Abstracts

Rationale: Epilepsy surgery is considered as a safe and effective treatment option for pediatric epilepsy and has been widely used. However, there are only a few long-term follow-up studies on pediatric epilepsy surgery. We tried to review long-term outcomes of epilepsy surgery in pediatric patients from a Korean single tertiary center. Methods: The electronic medical records of patients who had undergone epilepsy surgery from 1995 to 2016 were retrieved from Asan Medical Center Children’s Hospital. We reviewed medical records for demographic data and seizure characteristics. Surgical outcomes were defined based on International League Against Epilepsy (ILAE) surgery outcome scale and OC1-2 was considered as good outcome. Results: Among 206 retrieved cases, 95 (46.1%) were resective surgery cases (11 of hemispherectomy, 43 of lobectomy, 15 of corticectomy, 26 of lesionectomy) and 111 (53.9%) were palliative surgery including 63 of corpus callosotomy, 33 of vagus nerve stimulation, 14 of minimally invasive surgery, and 1 of corpus callosotomy plus vagus nerve stimulation. Good surgical outcome was observed in 66/95 (69.5%) resective surgery cases with a mean follow-up of 9.0 years (range 0.2-21.7) and a distinct epileptogenic lesion was detected in 78/95 (82.1%) resective surgery cases. Cases with good outcome tend to remain stable unless seizure recurred within first year after epilepsy surgery. Risk factors associated with poor outcomes were as follows: time from epilepsy diagnosis to surgery (HR, per year 1.092, 95% of CI 1.023-1.167, p = 0.0087), number of antiepileptic drugs before surgery (HR, per number 1.485, 95% of CI 1.176-1.876, p=0.0009), focal to generalized seizure (HR 0.415, 95% of CI 0.224-0.77, p=0.0053), and complete resection of lesions (HR 0.38, 95% of CI 0.183-0.791, p=0.0096). On the other hand, only 21 (18.9%) cases showed good outcomes and 55 (49.5%) cases had seizure reduction more than 50 percent of baseline (ILAE OC1-4) among 111 cases with palliative surgery cases with a mean 7.6 years (range 0.2-21.9) of follow-up duration. Conclusions: The long-term outcomes of resective epilepsy surgery was very good and one year surgical outcomes, early surgery, small number of AEDs, foal onset seizure and complete resection of lesion can determine the long-term outcomes of five years after surgery. Funding: There was no funding for this abstract.