M Carboni1, M Rubega2, G R Iannotti3, P De Stefano4, G Toscano5, S Tourbier6, F Pittau4, P Hagmann6, S Momjian7, K Schaller7, M Seeck4, C M Michel2, P van Mierlo8, S Vulliemoz9. 1. EEG and Epilepsy, Neuroscience Department, University Hospital and Faculty of Medicine of Geneva, Geneva, Switzerland; Functional Brain Mapping Lab, Department of Fundamental Neurosciences, University of Geneva, Geneva, Switzerland. Electronic address: Margherita.carboni@unige.ch. 2. Functional Brain Mapping Lab, Department of Fundamental Neurosciences, University of Geneva, Geneva, Switzerland. 3. EEG and Epilepsy, Neuroscience Department, University Hospital and Faculty of Medicine of Geneva, Geneva, Switzerland; Functional Brain Mapping Lab, Department of Fundamental Neurosciences, University of Geneva, Geneva, Switzerland; Department of Neurosurgery, University Hospital and Faculty of Medicine of Geneva, Geneva, Switzerland. 4. EEG and Epilepsy, Neuroscience Department, University Hospital and Faculty of Medicine of Geneva, Geneva, Switzerland. 5. EEG and Epilepsy, Neuroscience Department, University Hospital and Faculty of Medicine of Geneva, Geneva, Switzerland; Unit of Sleep Medicine and Epilepsy, C. Mondino National Neurological Institute, Pavia, Italy. 6. Connectomics Lab, Department of Radiology, University Hospital of Lausanne, Lausanne, Switzerland. 7. Department of Neurosurgery, University Hospital and Faculty of Medicine of Geneva, Geneva, Switzerland. 8. EEG and Epilepsy, Neuroscience Department, University Hospital and Faculty of Medicine of Geneva, Geneva, Switzerland; Medical Image and Signal Processing Group, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium. 9. EEG and Epilepsy, Neuroscience Department, University Hospital and Faculty of Medicine of Geneva, Geneva, Switzerland. Electronic address: Serge.Vulliemoz@unige.ch.
Abstract
OBJECTIVE: Epilepsy is a network disease with epileptic activity and cognitive impairment involving large-scale brain networks. A complex network is involved in the seizure and in the interictal epileptiform discharges (IEDs). Directed connectivity analysis, describing the information transfer between brain regions, and graph analysis are applied to high-density EEG to characterise networks. METHODS: We analysed 19 patients with focal epilepsy who had high-density EEG containing IED and underwent surgery. We estimated cortical activity during IED using electric source analysis in 72 atlas-based cortical regions of the individual brain MRI. We applied directed connectivity analysis (information Partial Directed Coherence) and graph analysis on these sources and compared patients with good vs poor post-operative outcome at global, hemispheric and lobar level. RESULTS: We found lower network integration reflected by global, hemispheric, lobar efficiency during the IED (p < 0.05) in patients with good post-surgical outcome, compared to patients with poor outcome. Prediction was better than using the IED field or the localisation obtained by electric source imaging. CONCLUSIONS: Abnormal network patterns in epilepsy are related to seizure outcome after surgery. SIGNIFICANCE: Our finding may help understand networks related to a more "isolated" epileptic activity, limiting the extent of the epileptic network in patients with subsequent good post-operative outcome.
OBJECTIVE:Epilepsy is a network disease with epileptic activity and cognitive impairment involving large-scale brain networks. A complex network is involved in the seizure and in the interictal epileptiform discharges (IEDs). Directed connectivity analysis, describing the information transfer between brain regions, and graph analysis are applied to high-density EEG to characterise networks. METHODS: We analysed 19 patients with focal epilepsy who had high-density EEG containing IED and underwent surgery. We estimated cortical activity during IED using electric source analysis in 72 atlas-based cortical regions of the individual brain MRI. We applied directed connectivity analysis (information Partial Directed Coherence) and graph analysis on these sources and compared patients with good vs poor post-operative outcome at global, hemispheric and lobar level. RESULTS: We found lower network integration reflected by global, hemispheric, lobar efficiency during the IED (p < 0.05) in patients with good post-surgical outcome, compared to patients with poor outcome. Prediction was better than using the IED field or the localisation obtained by electric source imaging. CONCLUSIONS: Abnormal network patterns in epilepsy are related to seizure outcome after surgery. SIGNIFICANCE: Our finding may help understand networks related to a more "isolated" epileptic activity, limiting the extent of the epileptic network in patients with subsequent good post-operative outcome.
Authors: Maarten Haemels; Donatienne Van Weehaeghe; Evy Cleeren; Patrick Dupont; Johan van Loon; Tom Theys; Koen Van Laere; Wim Van Paesschen; Karolien Goffin Journal: Acta Neurol Belg Date: 2021-02-05 Impact factor: 2.396
Authors: Nicolas Roehri; Lucie Bréchet; Martin Seeber; Alvaro Pascual-Leone; Christoph M Michel Journal: Brain Topogr Date: 2022-01-26 Impact factor: 3.020