About 50 million people carry the diagnosis of epilepsy world-wide, and up to 70% of newly diagnosed children and adults with epilepsy can be successfully treated and remain seizure-free with anti-epileptic medications.Conversely, over 20% of these patients are medically refractory.Currently, for these patients, non-pharmacological options include resective surgery, device implantation, and dietary modification.Among these non-pharmacological options, focal surgical resection has been reported to be 50% to 80% successful in achieving seizure freedom depending on the location of the epileptogenic zone.Recent studies have also demonstrated the superiority of early surgical management compared to medical management in temporal lobe epilepsy, whereas the delay in treatment has significant negative impact on the patients quality-adjusted-life-years.The pre-surgical evaluation of patients with medically refractory epilepsy thus aims to identify the epileptogenic zone for focal surgical resection.High resolution magnetic resonance imaging (MRI), functional MRI, positron emission tomography (PET), and ictal single photon emission computed tomography (SPECT) are among the most commonly used imaging modalities to identify structural and functional abnormalities for the pre-surgical evaluation of patients with medically refractory epilepsy.In addition to structural and functional imaging studies, ictal electroencephalogram (EEG) is used to identify the epileptogenic zone for focal surgical resection.Newer technologies in EEG acquisition and neuronal signal processing analysis have shown promise in improving the localization of the epileptogenic zone for surgical resection.