Dynamics underlying epileptic seizures span multiple scales in space and time, therefore, understanding seizure mechanisms requires identifying the relations between seizure components within and across these scales, together with the analysis of their dynamical repertoire. In this view, mathematical models have been developed, ranging from single neuron to neural population. In this study, we consider a neural mass model able to exactly reproduce the dynamics of heterogeneous spiking neural networks. We combine mathematical modeling with structural information from non invasive brain imaging, thus building large-scale brain network models to explore emergent dynamics and test the clinical hypothesis. We provide a comprehensive study on the effect of external drives on neuronal networks exhibiting multistability, in order to investigate the role played by the neuroanatomical connectivity matrices in shaping the emergent dynamics. In particular, we systematically investigate the conditions under which the network displays a transition from a low activity regime to a high activity state, which we identify with a seizure-like event. This approach allows us to study the biophysical parameters and variables leading to multiple recruitment events at the network level. We further exploit topological network measures in order to explain the differences and the analogies among the subjects and their brain regions, in showing recruitment events at different parameter values. We demonstrate, along with the example of diffusion-weighted magnetic resonance imaging (dMRI) connectomes of 20 healthy subjects and 15 epileptic patients, that individual variations in structural connectivity, when linked with mathematical dynamic models, have the capacity to explain changes in spatiotemporal organization of brain dynamics, as observed in network-based brain disorders. In particular, for epileptic patients, by means of the integration of the clinical hypotheses on the epileptogenic zone (EZ), i.e., the local network where highly synchronous seizures originate, we have identified the sequence of recruitment events and discussed their links with the topological properties of the specific connectomes. The predictions made on the basis of the implemented set of exact mean-field equations turn out to be in line with the clinical pre-surgical evaluation on recruited secondary networks.

Aix Marseille Université Inserm Institut de Neurosciences des Systèmes UMRS 1106 Marseille France

Assistance Publique Hôpitaux de Marseille Hôpital de la Timone Pôle d'Imagerie Marseille France

Assistance Publique Hôpitaux de Marseille Hôpital de la Timone Service de Neurophysiologie Clinique Marseille France

Consiglio Nazionale delle Ricerche Istituto dei Sistemi Complessi Sesto Fiorentino Italy

Faculté de Médecine de la Timone Centre de Résonance Magnétique et Biologique et Médicale Medical School of Marseille Aix Marseille Université Marseille France

Inria Sophia Antipolis Méditerranée Research Centre MathNeuro Team Valbonne France

Institut für Theoretische Physik Technische Universität Berlin Berlin Germany

Institute of Computer Science of the Czech Academy of Sciences Prague Czechia

MR Unit Department of Diagnostic and Interventional Radiology Institute for Clinical and Experimental Medicine Prague Czechia

National Institute of Mental Health Klecany Czechia

References provided by Crossref.org