title: Magnetoencephalography Reveals a Widespread Increase in Network Connectivity in Idiopathic/Genetic Generalized Epilepsy.
abstract: Idiopathic/genetic generalized epilepsy (IGE/GGE) is characterized by seizures, which start and rapidly engage widely distributed networks, and result in symptoms such as absences, generalized myoclonic and primary generalized tonic-clonic seizures. Although routine magnetic resonance imaging is apparently normal, many studies have reported structural alterations in IGE/GGE patients using diffusion tensor imaging and voxel-based morphometry. Changes have also been reported in functional networks during generalized spike wave discharges. However, network function in the resting-state without epileptiforme discharges has been less well studied. We hypothesize that resting-state networks are more representative of the underlying pathophysiology and abnormal network synchrony. We studied functional network connectivity derived from whole-brain magnetoencephalography recordings in thirteen IGE/GGE and nineteen healthy controls. Using graph theoretical network analysis, we found a widespread increase in connectivity in patients compared to controls. These changes were most pronounced in the motor network, the mesio-frontal and temporal cortex. We did not, however, find any significant difference between the normalized clustering coefficients, indicating preserved gross network architecture. Our findings suggest that increased resting state connectivity could be an important factor for seizure spread and/or generation in IGE/GGE, and could serve as a biomarker for the disease.
authors.affiliation: Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; Werner Reichardt Centre for Integrative Neuroscience, Tübingen, Germany; MEG Center, University of Tübingen, Tübingen, Germany; International Max Planck Research School for Cognitive and Systems Neuroscience, Tübingen, Germany.
authors.forename: Adham
authors.initials: A
authors.lastname: Elshahabi
authors.affiliation: Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: Klamer
authors.affiliation: Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; Werner Reichardt Centre for Integrative Neuroscience, Tübingen, Germany; International Max Planck Research School for Cognitive and Systems Neuroscience, Tübingen, Germany.
authors.forename: Ashish Kaul
authors.initials: AK
authors.lastname: Sahib
authors.affiliation: Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; Werner Reichardt Centre for Integrative Neuroscience, Tübingen, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Lerche
authors.affiliation: Werner Reichardt Centre for Integrative Neuroscience, Tübingen, Germany; MEG Center, University of Tübingen, Tübingen, Germany; CIMeC, Center for Mind/Brain Sciences, University of Trento, Trento, Italy.
authors.forename: Christoph
authors.initials: C
authors.lastname: Braun
authors.affiliation: Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; Werner Reichardt Centre for Integrative Neuroscience, Tübingen, Germany.
authors.forename: Niels K
authors.initials: NK
authors.lastname: Focke
mesh_terms: D000328:Adult; D004829:Epilepsy, Generalized / Q000503:physiopathology*; D030342:Genetic Diseases, Inborn / Q000503:physiopathology*; D006801:Humans; D015225:Magnetoencephalography; D008875:Middle Aged; D008959:Models, Neurological; D009415:Nerve Net / Q000503:physiopathology*