[Localizing and prognosis value of 99Tcm-ECD spect in patients with refractory temporal lobe epilepsies]

Interictal and ictal 99Tcm ECD-SPECT were retrospectively studied in 46 patients with refractory temporal lobe epilepsy. Forty two of these patients underwent an anterior temporal lobectomy with amygdalo-hippocampectomy or a cortical resection. SPECT findings as indicator of localization for the epileptogenic zone (EZ) and surgical prognosis were validated by comparison with other investigations including video-EEG monitoring with surface electrodes in all the patients, intracranial electrodes in 18 patients and the results of post-surgery outcome. Reliability of SPECT for localizing the epileptogenic zone (EZ) was found for mesial temporal epilepsy (28 patients) and the presumed bilateral temporal epilepsies (7 patients). In these latter cases, ECD-SPECT findings may serve to replace invasive methods with use of intracranial electrodes. SPECTs were unreliable when EZ was undetermined whether mesial or lateral by other non invasive investigations. Unilateral mesial temporal hyperperfusion associated with hypoperfusion of contralateral mesial structures evidenced by ictal SPECTs appear to be preoperative criteria for a successful outcome after surgery.