Functional connectivity of EEG's delta-band in epilepsy interictal seizures based on Granger causality analysis / 国际生物医学工程杂志

ABSTRACT

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 statesepileptiform 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 (leftT5,rightT6) 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.