The Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology reports on vagus nerve stimulation (VNS) for epilepsy. A total of 104 articles and responses in 130 patients were reviewed. Data on VNS in children was sparse; 5 of 12 children with intractable partial, generalized, and mixed seizures, followed for 2 to 14 months in an open-label study, had a 90% reduction in seizure frequency. In a randomized prospective trial in 114 adult patients, high levels of stimulation showed a significant response compared to low stimulation. The degree of improvement was modest, with a mean partial seizure reduction of 31%, and 39% of patients having a >50% reduction in seizure frequency. Young patients with auras and idiopathic epilepsy had more than a 50% responder rate, while secondarily generalized seizures were not controlled. The mechanism of VNS was undetermined. Left-sided implantations were safer, since right VNS caused bradycardia. Electrodes around the vagus were connected to an infraclavicular generator pack. Serious complications were rare, but hoarseness, throat pain, and cough were common complaints during stimulation. The device is costly, and improvement in quality of life for the patient needs to be determined. 
COMMENT. The panel considers vagal nerve stimulation a promising treatment for intractable partial seizures, but further controlled studies are recommended. Some predictors of a favorable response include age less than 34 years, idiopathic epilepsies, and early signs of effectiveness.