title: Postoperative cerebral hyperperfusion associated with impaired cognitive function in patients undergoing carotid endarterectomy.
abstract: OBJECTIVE
  Cognitive impairment occurs in 20 to 30% of patients following carotid endarterectomy (CEA). The purpose of the present study was to determine whether postoperative cerebral hyperperfusion is associated with impairment of cognitive function in patients undergoing that procedure.
  
  
  METHODS
  Cerebral blood flow (CBF) was measured using single-photon emission computerized tomography scanning before and immediately after CEA and on the 3rd postoperative day in 92 patients with ipsilateral internal carotid artery stenosis of 70% or greater. Hyperperfusion post-CEA was defined as a 100% increase or greater in CBF compared with preoperative values. Neuropsychological testing was also performed preoperatively and at the 1-, 3-, and 6-month follow-up examinations. At the 1-month postoperative neuropsychological assessment, 11 patients (12%) displayed evidence of cognitive impairment. In addition, the incidence of postoperative cognitive impairment in patients with post-CEA hype perfusion (seven [58%] of 12 patients) was significantly higher than that in patients without post-CEA hyperperfusion (four [5%] of 80 patients; p < 0.0001). A logistic regression analysis demonstrated that post-CEA hyperperfusion was the only significant independent predictor of postoperative cognitive impairment. Of the seven patients in whom post-CEA hyperperfusion and cognitive impairment were identified 1 month postoperatively, four (including three patients with hyperperfusion syndrome) remained cognitively impaired at the 3- and 6-month follow-up examinations.
  
  
  CONCLUSIONS
  Postoperative cerebral hyperperfusion is associated with impairment of cognitive function in patients undergoing CEA. Furthermore, the development of hyperperfusion syndrome is associated with the persistence of postoperative cognitive impairment.
authors.affiliation: Department of Neurosurgery and Cyclotron Research Center, Iwate Medical University, Morioka, Japan. kuogasa@iwate-med.ac.jp
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Ogasawara
authors.forename: Keiko
authors.initials: K
authors.lastname: Yamadate
authors.forename: Masakazu
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Endo
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fukuda
authors.forename: Kenji
authors.initials: K
authors.lastname: Yoshida
authors.forename: Kazunori
authors.initials: K
authors.lastname: Terasaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Inoue
authors.forename: Akira
authors.initials: A
authors.lastname: Ogawa
mesh_terms: D000368:Aged; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000503:physiopathology; D002343:Carotid Artery, Internal / Q000601:surgery; D016893:Carotid Stenosis / Q000601:surgery; D002560:Cerebrovascular Circulation / Q000502:physiology; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology*; D016894:Endarterectomy, Carotid / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011182:Postoperative Care; D011183:Postoperative Complications; D011300:Preoperative Care; D012720:Severity of Illness Index; D015899:Tomography, Emission-Computed, Single-Photon