Significance of MEG in Presurgical Epilepsy Evaluation Summary

sive procedure, records magnetic fields generated by spontaneous or evoked brain activity. Presurgical evaluation of pharmacoresistent patients with focal epilepsy is currently the most frequent diagnostic application. The source of epileptic or averaged evoked activity is localised and then overlaid onto magnetic resonance imag-ing (MRI) of the patient’s brain. For source local-isation advanced techniques use information extracted from the individual brain. The localisa-tion results can guide invasive recordings and help in neurosurgical operation planning. Owing to the physical constraints of MEG and EEG, source localisation can be improved by simulta-neous recording. Together with other diagnostic methods, MEG plays an important role for focus localisation in patients with intractable epilepsy