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Completed

NCT Number: NCT05801809

Understanding the Effects of Transauricular Vagus Nerve Stimulation on Neural Networks and Autonomic Nervous System

This trial aims to perform an exploratory, mechanistic, randomized double-blind sham-control trial in healthy participants to assess the physiologic effects of a single 60 minutes session of bilateral taVNS, on neural networks and autonomic function.

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Key information

Conditions

Healthy Volunteers

Age range

18 year–99 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Spaulding Hospital Cambridge

Cambridge, Massachusetts, 02138, United States

About this study

Several studies have shown promising results of taVNS to treat various disorders such as depression, anxiety, Alzheimer's disease, headache, obesity, and diabetes. However, no mechanistic studies have investigated the taVNS neural network and autonomic nervous system effects of this technique. Therefore, we aim to assess how taVNS can affect EEG metrics and HRV and assess its safety. Also, we aim to evaluate predictors that can influence the response to taVNS, so understanding the variables associated with response to taVNS can help the design of future clinical trials to maximize the effects of this intervention.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Able to provide informed consent to participate in the study.
  • Subject is older than 18 years.
  • Subjects should be naive to the stimulation (taVNS)

Exclusion criteria

  • Pregnancy.
  • Subjects who have had a neuropsychiatric or a cardiac disorder diagnosis and have received treatment and chronic medication in the past six months, or who have functional deficits as a result.
  • History of alcohol or drug abuse within the past 6 months as self-reported.
  • Presence of the following contraindication to transauricular vagus nerve stimulation
  • Ferromagnetic metal in the head and in the cranium (e.g., plates or pins, bullets, shrapnel)
  • Implanted cranial electronic medical devices (e.g., cochlear implants)
  • Implanted cardiac devices (e.g., pacemaker)
  • Unstable medical conditions (e.g. uncontrolled diabetes, uncompensated cardiac issues, heart failure, or chronic obstructive pulmonary disease).
  • Uncontrolled epilepsy, as defined by previous clinical seizures in the past 3 months in patients with treatment for epilepsy.
  • Suffering from severe depression (as defined by a score of >30 in the Beck Depression Inventory).

Treatment and study plan

Transauricular vagus nerve stimulation (taVNS)

Device

Transauricular vagus nerve stimulation (taVNS) is a simple technique in which small surface electrodes are placed over the skin of the ear that are thought to be innervated by the auricular branch of the vagus nerve (ABVN).

Primary outcomes

  1. Resting-state Electroencephalogram (EEG)

    Time frame: Change from baseline to 60 minutes post-intervention.

    Resting-state EEG was recorded using a 64-channel high-density EGI system (Electrical Geodesics, Inc., Eugene, USA) under the eyes closed condition. Data was filtered into standard frequency bands using short-time Fourier transformation (STFT): delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-13 Hz), beta (13-30 Hz), and gamma (30-80 Hz).

    Frontal asymmetry was computed as the difference in power between homologous left and right frontal electrodes (e.g., F3-F4) in the alpha band.

  2. Conditioned Pain Modulation (CPM) Response - Change in Pain Ratings on the Pain-6 Scale (0-10)

    Time frame: Change from baseline to 60 minutes post-taVNS.

    Pain intensity was measured using the Numeric Pain Scale (NPS; 0 = no pain, 10 = worst pain). Higher scores indicate worse pain. A "pain-6 temperature" was first identified (temperature that elicits NPS = 6).

    Test stimulus: Pain-6 temperature applied for 30s; participants rated pain at 10, 20, and 30s. The test-stimulus score is the average of the three NPS ratings.

    Conditioned stimulus: After 5 minutes, the left hand was immersed in 10-12°C water for 30s while the same pain-6 temperature was applied again. Pain was rated the same way, and the conditioned-stimulus score is the average of the three NPS ratings.

    CPM calculation = (test-stimulus average) - (conditioned-stimulus average). Positive values = better endogenous pain inhibition; negative values = worse.

Secondary outcomes

  1. Heart Rate Variability (HRV)

    Time frame: Post-intervention (after 60 minutes of taVNS)

    HRV from ECG on non-dominant hand. High-frequency HRV calculated from 5-min resting recordings; higher values indicate greater parasympathetic activity. Post-stimulation values (60 min) were analyzed.

Sponsors and collaborators

Lead sponsor

Spaulding Rehabilitation Hospital

Other

Registry information

Official study title

Understanding the Effects of Non-invasive Transauricular Vagus Nerve Stimulation (taVNS) on Neural Networks and Autonomic Nervous System: a Randomized Double-blind Sham-control Mechanistic Trial in Healthy Participants

Important dates

Study start
2023
Primary completion
2023
Study completion
2026
First posted
Apr 6, 2023
Registry last updated
Apr 24, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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