Abstracts

Rationale: The presence of MTS on MRI has been identified as the most important postoperative prognostic factor regarding seizures in patients with rTLE. Most of the published literature took EEG (or video-EEG) as the gold-standard in the preoperative investigation of these patients. We report a series of patients in whom we took MRI as the gold standard in their preoperative workup. Methods: Two-hundred patients with visually clearly defined unilateral MTS on MRI were studied (112 left and 88 right sided). Age ranged from 14 to 56 years. All patients underwent standard neuropsychological testing and were submitted to cortico-amygdalo-hyppocampectomy at the side of the MRI lesion, under general anesthesia and without intraoperative electrocorticography. The posterior limit of the cortical resection was defined by the vertical position of the central artery. No patient was submitted to video-EEG monitoring. Results: 89% of the patients were rendered seizure-free by surgery and 11% were in Engel II. Four patients submitted to left, dominant temporal lobe resection presented worsening of verbal memory postoperatively. Three of them had additional cortical damage due to peri-Wernicke’s neocortical venous infarct as documented by post-operative CT and MRI; one of them had no additional finding that would explain their memory worsening. No patient who underwent a non-dominant resection had any memory worsening. Conclusions: In patients with clear-cut MTS on MRI, video-EEG recording is not mandatory. Actually, if only localizatory video-EEG findings would be taken into account, it is likely that 15-20% of the patients with MTS would be denied surgery and would remain seizing despite adequate medical therapy. This study showed that these patients are very likely as good candidates for surgery as those in whom video-EEG was localizatory.