title: Identification and clinical impact of impaired cerebrovascular autoregulation in patients with malignant middle cerebral artery infarction.
abstract: OBJECTIVE
  To study cerebrovascular autoregulation and its impact on clinical course in patients with impending malignant middle cerebral artery infarction, we used invasive multimodal neuromonitoring, including measurement of cerebral perfusion pressure, tissue oxygen pressure, and microdialysis.
  
  
  METHODS
  Fifteen patients with a stroke that involved >50% of the middle cerebral artery territory were included. Probes were placed into the ipsilateral frontal lobe. Autoregulation was assessed by calculation of the cerebral perfusion pressure-oxygen reactivity index (COR) and the correlation coefficient (R) of cerebral perfusion pressure and tissue oxygen pressure at 24 and 72 hours after stroke.
  
  
  RESULTS
  COR and R at 24 hours after stroke were higher in the 8 patients with a malignant course (ie, massive edema formation) compared with the 7 patients with a benign course (COR, 1.99+/-1.46 versus 0.68+/-0.29; R, 0.49+/-0.28 versus 0.06+/-0.31; P<0.05), indicating impaired autoregulation in the malignant course group. At 72 hours, further increases in COR and R were observed in the malignant course group in contrast to the benign course group with stable values over time (COR, 3.31+/-2.38 versus 0.75+/-0.31; R, 0.75+/-011 versus 0.36+/-0.27; P<0.05). With a COR of 0.99, a cutoff value for prediction of a malignant course was found. The lactate-pyruvate ratio was higher in patients with a malignant compared with a benign course at both time points. COR, R, and the lactate-pyruvate ratio showed significant correlations with outcome parameters as a midline shift on cranial computed tomography and score on the modified Rankin scale after 3 months.
  
  
  CONCLUSIONS
  We found early impairment of cerebrovascular autoregulation in peri-infarct tissue of patients who developed malignant brain edema, whereas autoregulation was preserved in patients with a benign course. Impaired cerebral autoregulation seems to play a key role for development of a malignant course and might serve as a predictive marker. Impaired cerebral autoregulation also accentuates the need for consequent adjustment of cerebral perfusion pressure in patients with impaired autoregulation.
authors.affiliation: Max-Planck-Institut für neurologische Forschung, Gleueler Strasse 50, D-50931 Köln, Germany. chris@nf.mpg.de
authors.forename: Christian
authors.initials: C
authors.lastname: Dohmen
authors.forename: Bert
authors.initials: B
authors.lastname: Bosche
authors.forename: Rudolf
authors.initials: R
authors.lastname: Graf
authors.forename: Thomas
authors.initials: T
authors.lastname: Reithmeier
authors.forename: Ralf-Ingo
authors.initials: RI
authors.lastname: Ernestus
authors.forename: Gerrit
authors.initials: G
authors.lastname: Brinker
authors.forename: Jan
authors.initials: J
authors.lastname: Sobesky
authors.forename: Wolf-Dieter
authors.initials: WD
authors.lastname: Heiss
mesh_terms: D001794:Blood Pressure / Q000502:physiology; D001921:Brain / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology*; D001929:Brain Edema / Q000209:etiology / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D018450:Disease Progression; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000175:diagnosis / Q000378:metabolism* / Q000503:physiopathology*; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000503:physiopathology*; D010101:Oxygen Consumption / Q000502:physiology; D011237:Predictive Value of Tests; D011379:Prognosis; D019289:Pyruvic Acid / Q000378:metabolism; D014057:Tomography, X-Ray Computed
chemical_list: D019344:Lactic Acid; D019289:Pyruvic Acid