Abstracts

Rationale: Surgery for mesial temporal lobe epilepsy (TLE) is an effective treatment for the management of refractory epilepsy. High resolution MRI has improved patient selection for surgical intervention. MRI findings suggestive of mesial temporal sclerosis (MRI-MTS) correlates with improved outcome. Unfortunately, a large group of patients present with normal brain MRI (N-MRI). The purpose of this study is to compare outcome in the population with MRI-MTS vs N-MRI after selective anterior-mesial temporal lobe (AMTL)resection. Methods: A prospective database was established in 1998. Over 450 surgeries have been performed.Three-hundred and fifty patients underwent AMTL resection. Two-hundred and sixty eight patients underwent surgery in the setting of mesial TLE and unilateral ictal findings. No cases of dual pathology or poor localized epilepsy were part of the study. Outcome was analyzed based on a modified Engel classification, patient's demographics and MRI findings. Results: Two-hundred and fifty eight patients with one-year follow-up were entered in the study (MRI-MTS:172; N-MRI:86). In the MTS group 92% of the patients achieved adequate control (Engel I:85%; Engel II:7%). In the N-MRI group 81% were improved (Engel I:55%; Engel II:27%). Poor outcome (Engel III/IV) was seen in 8% in the MRI-MTS and 19% in the N-MRI. Patient's demographic and pathology results did not predict seizure control after surgery. Conclusions: Surgical treatment for mesial TLE is effective. MRI findings predict higher seizure control after surgery. A well selected group of patient with N-MRI will benefit from surgical intervention. Early referral to an epilepsy center can not be overemphasized even in situations when brain MRI is normal.