title: Prognostic value of CT angiography in patients with suspected vertebrobasilar ischemia.
abstract: BACKGROUND
  The outcome of vertebrobasilar ischemia depends on the clinical presentation and the presence or absence of vascular occlusion. The aim of our study was to analyze the CT angiography (CTA) predictors of outcome in patients with suspected vertebrobasilar ischemia.
  
  
  METHODS
  We studied patients with suspected acute vertebrobasilar ischemia between April 2002 and January 2006 and had CTA done within 24 hours of symptom onset. We reviewed the final diagnosis and 3-month follow-up and analyzed the clinical and CTA predictors of outcome.
  
  
  RESULTS
  Of the 133 patients, 21(15%), 18 (13%), and 16 (12%) had occlusion of basilar artery (BA), vertebral artery (VA), and posterior cerebral artery (PCA) respectively. The final diagnosis was stroke in 98 (73.6%), transient ischemic attack (TIA) in 10 (7.5%), and nonischemic in 25 (18.8%). No vascular occlusion was seen on CTA in patients with TIA and nonischemic diagnosis. At 3-month follow-up, we found a mortality rate of 10.6% and good functional outcome in 71.4%. The predictors of death in the multivariable analysis were the presence of BA occlusion (odds ratio[OR] 6.7, 95% CI, 1.4-30.6) and baseline National Institutes of Health Stroke Scale (NIHSS) (OR 1.14, 95% CI, 1.06-1.2). When patients with basilar occlusion were excluded, the presence of VA occlusion (OR 6.5, 95% CI, 1.34-31.4), age (OR 1.09, 95% CI, 1.03-1.14), and baseline NIHSS (OR 1.1, 95% CI, 1.03-1.18) predicted poorer outcome.
  
  
  CONCLUSIONS
  The presence or absence of a vascular occlusion is a critical factor for prognosis in suspected acute vertebrobasilar ischemia and is correlated with the location of occlusion.
authors.affiliation: Calgary Stroke Program, Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: P N
authors.initials: PN
authors.lastname: Sylaja
authors.forename: Volker
authors.initials: V
authors.lastname: Puetz
authors.forename: Imanuel
authors.initials: I
authors.lastname: Dzialowski
authors.forename: Andrea
authors.initials: A
authors.lastname: Krol
authors.forename: Michael D
authors.initials: MD
authors.lastname: Hill
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Demchuk
mesh_terms: D001488:Basilar Artery; D002545:Brain Ischemia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002533:Cerebral Angiography; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D014057:Tomography, X-Ray Computed; D014711:Vertebral Artery