title: Insights into Intrinsic Brain Networks based on Graph Theory and PET in right- compared to left-sided Temporal Lobe Epilepsy.
abstract: The human brain exhibits marked hemispheric differences, though it is not fully understood to what extent lateralization of the epileptic focus is relevant. Preoperative [(18)F]FDG-PET depicts lateralization of seizure focus in patients with temporal lobe epilepsy and reveals dysfunctional metabolic brain connectivity. The aim of the present study was to compare metabolic connectivity, inferred from inter-regional [(18)F]FDG PET uptake correlations, in right-sided (RTLE; n = 30) and left-sided TLE (LTLE; n = 32) with healthy controls (HC; n = 31) using graph theory based network analysis. Comparing LTLE and RTLE and patient groups separately to HC, we observed higher lobar connectivity weights in RTLE compared to LTLE for connections of the temporal and the parietal lobe of the contralateral hemisphere (CH). Moreover, especially in RTLE compared to LTLE higher local efficiency were found in the temporal cortices and other brain regions of the CH. The results of this investigation implicate altered metabolic networks in patients with TLE specific to the lateralization of seizure focus, and describe compensatory mechanisms especially in the CH of patients with RTLE. We propose that graph theoretical analysis of metabolic connectivity using [(18)F]FDG-PET offers an important additional modality to explore brain networks.
authors.affiliation: Department of Psychiatry and Psychotherapy, Medical University of Vienna, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Vanicek
authors.affiliation: Department of Psychiatry and Psychotherapy, Medical University of Vienna, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Hahn
authors.affiliation: Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Austria.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Traub-Weidinger
authors.affiliation: Department of Neurology, Medical University of Vienna, Austria.
authors.forename: Eva
authors.initials: E
authors.lastname: Hilger
authors.affiliation: Department of Psychiatry and Psychotherapy, Medical University of Vienna, Austria.
authors.forename: Marie
authors.initials: M
authors.lastname: Spies
authors.affiliation: Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wadsak
authors.affiliation: Department of Psychiatry and Psychotherapy, Medical University of Vienna, Austria.
authors.forename: Rupert
authors.initials: R
authors.lastname: Lanzenberger
authors.affiliation: Department of Neurology, Medical University of Vienna, Austria.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Pataraia
authors.affiliation: Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Austria.|Department of Neurology, Medical University of Vienna, Austria.|Department of Neurology, General Hospital Amstetten, Austria.
authors.forename: Susanne
authors.initials: S
authors.lastname: Asenbaum-Nan
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000737:chemistry; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography
chemical_list: D019788:Fluorodeoxyglucose F18