[Surgical treatment for pediatric intractable epilepsy--focusing on modified functional hemispherectomy in infants]

Our experience with modified functional hemispherectomy in 14 infants are presented. The etiology of intractable epilepsy was cortical dysgenesis in all of the cases. We applied our new surgical method, transopercular hemispherotomy, in which the frontal operculum was resected en bloc including the upper half of the insula. The corpus callosum was totally sectioned through the lateral ventricle. The resection cavity was communicated to the inferior ventricle, and the medial temporal structures were resected. Finally, the horizontal fibers emerging from the frontal lobe were sectioned along the posterior edge of the ala minor ossis sphenoidalis. There was no mortality or morbidity during and immediately after operation. In 12 cases with more than 1 year follow-up, remarkable seizure reduction was obtained in 75% of the cases and worthwhile improvement in the remaining 25%. No major complications were encountered, except for hydrocephalus in 3 cases and incomplete section of the callosum in 3. In cases showing catch-up of psychomotor development after surgery, swelling of the unaffected hemisphere was observed.