Abstracts

Rationale: Cortical dysplasia is a major cause of partial epilepsy in children with intractable seizures. Most of the surgical outcome publications relate to developmental lesions, and limited information is available from static pathology. The pediatric cases are usually extra-temporal compared to the adult population; variable results depending on seizure outcome are seen. It is still debated whether the outcome is related to the dysplasia itself or the location of the lesion. We wanted to evaluate outcomes for the non-dysplastic cases. Methods: We included a sample of patients less than 18 years of age operated on for non-dysplastic static focal cortical and cortical-subcortical lesions. All the cases were intractable, had a clear lesion by MRI, had a concordant neurophysiologic seizure onset (EEG or Video-Telemetry), and underwent neuropsychological evaluation. In all the cases, a lesionectomy was performed. The patients had a minimum of 2 years follow up. Variables indicating seizure control were followed. Results: A total of 43 patients that underwent pediatric epilepsy surgery were evaluated in the sample; only 7 patients were chosen. The resection were 3 temporal, 2 occipital, 1 parietal and 1 frontal in distribution. Intraoperative corticography was done in 3 cases, with cortical stimulation performed in only 1 patient, as the lesion involved eloquent cortex (2 stage procedure). The nature of the lesion was encephalomalacia-gliosis (with suspected vascular or anoxic insult) in 5 cases and non-calcified neurocysticercosis in 2 cases. The seizure outcomes were 6 patients Engel class 1, and 1 patient Engel class II (frontal resection). Successful anticonvulsant reduction was performed in all the cases. 2 patients are antiepileptic free at this point. Conclusions: Lesional epilepsy in pediatrics is mostly related to extra-temporal cortical dysplasias, and the response to surgery is variable depending on the location of the lesion. In our study of static non-developmental lesions, the temporal lobe involvement is not infrequent. The need for extensive functional preoperative testing is less, and the surgical response is very good with high rates of seizure freedom compared to the cortical developmental abnormalities. Finally, the location of the lesion - when eloquent cortex is not involved - does not influence the seizure outcome as much as other neuropathology does.