RESUMEN
ObjectiveThe purpose of this research was to investigate functional connectivity of 16-channel electroencephalograph(EEG) in δ frequency band based on Granger causality analysis.MethodsThe experimental data was recorded at a sampling rate of 200 Hz from temporal lobe epilepsy (TLE) patients(6 left and 3 right TLE,and 9 normals as control group.Ten of EEG segments of 20 s length for three different states:epileptiform discharges (ED) state in interictal durations,non-ED state for TLE patients,and control state for the normal.The δ band components (1～4 Hz) were filtered from EEGs.The functional connection values Iδ between two EEG δ components were calculated separately by Granger causality analysis.The two EEG components were from inferoposterior temporal lobe (left:T5,right:T6) to frontal lobe (Fp1,Fp2,F3,F4,and parietal lobe (C3,C4) for three states.ResultsThe Iδ values for ED state was 0.1323±0.0329～0.1670±0.028 9,which was significantly higher than that of non-ED state (0.0300±0.0130～0.0420±0.0072) (P＜0.05).The Iδ values for the control group (0.0153±0.0028～0.0193±0.0057) was much lower than that of ED state (P＜0.01),and no obvious distinctions were observed compared with non-ED state at P=0.05 level.ConclusionThere is a stronger connection of EEG' s δ bands from the inferoposterior temporal lobe to frontal and parietal lobe for the ED state,and the over-discharges transmission is from inferoposterior temporal lobe to other brain regions.There is a weaker connection from the top temporal lobe to frontal and parietal lobe for non-ED state and control group,and the onset zones is not inferoposterior temporal lobe.