[Site and propagation of focal epileptic activity: multichannel MEG/EEG analysis].

Electrophysiological examinations provide the basis for a deeper pathophysiological understanding of focal epileptic activity. In addition to electroencephalography, magnetoencephalography from field measurements is now available for biomagnetic diagnosis. As magnetoencephalography (MEG) is basically better suited for the localization of focal epileptic activity than EEG, an increase in MEG measurements has taken place over the last years.