title: Cognitive network reorganization following surgical control of seizures in Lennox-Gastaut syndrome.
abstract: We previously observed that adults with Lennox-Gastaut syndrome (LGS) show abnormal functional connectivity among cognitive networks, suggesting that this may contribute to impaired cognition. Herein we report network reorganization following seizure remission in a child with LGS who underwent functional magnetic resonance imaging (fMRI) before and after resection of a cortical dysplasia. Concurrent electroencephalography (EEG) was acquired during presurgical fMRI. Presurgical and postsurgical functional connectivity were compared using (1) graph theoretical analyses of small-world network organization and node-wise strength; and (2) seed-based analyses of connectivity within and between five functional networks. To explore the specificity of these postsurgical network changes, connectivity was further compared to nine children with LGS who did not undergo surgery. The presurgical EEG-fMRI revealed diffuse activation of association cortex during interictal discharges. Following surgery and seizure control, functional connectivity showed increased small-world organization, stronger connectivity in subcortical structures, and greater within-network integration/between-network segregation. These changes suggest network improvement, and diverged sharply from the comparison group of nonoperated children. Following surgery, this child with LGS achieved seizure control and showed extensive reorganization of networks that underpin cognition. This case illustrates that the epileptic process of LGS can directly contribute to abnormal network organization, and that this network disruption may be reversible.
authors.affiliation: Department of Medicine, The University of Melbourne, Heidelberg, Victoria, Australia.|Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.
authors.forename: Aaron E L
authors.initials: AEL
authors.lastname: Warren
authors.affiliation: Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.|The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Heidelberg, Victoria, Australia.|Department of Neurology, The Royal Children's Hospital, Parkville, Victoria, Australia.|Department of Paediatrics, The University of Melbourne, Heidelberg, Victoria, Australia.
authors.forename: A Simon
authors.initials: AS
authors.lastname: Harvey
authors.affiliation: Department of Medicine, The University of Melbourne, Heidelberg, Victoria, Australia.|The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Heidelberg, Victoria, Australia.
authors.forename: David F
authors.identifier: 0000-0002-7259-8238
authors.initials: DF
authors.lastname: Abbott
authors.affiliation: Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Vogrin
authors.affiliation: Department of Neurology, The Royal Children's Hospital, Parkville, Victoria, Australia.
authors.forename: Catherine
authors.initials: C
authors.lastname: Bailey
authors.affiliation: Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.|Department of Paediatrics, The University of Melbourne, Heidelberg, Victoria, Australia.|Department of Anaesthesia and Pain Management, The Royal Children's Hospital, Parkville, Victoria, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Davidson
authors.affiliation: Department of Medicine, The University of Melbourne, Heidelberg, Victoria, Australia.|The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Heidelberg, Victoria, Australia.|Department of Neurology, Austin Health, Melbourne, Victoria, Australia.
authors.forename: Graeme D
authors.initials: GD
authors.lastname: Jackson
authors.affiliation: Department of Medicine, The University of Melbourne, Heidelberg, Victoria, Australia.|Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.|The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Heidelberg, Victoria, Australia.|Department of Neurology, Austin Health, Melbourne, Victoria, Australia.
authors.forename: John S
authors.initials: JS
authors.lastname: Archer
mesh_terms: D038481:Anterior Temporal Lobectomy; D001921:Brain / Q000503:physiopathology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003072:Cognition Disorders / Q000175:diagnosis / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D065768:Lennox Gastaut Syndrome / Q000503:physiopathology* / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000503:physiopathology*; D009473:Neuronal Plasticity / Q000502:physiology*; D011183:Postoperative Complications / Q000175:diagnosis / Q000503:physiopathology*; D012815:Signal Processing, Computer-Assisted
keywords: Epileptic encephalopathy; Functional MRI; Graph theory; Lennox-Gastaut syndrome; Surgery