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

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

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.

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.

Inclusion Criteria:

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

Exclusion Criteria:

1. Pregnancy.

2. 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.

3. History of alcohol or drug abuse within the past 6 months as self-reported.

4. Presence of the following contraindication to transauricular vagus nerve stimulation

   1. Ferromagnetic metal in the head and in the cranium (e.g., plates or pins, bullets, shrapnel)
   2. Implanted cranial electronic medical devices (e.g., cochlear implants)
   3. Implanted cardiac devices (e.g., pacemaker)

5. Unstable medical conditions (e.g. uncontrolled diabetes, uncompensated cardiac issues, heart failure, or chronic obstructive pulmonary disease).

6. Uncontrolled epilepsy, as defined by previous clinical seizures in the past 3 months in patients with treatment for epilepsy.

7. Suffering from severe depression (as defined by a score of >30 in the Beck Depression Inventory).