Localization techniques for EEG and MEG in children and adolescents

The three-dimensional localization of sources of epileptogenic activity and event related potentials by EEG and MEG has shown a slowly increasing clinical use during the last ten years. More recent computational techniques allowing a combination of electrophysiological localization and MRI imaging give us a basis for meaningful anatomical interpretation of the findings. Clinical studies mainly cover the presurgical evaluation of patients with focal epilepsies. A high correlation of the results with gold standards, like invasive EEG diagnostics with implanted electrodes was found in these studies. Another meaningful application is the investigation of topical relations between brain dysplasias (arachnideal cyts, heterotopia) and epileptogenic activity. Till now, the published case numbers are not sufficient for a final judgement of the clinical value of these methods. Besides the applications in epilepsy, these methods are a promising research tool which is not widely introducted into clinical medicine.