title: Altered Network Characteristics of Spike-Wave Discharges in Juvenile Myoclonic Epilepsy.
abstract: Epilepsy is a disease marked by hypersynchronous bursts of neuronal activity; therefore, identifying the network characteristics of the epileptic brain is important. Juvenile myoclonic epilepsy (JME) represents a common, idiopathic generalized epileptic syndrome, characterized by spike-and-wave discharge (SWD) electroencephalographic (EEG) waveforms. We compare herein the network properties of periods of SWD and baseline activity using graph theory. EEG data were obtained from 11 patients with JME. Functional cortical networks during SWD and baseline periods were estimated by calculating the coherence between all possible electrode pairs in the delta, theta, alpha, beta and gamma bands. Graph theoretical measures, including nodal degree, characteristic path length, clustering coefficient, and small-world index were then used to evaluate the characteristics of epileptic networks in JME. We also assessed short- and long-range connections between SWD and baseline networks. Compared to baseline, increased coherence was observed during SWD in all frequency bands. The nodal degree of the SWD network, particularly in the frontal region, was significantly higher compared to the baseline network. The clustering coefficient and small-world index were significantly lower in the theta and beta bands of the SWD versus baseline network, but the characteristic path length did not differ among networks. Long-range connections were increased during SWD, particularly between frontal and posterior brain regions. Our study suggests that SWD in JME is associated with increased local (particularly in frontal region) connectivity. Furthermore, the SWD network was associated with increased long-range connections, and reduced small-worldness, which may impair information processing during SWD.
authors.affiliation: 1 Department of Biomedical Engineering, Hanyang University, Seoul, Korea.
authors.forename: Chany
authors.initials: C
authors.lastname: Lee
authors.affiliation: 1 Department of Biomedical Engineering, Hanyang University, Seoul, Korea.
authors.forename: Chang-Hwan
authors.initials: CH
authors.lastname: Im
authors.affiliation: 2 Department of Neurology, Korea University Medical Center, Korea University College of Medicine, Seoul, Korea.
authors.forename: Yong Seo
authors.initials: YS
authors.lastname: Koo
authors.affiliation: 3 Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jung-Ah
authors.initials: JA
authors.lastname: Lim
authors.affiliation: 3 Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Tae-Joon
authors.initials: TJ
authors.lastname: Kim
authors.affiliation: 3 Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jung-Ick
authors.initials: JI
authors.lastname: Byun
authors.affiliation: 3 Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jun-Sang
authors.initials: JS
authors.lastname: Sunwoo
authors.affiliation: 3 Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jangsup
authors.initials: J
authors.lastname: Moon
authors.affiliation: 4 Department of Neurology, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Dong Wook
authors.initials: DW
authors.lastname: Kim
authors.affiliation: 3 Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Soon-Tae
authors.initials: ST
authors.lastname: Lee
authors.affiliation: 3 Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Keun-Hwa
authors.initials: KH
authors.lastname: Jung
authors.affiliation: 3 Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Kon
authors.initials: K
authors.lastname: Chu
authors.affiliation: 3 Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.
authors.forename: Sang-Kun
authors.initials: SK
authors.lastname: Lee
authors.affiliation: 3 Department of Neurology, Laboratory for Neurotherapeutics, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.|5 Department of Neurology, Seoul National University Hospital, Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Ki-Young
authors.initials: KY
authors.lastname: Jung
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000503:physiopathology*; D004569:Electroencephalography / Q000379:methods; D058407:Electroencephalography Phase Synchronization; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D008297:Male; D020190:Myoclonic Epilepsy, Juvenile / Q000175:diagnosis / Q000503:physiopathology*; D009415:Nerve Net / Q000503:physiopathology*; D009473:Neuronal Plasticity; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: functional connectivity; graph theory; idiopathic generalized epilepsy; juvenile myoclonic epilepsy; spike-wave discharge