Vagus nerve stimulation in 16 children with refractory epilepsy

Purpose: Vagus nerve stimulation (VNS) has been reported to produce >90% reduction in the number of seizures in children with intractable epilepsy. These encouraging results need confirmation. Methods: Sixteen children, 10 boys and 6 girls aged 4-19 years, were treated with VNS (Cyberonics, Webster, TX, U.S.A.) for 12-24 months. Seizure frequency, seizure severity, changes in quality of life (QOL: visual analogue scale), and side effects were recorded. Eight children had partial and 8 had generalized seizures; 4 of the latter had Lennox-Gastaut syndrome (LGS). Results: During the tenth to twelfth month of VNS, 6 of 16 children experienced greater than or equal to 50% reduction in seizure frequency. One girl became seizure-free. Seizure severity showed an average decrease in the score from 15 to 11. After 10 months of treatment, QOL was estimated to have improved greater than or equal to 50% in 6 of 16 children. Reduction in seizure frequency, decreased seizure severity, and reported improvement in QOL did not entirely coincide. Six children experienced hoarseness, 1 had neck pain, 2 had hypersalivation, 2 experienced tiredness, 2 had aspiration episodes during liquid intake, and 6 had electrical transmission problems; in 4 the problem has been surgically corrected. Five stimulators were turned off due to lack of efficacy. Conclusions: Six of 16 children with refractory epilepsy treated with VNS improved, with a reduction not only in seizure frequency but also in seizure severity and in QOL.