Defining the spectrum of international practice in pediatric epilepsy surgery patients

Purpose: The Pediatric Epilepsy Surgery Sub-commission of the International League Against Epilepsy conducted a survey to determine the frequency of epilepsy procedures and etiologies. Methods: Data were gathered from 20 programs in the United States, Europe, and Australia on 543 patients (<18 years) for calendar year 2004. Results: Age at seizure onset was 1 year or less in 46% of patients. Intracranial electrodes were used in 27% of patients. The most common final operation was lobar and focal resections of the frontal and temporal lobes (41%), followed by cerebral hemispherectomy (16%), vagus nerve stimulator (16%), and multilobar resections (13%). Multiple-subpial transections were uncommon procedures (0.6%). The most frequent etiologies were cortical dysplasia (42%), tumors (19%), and atrophic lesions and strokes (10%). Less common were vascular lesions (1.5%), Rasmussen encephalitis (3%), Sturge-Weber (3%), and operations for infantile spasms (4%), and Landau-Kleffner/ESES (<2%). Children <4 years generally presented with daily seizures from cortical dysplasia and underwent multilobar or hemispherectomy. Previous surgeries before 2004 were reported in 22%, and occurred more commonly in patients with tumors (40%), hypothalamic hamartomas (47%), and vascular lesions (67%). U.S. centers reported more vagus nerve stimulator procedures, operated more often on children with no or subtle MRI findings, and used intracranial electrodes and functional neuroimaging more frequently than programs in Europe and Australia. Conclusions: The results of this international survey show the feasibility of international collaborations in determining epilepsy etiologies and procedures in children, and suggest differences in clinical practice between regions of the world. These results can guide the design of future studies in producing guidelines for therapy-resistant pediatric epilepsy surgery patients.