Theoretical Basis of Vagus Nerve Stimulation.

Despite a myriad of medical and surgical treatments for epilepsy developed over the past few decades, a large subset of patients remains refractory to treatment. Over this time period, vagus nerve stimulation (VNS) has become an accepted and viable treatment modality for this population. Since the earliest report of VNS implantation in 1988, tens of thousands of patients worldwide have received VNS therapy, and >100,000 patient-years of experience have been accrued. The mechanisms underlying the response to VNS therapy continue to be elucidated. As understanding of the VNS mechanisms of action continues to grow, more pathologies will arise as potential treatment indications. Furthermore, current treatment populations with refractory epilepsy, depression, and inflammatory diseases may enjoy improved response to stimulation.