Electromagnetic Source Imaging in Presurgical Evaluation of Children with Drug-Resistant Epilepsy

Our main goal of research is to develop novel biomarkers of epilepsy that augment the presurgical evaluation process and improve the surgical outcome of children suffering from drug-resistant epilepsy. We're trying to investigate whether non-invasive methods can precisely localize brain areas that correspond to the epileptogenic tissue. The most recent developments in our field are the ability to record MEG and high-density EEG data simultaneously with a high number of sensors, new EG technologies offering minimal preparation time, which is critical in children, and advanced algorithms that combine electric and magnetic source imaging into a unique solution.

We present evidence that combined electric and magnetic source imaging on simultaneous MEG and high-density EEG recordings outperform either modality alone in terms of localized accuracy. This is most likely due to the complementary and confirmatory sensitivity profiles of MEG and easy signals, and the increased number of sensors. We demonstrate a state-of-the-art setup that allows the simultaneous recording of magnetic and electric brain activity with more than 500 sensors covering the entire head.

With the setup, we demonstrate the non-invasive localization of interictal and ictal epileptiform activity and the mapping of the local areas so as not to resect during surgery. Our findings will help us understand the complementary and confirmatory information that magnetoencephalography and high-density electroencephalography recordings provide in different clinical scenarios where the localization of the epileptogenic focus is challenging due to the deep location of the source or its radial orientation with respect to the patient's cortical surface.