Abstracts

RATIONALE: Pathological substrates are known to be one of the most important factors determining the outcome of epilepsy surgery. Developmental disorders including cortical dysplasia are frequently found on MRI or pathological study as etiologies of pediatric epilepsy. We have investigated the correlation between pathological substrates and seizure oucomes in pediatric patients with intractable partial epilepsy. METHODS: We retrospectively reviewed the medical records of fifty two patients younger than 15 years of age underwent focal resection for intractable epilepsy since 1993 and had at least 1 year of follow-up. Pathologic results and seizure outcomes by Engel's classification were analyzed. Cortical dysplasia group was compared to non-dysplasia group for seizure outcome. RESULTS: Twenty-six patients underwent temporal lobectomy and 26 extratemporal focal resection. Pathologic analysis revealed 30 cases of cortical dysplasia, 9 hippocampal sclerosis, 4 neocortical gliosis, 4 tumor, 1 normal and 4 unavailable pathologic reports. 19 cases (73.1%) of temporal group, and 16 (61.5%) of extratemporal group had excellent seizure outcomes (class 1, 2) without statistical difference between the two groups (p=0.37). 17 cases (56.7%) with cortical dysplasia and 14 (77.8%) of non-dysplastic group showed good outcomes with no significant difference (p=0.14). In the temporal group, 8 out of 9 cases with hippocampal sclerosis achieved excellent outcomes in comparison with 50% (6/12) of cases with cortical dysplasia. However, there was no statistically significant difference between the two groups (p=0.16). In extratemporal group, 11 out of 18 cases (61.1%) with cortical dysplasia and 5 out of 8 (62.5%) with non-dysplastic pathology had good outcomes. CONCLUSIONS: Cortical dysplasia is the most common etiology in pediatric patients with intractable epilepsy. This indicates that epileptogenic zone may be wider and multiple, providing less localizing information in terms of electrographic abnormality and clinical semiology. Thus invasive recording is more often required and surgical outcome is less favorable than that of adult surgery group.