Testing how eTNS affects the brain: is it skin nerves or direct skull stimulation driving the effect?

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This exploratory study uses a randomized, sham-controlled crossover design in healthy adults to differentiate transcutaneous versus transcranial mechanisms of direct current trigeminal nerve stimulation (DC-eTNS). Each participant undergoes two MRI sessions: one with skin numbness via lidocaine and one without, while receiving active DC-eTNS and a sham stimulation. Functional MRI and physiological monitoring are collected to compare brain responses across conditions. The goal is to clarify which pathway predominantly mediates the observed brain activity changes during eTNS. The study is conducted at Xidian University in Xi'an and involves healthy, right-handed adults aged 18 to 40.

Why it matters

Who can join: the full rules

Inclusion Criteria:

1. Healthy volunteers, aged 18 to 40 years old.
2. Right-handed.
3. Generally healthy with no history of neurological, psychiatric, or severe cardiovascular diseases.
4. Normal physical and neurological examinations.
5. Capable of understanding the study procedures and voluntarily signing the written informed consent form.

Exclusion Criteria:

1. Known allergy, hypersensitivity, or adverse reactions to Lidocaine or other amide-type local anesthetics. (Crucial for this specific study design)
2. Contraindications to MRI scanning (e.g., claustrophobia, cardiac pacemakers, artificial cochlea, metallic braces, or any other ferromagnetic implants).
3. Female participants who are pregnant, lactating, or suspect they might be pregnant.
4. Contraindications to transcranial or transcutaneous electrical stimulation (e.g., personal or family history of epilepsy/seizures, implanted brain stimulators).
5. Any active skin disease, inflammation, lesions, cuts, or abrasions on the forehead (specifically over the supraorbital area), which could alter electrical impedance or anesthetic absorption.
6. History of trigeminal neuralgia, facial nerve palsy, or chronic facial pain. Current or recent (within the past month) use of any medications known to affect the central nervous system, autonomic nervous system, or pain perception (e.g., analgesics, antidepressants, beta-blockers, or sedatives).
7. History of substance abuse, heavy smoking, or excessive daily consumption of alcohol or caffeine.
8. Irregular sleep patterns, shift work, or severe sleep deprivation within 24 hours prior to the scanning sessions.

Where it's running

• Xidian University
  Xi'an, Shaanxi, China Recruiting

Study contacts

• Study coordinator: Xue-Juan Yang
• Email: xjyang@xidian.edu.cn
• Phone: 13227038185

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.