A neurofunctional evaluation strategy for presurgical selection of temporal lobe epilepsy patients.

Temporal lobe epilepsy (TLE) is the prototype of a surgi- cally correctable syndrome. Successful surgical outcomes depend on a thorough presurgical evaluation aimed primarily at identifying the epileptogenic zone. Objective Describe the noninvasive presurgical selection and evalu- ation strategy for TLE patients introduced at the International Neuro- logical Restoration Center (CIREN) in Havana, Cuba, and evaluated between 2001 and 2006 for its accuracy in identifying candidates for non-lesional resection surgery. Methods Ictal onset electrographic patterns of 1,679 seizures in 72 patients with drug-resistant partial epilepsy, obtained through long- term scalp Video EEG (V-EEG) monitoring, were evaluated. The correlation between the V-EEG-defined epileptogenic zone and the dysfunction shown by single photon emission computed tomography (ictal and interictal brain SPECT) and nuclear magnetic resonance spectroscopy (MRS) was established. R esults V-EEG monitoring determined that 44.4% of evaluated patients had complex partial temporal lobe seizures. Identification of patients with medial temporal epilepsy (MTE) increased as a result of lateralization and localization of the dominant mean ictal pattern frequency (5.56 ± 1.31 Hz) during the period of maximum spectral power VARETA localization of an ictal epileptiform activity source coincided with the epileptogenic zone in all TLE patients who subsequently underwent a successful temporal lobectomy. Semi- quantitative analysis of ictal and interictal brain SPECT images, as well as metabolic ratios measured by MRS, combined with V-EEG findings, enabled localization/lateralization of the epileptogenic zone in TLE patients whose MRIs were normal or showed bilateral structural abnormalities. Conclusions Confirmation of correct localization/lateralization of the epileptogenic zone following successful surgical outcomes in selected TLE patients led CIREN to develop a surgical treatment strategy for patients in Cuba with drug-resistant temporal lobe epilepsy. This strat- egy offers an appropriate, cost-effective treatment alternative for de- veloping countries like Cuba, with the benefit of significantly improving TLE patients' quality of life.