Fig. 1

SEEG recordings of Patient 3. a Location of the SEEG electrodes shown on the 3D MRI image, The electrodes mainy explored perisylvian region of left hemisphere. b Seizures started with low voltage fast activities in the postcentral gyrus (external leads of electrode M). c Axis X indicates time of selected seizure, axis y indicates electrodes, ER(Energy Ratio)of high frequencies changes was depicted in a color scale (From red to blue ER intensity decreased), Quantification of the seizure onset was in the same position(electrode M) as visually seen. d Axis X indicates electrodesrodes, axis Y indicates EI values, highest EI quoted on the chart demonstrating maximal epileptogenicity in the electrode M. e EI values were superimposed on the axial planes of MRI, (color scale:From red to blue EI value decreased),seizure onset was confined to a single gyrus. PrCGI:precentral gyrus of insular; PoCGI:postcental gyrus of insular; PCC:posterior cingular cortex; PCL:paracentral lobule; PoCG:postcentral gyrus; PrCG:precentral gyrus; Pop:parietal operculum MFG:middle frontal gyrus