Abstracts

Rationale: For children with refractory epilepsy that does not respond to conventional medical therapy, vagal nerve stimulation(VNS) has been performed as a viable treatment choice since the early 1990s. We have reviewed pediatric epilepsy patients who have implanted VNS at Severance Children’s Hospital, Seoul, from year 2004 to 2013 to analyze prognostic factors of the procedure and seizure outcome.Methods: A retrospective review of past medical charts of total 77 pediatric neurology patients was done and 1 patient was excluded due to incomplete application. Demographic data and epilepsy related study results were collected and most recent seizure outcome was determined.Results: Out of total 77 pediatric epilepsy patients with VNS insertion, 57 patients has been followed up for more than 12 months post-operatively. After following up for average 50.56 months after the implantation, 25 patients (43.86%) showed more than 50% seizure reduction with 6 patients with rare seizures or none at all at final follow up visit, and 12 patients (21.05%) showed less than 50% seizure improvement, while 20 patients(35.09%) had seen no improvement or aggravation of seizures. But only 12 patients were able to reduce the number of antiepileptic medications after surgery. 12.28% (n=7) of the patients went unto have additional epilepsy surgery, such as corpus callosotomy, or respective surgery due to intractable seizures. Etiology may play a role as a prognostic factor as patients suspected of metabolic disease or mitochondrial disease have shown less favorable outcome.Conclusions: While VNS implantation does show moderate degree of seizure control, careful pre-surgical evaluation of the patients’ etiology may predict more accurate likelyhood of seizure control.