title: The natural history of radiographically defined vertebrobasilar nonsaccular intracranial aneurysms.
abstract: BACKGROUND
  Vertebrobasilar nonsaccular intracranial aneurysms (VBNIA) are characterized by dilatation, elongation, and tortuosity of the vertebrobasilar system.
  
  
  METHODS
  The medical records and imaging of patients with vertebrobasilar fusiform aneurysms or dolichoectasia between 1989 and 2001 were reviewed. Prospective follow-up was obtained.
  
  
  RESULTS
  One hundred and fifty-nine patients were identified (74% male) with 719 patient years of follow-up. Presenting events included: hemorrhage (3%), ischemia (28%), and compression (22%). The remainder were incidental. The 1-, 5-, and 10-year risk of cerebral infarction (CI) due toVBNIA is 2.7, 11.3, and 15.9% respectively. The risk of recurrent CI is 6.7% per patient year. Median survival was 7.8 years and death was most commonly due to ischemia.
  
  
  CONCLUSIONS
  VBNIA are more common in men and typically present in the 6-7th decade. Recurrent CI is more common than hemorrhage risk.
authors.affiliation: Department of Neurology, Mayo Clinic College of Medicine, Rochester, Minn. 55905, USA. flemming.kelly@mayo.edu
authors.forename: Kelly D
authors.initials: KD
authors.lastname: Flemming
authors.forename: David O
authors.initials: DO
authors.lastname: Wiebers
authors.forename: Robert D
authors.initials: RD
authors.lastname: Brown
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Link
authors.forename: John
authors.initials: J
authors.lastname: Huston
authors.forename: Robyn L
authors.initials: RL
authors.lastname: McClelland
authors.forename: Teresa J H
authors.initials: TJ
authors.lastname: Christianson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020520:Brain Infarction / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012008:Recurrence; D012307:Risk Factors; D017678:Sex Distribution; D020521:Stroke / Q000000981:diagnostic imaging* / Q000473:pathology; D016019:Survival Analysis; D014715:Vertebrobasilar Insufficiency / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology