title: Dynamic cerebral autoregulation associates with infarct size and outcome after ischemic stroke.
abstract: OBJECTIVE
  Cerebral autoregulation is particularly challenged in acute ischemic stroke. We investigated (1) clinical and radiological factors related to dynamic cerebral autoregulation (DCA) in acute stroke and (2) the relationship between DCA and clinical outcome of stroke.
  
  
  METHODS
  A total of 45 patients with middle cerebral artery (MCA) stroke were analyzed pooling two previous studies. DCA was measured by transcranial Doppler in both MCAs early (within 48 h from onset) and late (day 5-7) using low-frequency phase and correlation analysis (index Mx). Outcome was assessed by modified Rankin scale after a mean period of 4 months.
  
  
  RESULTS
  Mx increased (i.e. autoregulation worsened) between the early and late measurement, more so on affected (P = 0.005) than on unaffected sides (P = 0.014). Poorer autoregulation as indicated by lower ipsilateral phase (early and late) and higher Mx (late measurement) were significantly related to larger infarction. More severe stroke was significantly related to poorer ipsilateral Mx and phase. Ipsilateral phase in the early (P = 0.019) and Mx in the late measurement (P =0..016) were related to poor clinical outcome according to univariate analysis.
  
  
  CONCLUSIONS
  Impairment of DCA ipsilateral to acute ischemic stroke is associated with larger infarction. Dysautoregulation tends to worsen and spread to the contralateral side over the first days post-stroke and is associated with poor clinical outcome.
authors.affiliation: Department of Neurology, University of Freiburg, Germany. matthias.reinhard@uniklinik-freiburg.de
authors.forename: M
authors.initials: M
authors.lastname: Reinhard
authors.forename: S
authors.initials: S
authors.lastname: Rutsch
authors.forename: J
authors.initials: J
authors.lastname: Lambeck
authors.forename: C
authors.initials: C
authors.lastname: Wihler
authors.forename: M
authors.initials: M
authors.lastname: Czosnyka
authors.forename: C
authors.initials: C
authors.lastname: Weiller
authors.forename: A
authors.initials: A
authors.lastname: Hetzel
mesh_terms: D000368:Aged; D020520:Brain Infarction / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology*; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography