Vagus nerve stimulation involves electrical stimulation of the left vagus nerve, achieved via an electrode wrapped around the vagus nerve. Implantation of the vagus nerve stimulator is performed in the neck, where the vagus nerve is identified through an open surgical procedure; it is best localized dorsomedially between the common carotid artery and the internal jugular vein, although it is also subject to considerable variability in this location1. Vagus nerve stimulation is always performed on the left vagus nerve. Animal studies demonstrated a significantly greater reduction in heart rate with stimulation of the right vagus nerve2. The main complication of surgical placement is vocal fold paresis3. The primary indication for vagus nerve stimulation is drug-resistant epilepsy4. In a retrospective study over 12 years, a reduction in seizure frequency of 26% in the first year, 30% after 5 years, and 52% after 12 years was observed5. Vagus nerve stimulation is also used in some cases for various psychiatric disorders, such as treatment-resistant depression.
Adverse effects
Vagus nerve stimulation can cause, among others, the following chronic adverse effects:
References
Hammer, Niels, et al. "Cervical vagus nerve morphometry and vascularity in the context of nerve stimulation-A cadaveric study." Scientific reports 8.1 (2018): 1-9. ↩ ↩
Woodbury, D.M., Woodbury, J.W., 1990. Effects of vagal stimulation on experimentally induced seizures in rats. Epilepsia 31 (Suppl 2), S7–S19. ↩ ↩
Vagus nerve stimulation (VNS). In: Greenberg M, ed. Handbook of Neurosurgery. 9th Edition. Thieme; 2019. ↩ ↩ ↩ ↩
Uthman BM, Reichl AM, Dean JC, et al. Effectiveness of vagus nerve stimulation in epilepsy patients: a 12-year observation. Neurology. 2004;63:1124-1126 ↩ ↩
Rychlicki, F., Zamponi, N., Cesaroni, E. et al. Complications of vagal nerve stimulation for epilepsy in children. Neurosurg Rev 29, 103–107 (2006). ↩ ↩ ↩ ↩ ↩ ↩