Dynamic Simulation Of Hypsarrhythmia From Brainstem Dysfunction

Epilepsy is one of the most common nervous system diseases. The characteristic of epilepsy is that neurons in brain release abnormal electrical impulses excessively. Infantile spasm (IS) is a kind of children epilepsy with physical and intellective maldevelopment. This article focuses on the mechanism research on the neuronal population level of hypsarrhythmia resulted from brainstem dysfunction, which is the hypothesis for the pathogenesis of the IS.Based on the theories and methods of dynamic system modeling and simulation, a nonlinear dynamic model on the Simulink platform of Matlab is simulated. The model would research whether the mechanism of brainstem is the responsible structure in neuron information direction.The research results are as follows:(1) The brainstem-thalamus-cerebral cortex physiology model is simulated based on their mutual enginery relations.(2) Based on the physiology model, the brainstem-thalamus-cerebral cortex information conduction normal model is simulated on the Simulink.(3) In the information conduction normal model some parameter values need to be changed, for example the synapse contact values C1 and C2, and the brainstem-thalamus-cerebral cortex information conduction obstacle model is builded to research epilepsy electric activation in related cortex made by brainstem dysfunction.Though the model simulation is not real EEG, it reflects the effect of EPSP and IPSP of thalamus neuronal population. The model output corresponds to the cerebral cortex EEG Two quantitative indices are given to analyze the simulationresults. One is the peak-peak amplitude of the model output, the other is correlation dimension. The conclusions are:1. Base on the physiology background, the brainstem-thalamus-cerebral cortex nonlinear dynamic Simulink model could describe the neural electric activation in the normal and abnormal status of brainstem. The model simulated hi this article could be used on clinical research in epilepsy caused by brainstem dysfunction and extended to other cerebral diseases.2. When the cerebral cortex's inhibition effect on the brainstem neuronal population decreases or excitatory effect increases, there may exist obstacles in neural information conduction from cerebral cortex to brainstem. The result of it may be brainstem dysfunction, so the hypsarrhythmia is occurred consequently. The simulation validates the hypothesis that brainstem is the responsible structure for IS and other similar epilepsies.