title: Early diffusion weighted MRI as a negative predictor for disabling stroke after ABCD2 score risk categorization in transient ischemic attack patients.
abstract: OBJECTIVE
  The prognostic value early diffusion-weighted magnetic resonance imaging (DWMRI) adds in the setting of transient ischemic attack (TIA), after risk stratification by a clinical score, is unclear. The purpose of this study is to evaluate, after ABCD2 score risk categorization in admitted TIA patients, whether negative DWMRI performed within 24 hours of symptom onset improves on the identification of patients at low risk for experiencing a disabling stroke within 90 days.
  
  
  METHODS
  At 15 North Carolina hospitals, we enrolled a prospective nonconsecutive sample of admitted TIA patients. We excluded patients not undergoing a DWMRI within 24 hours of admission and patients for whom a dichotomized (< or = or >3) ABCD2 score could not be calculated. We conducted a medical record review to determine disabling ischemic stroke outcomes within 90 days.
  
  
  RESULTS
  Over 35 months, 944 TIA patients met inclusion criteria, of whom 4% (n=41) had a disabling ischemic stroke within 90 days. In analyses stratified by low versus moderate/high ABCD2 score, the combination of a low risk ABCD2 score and a negative early DWMRI had excellent sensitivity (100%, 95% CI 34 to 100) for identifying low-risk patients. In patients classified as moderate to high risk, a negative early DWMRI predicted a low risk of disabling ischemic stroke within 90 days (sensitivity 92%, 95% CI 80 to 97; NLR 0.11, 95% CI 0.04 to 0.32).
  
  
  CONCLUSIONS
  After risk stratification by the ABCD2 score, early DWMRI enhances the prediction of a low risk for disabling ischemic stroke within 90 days. Further study is warranted in a large, consecutive TIA population of early DWMRI as a sensitive negative predictor for disabling stroke within 90 days.
authors.affiliation: Department of Emergency Medicine, Carolinas Medical Center, Charlotte, NC, USA. andrew.asimos@carolinashealthcare.org
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Asimos
authors.forename: Wayne D
authors.initials: WD
authors.lastname: Rosamond
authors.forename: Anna M
authors.initials: AM
authors.lastname: Johnson
authors.forename: Marlow F
authors.initials: MF
authors.lastname: Price
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Rose
authors.forename: Carol V
authors.initials: CV
authors.lastname: Murphy
authors.forename: Charles H
authors.initials: CH
authors.lastname: Tegeler
authors.forename: Ana
authors.initials: A
authors.lastname: Felix
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002536:Cerebral Arteries / Q000473:pathology* / Q000503:physiopathology; D015331:Cohort Studies; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004185:Disability Evaluation; D018450:Disease Progression; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000150:complications* / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D020521:Stroke / Q000473:pathology* / Q000503:physiopathology; D013997:Time Factors