ON THE SPATIAL ORGANIZATION OF EPILEPTIFORM ACTIVITY

Abstract

The generation and progression of epileptiform activity, especially that associated with ictal paroxysmal neuronal discharges (seizures), is usually studied in terms of its temporal evolution rather than its spatial organization. The characterization of the spatio-temporal dynamics of epileptiform activity represents a major challenge in neuroscience, due to the very intricate nature of brain structure and function. Our study is an initial attempt to reveal the structure hidden under the spatial organization of the synchronization patterns in neuronal activity associated with epilepsy. Analysis of the phase synchronization patterns from magnetoencephalographic recordings in an epileptic patient revealed a decrease in complexity during seizures. Distinct patterns of synchronized activity were observed during interictal and ictal (seizure) activity, and new tools to quantify and visualize the information contained in a synchrony pattern are proposed. The results reported here support previous observations on the high local synchronization in seizures.