Image-guided, frameless stereotactic sectioning of the corpus callosum in children with intractable epilepsy

Corpus callosotomy is an effective neurosurgical procedure for children wit h intractable atonic or drop attack seizures. While this procedure has not changed significantly over the past three decades, some technical issues re main to be resolved. These include the intraoperative determination of the extent of the callosotomy, the need to stage the procedure, as well as side of approach of craniotomy. We report our 8-year experience with corpus cal losotomy using a frameless stereotactic image-guided system (ISG Viewing Wa nd((R))). Seventeen children with atonic seizures underwent sectioning of t he corpus callosum. The mean patient age was 10.5 years. Six children under went complete callosotomy while 11 underwent resection of the anterior two- thirds. MRI 3D reconstruction of the sagittal sinus and draining cerebral v eins was undertaken in all cases. The side of the craniotomy was determined on the basis of favorability of the draining veins with respect to the ext ent of the callosotomy. The extent of the callosotomy was determined by int raoperative feedback using the ISG Viewing Wand((R)). Nine of 11 patients i n the partial callosotomy group and 4 of 6 patients in the complete calloso tomy group showed significant improvement in atonic seizures. We conclude t hat the use of frameless stereotaxy can function as an important adjunct in the planning and conduction of successful sectioning of the corpus callosu m in children with intractable seizures.