Recent advances in devices for vagus nerve stimulation.

INTRODUCTION: Vagus nerve stimulation (VNS) has become a valuable treatment option for refractory epilepsy and depression. To improve clinical efficacy and minimize side effects, novel device technology for VNS is under development and investigation. AREAS COVERED: For epilepsy, the AspireSR®, and SenTiva™ VNS therapy systems are the two most recently developed VNS devices. These novel devices have implemented a closed-loop approach and contain a cardiac based seizure detection algorithm. The mechanism of action of VNS remains to be further elucidated, but as preclinical research reveals VNS induced effects on brain plasticity, the autonomic nervous system and the inflammatory response, the indications of VNS are expanding. VNS devices are currently being investigated for stroke rehabilitation, treatment of chronic heart failure and rheumatoid arthritis. Recently devices to noninvasively affect vagus nerve functioning have been developed, with the aim of achieving similar effects without the drawbacks of a surgical procedure and continuous stimulation. EXPERT COMMENTARY: Several animal and human trials have shown promising results with minimal adverse events. However, further research needs to be conducted to validate the use of these devices and decide on optimal stimulation parameters.