title: Risk factors for multiple intracranial aneurysms.
abstract: OBJECTIVE
  Risk factors that predispose to the formation of multiple intracranial aneurysms, which are present in up to 34% of patients with intracranial aneurysms, are not well defined. In this study, we examined the association between known risk factors for cerebrovascular disease and presence of multiple intracranial aneurysms.
  
  
  METHODS
  We reviewed the medical records and results of conventional angiography in all patients with a diagnosis of intracranial aneurysms admitted to the Johns Hopkins University hospital between January 1990 and June 1997. We determined the independent association between various cerebrovascular risk factors and the presence of multiple aneurysms using logistic regression analysis.
  
  
  RESULTS
  Of 419 patients admitted with intracranial aneurysms (298 ruptured and 121 unruptured), 127 (30%) had multiple intracranial aneurysms. In univariate analysis, female gender (odds ratio [OR] = 1.9; 95% confidence interval [CI], 1.1-3.3) and cigarette smoking at any time (OR = 1.8; 95% CI, 1.1-3.0) were significantly associated with presence of multiple aneurysms. In the multivariate analysis, cigarette smoking at any time (OR = 1.7; 95% CI, 1.1-2.8) and female gender (OR = 2.1; 95% CI 1.2-3.5) remained significantly associated with multiple aneurysms. Hypertension, diabetes mellitus, and alcohol and illicit drug use were not significantly associated with presence of multiple aneurysms.
  
  
  CONCLUSIONS
  Cigarette smoking and female gender seem to increase the risk for multiple aneurysms in patients predisposed to intracranial aneurysm formation. Further studies are required to investigate the mechanism underlying the association between cigarette smoking and intracranial aneurysm formation.
authors.affiliation: Division of Neurosciences Critical Care, The Johns Hopkins Medical Institutions, Baltimore, Maryland, USA.
authors.forename: A I
authors.initials: AI
authors.lastname: Qureshi
authors.forename: J I
authors.initials: JI
authors.lastname: Suarez
authors.forename: P D
authors.initials: PD
authors.lastname: Parekh
authors.forename: G
authors.initials: G
authors.lastname: Sung
authors.forename: R
authors.initials: R
authors.lastname: Geocadin
authors.forename: A
authors.initials: A
authors.lastname: Bhardwaj
authors.forename: R J
authors.initials: RJ
authors.lastname: Tamargo
authors.forename: J A
authors.initials: JA
authors.lastname: Ulatowski
mesh_terms: D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects; D017542:Aneurysm, Ruptured / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery; D002533:Cerebral Angiography; D048909:Diabetes Complications; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications; D013287:Illicit Drugs; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects; D019966:Substance-Related Disorders / Q000150:complications
chemical_list: D013287:Illicit Drugs