Left vagus nerve stimulation in children with refractory epilepsy: an update.

This report updates previous reports regarding the tolerance and efficacy of periodic vagus nerve stimulation in a group of 19 children with medically and surgically intractable epilepsy. After vagal stimulator implantation, follow-up continued from 2 months to 30 months, with the study period ending in October 1995. Of the 19 patients, 6 (32%) had more than a 90% reduction in the number of monthly seizures, and 10 (53%) had more than a 50% reduction. Global evaluation scores indicated that only 1 patient had deterioration from baseline, 5 had no change, and the remainder had modest to remarkable improvement. All 3 children with unsuccessful corpuscallosotomy had improvement after implantation of the stimulator, and 5 of 6 children with Lennox-Gastaut syndrome had a 90% reduction of seizures. Five patients required fewer antiepileptic medications, and 1 patient had an increase in medication. Adversities included 2 possible wound infections, 1 instance of generator failure, and hoarseness during stimulation in all patients. Changing stimulation parameters to increase the rate of stimulation and reduce the interval between stimulations resulted in improved seizure control in 4 of 5 patients. Periodic VNS was well tolerated by these children and may have a role in the management of refractory epilepsy.