A Comparison of Inverse Problem Methods for Source Localization of Epileptic Meg Spikes

Locating electromagnetic sources among magnetoencephalography (MEG) allows the definition of responsible generators of excessive discharges in epilepsy. Source localization of MEG biomarkers is considered as a diagnostic aid for neurologists (pre surgical investigation of epilepsy ). Several techniques are proposed to resolve forward and inverse problem of source localization. Our goal in this study is to compare three distributed methods of inverse problem: MNE, sLORETA and dSPM in defining networks connectivity of spiky epileptic events. We used a pre processing chain to evaluate the rate of epileptic spikes connectivity among MEG for five pharmaco resistant patients and two groups of spiky events. For each inverse technique, we calculated the cross correlation between active sources, in fact dsPM shows the highest level of connectivity, MNE gives also a connectivity between the entire active sources but with lowest rate then sLORETA finally dsPM depicts a low number of connection between active regions. These results promote the combination of several localization methods during the investigation of epileptogenics zones.