Interictal spike localisation with methohexitone: preoperative activation and surgical follow-up.

Thirty-four patients with intractable temporal lobe epilepsy underwent preoperative and perioperative EEG activation with methohexitone sodium. Subsequently, all patients underwent anterior temporal lobectomy with deep structure preservation. Preoperative spike localisation with methohexitone was concordant with peroperative recording in most cases. Large doses of methohexitone were administered to two patients, rendering the EEG almost isoelectric. Areas of abnormal spiking activity were refractory to the effects of methohexitone, and recovery was marked by an increase in spike frequency. Postoperative clinical evaluation confirmed the specificity of methohexitone for abnormally epileptogenic tissue.