Vagus nerve stimulation is effective in treatment of seizures in some cases. The stimulator is a battery powered device similar to a pacemaker and is implanted under the skin in the upper left chest wall. From the stimulator a lead is tunneled under the skin and attached to the left vagus nerve in the lower part of the neck. The batteries last from three to five years and need replacement after that.
Studies suggest that stimulation of the vagus nerve may reduce seizures by up to 50% in about 50% of the patients who undergo this procedure. The American Academy of Neurology now recommends this procedure for patients over 12 years old who have partial seizures that do not respond to medication and who are not appropriate surgical candidates. Its effectiveness in generalized seizures is unknown. It should be noted that vagal stimulation does not eliminate seizures in most patients.
Some minor side effects due to vagal nerve stimulation include shortness of breath, hoarseness, sore throat, coughing, ear and throat pain, or nausea and vomiting. Reducing the intensity of stimulation effectively treats these minor adverse effects. No serious adverse side effects have been reported.