The role of the interictal EEG in selecting candidates for resective epilepsy surgery.

The interictal EEG is a noninvasive and useful test for selecting candidates for resective epilepsy surgery, although it has many pitfalls. It is an essential test for the most common drug-resistant epilepsy, mesial temporal sclerosis, and predicts good outcome when interictal epileptiform discharges are concordant with unilateral hippocampal atrophy or sclerosis, and predicts poor outcome when interictal epileptic discharges are discordant with the lesion. Its role in other types of epilepsy surgery, including nonlesional cases and corpus callosotomy, is less clear. Future research gathering large multicenter prospective data is needed to maximize the role of this classic neurophysiological test in the evaluation of candidates for epilepsy surgery.