Abstracts

Hemispherectomy has been used to treat a subset of patients with medically intractable epilepsy arising from primarily one hemisphere such as occurs with hemimegalencephaly or Rasmussen[apos]s Syndrome. This study is a retrospective chart review investigating the efficacy and the subsequent functional and developmental outcome in pediatric patients undergoing hemispherectomy. This retrospective chart review includes 10 patients who underwent hemispherectomy for intractable epilepsy between 2001 and 2005 at Texas Children[apos]s Hospital. Efficacy of hemispherectomy was assessed by family reports of reduction in seizure frequency and by review of the number of antiepileptic drugs being used for treatment. Functional outcome was assessed by chart review of physical exam and developmental history data obtained during clinic visits prior to and following hemispherectomy. Duration of followup ranged from 3 months to 3.5 years post-hemispherectomy. This study includes 7 males and 3 females whose age at the time of hemispherectomy ranged from 4 months to 16 years with a mean age of 5.8 years (median 3 years). All ten patients experienced a reduction in seizure frequency post-hemispherectomy. Seven of the ten patients were seizure-free at the time of last followup. Two patients have simple partial motor seizures of the face and one patient has generalized seizures. The mean number of antiepileptic drugs (AEDs) being taken by each patient at the time of surgery was 2.6 (range from 1 to 5). Following surgery, the mean number of drugs being taken at the time of last followup was 0.9. Five of the ten patients are completely off AED therapy. Of the patients still on therapy, three are on single-drug regimens, one is on two medications, and the patient who continues to have generalized seizures is on four drug therapy in addition to the ketogenic diet and vagus nerve stimulation. Cognitive status of the patients prior to surgery ranged from mild IQ impairment to severe mental retardation. Prior to surgery, seven of the patients had some degree of hemiplegia and three had no hemiplegia. Following hemispherectomy, all patients experienced some degree of hemiplegia though seven are able to continue to ambulate. Surgical pathology indicates three patients had Rasmussen[apos]s Syndrome, five had hemimegalencephaly/cortical dysplasia, and two had atrophy/gliosis. Data from this group of patients indicate that hemispherectomy can be an effective therapy for some patients with intractable epilepsy. All of our patients experienced some reduction in seizure burden and 70% are seizure free. All of our patients exhibit some degree of hemiplegia but functional outcome in many cases improved compared to the their presurgical baseline function.