Abstracts

Rationale: The purpose of this study is to describe the effect of Vagus Nerve Stimulator (VNS) on the Status Epilepticus (SE) in pediatric patients with medically intractable epilepsy.Methods: Retrospective chart review was conducted on patients who underwent VNS implantation from November 2011 to April 2014 at Children’s Hospital of Pittsburgh (CHP) of UPMC. Only the patients who had the history of SE prior to VNS implant were included for this study. The primary outcome was the presence/absence of SE during 1 year post VNS implant.Results: Out of 81 consecutive patients who had VNS implantation during study period, 16 patients (12 male) had status epilepticus prior to its implantation. Three patients were excluded as two of them followed by other institution after implant, and in one patient the VNS was turned off within 1 month because of discomfort. Out of 13 patients with sufficient follow up data, two patients had VNS explanted secondary to infection. The final cohort consisted of 11 patients. All these patients had epilepsy surgery work up and deemed not to be epilepsy surgical patients. All patients tried at least three antiepileptic medications prior to VNS. The median age of seizure onset was 1.5 years (neonatal to 8 years). The median age of VNS implantation was 8.2 years (3.1 yrs-15.4 years). 8/11 (73%) had known etiology for epilepsy and congenital brain malformation was the most common known etiology (4/8, 50%). 9/11 (82%) patients had autistic spectrum disorder and/or mental retardation. 10/11 (91%) of patients had at least once a month generalized convulsive seizures and 9/11 (82%) had multiple SE prior to VNS. 6/11 (54%) of patients had SE within 1 year prior to VNS (three with multiple SE) and only 2 /11 (8%) had SE at 1 year follow up. When we focused on those six patients who had SE within 1 year prior to VNS implant, only one patient had SE at 1 year follow up.Conclusions: Vagus Nerve Stimulator appears to have specific efficacy in reducing SE in pediatric patients with medically intractable epilepsy.