Epilepsy is a highly prevalent neurological disease characterised by recurrent seizures that result from abnormal electrical discharges in the outer layers of the brain (ie. braincortex). The aim of this project is to increase the number of patients with uncontrolled epilepsy (ie. refractory epilepsy) that may benefit from brain surgery. This requires precise localisation of the brain region that is responsible for provoking seizures (ie. the epileptogenic zone). It has been shown that surgical outcome is optimal when the region of abnormal electrical discharges corresponds to an identifiable anatomical abnormality in the brain cortex. The currently available diagnostic tools during the presurgical evaluation protocol consist of neurophysiological tools (video-EEG monitoring) investigating the abnormal electrical discharges and imaging tools (3 Tesla magnetic resonance imaging, positron emmision tomography) investigating the underlying anatomical abnormality. Despite the fact that these techniques are state-of-the-art, they are unable to identify the epileptogenic zone in all patients in a noninvasive way leading to subsequent succesful surgery. Because of the limited resources only a small number of patients is eligible for invasive investigation of a suspected epileptogenic zone using brain electrodes (ie. invasive video-EEG monitoring). This invasive and expenisve neurophysiological technique is associated with medical risks. A substantial number of patients cannot undergo surgery and remain prone to uncontrolled seizures.