Acute Effects of Transcutaneous Electrical Nerve Stimulation at Acupoints on Nociceptive Transmission: A Mechanism Study Using Pain-Related Evoked Potentials

China Medical University

Status: Enrolling

Conditions: Pain Management

Treatments: Device: transcutaneous electrical nerve stimulation (TENS); Device: EEG machine

Study type: Interventional

Funder types: Other

Identifiers

NCT07267052

CMUH114-REC3-149

Details and patient eligibility

About

The goal of this clinical trial is to learn if transcutaneous electrical nerve stimulation (TENS) applied to acupoints can modulate pain transmission and cortical processing in healthy adult volunteers. The main questions it aims to answer are:

• Does TENS at Zhongzhu (SJ3) and Hegu (LI4) change pain-related evoked potentials (PREPs)?
• Does acupoint electrical stimulation alter nociceptive pathways reflected by PREP waveform modulation?

Researchers will compare PREPs recorded before and after TENS at the two acupoints to see if TENS produces measurable effects on cortical nociceptive responses.

Participants will receive low-frequency TENS applied to Zhongzhu (SJ3) and Hegu (LI4), and undergo PREP assessments before and after the intervention to measure cortical responses to standardized noxious stimuli.

Full description

This study aims to investigate the modulatory effects of transcutaneous electrical nerve stimulation (TENS) applied to acupuncture points on pain transmission and cortical processing in healthy adults. Pain-related evoked potentials (PREPs) will be used as the primary neurophysiological measure to examine changes before and after TENS applied to two clinically recognized analgesic acupoints, Zhongzhu (SJ3) and Hegu (LI4). A within-subject design will be adopted, and participants aged 18 years or older will undergo two experimental sessions in randomized order. Each session will include baseline PREP assessment, a 20-minute low-frequency TENS intervention at the assigned acupoint, and a follow-up PREP measurement. PREP waveform characteristics, including N2 and P2 amplitudes and latencies, will be analyzed to determine whether acupoint stimulation alters nociceptive transmission. Subjective pain reports and adverse responses will also be collected to assess tolerability. The findings of this research are expected to provide insight into the neurophysiological basis of acupuncture analgesia and contribute to the development of more refined acupoint-based electrical therapies.

Enrollment: 35 estimated patients

Sex: All

Ages: 20+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Participants will be healthy adults aged 20 years or older. All participants must meet the inclusion criteria, including the absence of chronic medical conditions, no history of drug allergies or skin disorders, and no current use of medications that could affect study outcomes. To ensure the reliability of the results, participants are required to maintain a regular daily routine and have no history of substance or medication abuse.

Exclusion criteria

• Participants with a history of malignant tumors, hand disorders, implanted cardiac pacemakers, pregnancy, epilepsy, or any other condition that may interfere with the study procedures will be excluded from the study.

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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35 participants in 1 patient group

TENS Group

Experimental group

Description:

Acupoint TENS Intervention (TENS Group) Participants in this group received low-frequency transcutaneous electrical nerve stimulation (TENS) applied to clinically recognized analgesic acupoints, Zhongzhu (SJ3) and Hegu (LI4). Each participant completed two intervention sessions in a randomized order, with at least 48 hours between sessions. During each session, participants first underwent a baseline assessment of pain-related evoked potentials (PREPs), followed by a 20-minute TENS application delivered through surface electrodes placed directly over the target acupoint. The stimulation parameters included low frequency and low-intensity currents adjusted to a comfortable but perceptible level. Immediately after the stimulation period, participants received a follow-up PREP assessment to evaluate changes in nociceptive cortical processing. Subjective pain responses and any discomfort or adverse reactions were recorded throughout the procedure. The entire protocol was designed to deter

Treatment:

Device: EEG machine

Device: transcutaneous electrical nerve stimulation (TENS)