title: The severity of ischemia determines and predicts malignant brain edema in patients with large middle cerebral artery infarction.
abstract: BACKGROUND
  In order to determine the impact of the severity of ischemia on malignant edema formation, we investigated various degrees of perfusional deficit by (11)C-flumazenil PET in patients with large middle cerebral artery (MCA) infarction.
  
  
  METHODS
  17 patients with large MCA stroke were included. Cerebral blood flow (CBF) was measured 15.9 ± 6.4 h after the ictus. Patients were divided into a malignant (n = 9) and a benign group (n = 8) as a function of their clinical courses and edema. Edema was measured as maximal midline shift on follow-up CTs. Total hypoperfusion volume was divided into different subvolumes according to the degree of CBF reduction.
  
  
  RESULTS
  Subvolumes of severe ischemia relative to total ischemic area were significantly larger in the malignant group than in the benign group and were significantly correlated with edema formation. The highest correlation and best predictive values for edema formation with a sensitivity, specificity, and a positive and negative predictive value of 100% were found for subvolumes with severe ischemia. Correlation coefficients and prediction decreased for subvolumes with less severe perfusional deficit, pointing to the risk of misclassifying patients when relying on the volume of total perfusional deficit alone.
  
  
  CONCLUSIONS
  Malignant MCA infarction seems to be determined more by the volume of severe perfusional deficit than that of total perfusional deficit. Assessment of severely ischemic areas allows prediction of malignant edema formation and might help to select candidates for hemicraniectomy.
authors.affiliation: Max Planck Institute for Neurological Research, University of Cologne, Cologne, Germany. christian.dohmen@uk-koeln.de
authors.forename: Christian
authors.initials: C
authors.lastname: Dohmen
authors.forename: Norbert
authors.initials: N
authors.lastname: Galldiks
authors.forename: Bert
authors.initials: B
authors.lastname: Bosche
authors.forename: Lutz
authors.initials: L
authors.lastname: Kracht
authors.forename: Rudolf
authors.initials: R
authors.lastname: Graf
mesh_terms: D000368:Aged; D001929:Brain Edema / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery; D002560:Cerebrovascular Circulation; D016009:Chi-Square Distribution; D056424:Decompressive Craniectomy; D005260:Female; D005442:Flumazenil; D005858:Germany; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D055420:Perfusion Imaging / Q000379:methods; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011379:Prognosis; D019275:Radiopharmaceuticals; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013997:Time Factors; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D005442:Flumazenil