title: Cognitive alteration after carotid revascularization is correlated with cortical GABA(B)-ergic modulations.
abstract: The present study evaluates the hypotheses that a GABAergic mechanism underlies neurobehavioral sequelae of carotid stenosis and that it can be reversed by carotid revascularization. We used the Rivermead Behavioural Memory Test (RBMT), short interval intracortical inhibition (SICI), intracortical facilitation (ICF), long interval intracortical inhibition (LICI), and cortical silent period (CSP) to evaluate cognitive function and cerebral cortical excitability in 16 carotid artery stenosis patients with cognitive impairment before carotid arterial stenting (CAS) and 1 month later. We compared the pre- and post-CAS results and those of 16 healthy controls. CSP was prolonged in patients compared with controls (195.8±18ms vs. 157.8±13.9ms; p<0.0001, unpaired t-test). Patients tended to a have high resting motor threshold and less pronounced SICI and ICF than controls, but differences were not significant. Decreased RBMT score was correlated with hyperperfusion and CSP increase after CAS. RBMT score increase was correlated with CSP normalization. LICI showed positive correlation with CSP. CSP may provide a means of probing the integrity of GABA(B)-ergic networks in an ischemic human brain. CSP and LICI are potential tools to explore neuronal function for improvement as well as impairment after carotid revascularization.
authors.affiliation: Department of Neurosurgery, School of Medicine, Oita University, 1-1 Idaigaoka, Hasamamach, Oita 879-5593, Japan.
authors.forename: Kumi
authors.initials: K
authors.lastname: Murata
authors.forename: Minoru
authors.initials: M
authors.lastname: Fujiki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ooba
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kubo
authors.forename: Masaki
authors.initials: M
authors.lastname: Morishige
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Abe
authors.forename: Keisuke
authors.initials: K
authors.lastname: Ishii
authors.forename: Hidenori
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Hiro
authors.initials: H
authors.lastname: Kiyosue
authors.forename: Hiromu
authors.initials: H
authors.lastname: Mori
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016893:Carotid Stenosis / Q000150:complications / Q000628:therapy*; D002404:Catheterization; D002540:Cerebral Cortex / Q000098:blood supply / Q000378:metabolism* / Q000503:physiopathology; D003072:Cognition Disorders / Q000209:etiology / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008568:Memory; D008875:Middle Aged; D009483:Neuropsychological Tests; D018080:Receptors, GABA-B / Q000502:physiology*; D015607:Stents; D050781:Transcranial Magnetic Stimulation
chemical_list: D018080:Receptors, GABA-B