title: Structural-functional coupling changes in temporal lobe epilepsy.
abstract: Alterations in both structural connectivity (SC) and functional connectivity (FC) have been reported in temporal lobe epilepsy (TLE). However, the relationship between FC and SC remains less understood. This study used functional connectivity MRI and diffusion tensor imaging to examine coupling of FC and SC within the limbic network of TLE, as well as its relation to epilepsy duration, regional changes, and disease laterality in 14 patients with left TLE, 10 with right TLE, and 11 healthy controls. Structural and functional networks were separately constructed and the correlation estimated between structural and functional connectivity. This measure of SC-FC coupling was compared between left/right TLE and controls, and correlated with epilepsy duration. Elastic net regression was used to investigate regional structural and functional changes associated with SC-FC coupling. SC-FC coupling was decreased in left TLE compared to controls, and accompanied by reductions in FC for left and right TLE and in SC for left TLE. When examined in relation to disease duration, an increase in SC-FC coupling with longer epilepsy duration was observed, associated predominantly with structural loss of the fusiform and frontal inferior orbital gyrus in left TLE and functional hub redistribution in right TLE. These results suggest that decoupling between structural and functional networks in TLE is modulated by several factors, including epilepsy duration and regional changes in the fusiform, frontal inferior orbital gyrus, posterior cingulate, and hippocampus. SC-FC coupling may provide a more sensitive biomarker of disease burden in TLE than biomarkers based on single imaging modalities.
authors.affiliation: Department of Statistics, Rice University, Houston, TX, USA.
authors.forename: Sharon
authors.initials: S
authors.lastname: Chiang
authors.affiliation: Department of Neurology, University of California, Los Angeles, CA, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Stern
authors.affiliation: Department of Neurology, University of California, Los Angeles, CA, USA; Department of Neurobiology, University of California, Los Angeles, CA, USA; Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA, USA; The Brain Research Institute, University of California, Los Angeles, CA, USA.
authors.forename: Jerome
authors.initials: J
authors.lastname: Engel
authors.affiliation: Department of Neurology, Baylor College of Medicine, Houston, TX, USA; Neurology Care Line, VA Medical Center, Houston, TX, USA. Electronic address: zulfi.haneef@bcm.edu.
authors.forename: Zulfi
authors.initials: Z
authors.lastname: Haneef
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply* / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D004833:Epilepsy, Temporal Lobe / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000098:blood supply / Q000473:pathology; D010100:Oxygen / Q000097:blood; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Connectomics; Diffusion tensor imaging; Elastic net; Functional magnetic resonance imaging; Limbic network; Temporal lobe epilepsy