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Not yet recruitingNCT07688525Updated Jul 7, 2026

Pain Beliefs and Intracortical Excitability During Experimental Pain

An interventional study of Topical Capsaicin Cream (1%) in Kinesiophobia (Fear of Movement) and Experimental Pain, sponsored by Université de Sherbrooke. Not yet recruiting at 1 site in Canada. Open to participants aged 18 Years to 35 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-07-07.

Sponsored by Université de Sherbrooke · Not applicable, Interventional, and Basic science

Phase
Not applicable
Study type
Interventional
Enrollment
30
Allocation
Not applicable
Ages
18 Years to 35 Years
Sex
All
01

Study summary

Pain can influence the way the motor system functions. However, responses to pain vary widely between individuals, and this variability may be partly related to pain-related beliefs such as kinesiophobia.

This study examines whether temporary experimental pain changes intracortical excitability in the motor cortex, and whether this response differs according to baseline kinesiophobia. Healthy adults will complete one experimental session. Motor cortex excitability will first be assessed at baseline using transcranial magnetic stimulation, a non-invasive brain stimulation technique. A topical capsaicin cream will then be applied to the forearm to induce temporary, moderate experimental pain. Once pain is established, the same neurophysiological assessments will be repeated.

The main objective is to measure changes in short-interval intracortical inhibition before and during capsaicin-induced pain, with particular attention to whether these changes are associated with baseline kinesiophobia.

Secondary objectives are to characterize other markers of motor cortex excitability, including long-interval intracortical inhibition, short-interval intracortical facilitation, intracortical facilitation, and corticospinal excitability assessed using input-output recruitment curves. Pain intensity will be monitored using a visual analog scale to characterize the experimental pain response. Baseline kinesiophobia will be assessed using the Tampa Scale of Kinesiophobia and examined as a factor associated with interindividual variability in neurophysiological responses to experimental pain.

The researchers expect that changes in motor cortex excitability during experimental pain will vary between individuals, and that individuals with higher kinesiophobia may show smaller changes in motor cortex excitability during capsaicin-induced pain.

Read the detailed description

Pain is not only a sensory experience. It is also influenced by psychological, emotional, and contextual factors, including how people interpret pain and the threat they associate with movement. In the presence of pain, individuals often modify the way they move. These adaptations may be protective in the short term, but when maintained over time, they may contribute to persistent movement avoidance and disability.

Within the fear-avoidance framework, kinesiophobia, or fear of movement, is considered an important factor in the relationship between pain, movement, and disability. Individuals with higher kinesiophobia may perceive movement as threatening or potentially harmful. This may influence not only motor behavior, but also the way the nervous system prepares and controls movement. However, the neurophysiological mechanisms linking pain-related beliefs, experimental pain, and motor control remain incompletely understood.

The primary motor cortex is a key brain region involved in voluntary movement. Its excitability can be assessed using transcranial magnetic stimulation, a non-invasive brain stimulation technique. When applied over the primary motor cortex, transcranial magnetic stimulation can evoke motor responses that are recorded from a target muscle using surface electromyography. These responses provide information about corticospinal excitability and about intracortical inhibitory and facilitatory mechanisms.

Previous studies suggest that experimental pain can modify motor cortex excitability, but the direction and magnitude of these changes vary considerably between individuals. Pain-related beliefs, especially kinesiophobia, may partly explain this variability. This study therefore focuses on whether experimental pain changes intracortical excitability in the motor cortex and whether this response differs according to baseline kinesiophobia.

The main objective is to quantify changes in short-interval intracortical inhibition before and during experimental pain induced by topical capsaicin, with particular attention to whether these changes vary according to the participant's baseline level of kinesiophobia. Short-interval intracortical inhibition is used as the primary neurophysiological measure because it reflects inhibitory activity within the motor cortex.

Secondary objectives are to characterize other markers of motor cortex excitability during experimental pain. These include long-interval intracortical inhibition, intracortical facilitation, and corticospinal excitability assessed using input-output recruitment curves. These complementary measures are included to provide a broader characterization of inhibitory, facilitatory, and corticospinal responses to experimental pain.

Healthy adults will complete one experimental session. At the beginning of the session, participants will complete questionnaires assessing pain-related beliefs, including kinesiophobia. Baseline neurophysiological assessments will then be performed using transcranial magnetic stimulation applied over the primary motor cortex, with electromyographic recordings from the first dorsal interosseous muscle of the hand.

After baseline measurements, topical capsaicin cream will be applied to the forearm to induce temporary, moderate experimental pain. Pain intensity will be monitored using a visual analog scale. Once experimental pain is established, the same transcranial magnetic stimulation assessments will be repeated.

