Cognitive outcome after EC-IC bypass surgery in hemodynamic cerebral ischemia

Acta Neurochir (Wien). 2011 Jun;153(6):1303-11; discussion 1311-2. doi: 10.1007/s00701-011-0949-x. Epub 2011 Feb 6.

Abstract

Objective: The purpose of this study was to evaluate cognitive functions in patients undergoing extracranial-intracranial (EC-IC) bypass surgery for cerebral ischemia.

Population and methods: From August 2003 to January 2009, 276 patients with occluded internal carotid arteries (ICA) were screened. Forty of these met the criteria for a low-flow EC-IC bypass. These patients were identified based on evidence of exhausted vasomotor reactivity (VMR) using the Doppler CO(2) test and CT perfusion. These patients were invited to have a complete battery of neuropsychological tests preoperatively and 12 months after surgery. Complete neurocognitive testing was finished in 20 patients.

Results: This group of 20 patients showed preoperative cognitive impairment ranging from mild to medium-severe. There were no cases of stroke ipsilateral to the operated side during the follow-up period. VMR improvement was seen in all patients within 6 months of surgery. A comparison using a paired t-test demonstrated significant improvement 12 months after surgery in the following neuropsychological tests: WAIS-R (p = 0.01), Number Collection Test (p = 0.02), Trail Making Test (p = 0.03), and Benton Visual Retention Test (p = 0.05). Repeat analysis of variance (ANOVA) suggested the following predictors associated with cognitive improvement:the presence of ophthalmic collateral flow (p = 0.04), preoperative amaurosis fugax (p = 0.02), and external watershed infarction detected by MRI (p = 0.04).

Conclusion: Patients with occlusion of the ICA and exhausted VMR have cognitive impairment prior to EC-IC bypass surgery. Twelve months after surgery, there is significant improvement in various areas of cognition.

MeSH terms

  • Adult
  • Aged
  • Angiography, Digital Subtraction
  • Brain Ischemia / physiopathology
  • Brain Ischemia / surgery*
  • Carotid Artery, Internal / physiopathology
  • Carotid Artery, Internal / surgery*
  • Carotid Stenosis / surgery*
  • Cerebral Angiography
  • Cerebral Infarction / diagnosis
  • Cerebral Infarction / physiopathology
  • Cerebral Revascularization*
  • Cognition Disorders / diagnosis*
  • Cognition Disorders / physiopathology
  • Female
  • Follow-Up Studies
  • Hemodynamics / physiology*
  • Humans
  • Ischemic Attack, Transient / physiopathology
  • Ischemic Attack, Transient / surgery*
  • Male
  • Middle Aged
  • Neuropsychological Tests / statistics & numerical data
  • Postoperative Complications / diagnosis*
  • Postoperative Complications / physiopathology
  • Psychometrics
  • Tomography, X-Ray Computed
  • Treatment Outcome
  • Vascular Resistance / physiology
  • Wechsler Scales / statistics & numerical data