Abstracts

Rationale: Compared to temporal lobe epilepsy (TLE) in adolescents and adults, TLE in children is heterogeneous syndrome, in terms of seizure semiology and etiology, and often presents severe manifestations in the setting of seizure control and cognitive deterioration even in surgical cases.Methods: We analyzed the results of epilepsy surgery for children who underwent temporal lobectomy before age 15 years. All patients had apparent MRI abnormality in unilateral temporal lobe. Mean age at seizure onset was 54 months, mean age at surgery was 100 months, and mean follow-up time was 98 months. We retrospectively analyzed etiologies, seizure semiology, EEG findings, seizure outcomes, and developmental outcomes.Results: Etiologies were as follows：Focal cortical dysplasia (FCD) in 6 patients, FCD + hippocampal sclerosis (HS) in 5, HS alone in 3, tumors in 5, tumor + FCD in 1, tumor + HS in 1, and gliosis in 1. Tumors were identified in seven patients (5, Ganglioglioma; 1, DNT; 1, Meningioangiomatosis). Mean age of onset was younger in patients with FCD or tumors than those with HS alone. Regarding seizure semiology, about 80 % of patients had complex partial seizure. However, epileptic spasms (n=2) and apneic seizure (n=5) were observed in infantile patients. The interictal EEG before surgery was normal in one case. In 19 patients, interictal EEG abnormalities were lateralized and concordant with MRI lesion side. Two patients had independent bitemporal spikes. Seven patients (six patients with FCD and one with DNT) had extratemporal spikes. In patients with HS alone, interictal EEG abnormalities were well localized over anterior temporal area. Seizure outcome was classified according to Engel classification. 14 cases (64%) were seizure-free (Class I), 2 cases were class II, and 3 cases were class III and IV respectively. In terms of etiology, the seizure-free rate of FCD group, tumor group, HS alone group, and FCD with HS were 57 %, 86%, 66%, and 40%, respectively. Postoperative developmental outcome was better in tumor group and HS alone group than FCD/ FCD + HS group. There was no correlation between seizure outcome and age of seizure onset. However, developmental quotient or intellectual quotient after surgery was significantly lower in patients who seizure begun before age 6 than those after age 6 (p=0.004).Conclusions: In this study, the seizure outcome of TLE in children was obviously lower than previous reports of mesial temporal lobe epilepsy associated with HS. FCD and tumors were major part in etiology, which was relevant to both seizure and developmental outcome. These results indicated that TLE in children includes a different clinico-pathological entity from TLE in adolescents and adults.