Abstracts

Rationale: Epilepsy surgery is currently the most effective overall treatment for patients with refractory partial epilepsy. Although more than 60% of patients become seizure free after receiving anterior temporal lobectomy (ATL) and selective amygdalohippocampectomy (SAH), the remaining patients experience recurrent seizures after surgical treatment. For those who failed the first surgery, further treatment options are quite limited, and at times, second surgery may improve seizure outcome. We reviewed our surgery patients to document the success of reoperation after failed ATL and SAH and to identify favorable prognostic variables influencing good seizure outcome. Methods: Data were obtained retrospectively from our epilepsy surgery database at the Barrow Neurological Institute between 2004 and 2009. In order to present more uniform patient population, we included patients who had temporal lobe surgery initially followed by second surgery for seizure control. Patients with minimum of 12 months follow up were included in the study. Demographic details, seizure history, presurgical evaluation, and postoperative follow up data were evaluated. Results: 6 patients with temporal lobe epilepsy were identified from our database that had second resective surgery and met the other criteria. The initial surgery was ATL in 3 of 6 patients and SAH in the remaining 3. Before the initial surgery, all 6 patient s brain MRI scans showed suggestive findings of mesial temporal sclerosis. Recurrence of seizure occurred within the first postoperative year in 5 out of 6 patients. Repeat MRI brain prior to second surgery showed residual amygdala and hippocampus in all 6 patients. Phase II evaluation with depth electrodes confirmed the ictal onset from the remnant tissue. All patients underwent complete resection of the remnant temporal lobe including mesial temporal structures and ipsilateral anterior temporal lobe. Seizure outcome after second surgery is more favorable if the initial surgery was SAH (N=3), of which 2 patients (N=2; 66%) has Engel Class I (free of disabling seizures) and 1 patient (N=1; 33%) has Engel Class 2 (rare disabling seizures) seizure outcome. Significant improvement was seen even in patient who had ATL (N=3) of which 1 patients (N=1; 33%) has Engel Class 2 and 2 patients (N=2; 66%) has Engel Class 3(worthwhile improvement) seizure outcome. Conclusions: Second resective surgery for epilepsy has favorable seizure free outcome in patients with temporal lobe who failed initial surgery, especially those who failed SAH. Phase II investigations prior to reoperation can provide useful information in identifying