Computational modeling of simultaneously recorded scalp and depth EEG signals

ISBN : 978-2-9532965-0-1In epileptic patients candidate to surgery, the interpretation of electrophysiological signals recorded non-invasively (scalp EEG) and invasively (depth EEG) is a difficult but central question. Indeed, the localization of the epileptogenic zone, the determination of its organisation and the definition of subsequent therapeutic strategy is still largely based on the analysis of electrophysiological data. This issue is addressed in the present work through a realistic modeling of both scalp and depth EEG signals. The model is based on an anatomically and physiologically relevant description of the neuronal sources of brain electrical activity that combines a distributed dipole source model and a model of coupled neuronal populations. EEG signals are then simulated by solving the forward problem in the head volume conductor, simultaneously on scalp and depth electrodes. The model was used to study the influence, on simulated EEG signals, of source-related parameters (spatial extent, position, synchronization) leading to the generation of transient epileptic activity (interictal spikes). More generally, this modeling approach helps in the understanding of the relationship between the properties of signals collected by electrodes (scalp and depth) and the underlying spatio-temporal organization of the neuronal sources