Epileptic neuronal networks: methods of identification andclinical relevance.

• Main Authors: Hermann eStefan, Fernando Henrique Lopes Da Silva
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2013-03-01
• Series: Frontiers in Neurology
• Subjects: MEG/EEG; Epileptic Networks; neurophysiological classification; basic concepts; methods of identification
• Online Access: http://journal.frontiersin.org/Journal/10.3389/fneur.2013.00008/full

The main objective of this paper is to examine evidence for the concept that epileptic activityshould be envisaged in terms of functional connectivity and dynamics of neuronal networks,Basic concepts regarding structure and dynamics of neuronal networks are briefly described.Particular attention is given to approaches that are derived, or related, to the concept ofcausality, as formulated by Granger. Linear and non linear methodologies aiming atcharacterizing the dynamics of neuronal networks applied to EEG/MEG and combined EEG/fMRI signals in epilepsy are critically reviewed. The relevance of functional dynamicalanalysis of neuronal networks with respect to clinical queries in focal cortical dysplasias,temporal lobe epilepsies and "generalized epilepsies is emphasized. In the light of theconcepts of epileptic neuronal networks, and recent experimental findings, the dichotomicclassification in focal and generalized epilepsy is re-evaluated. It is proposed that so-called"generalized epilepsies", such as absence seizures, are actually fast spreading epilepsies, theonset of which can be tracked down to particular neuronal networks using appropriatenetwork analysis. Finally new approaches to delineate epileptogenic networks are discussed.