Abstracts

Rationale: Corpus callosotomy and vagal nerve stimulation (VNS) are palliative and adjunctive procedures performed for patients with refractory epilepsy. Although they both reduce seizures, there is little reported data on the comparison of corpus callosotomy and VNS in children. We have retrospectively reviewed children who have undergone corpus callosotomy and VNS surgery in our center and examined their features and surgical outcomes. Methods: We identified patients from our epilepsy surgery database who had corpus callosotomy or VNS for medically intractable epilepsy. The database and medical records were queried for seizure type, etiology, Engle outcome, morbidity and complications. Only patients with follow up of more than 6 months after both procedures were included. Results: Fifteen out of 308 patients (4.8%) had corpus callosotomy surgery performed. Seizure types included: complex partial seizures (cps) (1), generalized tonic clonic (GTC) (1), mixed (12), and Lennox-Gastaut syndrome (1). Etiologies included: chromosomal abnormality (1), encephalitis/infectious (1), cerebral malformation (5), tuberous sclerosis complex (1), perinatal injury (1), mesial temporal sclerosis (1), and unknown (5). Thirty nine out of 308 patients (12.6 %) had VNS placement with more than 6 months follow up. Seizure types included: cps (5), myoclonic (1), mixed (28), and Lennox-Gastaut syndrome (5). Etiologies included: chromosomal abnormality (3), mesial temporal sclerosis (1), encephalitis/infectious (3), nonaccidental trauma (3), cerebral malformation (4), tuberous sclerosis complex (1), Aicardi syndrome (1), Angelman syndrome (1), and unknown (22). Surgical outcome for corpus callosotomy include 20% (n = 3) with Engle outcome Class II, 53% (n = 8) with Class III and 26 % (n = 4) with Class IV outcome. One patient went on to have VNS placement. For VNS, 15 % (n = 6) had Class II Engle outcome, 23% (n = 9) had Class III outcome, and 58% (n = 23) had Class IV outcome. One patient failed to follow up in clinic and had no outcome data. Six out of 40 (15%) patients with VNS stimulator went on to have a corpus callosotomy. Two complications were seen with corpus callosotomy. One had a superficial wound, and another required drainage of a cephalhematoma, after picking on the suture site. Four complications were seen with VNS and include 1) infection that required a new pulse generator; 2) chronic infection requiring removal of the VNS; 3) hoarseness and imbalance; and 4) pain around the incision site. Conclusions: Children with intractable epilepsy can have a reduction in their seizures with both corpus callosotomy and VNS surgery. Corpus callosotomy surgery was more effective in reducing seizures compared to VNS. Children were more likely to have corpus callosotomy surgery after VNS than vice versa. Minimal complications were seen with both surgeries.