Vagus nerve stimulation (VNS) is a Food and Drug Administration approved somatic treatment for drug-resistant epilepsy and depression. In vivo VNS systems, however, are an option limited to patients who have failed to respond to multiple treatment options. Transcutaneous VNS (tVNS) is a non-invasive method based on afferent/efferent vagus nerve distribution on the surface of the ear. The safe and low-cost characteristics of tVNS have the potential to significantly expand the clinical application of VNS.
In a study to investigate how tVNS can modulate the default mode network (DMN) functional connectivity (FC) in mild or moderate major depressive disorder (MDD) patients, tVNS was shown to significantly modulate the DMN FC of MDD patients.