Vagus nerve stimulation for drop attacks in a pediatric population

A retrospective analysis of 43 patients with drop attack seizures who were treated with vagus nerve stimulation (VNS) was undertaken to determine the efficacy of VNS and to determine pre-implantation characteristics associated with VNS success. It was found that on last follow-up, 46% of patients had at least a 75% reduction in drops per day. Forty-six percent of patients had less than a 50% reduction in drops per day and were considered nonresponders. Univariate analysis failed to uncover significant associations between pre-implantation characteristics and VNS success. It was found that atonic head nods were more amenable to VNS treatment as compared with atonic or tonic drop attacks. In addition, patients with focal or lateralized epileptiform abnormalities responded better to VNS compared with those with more diffuse or poorly localized findings on ictal and/or interictal recordings. Our data suggest that VNS offers significant palliative benefit to many children with medically intractable drop attack seizures.