Abstracts

Rationale: Medically refractory epilepsy is common in patients with ASD. The neuropathological basis of epilepsy in ASD is poorly understood and there are few published studies of epilepsy surgery in ASD of unknown cause. Purpose: to review the electro-clinical, imaging, neuropathology and outcomes following epilepsy surgery in children with ASD of unknown etiology and medically refractory epilepsy. Methods: Retrospective chart review of patients with ASD of unknown etiology who underwent epilepsy surgery between January 1997 and May 2011. They were identified from the epilepsy database. The exclusion criteria included patients with ASD due to known chromosomal abnormalities, tuberous sclerosis complex or diffuse hemispheric structural disease. Results: The study population comprised 13 patients (11 males). Seizures were refractory to a mean of 7 AEDs, VNS (2) and ketogenic diet (1). 12 had focal seizures and 2 had a history of infantile spasms. MR imaging showed a structural lesion in 9 (bilateral in 3) and subtle changes or normal in 4. Focal cortical resection involved temporal lobe in 8, frontal lobe in 4 and parieto-occipital lobes in 1. Neuropathogical findings comprised mesial temporal lobe sclerosis in 4, which was associated with cortical dysplasia (FCD) in 3; tumors in 4 and FCD non specified in 2. Non-specific changes were seen in 2 patients. At mean follow-up of 4 years (1-10 years), 9 patients had Engel Class I outcome, 2 Class II outcomes. One patient with IVa outcome died due to SUDEP. Conclusions: 70% patients with ASD of unknown etiology were seizure free following resective surgery. The neuropathogical basis was variable. ASD is not a contraindication for epilepsy surgery.