The efficacy of vagus nerve stimulation (VNS) was evaluated in 24 patients, aged 4 to 40 years (median 18 years), at the New York Presbyterian Hospital-Cornell Medical Center, NY; Mercy Children’s Hospital, Kansas City; and University of California at San Diego. Seizure rates during a 1-month baseline were compared to those with 3 months of VNS. Improvements occurred in 22 (88%); 16 had >30% reduction, and 11 had >50% reduction in seizure rate. The median seizure rate reduction was 46%. Idiopathic epilepsy patients improved more than those with symptomatic epilepsy (-60% cf -40%). Generalized tonic seizures responded better than generalized tonic-clonic seizures (-70% cf -33%). Patients with higher baseline seizure rates responded better. Age at onset of epilepsy (median 2, range 0-14 years) was also a predictor of response; seizures developing in later childhood were more responsive.

Adverse events included cough (6 patients), abdominal pain (2), and anorexia, hiccups, dysphagia, emesis, and fatigue (1 each). All were considered mild except one moderate cough and one with anorexia. The median heart rate was slowed compared to baseline. [1]

COMMENT. Vagus nerve stimulation may be indicated in older children and adolescents with drug-refractory epilepsies, especially generalized tonic seizures. This pacemaker device, connected by two stimulating electrodes to the left vagus nerve, appears to be safe and generally well tolerated. Transient hoarseness is the most common adverse effect, but cough and anorexia may also occur. Further studies are needed to define the types of seizures responsive to VNS in children.