Abstracts

Rationale: Temporal lobe epilepsy with mesial temporal sclerosis (MTS) is known as the most common intractable partial epilepsy in adults. The MTS can be suspected on MRI when hippocampal atrophy is associated with T2-weighted signal hyperintensity. However, over the years, we have noticed that a number of children with MRI evidence of hippocampal sclerosis have favorable outcome. We sought to define the clinical characteristics and evolution of these children. Methods: We reviewed the medical record of the patients who were diagnosed as epilepsy and showed hippocampal abnormality on initial MRI, from 1995 to 2007 in pediatric neurology clinics in Asan Medical Center. Data were collected retrospectively on demographics, febrile seizure, age at first seizure, age at diagnosis, responses to treatment, follow-up duration and EEG results. Good seizure control is defined as two or fewer seizures per year. We also made group comparisons and correlation of clinical data. Results: 32 children were initially found. Four were excluded because of follow-up loss and short-term follow-up period. The mean age of seizure onset was 78.5 (3-170) months and the mean follow-up duration was 6.3 (1-17) years. Thirteen patients of 28 (46.4 %) children with epilepsy with unilateral hippocampal sclerosis were medically controlled. Temporal lobectomy was done in ten of other 15 patients and the nine patients were seizure free after surgery. There was no difference in onset age, follow-up duration, diagnostic delay, patterns of EEG and existence of initial precipitating injury, but significant difference in seizure frequency before diagnosis was noticed between medically controlled group and intractable group (p<0.01). Conclusions: The fact that near half of epileptic children with hippocampal sclerosis showed benign outcomes argues against the traditional belief that TLE accompanied by MTS was synonymous with drug resistant epilepsy. Higher seizure frequency can be a valuable predictor of the medical intractability in children with hippocampal sclerosis.