title: Patient-specific connectivity pattern of epileptic network in frontal lobe epilepsy.
abstract: There is evidence that focal epilepsy may involve the dysfunction of a brain network in addition to the focal region. To delineate the characteristics of this epileptic network, we collected EEG/fMRI data from 23 patients with frontal lobe epilepsy. For each patient, EEG/fMRI analysis was first performed to determine the BOLD response to epileptic spikes. The maximum activation cluster in the frontal lobe was then chosen as the seed to identify the epileptic network in fMRI data. Functional connectivity analysis seeded at the same region was also performed in 63 healthy control subjects. Nine features were used to evaluate the differences of epileptic network patterns in three connection levels between patients and controls. Compared with control subjects, patients showed overall more functional connections between the epileptogenic region and the rest of the brain and higher laterality. However, the significantly increased connections were located in the neighborhood of the seed, but the connections between the seed and remote regions actually decreased. Comparing fMRI runs with interictal epileptic discharges (IEDs) and without IEDs, the patient-specific connectivity pattern was not changed significantly. These findings regarding patient-specific connectivity patterns of epileptic networks in FLE reflect local high connectivity and connections with distant regions differing from those of healthy controls. Moreover, the difference between the two groups in most features was observed in the strictest of the three connection levels. The abnormally high connectivity might reflect a predominant attribute of the epileptic network, which may facilitate propagation of epileptic activity among regions in the network.
authors.affiliation: Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada ; Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Luo
authors.affiliation: Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada ; Department of Neurology, West China Hospital of Sichuan University, Chengdu, China.
authors.forename: Dongmei
authors.initials: D
authors.lastname: An
authors.affiliation: Key Laboratory for Neuroinformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China.
authors.forename: Dezhong
authors.initials: D
authors.lastname: Yao
authors.affiliation: Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
authors.forename: Jean
authors.initials: J
authors.lastname: Gotman
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology*; D001931:Brain Mapping; D004569:Electroencephalography; D017034:Epilepsy, Frontal Lobe / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000098:blood supply / Q000503:physiopathology*; D010100:Oxygen / Q000097:blood; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Epileptic network; Frontal lobe epilepsy; Functional connectivity; fMRI