Comparison of neuronal excitation between extruded slab partial head model and full head model in subdural cortical stimulation

Cortical stimulation (CS) is an appealing and emerging treatment for neurological disorders. CS is known to promote functional recovery effectively; however, its underlying mechanism and the optimal parameters for the effective treatment are not clearly understood. In this work, we developed a realistic three-dimensional full head and chest model for subdural CS. Our proposed model was compared at the neuron level with an existing simplified extruded slab partial head model depicting around precentral gyral cortex only. Each model was coupled with the pyramidal neuronal model in order to investigate an extent of neuronal excitation. We found that the crown of the cortex was the most excitable area in the unipolar stimulation, while in the bipolar stimulation, the lip and bank were excited more easily than other areas. Finally, it was evident that our proposed model was substantially different in excitation threshold from the existing simplified model, which is compelling to do computational CS study on more realistic head models.