Focal epilepsies are defined by the recurrent expression of spontaneous seizures originating in a restricted brain region. It is assumed that epileptic activities, rather than simple changes in excitation/inhibition balance, result from a combination of epileptogenic cellular properties with local network interactions in the EF region, but the sudden switch of neuronal activities at the onset of focal seizures remains considered as largely unpredictable. Structural, functional, and cognitive alterations are observed at the large-scale level, extending beyond the initial epileptic focus (EF). Understanding the contribution of cortical and subcortical neuronal networks in the generation of ictal and interictal epileptic activities would have great clinical significance for the diagnosis of epileptic diseases and for the selection of therapeutic strategies such as surgical resections or network modulations. It has been proposed that large-scale network mechanisms are crucial to understanding the initiation and modulation of epileptic activities (A. Matsumoto et al., 2013). Previous studies in both the kainate mouse model and TLE patients suggest that by increasing large-scale synchronization, low-frequency oscillations are involved in generating epileptic activities (Sheybani et al., 2019, 2021). While it is known that epileptic activity can propagate from the focus, we speculate that remote regions might, in turn, affect the activity of the focus.

Here we propose to study whether and how local activities in the EF interact with remote brain regions to generate epileptic discharges. We propose to explore the contribution of activities in remote areas to the generation of focal paroxysmal discharges and investigate the putative large-scale network mechanisms that might be involved.