Abstracts

Rationale: To determine predictive factors of clinical outcome following reoperation after comprehensive epilepsy surgery. Methods: The authors retrospectively studied the operative outcome in 19 consecutive patients who underwent reoperation for intractable epilepsy. We monitored the patients at least 1 year after reoperation. Epidemiologic data and preoperative electrographic and radiologic findings were examined. Results: Average age of seizure onset was 2.01 2.51 year. The average duration between seizure onset and first operation was 2.68 3.39 year. The mean duration between the primary operation and second operation was 1.98 2.24 year. Twelve patients(63.15%) had cortical dysplasia , three had Rasmussen encephalitis, Cerebromalacia, Hippocampal sclerosis and the other four had unknown etiology. Among fourteen patients with cortical dysplasia, six had mild malformation of cortical dysplasia and eight had focal cortical dysplasia. The primary operation were resective surgery (n=13, 68.42%)and hemispherotomy(n=6, 31.57%). Four patients (21.05%) underwent three times of operations. Sixteen patients underwent reoperation due to incomplete resection (84.21%) and three due to late recurrence (15.78%). The outcome was Engel class 1, 2 in thirteen patients(68.42%)and Engel class 3, 4 in six patients (31.57%). Statistically significant factors related to reoperation outcome were sustained electrographic abnormalities in postoperative EEG and concordance between SISCOM and other tools including Brain MRI, FDG-PET and video EEG monitoring(P<0.005). Twelve patients(63.15%) had subdural hemorrhage as postoperative complication and eleven (57.89%) had permanent neurologic deficits. Conclusions: Reoperation may be an alternative treatment option for patients with intractable epilepsy who failed to control seizure after initial operation.