms in patients of working age who have suffered a subarachnoid hemorrhage. Patients with hypertension seem to have more aneurysms than those without.