Mesial temporal lobe epilepsy is due to hippocampal sclerosis. These patients have epilepsy refractory to medical therapy and hence need devices like vagal nerve stimulation. Definitive treatment involves 1. Resection of Antero-medial temporal lobe or limited removal of hippocampus and amygdala (Amygdalo hippocampectomy) 2. Focal seizures, abolished by focal neo coical resection with removal of identified lesion (Lesionectomy).