Abstracts

Patients with medically refractory temporal lobe epilepsy may be excellent candidates for epilepsy surgery. However, lateralization of the ictal onset zone is not always clear from non-invasive studies. In such cases, bilateral temporal depth electrode implantation may be undertaken prior to considering temporal lobe resection. Although intraoperative pharmacologic activation is known to increase interictal epileptiform discharges on electrocorticography, the clinical relevance of this procedure has not been established., We performed a retrospective review of all epilepsy patients who underwent bilateral temporal depth electrode implantation during the period 1997-2005 and received intraoperative alfentanil activation. We identified ten patients and characterized the data provided by EEG (interictal and ictal), MRI, intraoperative electrocorticography (before and after pharmacologic activation) and subsequent prolonged intracranial EEG monitoring, with respect to localization of the ictal onset zone. We focused on the correlation between pharmacologic activation and lateralization of the epileptogenic temporal lobe as determined by intracranial EEG monitoring., 6 females and 4 males meeting inclusion criteria were identified. Administration of alfentanil intraoperatively caused increased activation of epileptiform discharges bilaterally in 5 patients, and no definite activation in another 3 patients. In the remaining 2 patients, the side of pharmacologic activation did not correspond with the epileptogenic temporal lobe determined on subsequent prolonged intracranial monitoring., Intraoperative pharmacologic activation does not appear to be useful in patients with temporal lobe epilepsy of unclear lateralization.,