Identification Of The Epileptogenic Zone From Stereo-EEG Signals: A Connectivity-Graph Theory Approach

In the context of focal drug-resistant epilepsies, the surgical resection of the epileptogenic zone (EZ), the cortical region responsible for the onset, early seizures organization and propagation, may be the only therapeutic option for reducing or suppressing seizures. The rather high rate of failu...

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Main Authors: Ferruccio ePanzica, Giulia eVarotto, Fabio eRotondi, Roberto eSpreafico, Silvana eFranceschetti
Format: Article
Language:English
Published: Frontiers Media S.A. 2013-11-01
Series:Frontiers in Neurology
Subjects:
Online Access:http://journal.frontiersin.org/Journal/10.3389/fneur.2013.00175/full
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spelling doaj-f4eb0f641f6141a8938e13d80033cd582020-11-24T23:49:20ZengFrontiers Media S.A.Frontiers in Neurology1664-22952013-11-01410.3389/fneur.2013.0017567054Identification Of The Epileptogenic Zone From Stereo-EEG Signals: A Connectivity-Graph Theory ApproachFerruccio ePanzica0Giulia eVarotto1Fabio eRotondi2Fabio eRotondi3Roberto eSpreafico4Silvana eFranceschetti5Fondazione IRCCS Istituto Neurologico Carlo BestaFondazione IRCCS Istituto Neurologico Carlo BestaFondazione IRCCS Istituto Neurologico Carlo BestaUniversità degli Studi di GenovaFondazione IRCCS Istituto Neurologico Carlo BestaFondazione IRCCS Istituto Neurologico Carlo BestaIn the context of focal drug-resistant epilepsies, the surgical resection of the epileptogenic zone (EZ), the cortical region responsible for the onset, early seizures organization and propagation, may be the only therapeutic option for reducing or suppressing seizures. The rather high rate of failure in epilepsy surgery of extra-temporal epilepsies highlights that the precise identification of the EZ, mandatory objective to achieve seizure freedom, is still an unsolved problem that requires more sophisticated methods of investigation.Despite the wide range of non-invasive investigations, intracranial stereo-EEG (SEEG) recordings still represent, in many patients, the gold standard for the EZ identification. In this contest, the EZ localization is still based on visual analysis of SEEG, inevitably affected by the drawback of subjectivity and strongly time-consuming. Over the last years, considerable efforts have been made to develop advanced signal analysis techniques able to improve the identification of the EZ. Particular attention has been paid to those methods aimed at quantifying and characterising the interactions and causal relationships between neuronal populations, since is nowadays well assumed that epileptic phenomena are associated with abnormal changes in brain synchronisation mechanisms, and initial evidence has shown the suitability of this approach for the EZ localisation. The aim of this review is to provide an overview of the different EEG signal processing methods applied to study connectivity between distinct brain cortical regions, namely in focal epilepsies. In addition, with the aim of localizing the EZ, the approach based on graph theory will be described, since the study of the topological properties of the networks has strongly improved the study of brain connectivity mechanisms.http://journal.frontiersin.org/Journal/10.3389/fneur.2013.00175/fullconnectivitycausalitybrain networksepilepsy surgeryepileptogenic zonegraph theory
collection DOAJ
language English
format Article
sources DOAJ
author Ferruccio ePanzica
Giulia eVarotto
Fabio eRotondi
Fabio eRotondi
Roberto eSpreafico
Silvana eFranceschetti
spellingShingle Ferruccio ePanzica
Giulia eVarotto
Fabio eRotondi
Fabio eRotondi
Roberto eSpreafico
Silvana eFranceschetti
Identification Of The Epileptogenic Zone From Stereo-EEG Signals: A Connectivity-Graph Theory Approach
Frontiers in Neurology
connectivity
causality
brain networks
epilepsy surgery
epileptogenic zone
graph theory
author_facet Ferruccio ePanzica
Giulia eVarotto
Fabio eRotondi
Fabio eRotondi
Roberto eSpreafico
Silvana eFranceschetti
author_sort Ferruccio ePanzica
title Identification Of The Epileptogenic Zone From Stereo-EEG Signals: A Connectivity-Graph Theory Approach
title_short Identification Of The Epileptogenic Zone From Stereo-EEG Signals: A Connectivity-Graph Theory Approach
title_full Identification Of The Epileptogenic Zone From Stereo-EEG Signals: A Connectivity-Graph Theory Approach
title_fullStr Identification Of The Epileptogenic Zone From Stereo-EEG Signals: A Connectivity-Graph Theory Approach
title_full_unstemmed Identification Of The Epileptogenic Zone From Stereo-EEG Signals: A Connectivity-Graph Theory Approach
title_sort identification of the epileptogenic zone from stereo-eeg signals: a connectivity-graph theory approach
publisher Frontiers Media S.A.
series Frontiers in Neurology
issn 1664-2295
publishDate 2013-11-01
description In the context of focal drug-resistant epilepsies, the surgical resection of the epileptogenic zone (EZ), the cortical region responsible for the onset, early seizures organization and propagation, may be the only therapeutic option for reducing or suppressing seizures. The rather high rate of failure in epilepsy surgery of extra-temporal epilepsies highlights that the precise identification of the EZ, mandatory objective to achieve seizure freedom, is still an unsolved problem that requires more sophisticated methods of investigation.Despite the wide range of non-invasive investigations, intracranial stereo-EEG (SEEG) recordings still represent, in many patients, the gold standard for the EZ identification. In this contest, the EZ localization is still based on visual analysis of SEEG, inevitably affected by the drawback of subjectivity and strongly time-consuming. Over the last years, considerable efforts have been made to develop advanced signal analysis techniques able to improve the identification of the EZ. Particular attention has been paid to those methods aimed at quantifying and characterising the interactions and causal relationships between neuronal populations, since is nowadays well assumed that epileptic phenomena are associated with abnormal changes in brain synchronisation mechanisms, and initial evidence has shown the suitability of this approach for the EZ localisation. The aim of this review is to provide an overview of the different EEG signal processing methods applied to study connectivity between distinct brain cortical regions, namely in focal epilepsies. In addition, with the aim of localizing the EZ, the approach based on graph theory will be described, since the study of the topological properties of the networks has strongly improved the study of brain connectivity mechanisms.
topic connectivity
causality
brain networks
epilepsy surgery
epileptogenic zone
graph theory
url http://journal.frontiersin.org/Journal/10.3389/fneur.2013.00175/full
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