title: Potential value of post stroke extracranial arterial blood flow volume in the prediction of stroke functional outcome.
abstract: OBJECTIVE
  Cerebral vasoreactivity and collateral circulation are important protective mechanisms against cerebral ischemia. Previous studies suggest that the efficiency of these mechanisms can be reflected by extracranial arterial blood flow volume. Brain damage leading to neurological impairments can influence patients' functional recovery after stroke. This study attempted to explore the potential value of post stroke extracranial arterial blood flow volume in the prediction of stroke patients' functional outcome.
  
  
  METHODS
  We prospectively studied 362 consecutive patients who were hospitalized for recent acute strokes. All patients underwent extracranial arterial blood flow volume measurement of the carotid and vertebral arteries by color velocity imaging quantification within 3 days after admission. Their functional recovery was assessed 6 months after stroke. The effect of post stroke extracranial arterial blood flow volume on patients' functional outcome was tested by multivariate ordinal regression after controlling for other independent variables. Significance was at p<0.05.
  
  
  RESULTS
  Post stroke extracranial arterial blood flow volume together with age, pre-stroke modified Rankin scale, the National Institutes of Health Stroke Scale and diabetes mellitus had significant effects on the patients' 6-month functional outcome as measured by the modified Rankin scale after controlling for other independent variables (p<0.05).
  
  
  CONCLUSIONS
  Post stroke extracranial arterial blood flow volume is an independent outcome predictor. The graded predictive power of this parameter is potentially more superior than other outcome predictors by allowing classification of stroke outcome according to the degree of severity. A large prospective study is thus warranted to investigate its clinical value in the management of stroke patients.
authors.affiliation: Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, SAR, China. stellaho@cuhk.edu.hk
authors.forename: Stella S Y
authors.initials: SS
authors.lastname: Ho
authors.forename: Wynnie W M
authors.initials: WW
authors.lastname: Lam
authors.forename: K S
authors.initials: KS
authors.lastname: Wong
authors.forename: Cecilia S F
authors.initials: CS
authors.lastname: Leung
authors.forename: C
authors.initials: C
authors.lastname: Metreweli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001810:Blood Volume / Q000502:physiology*; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D020127:Recovery of Function / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology*; D012720:Severity of Illness Index; D020521:Stroke / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016896:Treatment Outcome; D018615:Ultrasonography, Doppler, Color; D014711:Vertebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*