Analysis of reoperation of 22 patients with mesial temporal Lobe Sclerosis

Objective: We analyzed the outcome of reoperation in cases of incomplete resection of mesial temporal lobe structures in patients with mesial temporal sclerosis (MTS) who had no satisfactory outcome after initial surgery for temporal lobe epilepsy (TLE). Methods: We analyzed 22 consecutive patients with MTS (follow-up 18 to 112 months, mean 42.8) by evaluating noninvasive EEG/video monitoring before first and second surgery (interictal epileptiform discharges=IED, ictal EEG, semiology) and MRI (resection index after first and second surgery of amygdala, hippocampus, lateral temporal lobe). Results: Nine of 22 patients became seizure-free; another 4 patients had a running down of seizures and have eventually become seizure-free (16 to 51 months, mean 30.3). Recurrence of seizures is associated with: 1) ictal EEG with evolution of an independent pattern over the contralateral temporal lobe (0 of 5 patients seizure-free versus 5 of 7 patients non-seizure-free; p=0.046); 2) smaller quantity of lateral temporal lobe resection in second surgery (1.06±0.59cm versus 2.18±1.37cm; p=0.019). No significant correlation with outcome was found for lateralization of IED, change of semiology, other resection indices, begin and duration of epilepsy, duration of follow-up, and side of surgery. Conclusions: Patients have a less favorable outcome of reoperation if they show ictal scalp EEG with contralateral propagation and if they undergo only a small second resection of the lateral temporal lobe.