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Understanding Light's Effect on Pain

This study aims to understand how different types of light can affect pain. Researchers are looking at how specific colored lights, including S-cone modulating visual stimulus (a light that appears white but targets certain cells in your eye), Equal Energy White Visual Stimulus, and Green light visual stimulus, change brain activity in people with chronic musculoskeletal pain (cMSP) and healthy volunteers. You would undergo MRI scans while experiencing these lights and a mild pressure pain stimulus. The study will measure brain activity patterns to see how light influences pain signals. The goal is to uncover the biological reasons why light might help relieve pain. This study is currently recruiting 60 participants, including those with cMSP and healthy controls.

Study design
This interventional study plans to enroll 60 participants, including 30 with chronic musculoskeletal pain and 30 healthy controls. It is not specified if the study is randomized or blinded.
What's involved
You would undergo a comprehensive assessment, quantitative sensory testing, and MRI scanning sessions lasting about one hour each. During the MRI, you will experience different light stimuli and a pressure pain stimulus on your calf.
Compensation
Not stated in the trial record.
Follow-up
Pain assessments will be performed briefly after each scan block during the ~1 hour scanning session. The primary endpoints are measured during the scanning sessions.

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NCT07245303

Neural Mechanisms of Light Driven Analgesia

Recruiting
NAAges 18+Interventional
University of North Carolina, Chapel Hill
~60 participants
Updated 2026-05-13 on ClinicalTrials.gov
What's tested:S-cone modulating visual stimulusEqual Energy White Visual StimulusGreen light visual stimulus (S-OFF)Evoked Pressure Pain Stimulus

At a glance

Recruiting sites
1 of 1 listed site is recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Resting State Functional Connectivity-seed Voxel Analysis in Participants with cMSP and Healthy Controls
Measured over During 8 minute resting state scan as part of the ~1 hour scanning session
+2 more outcomes measured

Conditions

Musculoskeletal Pain
Fibromyalgia
Healthy Controls Group - Age and Sex-matched

Explore related trials

Congenital stationary night blindnessFibromyalgiaMusculoskeletal Pain

Where it's being run

1 sites across 1 states
North Carolina1

Study leadership

  • Matthew Mauck, MD, PhD · PRINCIPAL_INVESTIGATOR · University of North Carolina, Chapel Hill

Who to contact

Matthew Mauck, MD, PhD
[email protected]
919-966-5136
Email the study team

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Do you actually qualify for this trial?

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Eligibility criteria

Inclusion

Adults ≥18 years of age.
Individuals who do not have any plans for medication or treatment changes for the next 3 months.
Participants must be willing and able to undergo an MRI.
Participants must not be claustrophobic
Participants must be alert and oriented and able to provide informed consent.
Individuals must be able to speak and read English.
To be eligible, participants must have a score of ≥7 on the Widespread pain index (WPI) and ≥5 on the symptom severity scale (SSS), or 4-6 on the WPI and ≥9 on the SSS in the 2016 Fibromyalgia Questionnaire.
Pain symptoms must have been present for 3 months or longer.
Pain must be present in 4 out of 5 body regions.
Individuals enrolled will have an average pain severity ≥4 on the 0-10 NRS over the month prior to enrollment to recruit individuals with moderate to severe chronic MSP.
2 additional participants without chronic MSP will be recruited with diagnosed congenital stationary night blindness

Exclusion

Presence of retinal vision disorders or conditions resulting in vision impairment.
Patient-reported photosensitivity, photophobia, or aversion (as may occur in autoimmune diseases such as systematic lupus erythematosus).
Disorders including uveitis, cataracts, color-blindness, history of seizure disorder.
Plans for analgesic treatment plan changes in next 3 months (surgery, analgesic medication changes, injections, pain procedures, etc).
Prisoner Status.
Pregnancy.
Contraindications to MRI imaging. These include the presence of implanted/embedded ferromagnetic materials, implanted medical devices that are not MRI compatible, and claustrophobia.

What this trial measures

  • Resting State Functional Connectivity-seed Voxel Analysis in Participants with cMSP and Healthy ControlsDuring 8 minute resting state scan as part of the ~1 hour scanning session

    Functional connectivity assessed under three lighting conditions will be assessed with a seed voxel analysis with the seed region of interest set as the pregeniculate nucleus. A map of connectivity will be generated and displayed over inflated brain space. This map will be constructed by calculating the Fisher-transformed correlation coefficients between each voxel with the BOLD times series for the Pregeniculate nucleus. The higher the correlation coefficient, the stronger connectivity of each voxel to the pregeniculate. The correlation coefficient will be plotted as an map.

  • Whole Brain Evoked Activation Patterns in Response to Chromatic Stimuli Contrasted with Achromatic Stimuli in Participants with cMSP and Healthy ControlsDuring 6 minute functional imaging scan within the ~1 hour scanning protocol

    A generalized linear model (GLM) using Statistical Parametric Mapping (SPM) version 12 will be constructed. Blood oxygenation level dependent (BOLD) activation signal time series collected under the dynamic S-cone modulating stimulus condition will be contrasted to those collected during the equal energy stimulus condition. SPM will be used to create a contrast vector between the two conditions and a T-map will be created where the T-statistic for the contrast at each voxel will be plotted. The larger the t-statistic for each voxel the larger the contrast between the two light conditions.

  • Whole Brain Evoked Activation Patterns in Response to Chromatic Stimuli Contrasted with Achromatic Stimuli in Patients with cMSP and Healthy Controls Exposed to a Pressure Pain StimulusDuring 6 minute functional imaging scan within the 1 hour scanning protocol

    A generalized linear model (GLM) using Statistical Parametric Mapping (SPM) version 12 will be constructed. Blood oxygenation level dependent (BOLD) activation signal time series collected under the dynamic S-cone modulating stimulus condition will be contrasted to those collected during the equal energy stimulus condition in context of an evoked pressure pain stimulus. SPM will be used to create a contrast vector between the two conditions and a T-map will be created where the T-statistic for the contrast at each voxel will be plotted. The larger the t-statistic for each voxel the larger the contrast between the two light conditions.