MEG evaluation in temporal lobe epilepsy

Introduction Temporal lobe epilepsies represent the most frequent form of focal epilepsies [1]. The seizures are frequently difficult to control with antiepileptic medication and eventually 30-50% of patients have to be considered as medically refractory. Epilepsy surgery can be considered as a valuable treatment option for these patients rendering 70-90% of them seizure-free [2]. Thus, exact localization of both the epileptogenic zone and essential brain regions which can only be accomplished during a thorough presurgical work-up is crucial for a successful surgical treatment and the improvement of noninvasive methods is clinically warranted. Magnetoencephalography (MEG) could improve the non-invasive evaluation of temporal lobe epilepsy patients for several reasons. First, MEG provides a superior spatial resolution as compared to scalp-EEG because magnetic fields are far less distorted than electric fields by the resistive properties of the skull and scalp measured [3]. Second, t