NCT06726018

Exploring Pain Modulation Mechanisms: A Study of TMS and Repeated Conditioned Pain Modulation

Not yet recruiting NA Last updated 3 December 2025

What this trial tests

NA trial testing Conditioned Pain Modulation (CPM) in Healthy Adult in 75 participants. Not yet recruiting.

Timeline

1 January 2026

Primary endpoint
1 December 2026

1 July 2027

Quick facts

Lead sponsor	Priyanka Rana, PT, MPT, PhD
Phase	NA
Status	Not yet recruiting
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	double
Primary purpose	treatment
Enrollment	75
Start date	1 January 2026
Primary completion	1 December 2026
Estimated completion	1 July 2027
Sites	1 location across United States

Drugs / interventions tested

• Conditioned Pain Modulation (CPM)

Conditions studied

• Healthy Adult — all drugs for Healthy Adult →

Sponsor

Priyanka Rana, PT, MPT, PhD

Who can join

Adults 18 to 75, any sex, with Healthy Adult. Healthy volunteers can join.

What's being measured

Primary outcomes are the specific endpoints the trial is designed to prove or disprove.

• Conditioned Pain Modulation as an assessment
  Time frame: Two-weeks
  Participants will receive a testing stimulus of pressure applied per ascending intensity at the web space of the foot until the pain reaches 40 out of 100, then discontinued. After testing the stimulus, Participants will receive a conditioning stimulus contact heat stimulus applied to the thenar of the left hand for 60 s at an intensity of 46.5 ◦C. Subjects will be asked to rate the heat pain duri
• Transcranial Magnetic Stimulation
  Time frame: Two-weeks
  Individuals meeting the TMS safety criteria will undergo baseline TMS to determine the resting motor threshold, short-interval intracortical inhibition (SICI) protocols. Both are established, reliable, valid protocols to measure motor cortical excitability and inhibition, respectively. TMS will be delivered using a D702 coil connected to Magstim 2002 magnetic stimulators via a Bistim unit (Magstim
• Quantitative Sensory Testing
  Time frame: Two-weeks
  Slow Ramp Protocol: A computer-controlled TSAII NeuroSensory Analyzer (Medoc, Inc.) will deliver a thermal stimulus to the dominant forearm, starting at 35°C and increasing to 51°C in 1°C increments, each lasting 1 seconds. Participants will report when the sensation changes from warmth to pain (pain threshold) and when it becomes intolerable (pain tolerance). The procedure will be repeated twice

Sponsor's own description

Conditioned pain modulation (CPM) is the behavioral measure of diffuse noxious inhibitory control (DNIC), an endogenous pain inhibitory pathway in which pain inhibits pain. CPM is less efficient in individuals with chronic pain conditions, and it is a predictor for the development of chronic pain. Continuous stimulation of central/cortical mechanisms through engaging CPM might alter pain processing and improve pain inhibition. Transcranial Magnetic Stimulation (TMS) is a valuable tool for assessing how effectively the brain's central and cortical mechanisms engage in pain inhibition, particularly through pathways like CPM.

While alterations in cortical excitability related to analgesic-induced pain inhibition have been documented, the effects of continuous stimulation of central pain pathways, along with the mediating influence of psychosocial factors, remain underexplored. This study aims to investigate the central pain modulatory mechanisms, as assessed by CPM, and cortical excitability, as measured by TMS, in healthy participants. Additionally, the study will evaluate the impact of sociocultural factors, including ethnic identity, optimism, resilience, perceived stress, and marginalization, on the magnitude and efficiency of CPM responses.

The successful completion of this research will determine how cortical excitability changes due to training and whether these changes are mediated by psychosocial factors.

Publications & conference data

No peer-reviewed publications indexed yet for this trial.