Abstracts

RATIONALE: To evaluate the effect of remifentanil on electrocorticography (ECoG) in patients undergoing anterior temporal lobectomy for intractable partial epilepsy. Remifentanil is an ultra-short acting and short-duration opioid used for surgical anesthesia that may have a proconvulsant effect similar to alfentanil (Cascino et al., J of Clin Neurophysiol 1993;10:520-525). METHODS: Twenty patients were administered remifentanil (2.5 ug/kg) during epilepsy surgery. The pre-excision ECoG was performed using 3 monopolar depth electrodes placed in the medial temporal lobe and 2 eight contact subdural strip electrodes placed over the lateral temporal neocortex. The total number of epileptiform discharges was determined during each of 5 one-minute epochs prior to and following the administration of remifentanil. The maximum number of spikes both before and after remifentanil were compared using a one-sided rank sum test (p?0.05 significant) and then classified into neocortical vs. mesial temporal activation. The mean age of the patients at the time of surgery was 39.1 years (range, 21-56). Preoperative MRI revealed unilateral hippocampal atrophy in 10 patients, bilateral hippocampal atrophy in 2 patients and lesional pathology in 2 patients. All patients underwent a lateral temporal neocortical resection and an amygdalohippocampectomy. RESULTS: In 17 of 20 patients the total number of epileptiform discharges and the number of depth spikes increased significantly following remifentanil administration (p<0.01). The mean total number of spikes per epoch before and after remifentanil was 61.6 with 33.4 depth spikes and 86.1 with 54.6 depth spikes, respectively. One patient had an electrographic mesial temporal seizure following remifentanil administration. No patients had acute postoperative seizures. CONCLUSIONS: Remifentanil may activate epileptiform activity during ECoG in patients undergoing surgical treatment for temporal lobe epilepsy.