ABSTRACT
The Vagus Nerve Stimulation Therapy System ....................................................... 37 Implantation Procedure ................................................................................ 38
Potential Complications ..................................................................... 39 Stimulation Parameters .................................................................................40 Mechanisms of Action .................................................................................. 41 Seizure Efcacy: Clinical Trials................................................................... 42 Special Patient Populations........................................................................... 42
Safety .......................................................................................................................44 Adverse Events..............................................................................................44 Device Safety ................................................................................................44
Candidate Selection ................................................................................................. 45 Cost Effectiveness ....................................................................................................46 Conclusion ................................................................................................................46 References ................................................................................................................46
Vagus nerve stimulation (VNS), which attenuates seizure frequency, severity, and duration by chronic intermittent stimulation of the vagus nerve, is intended for use as an adjunctive treatment with antiepileptic drug (AED) therapies. As of January 2008, more than 45,000 patients with epilepsy have been implanted with the VNS therapy system worldwide, with approximately 30% of those patients being younger than age 18 at the time of their rst implant. Approximately one-third of patients receiving VNS therapy experience at least a 50% reduction in seizure frequency with no adverse cognitive or systemic effects.6 Moreover, clinical ndings indicate that the effectiveness of VNS therapy continues to improve over time, independent of changes in AEDs or stimulation parameters.18 Tolerance does not appear to be a factor with VNS therapy, even after extended periods of time.26 Response to VNS therapy may be delayed for some patients. The long-term safety and effectiveness seen with this treatment have made VNS therapy a mainstream treatment option for a broad range of epilepsy patients, including children and adolescents.
