Abstracts

Rationale: To review the role of corpus callsostomy in the management of refractory epilepsy since the introduction of vagal nerve stimulation at a surgical epilepsy center, we retrospectively reviewed the charts of patients who underwent corpus callosotomy at our institution since the introduction of vagal nerve stimulation. Methods: We retrospectively reviewed the records of 54 consecutive children who underwent corpus callosotomy at our institution from 1995 through 2004. Candidate patients had medically refractory seizures, multifocal seizure onset and rapid secondary generalization. Most had drop attacks with seizure generalization. Twenty one patients underwent complete callosotomy, and 31 had partial anterior callosotmies. Six patients underwent a completion of a prior partial callosotomy. Thirty one patients underwent VNS implantation prior to callosotomy and 5 patients had a VNS placed after callosotomy. An IRB approved quality of life telephone interview was obtained from 37 of the patients' families. Results: Overall, 80% of patients achieved a 50% reduction in targeted seizure frequency, and 50% of patients experienced an 80% reduction of targeted seizure frequency. A transient disconnection syndrome occurred in 52% of patients undergoing callosotomy. Neuropsychiatric testing at three to six months following surgery demonstrated resolution of the disconnection syndrome. Patients who underwent VNS before or after callosotomy had a less impressive reduction in seizures than patients who underwent a callosotomy alone. In three cases, seizures lateralized to one hemisphere after callosotomy and the patients underwent focal resections with or without multiple subpial transections with good seizure control. Five patients became seizure free (on antiepileptic medications) following callosotomy. The seizure free patients experienced seizure onset younger (2 years vs 3 years of age) and came to surgery sooner (4.6 years after first seizure vs 7.8 years after first seizure) than patients with continuing seizure activity after callosotomy. Conclusions: Corpus callosotmy remains an effective treatment for some medically refractory epilepsies. Ie is particularly effective in controlling drop seizures. Corpus callosotomy rarely renders patients seizure free with continued antiepileptic medication. Corpus callosotmy may cause seizures to lateralize, sometimes allowing focal resective treatment of the patient's seizure focus. Corpus callosotomy continues to be effective in the VNS era.