title: Identification of Focal Epileptogenic Networks in Generalized Epilepsy Using Brain Functional Connectivity Analysis of Bilateral Intracranial EEG Signals.
abstract: Simultaneous bilateral onset and bi-synchrony epileptiform discharges in electroencephalogram (EEG) remain hallmarks for generalized seizures. However, the possibility of an epileptogenic focus triggering rapidly generalized epileptiform discharges has been documented in several studies. Previously, a new multi-stage surgical procedure using bilateral intracranial EEG (iEEG) prior to and post complete corpus callosotomy (CC) was developed to uncover seizure focus in non-lateralizing focal epilepsy. Five patients with drug-resistant generalized epilepsy who underwent this procedure were included in the study. Their bilateral iEEG findings prior to complete CC showed generalized epileptiform discharges with no clear lateralization. Nonetheless, the bilateral ictal iEEG findings post complete CC indicated lateralized or localized seizure onset. This study hypothesized that brain functional connectivity analysis, applied to the pre CC bilateral iEEG recordings, could help identify focal epileptogenic networks in generalized epilepsy. The results indicated that despite diffuse epileptiform discharges, focal features can still be observed in apparent generalized seizures through brain connectivity analysis. The seizure onset localization/lateralization from connectivity analysis demonstrated a good agreement with the bilateral iEEG findings post complete CC and final surgical outcomes. Our study supports the role of focal epileptic networks in generalized seizures.
authors.affiliation: Comprehensive Pediatric Epilepsy Center, Florida Hospital for Children, 601 Rollins Street, Orlando, FL, 32803, USA. po-ching.chen@flhosp.org.|MEG Lab, Florida Hospital for Children, Orlando, FL, USA. po-ching.chen@flhosp.org.|Functional Brain Mapping and Brain-Computer Interface Lab, Florida Hospital for Children, Orlando, FL, USA. po-ching.chen@flhosp.org.
authors.forename: Po-Ching
authors.initials: PC
authors.lastname: Chen
authors.affiliation: Comprehensive Pediatric Epilepsy Center, Florida Hospital for Children, 601 Rollins Street, Orlando, FL, 32803, USA.|MEG Lab, Florida Hospital for Children, Orlando, FL, USA.
authors.forename: Eduardo M
authors.initials: EM
authors.lastname: Castillo
authors.affiliation: Comprehensive Pediatric Epilepsy Center, Florida Hospital for Children, 601 Rollins Street, Orlando, FL, 32803, USA.
authors.forename: James
authors.initials: J
authors.lastname: Baumgartner
authors.affiliation: Comprehensive Pediatric Epilepsy Center, Florida Hospital for Children, 601 Rollins Street, Orlando, FL, 32803, USA.
authors.forename: Joo Hee
authors.initials: JH
authors.lastname: Seo
authors.affiliation: Comprehensive Pediatric Epilepsy Center, Florida Hospital for Children, 601 Rollins Street, Orlando, FL, 32803, USA.|MEG Lab, Florida Hospital for Children, Orlando, FL, USA.|Functional Brain Mapping and Brain-Computer Interface Lab, Florida Hospital for Children, Orlando, FL, USA.
authors.forename: Milena
authors.initials: M
authors.lastname: Korostenskaja
authors.affiliation: Comprehensive Pediatric Epilepsy Center, Florida Hospital for Children, 601 Rollins Street, Orlando, FL, 32803, USA.
authors.forename: Ki Hyeong
authors.initials: KH
authors.lastname: Lee
mesh_terms: D001921:Brain / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D003337:Corpus Callosum / Q000601:surgery; D000069279:Drug Resistant Epilepsy / Q000503:physiopathology* / Q000601:surgery; D000069280:Electrocorticography; D004828:Epilepsies, Partial / Q000503:physiopathology* / Q000601:surgery; D004829:Epilepsy, Generalized / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009434:Neural Pathways / Q000503:physiopathology
keywords: Brain electrical activity mapping; Corpus callosum; Electroencephalography; Generalized epilepsy; Implanted electrodes; Neurosurgery