ABSTRACT

This prospective study aims to compare the diagnostic value of different preoperative examinations in patients who underwent TLE surgery for treatment-resistant temporal lobe epilepsy, following histopathological evaluations, and to evaluate the seizure-freedom rates observed during the postoperative follow-up.

In this study, 35 patients who were followed-up in our clinic diagnosed with drug-resistant TLE were evaluated prospectively. The epileptic focus was determined for all patients. The different preoperative, noninvasive examinations were compared to each other, and with postoperative pathology results. Patients were followed up for two years after surgery.

Concerning determining the epileptic focus, our findings showed that PET and cranial MRI had similar effectiveness compared to ictal EEG and semiology, which represent the gold standard in preoperative examinations. When we correlated the imaging methods with ictal EEG, PET scan had a considerably high lateralization value in determining the epileptic focus and had 100% sensitivity. In terms of detecting the epileptic focus, MRI had a sensitivity of 97%, routine EEG had a sensitivity of 82.9%, and MRS had a sensitivity of 79.4%. During the postoperative period, hippocampal sclerosis was observed in 71.4% of the patients. The postoperative seizure-free rate was 82.8% in the sixth month and in the first year, whereas this rate was 74.3% in the second year.

In conclusion, as in the present study, each preoperative examination has an impact on localizations and prognosis; it is also important for a good surgical prognosis that results are consistent and focused on a single location.

Keywords: Epilepsy surgery, temporal lobe epilepsy, video-EEG