Schematic representation of potential foci responsible for seizure persistence following temporal lobe epilepsy surgery: (a) the ipsilateral mesial temporal structures from incomplete resection (green); (b) the contralateral mesial temporal lobe (blue); (c) the lateral temporal neocortex following selective amygdalohippocampectomy (yellow); (d) the extratemporal lobe epilepsy masquerading as temporal lobe epilepsy such as an orbitofrontal (red), insular (orange), or occipital epileptogenic (purple) zone; (e) the dual pathology such as an unrecognized subtle end-of-sulcus cortical dysplasia in the occipital lobe (purple); (f) a large epileptogenic zone extending to extratemporal structures (temporal epilepsy plus) such as the insula (orange).