Effects of EC-IC bypass surgery on cognitive impairment in patients with hemodynamic cerebral ischemia.
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.
Sasoh
Masayuki
M
Department of Neurosurgery, Iwate Medical University, Morioka, Japan.
Ogasawara
Kuniaki
K
Kuroda
Kiyoshi
K
Okuguchi
Taku
T
Terasaki
Kazunori
K
Yamadate
Keiko
K
Ogawa
Akira
A
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