title: Cognitive outcome differences on the side of carotid artery stenting.
abstract: OBJECTIVE
  The right and left sides of the brain play different roles in cognition. Therefore, the side of treatment should be taken into consideration when evaluating cognitive outcome following revascularization. Thus, we designed a study to evaluate changes in right hemisphere cognitive function in patients undergoing right carotid artery stentings (CAS) and left hemispheric cognitive function in patients undergoing left CAS. In addition, we studied CAS-related changes in regional cerebral blood flow to determine potential correlations with changes in cognitive function.
  
  
  METHODS
  We performed a prospective assessment of 39 CAS patients, all of whom were right-handed. Patients with contralateral stenotic lesions were excluded. Twenty-one patients underwent CAS of the right internal carotid artery (Right CAS group) and 18 underwent CAS of the left internal carotid artery (Left CAS group). Neuropsychological testing was performed preoperatively and 6 months after endovascular treatment. Cerebral blood flow was determined by 123I-labeled N-isopropyl-p-iodoamphetamine single-photon emission computed tomography before and 6 months after CAS.
  
  
  RESULTS
  In the Right CAS group, postoperative performance intelligence quotient score (91.1±18.2) was significantly improved compared with the preoperative score (84.9±16.7; P<.001). In the Left CAS group, postoperative verbal intelligence quotient score (104.0±18.8) was significantly higher than that before endovascular treatment (97.9±15.8; P<.005). Postoperative regional cerebral blood flow was not significantly different from that before endovascular treatment in either group. However, regional cerebrovascular reactivity of the treated side showed significant improvement after treatment.
  
  
  CONCLUSIONS
  Amelioration of cognitive function may be dependent on the side of revascularization. Performance intelligence quotient improved after CAS in patients with severe carotid artery stenosis on the right side. Verbal intelligence quotient also improved on the left side after endovascular treatment. These effects seemed to involve improvement in regional cerebrovascular reactivity by CAS.
authors.affiliation: Department of Neurosurgery, Yamaguchi University School of Medicine, Yamaguchi, Japan. hishi@yamaguchi-u.ac.jp
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Ishihara
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Oka
authors.forename: Satoshi
authors.initials: S
authors.lastname: Shirao
authors.forename: Shoichi
authors.initials: S
authors.lastname: Kato
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Sadahiro
authors.forename: Masami
authors.initials: M
authors.lastname: Osaki
authors.forename: Michiyasu
authors.initials: M
authors.lastname: Suzuki
mesh_terms: D000368:Aged; D017130:Angioplasty / Q000009:adverse effects* / Q000295:instrumentation*; D016893:Carotid Stenosis / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D002560:Cerebrovascular Circulation; D054022:Cerebrum / Q000098:blood supply* / Q000000981:diagnostic imaging; D003071:Cognition; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007360:Intelligence; D007361:Intelligence Tests; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D055420:Perfusion Imaging / Q000379:methods; D011446:Prospective Studies; D012039:Regional Blood Flow; D012720:Severity of Illness Index; D015607:Stents; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome