Therapeutic Effects of Vagus Nerve Stimulation in Intractable Childhood Epilepsy: Experience for 12 Months after VNS Implantation

Vagus nerve stimulation (VNS) is presently considered an effective mode of treatment in intractable epilepsy. Its efficacy in children, however, has not been as well studied. This study was performed to evaluate the efficacy of the procedure in the pediatric age group. 6 patients who received VNS implantation in Chonnam National University Hospital from July 2006 to February 2008 have been evaluated about the efficacy of seizure control and the presence of side effects after VNS implantation for more than a year at least. Mean age of the patients at the time of VNS implantation were 10 years 3 months. Mean duration of follow-up was 14 months. Six patients included three cases with Lennox-Gastaut syndromes, one generalized tonic seizure, one generalized tonic clonic seizure, and one complex partial seizure. Three patients showed more than 50 % reduction in seizure frequency compared with baseline at 3 months after the implantation. Among them, one showed complete seizure ablation, another showed no change in seizure frequency and the other showed increased frequency of seizure at 9 months after the implantation. The other three patients showed no change in seizure frequency. One of them, however, showed reduction of seizure intensity. Cough (2 cases), hoarseness (2), and wobbling voice (1) developed after VNS implantation. Most of these adverse effects disappeared without any treatment. In this study, one patient showed complete seizure ablation, but VNS was insignificant in five patients. Long-term follow up an