Clinical Utility of ESI in Presurgical Evaluation of Patients With Epilepsy

This study evaluates to what extend electrical source imaging (ESI) provides nonredundant information in the evaluation of epilepsy surgery candidates. Epilepsy surgery normally requires an extensive multimodal workup to identify the epileptic focus. This workup includes Magnetic Resonance Imaging (MRI), electroencephalography (EEG) without source imaging, video monitoring and when needed Positron Emission Tomography (PET), Magnetoencephalography (MEG), Single Photon Emission Computed Tomography (SPECT) and invasive EEG recordings using implanted electrodes. ESI estimates the location of the epileptic source with a high sensitivity and specificity using inverse source estimation methods on non-invasive EEG recordings. This study aims to investigate the clinical utility of ESI using low-density (LD, 25 channels) and high-density (HD, 256 channels) EEG. Clinical utility is defined in this study as the proportion of patients in whom the patient management plan was changed, based on the results of ESI. Should ESI be added to the routine work-up of epilepsy surgery candidates.