Disinhibition-induced transitions between absence and tonic-clonic epileptic seizures.

Denggui Fan,Qingyun Wang,Matjaž Perc

doi:10.1038/srep12618

Denggui Fan, Qingyun Wang + Show 1 more

Open Access

https://doi.org/10.1038/srep12618

Copy DOI

Abstract

Electrophysiological experiments have long revealed the existence of two-way transitions between absence and tonic-clonic epileptic seizures in the cerebral cortex. Based on a modified spatially-extended Taylor & Baier neural field model, we here propose a computational framework to mathematically describe the transition dynamics between these epileptic seizures. We first demonstrate the existence of various transition types that are induced by disinhibitory functions between two inhibitory variables in an isolated Taylor & Baier model. Moreover, we show that these disinhibition-induced transitions can lead to stable tonic-clonic oscillations as well as periodic spike with slow-wave discharges, which are the hallmark of absence seizures. We also observe fascinating dynamical states, such as periodic 2-spike with slow-wave discharges, tonic death, bursting oscillations, as well as saturated firing. Most importantly, we identify paths that represent physiologically plausible transitions between absence and tonic-clonic seizures in the modified spatially-extended Taylor & Baier model.

Highlights

Nature, both the tonic-clonic and absence seizures can usually alternatively appear in one complete recording from the same patient[15,34,35]
Based on electrophysiological experiments, we extend a spatial Taylor & Baier network model to investigate its transition dynamics, which can be related to the epileptic seizures
Based on the proposed dynamic models of neural populations, we have investigated the disinhibitory effect of inhibitory variables I1 and I2 on firing transitions of neural populations

Summary

Introduction

Nature, both the tonic-clonic and absence seizures can usually alternatively appear in one complete recording from the same patient[15,34,35]. As a low computation and complexity alternative, the neural field model can be used to describe the large-scale dynamics of neuronal populations within the cerebral cortex that reproduces the realistic firing rates for each neuronal population[1,42] Because it is over-simplified, the neural field model can not yet represent realistic evolutions of the neural population activities and its spatial distribution. Due to its validity on both the local and global scales, the spatially-extended field model network can well produce typical dynamical behaviors of neural systems, which can be a good prototype of macroscopic absence seizure in epilepsy[43]. Both the absence and tonic-clonic seizures are pathological nonlinear phenomena in the EEG of patients with epileptic disorders. We study the transition dynamics of absence and tonic-clonic seizures, and the spatiotemporally synchronous evolutions of epileptic seizures by means of an isolated modified Taylor & Baier model, and the spatially-extended modified Taylor & Baier model

Methods

Results

Conclusion