Seventy percent of children undergoing epilepsy surgery have a significant improvement in seizure control and psychosocial outcome. However, many with intractable seizure are not being referred as potential candidates for surgery. Approximately one third of children with partial complex seizures continue to have intractable epilepsy with debilitating psychological consequences. Patients with intractable seizures despite adequate trials of anticonvulsant medication should be referred for surgical evaluation. Surgery should not be postponed beyond 4 years and in selected cases should be done earlier unless other medical or neurological conditions are such that improvement in seizure control will not measurably alter their quality of life. The goal of presurgical evaluation is to localize the epileptogenic region and define adjacent functional cortex. The initial phase (Phase 1) of evaluation includes non-invasive electrophysiological studies with continuous video-EEG monitoring. Neuroanatomical (MRI, CT) and functional (PET, SPECT) studies and neuropsychological evaluation are also performed to define regions of focal dysfunction. If the information from phase 1 evaluation does not provide sufficient data for adequate localization intracranial recording techniques (depth, subdural or epidural recording) may be necessary (phase 2). No one technique is the procedure of choice and it is likely that the specific advantages of each method will dictate their appropriate application in the future.
