title: Effects of EC-IC bypass surgery on cognitive impairment in patients with hemodynamic cerebral ischemia.
abstract: BACKGROUND
  Chronic ischemia because of internal carotid artery (ICA) occlusive disease may result in dementia. The goal of this study was to assess cognitive impairment in symptomatic patients with hemodynamic cerebral ischemia and determine the efficacy of extracranial-intracranial (EC-IC) bypass in restoring neuropsychologic integrity.
  
  
  METHODS
  Twenty-five patients were defined by clinical and neuroradiological criteria as suffering from hemodynamic cerebral ischemia because of unilateral ICA or middle cerebral artery occlusion. Subjects underwent assessment of cerebral blood flow and metabolism using positron emission tomography (PET) before and after bypass surgery. To provide data regarding cognition, changes in the Japanese Wechsler Adult Intelligence Scale Revised (WAIS-R) were recorded.
  
  
  RESULTS
  Preoperative study of patients revealed significant impairment in cerebral blood flow and metabolism as well as reduced WAIS-R score. Among the factors considered, only elevated regional oxygen extraction fraction and reduced regional cerebral metabolic rates of oxygen were significantly associated with preoperative cognitive impairment (p = 0.0032 and p = 0.0255, respectively; logistic regression analysis). After bypass surgery, cerebral blood flow and metabolism improved significantly, and the WAIS-R score increased.
  
  
  CONCLUSIONS
  Symptomatic patients with hemodynamic cerebral ischemia displayed impaired cognition that was partially alleviated with EC-IC bypass surgery.
authors.affiliation: Department of Neurosurgery, Iwate Medical University, Morioka, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sasoh
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Ogasawara
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kuroda
authors.forename: Taku
authors.initials: T
authors.lastname: Okuguchi
authors.forename: Kazunori
authors.initials: K
authors.lastname: Terasaki
authors.forename: Keiko
authors.initials: K
authors.lastname: Yamadate
authors.forename: Akira
authors.initials: A
authors.lastname: Ogawa
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000601:surgery*; D002545:Brain Ischemia / Q000150:complications* / Q000175:diagnosis / Q000601:surgery*; D002548:Cerebral Revascularization / Q000379:methods*; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000150:complications / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care; D011300:Preoperative Care; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014055:Tomography, Emission-Computed; D014888:Wechsler Scales