Abstracts

Rationale: Mesial Temporal Sclerosis (MTS) has been well-recognized as a cause of intractable epilepsy in children and adults. While the clinical features and outcome of MTS in adults have been well described, such features have not been as extensively characterized in children. We reviewed the clinical features and outcomes of 22 children with intractable complex partial seizures with MTS who subsequently underwent surgical treatment. Methods: The Institutional Review Board at Children's Hospital Boston approved this study. Cases were ascertained from an epilepsy surgery database in the Division of Epilepsy and Clinical Neurophysiology. We retrospectively reviewed medical records of 22 consecutive children (11 girls and 11 boys) with intractable complex partial seizures and MTS who subsequently underwent surgical resection between 1994 and 2003. The postoperative follow up period was 1-11 years (mean 3.6 years), and age of last follow up was 19+/-5.6 years. Clinical factors were compared, such as age of seizure onset, antiepileptic drugs, age at time of resection, and frequency of seizures before and after the surgical treatment. Results: Eleven children had left MTS, and 11 had right MTS. Age of partial seizure onset was 0.3-7 years (mean 3.4+/-2.3 years). Eight had a history of febrile seizures before onset of partial seizures. Seven had multiple seizures per day. Age of surgery was 2-20 years, mean 10.8+/-5.1 years. Twenty-one of 22 underwent temporal resection, and one had implantation of subdural electrodes but no resection. One died in the postoperative period. For seizure outcome, seven became seizure-free, and two had only rare auras. Two underwent a second surgery and had seizure reduction. Three patients underwent implantation of a vagus nerve stimulator and had seizure reduction (See Table). Conclusions: In our 22 children with MTS, the majority of children had onset of partial seizures during early ages, with frequent seizures and multiple trials of antiepileptic drugs before undergoing surgical treatment. Such factors suggest a progressive course to a more severe epilepsy, requiring earlier surgical treatment, compared to typical adult MTS cases. Overall our patients collectively had frequent seizures prior to surgery (mean 42/month, range 1.5-510), higher than reported adult cases (median 5.1/month, range 2.4-9). Following resection, only seven of 22 patients (32%) became seizure-free, and 9/22 (41%) had Engel class Ia outcome. In adults, in the reported randomized, controlled trial of surgery for temporal lobe epilepsy, 38% of the patients were seizure free and 58% had Engel class Ia outcome. The difference between the pediatric and adult population in outcome may reflect a more severe form of epilepsy in this group, although it is possible that subtle dual pathology may have been undetected. While further larger scales studies will be necessary to confirm this trend, MTS in children have difference in features compared to MTS in adults.