Abstracts

Vagus nerve stimulation (VNS) is approved for use in patients with refractory epilepsy over the age of 12 years. While this procedure is widely used, there is little data on adverse side effects in young children. The objective of this study was to evaluate the efficacy and tolerability of this procedure in children, with special emphasis on any associated complications. A retrospective chart review was conducted on 26 children from our institution who had VNS-implantation for refractory epilepsy over the period 1998- 2004. Ages ranged from 3 to 17 years with 16 males and 10 females. Seventy-seven percent had moderate/severe mental retardation. Sixty-five percent had more than 30 seizures per month. Symptomatic-generalized epilepsy was the predominant epilepsy syndrome seen in 77% of children. The duration of VNS treatment ranged from 1 month - 6.5 years (mean = 1.9 years). Twenty of 26 patients were on rapid cycling. More than 50% reduction in seizure frequency was noted in 54% with 2 patients achieving seizure-freedom. Twenty-three percent had less than 50% seizure-reduction. Fifteen percent patients had definite abortion of seizures with the use of the magnet. VNS was explanted in one patient due to intractable cough persisting in spite of stimulation being turned off for one month. Another patient underwent explantation twice for infection. Obstructive sleep apnea (OSA) was seen in 35% (n=9); 6/9 underwent tonsillectomy/adenoidectomy. VNS appears to be an effective treatment option in children with refractory epilepsy. Development of intractable cough in one patient in spite of device being turned off, and recurrent infection-related explantation in another are unusual complications. OSA is a frequent concomitant condition and polysomnography before implantation of VNS should be considered to identify patients with pre-existing OSA.