Electric current distribution in pre-surgical neurostimulation using stereo-EEG electrodes

SANTIAGO COLLAVINI; C.H. MURAVCHIK; FERNANDEZ CORAZZA, MARIANO; S. KOCHEN; J.P. PRINCICH

Córdoba

Congreso; XXI Congreso Argentino de Bioingeniería SABI 2017; 2017

Abstract - Deep electrodes are implanted in patients withrefractory epilepsy to study the epileptogenic network as a presurgicalprocedure. These electrodes are typically used tomeasure the neuronal activity, known as stereoelectroencephalography, but also to stimulate different brainregions. By analyzing the stimulation responses, medical doctorsdetect eloquent areas and study the epileptogenic network.Significant differences in the stimulation set-up that producespost-discharges were found when using different types ofelectrodes. Although almost all centers around the world use thesame protocol, they use different electrode types and the electriccurrent density distribution was not studied in detail. By meansof electrical FEM models, we analyze and compare the currentdensity distribution for four different electrode types in ahomogeneous medium. We also developed a detailed FEM modelof the brain of a specific patient to better study the electriccurrent flow in a more realistic scenario. We found that differentelectrodes require up to three times more intensity in the injectedcurrent to produce the same current densities, which is consistentwith the findings of the specialists in the clinical use of theseelectrodes.