23 - Transition to Ictal Activity in Temporal Lobe Epilepsy: Insights From Macroscopic Models

Abstract

Temporal lobe epilepsy (TLE) is one of the most common forms of partial epilepsy, which is characterized by recurrent seizures originating in one or several anatomic divisions of the temporal lobe and propagating through interconnected neuronal networks within or outside the temporal region. This chapter presents some insights into transition mechanisms to ictal activity in human TLE that can be drawn from this modeling approach. It begins with a brief historical background on neuronal population models and presents some general features. Following this, it describes electroencephalographic signals recorded during transition from interictal to ictal activity along with the recording techniques namely stereoelectroencephalography (SEEG). These signals constitute input data to models, which are presented in this chapter. The first model is a generic model of neuronal population used to interpret transition from normal background activity to spiking activity. Thereafter, the chapter presents a second model adapted to the organization of neurons and interneurons in the hippocampus and emphasizes on the capacity of this model to explain typical activities recorded from this structure in patients. Finally, it highlights some perspectives related to modeling approaches aimed at improving the understanding of basic processes underlying epileptic behavior.