[Clinical Application of Transcutaneous Auricular Vagus Nerve Stimulation]

Transcutaneous auricular vagus nerve stimulation (taVNS) refers to stimulation of the vagus nerve through the skin of the left cymba conchae and is a unique strategy that is investigated as a useful therapeutic approach for a variety of conditions including epilepsy, depression, cardiac diseases, tinnitus, and migraine. A randomized double-blind clinical trial was performed in patients with drug-resistant epilepsy. Although several pilot studies were performed before this trial and showed that taVNS was safe, well tolerated, and feasible for long-term treatment, no statistically significant difference was observed between the high- and low-stimulation groups, and further studies are warranted to gain a deeper understanding of this subject. A tingling sensation or pain at the site of stimulation is the most common adverse effect associated with taVNS. Therefore, intermittent stimulation, ranging from 30 minutes to several hours, is provided during each session several times a day. Currently, taVNS is not approved for insurance coverage by the Japan Ministry of Health, Labour, and Welfare. Further studies and investigations are necessary in the near future.