NCT06518356

Mastoid taVNS-fMRI

Investigating the Direct Brain Effects of Activating the Auricular Branch of the Vagus Nerve From the Cymba Concha or Mastoid Process: a Sham-controlled fMRI Study

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 24 (actual)
• Sponsor: Medical University of South Carolina · Academic / Other
• Sex: All
• Age: 18 Years – 65 Years
• Healthy volunteers: Accepted

Summary

The purpose of this study is to explore whether stimulating different outer parts of the ear using a non-invasive form of ear stimulation called transcutaneous auricular vagus nerve stimulation (taVNS) will create different brain activation images. Investigators will recruit 24 healthy participants. The ear stimulation will be delivered while taking brain images using a magnetic resonance imaging (MRI) machine.

Detailed description

Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive neuromodulation technique that delivers electric stimulation to the auricular branch of the vagus nerve (ABVN). This technique has been demonstrated effective in the treatment of depression and addiction in previous studies. Most previous applications of taVNS targeted the ABVN via the cymba conchae or tragus sites. The mastoid process (mastoid site) is an important dermatome innervated by the ABVN, but there is currently a lack of knowledge on how taVNS on the mastoid site affects brain activity and whether it differs from the effect of stimulating the cymba site. In this proposed study, the investigators plan to explore whether delivering taVNS to the mastoid site and the cymba site can induce different patterns of brain activity. Ultimately, if successful, this project will not only deepen our knowledge in basic neuroscience but also have great value in clinical applications since the mastoid site is a much more accessible ABVN target compared to other sites.

Conditions

• Auricular Stimulation

Interventions

Type	Name	Description
DEVICE	Transcutaneous Auricular Neurostimulation (tAN)	The intervention the investigators are studying is called transcutaneous auricular neurostimulation (tAN). tAN is simply electrical nerve stimulation administered at the ear which targets the auricular branch of the vagus nerve (ABVN) at the cymba conchae and mastoid process, and to a sham site (earlobe).

Timeline

• Start date: 2024-08-26
• Primary completion: 2025-04-28
• Completion: 2025-04-28
• First posted: 2024-07-24
• Last updated: 2025-07-04

Locations

1 site across 1 country: United States