title: Significance of large vessel intracranial occlusion causing acute ischemic stroke and TIA.
abstract: OBJECTIVE
  Acute ischemic stroke due to large vessel occlusion (LVO)-vertebral, basilar, carotid terminus, middle and anterior cerebral arteries-likely portends a worse prognosis than stroke unassociated with LVO. Because little prospective angiographic data have been reported on a cohort of unselected patients with stroke and with transient ischemic attack, the clinical impact of LVO has been difficult to quantify.
  
  
  METHODS
  The Screening Technology and Outcome Project in Stroke Study is a prospective imaging-based study of stroke outcomes performed at 2 academic medical centers. Patients with suspected acute stroke who presented within 24 hours of symptom onset and who underwent multimodality CT/CT angiography were approached for consent for collection of clinical data and 6-month assessment of outcome. Demographic and clinical variables and 6-month modified Rankin Scale scores were collected and combined with blinded interpretation of the CT angiography data. The OR of each variable, including occlusion of intracranial vascular segment in predicting good outcome and 6-month mortality, was calculated using univariate and multivariate logistic regression.
  
  
  RESULTS
  Over a 33-month period, 735 patients with suspected stroke were enrolled. Of these, 578 were adjudicated as stroke and 97 as transient ischemic attack. Among patients with stroke, 267 (46%) had LVO accounting for the stroke and 13 (13%) of patients with transient ischemic attack had LVO accounting for transient ischemic attack symptoms. LVO predicted 6-month mortality (OR, 4.5; 95% CI, 2.7 to 7.3; P<0.001). Six-month good outcome (modified Rankin Scale score <or=2) was negatively predicted by LVO (0.33; 0.24 to 0.45; P<0.001). Based on multivariate analysis, the presence of basilar and internal carotid terminus occlusions, in addition to National Institutes of Health Stroke Scale and age, independently predicted outcome.
  
  
  CONCLUSIONS
  Large vessel intracranial occlusion accounted for nearly half of acute ischemic strokes in unselected patients presenting to academic medical centers. In addition to age and baseline stroke severity, occlusion of either the basilar or internal carotid terminus segment is an independent predictor of outcome at 6 months.
authors.affiliation: Department of Neurology, University of California, San Francisco, CA 94143-0114, USA. smithw@neurology.ucsf.edu
authors.forename: Wade S
authors.initials: WS
authors.lastname: Smith
authors.forename: Michael H
authors.initials: MH
authors.lastname: Lev
authors.forename: Joey D
authors.initials: JD
authors.lastname: English
authors.forename: Erica C
authors.initials: EC
authors.lastname: Camargo
authors.forename: Maggie
authors.initials: M
authors.lastname: Chou
authors.forename: S Claiborne
authors.initials: SC
authors.lastname: Johnston
authors.forename: Gilberto
authors.initials: G
authors.lastname: Gonzalez
authors.forename: Pamela W
authors.initials: PW
authors.lastname: Schaefer
authors.forename: William P
authors.initials: WP
authors.lastname: Dillon
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Koroshetz
authors.forename: Karen L
authors.initials: KL
authors.lastname: Furie
mesh_terms: D000208:Acute Disease; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001488:Basilar Artery / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D002545:Brain Ischemia / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D002533:Cerebral Angiography; D002536:Cerebral Arteries / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D015897:Comorbidity; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012720:Severity of Illness Index; D020521:Stroke / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D014057:Tomography, X-Ray Computed