title: Reorganized cerebral metabolic interactions in temporal lobe epilepsy.
abstract: Patients with left temporal lobe epilepsy demonstrate language impairments that are not well understood. To explore abnormal patterns of brain functional connections with respect to language processing, we applied a principal component analysis to resting regional cerebral metabolic data obtained with positron emission tomography in patients with right- and left-sided temporal lobe epilepsy and controls. Two principal components were expressed differentially among the groups. One principal component comprised a pattern of metabolic interactions involving left inferior frontal and left superior temporal regions-corresponding to Broca's and Wernicke's areas, respectively-and right mesial temporal cortex and right thalamus. Functional couplings between these brain regions were abnormally enhanced in the left-sided epilepsy patients. The right thalamic left superior temporal coupling was also abnormally enhanced in the right-sided epilepsy patients, but differentially from that in the left-sided patients. The other principal component was characterized by a pattern of metabolic interactions involving right and left mid prefrontal and right superior temporal cortex. Although both the right- and left-sided epilepsy patients showed decreased functional couplings between left mid prefrontal and the other brain regions, a weaker right-left mid prefrontal coupling in the left-sided epilepsy patients best distinguished them from the right-sided patients. The two mutually independent, abnormal metabolic patterns each predicted verbal intelligence deficits in the patients. The findings suggest a site-dependent reorganization of two independent, language-subserving pathways in temporal lobe epilepsy.
authors.affiliation: Department of Neurology, Heinrich-Heine-University, Duesseldorf, Germany.
authors.forename: N P
authors.initials: NP
authors.lastname: Azari
authors.forename: U
authors.initials: U
authors.lastname: Knorr
authors.forename: S
authors.initials: S
authors.lastname: Arnold
authors.forename: C
authors.initials: C
authors.lastname: Antke
authors.forename: A
authors.initials: A
authors.lastname: Ebner
authors.forename: H
authors.initials: H
authors.lastname: Niemann
authors.forename: K D
authors.initials: KD
authors.lastname: Pettigrew
authors.forename: O W
authors.initials: OW
authors.lastname: Witte
authors.forename: R J
authors.initials: RJ
authors.lastname: Seitz
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D016022:Case-Control Studies; D004292:Dominance, Cerebral / Q000502:physiology; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D005163:Factor Analysis, Statistical; D005260:Female; D005625:Frontal Lobe / Q000378:metabolism / Q000503:physiopathology; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007806:Language Disorders / Q000145:classification / Q000000981:diagnostic imaging / Q000503:physiopathology; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009434:Neural Pathways / Q000503:physiopathology; D013702:Temporal Lobe / Q000378:metabolism / Q000503:physiopathology; D013788:Thalamus / Q000378:metabolism / Q000503:physiopathology; D014055:Tomography, Emission-Computed; D014705:Verbal Behavior / Q000502:physiology
chemical_list: D005947:Glucose