title: Cerebrovascular reserve may be a more accurate predictor of stroke than degree of ICA or MCA stenosis.
abstract: BACKGROUND
  It is currently unclear whether the degree of stenosis or the cerebrovascular reserve (CVR) is a better predictor of ischemic stroke.
  
  
  METHODS
  In this study, CVR was measured by perfusion computed tomography with inhalation of 5% CO2 in 37 symptomatic patients with internal carotid artery (ICA) or middle cerebral artery (MCA) stenosis or occlusion. Patients were divided into groups according to the degree of stenosis: ≥70% stenosis (stenosis group 1) or <70% stenosis (stenosis group 2); and according to CVR: ≥10% CVR (CVR group 1) or <10% CVR (CVR group 2). All patients were given medical treatment.
  
  
  RESULTS
  During a mean follow-up period of 56.9 months (range 24-73 months), recurrent ipsilateral ischemic stroke occurred in 7 patients. Ischemic stroke occurred in 0 of 19 patients in CVR group 1 (annual risk 0%), 7 of 18 patients in CVR group 2 (annual risk 7.7%), 3 of 18 patients in stenosis group 1 (annual risk 3.3%), and 4 of 19 patients in stenosis group 2 (annual risk 4.7%). Comparisons using Pearson's chi-square test showed a significant difference in the rate of ischemic stroke between CVR group 1 and CVR group 2 (odds ratio 1.700; 95% confidence interval 1.142-2.530; P=0.003), but no significant difference between stenosis group 1 and stenosis group 2 (P=0.691).
  
  
  CONCLUSIONS
  Cerebrovascular reserve may be a more accurate predictor of stroke than degree of ICA or MCA stenosis.
authors.affiliation: Department of Neurology, Capital Medical University Chaoyang Hospital, Beijing, China (mainland).
authors.forename: Mingyong
authors.initials: M
authors.lastname: Liu
authors.affiliation: Department of Neurology, Capital Medical University Chaoyang Hospital, Beijing, China (mainland).
authors.forename: Lichun
authors.initials: L
authors.lastname: Zhou
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000503:physiopathology*; D003251:Constriction, Pathologic / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000473:pathology*; D012008:Recurrence; D020521:Stroke / Q000503:physiopathology*