EEG-MEG source characterization in post surgical epilepsy: the influence of large cerebrospinal fluid compartments

A study on the effect of including a large post-surgical cavity filled with cerebrospinal fluid (CSF) in the modeling of EEG-MEG in epilepsy was performed. Real, simultaneous EEG-MEG data and volume conductor models constructed on the basis of 3DT1 MRI data of the same patient were used. Results show that for MEG and EEG source localization errors remain limited to 0.5 cm, but source strengths found are more consistent when CSF is included. Also the localization differences between EEG and MEG are smaller and the fit to MEG data is substantially better.