Abstracts

Rationale: Temporol lobe epilepsy (TLE) is a homogenous entity mostly associated with hippocampal sclerosis (HS) in adults whereas children may have more diverse etiologies. Resective surgery is successful in management of seizures both in children and adults with refractory TLE. We describe outcomes in patients with childhood onset refractory TLE.Methods: We reviewed patients who had surgery for refractory epilepsy at Hacettepe University Children s Hospital and identified 107 patients who underwent resection for TLE; 100 patients had a minumum postoperative follow up of one year. Presurgical evaluation included clinical assessment, interictal EEG, scalp video-EEG, MRI and neuropsychological evaluation. Seizure outcome was determined using Engel Classification System. Results: The mean age at seizure onset was 3.9 years ranging between first day of life and 14 years, age at surgery was 9.7 years ranging between 1-20 years. All patients had partial onset seizures and abnormal MRI, 80% had focal convergent EEG findings. Preoperative neuropsychological tests were available in 81 patients and showed normal IQ in 48%, mild intellectual disability (ID) in 37%, moderate ID in 11% and severe ID in 4%. 51% of the patients underwent surgery on the right temporal lobe and 49% on the left; 56% had temporal lobectomy with amygdalohippocampectomy, 44% underwent temporal lobectomy or temporal lesionectomy. Histopathology revealed CNS tumor in 37%, HS in 25%, HS associated with other pathology in temporal lobe 14%, gliosis in 8%, cortical dysplasia in 11 %, and other pathology in the remaining 5%. At mean follow-up of 7 years (1-19 years), out of 100 patients 74 were seizure free, 8 were classified as Class II, 10 as Class III and 8 as Class IV; overall 82 % had Class I-II outcome. Patients experienced significant decrease in the number of antiseizure medications postoperatively (p< 0.0001). EEG also improved significantly following surgery (p<0.0001). Seizure outcome was not associated with age at seizure onset, preoperative seizure frequency, presence of secondarily generalized seizures, history of febrile seizures, preoperative IQ, age at the time of surgery, and surgical technique. Patients with HS (with or without other pathology in the temporal lobe) had the most favorable seizure outcome. Neuropsychological tests showed no significant change following surgery.Conclusions: A high percentage of our patients with childhood onset refractory TLE benefit from epilepsy surgery. All our patients have abnormal MRI suggestive of patient selection bias. Although our patients experienced favorable seizure control and decreased exposure to antiseizure medications, neuropsychological tests showed preserved cognitive functions rather than improvement.