S196 New approach to presurgical evaluation in epilepsy surgery

Abstract

Introduction and aim In order to investigate and map the precise epileptic mechanism(network) and seizure onset zone during the planning of epilepsy surgery we use more and more complex imaging and electrophysiological studies. The analysis and evaluation of the ever growing datasets needs such a complex platform which can integrate the spatial information derived from the preoperative structural and functional imaging data with the electrophysiological data coming from the implanted intracranial electrodes. Materials and methods With the development of a custom made Matlab based software we can co-register preoperative structural and functional images with the postimplantation structural images containing the implanted electrodes. We created a special interface to combine imaging data and electrophysiological datato integrate the electrophysiological maps (interictal discharges, seizure onset zone, high frequency oscillations, cortical electrical stimulation, cortico-cortical evoked potentials) into the same space where the imaging data is presented. Results The coregistration of the different structural and functional (fMRI, DTI) 3D imaging data is already possible using open source softwares. The coregistered images are automatically transformed to the patients own MRI space and to standard space as well where using the postimplantation CT images we can determine the exact position of the electrodes.Using our custom made software now we can visualize the most important electrophysiological and stimulation data on the patient’s individual anatomy using the location of the electrodes as connection between different modalities. Conclusions The presented method allows the precise and automated coregistration of different imaging modalities and electrophysiological data. The integration of the complex electrophysiological data and maps into the same space allows more precise decision mapping in complex epilepsy surgical cases and allows more precise demarcation of the epileptogenic zone. The most difficult challenge to solve in today’s epilepsy surgery is to integrate all the information collected in one patient to create the best surgical plan and to resulting in the best epileptological outcome possible. Grant KTIA NAP_13-1-2013-0001.