Each participant serves as their own control, with neurophysiological measures compared between the baseline condition and the experimental pain condition. The investigators hypothesize that changes in motor cortex excitability during experimental pain will vary between individuals. This variability is expected to be partly related to kinesiophobia, with individuals reporting higher kinesiophobia showing smaller changes in motor cortex excitability during capsaicin-induced pain.

02

Conditions studied

  • Kinesiophobia (Fear of Movement)
  • Experimental Pain

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Keywords

  • Experimental pain
  • Topical capsaicin
  • Kinesiophobia
  • Fear of movement
  • Motor cortex excitability
  • Intracortical excitability
  • Corticospinal excitability
  • Transcranial magnetic stimulation
03

In context

Kinesiophobia

285 studies on the registry are indexed under Kinesiophobia; 91 are open to participants now.

This study's planned enrollment of 30 is below the median of 52 across 174 interventional studies indexed under Kinesiophobia.

Browse Kinesiophobia studies →

Lead sponsor

Université de Sherbrooke is the lead sponsor of 295 studies on the registry; 65 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 35 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Aged 18 to 35 years, inclusive
  • Healthy
  • Able to understand the study information and experimental procedures
  • Able to provide

Exclusion criteria

Exclusion Criteria:

  • History of psychiatric disorders (including intellectual disability or severe cognitive, behavioral, or affective impairment) that could interfere with understanding the study or providing .
  • History of neurological disorders, including epilepsy, stroke, brain or spinal cord surgery, or any neurological disease affecting motor or sensory function.

Inability to provide informed consent (e.g., dementia, significant hearing impairment, insufficient language proficiency).

  • Any pain condition within the past 3 months, regardless of origin.
  • Recent musculoskeletal injury or surgery within the past 3 months.
  • to transcranial magnetic stimulation (TMS), including a history of epilepsy or the presence of intracranial metallic objects, cochlear implants, or other non-removable metallic implants in or near the head.
  • Use of analgesic or psychotropic medications.
  • Individuals under legal guardianship or curatorship.
  • Pregnant or breastfeeding women.
  • Presence of a cardiac pacemaker or other implanted electronic medical device.
  • Known allergy or previous skin reaction to capsaicin
Terms in these criteria, in plain language(2)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

05

Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
30 participants (estimated)

Study arms

  • Experimental
    Experimental pain

    Participants complete one experimental session. Motor cortex excitability is first assessed at baseline using transcranial magnetic stimulation with electromyographic recordings from the first dorsal interosseous muscle. Topical capsaicin cream is then applied to the forearm to induce temporary, moderate experimental pain. Once pain is established, the same neurophysiological assessments are repeated during the pain condition.

    Drug: Topical Capsaicin Cream (1%)

Interventions

  • Topical capsaicin cream (1%) is applied to the forearm to induce temporary, moderate experimental pain. Motor cortex excitability is assessed before and during capsaicin-induced pain using transcranial magnetic stimulation.

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What researchers measure

Primary outcomes

  1. Change in Short-Interval Intracortical Inhibition

    Short-interval intracortical inhibition will be assessed using paired-pulse transcranial magnetic stimulation over the primary motor cortex, with electromyographic recordings from the first dorsal interosseous muscle. A subthreshold conditioning stimulus set at 80% of resting motor threshold will be followed by a suprathreshold test stimulus set at 120% of resting motor threshold, with an interstimulus interval of 3 ms. Fifteen conditioned trials will be recorded for this measure. The outcome will be expressed as the change in conditioned motor evoked potential amplitude relative to the unconditioned test response from pre- to post-application of topical capsaicin cream.

    Time frame: At baseline (before capsaicin cream application); at pain stabilization (after capsaicin cream application)

Secondary outcomes

  1. Change in Short-Interval Intracortical Facilitation

    Short-interval intracortical facilitation will be assessed using paired-pulse transcranial magnetic stimulation over the primary motor cortex, with electromyographic recordings from the first dorsal interosseous muscle. A suprathreshold conditioning stimulus set at 120% of resting motor threshold will be followed by a subthreshold test stimulus set at 80% of resting motor threshold, with an interstimulus interval of 2 ms. Fifteen conditioned trials will be recorded for this measure. The outcome will be expressed as the change in conditioned motor evoked potential amplitude relative to the unconditioned test response from pre- to post-application of topical capsaicin cream.

    Time frame: At baseline (before capsaicin cream application); at pain stabilization (after capsaicin cream application)

  2. Change in Pain Intensity

    Pain intensity will be assessed using a visual analog scale ranging from 0 to 10, where 0 indicates no pain and 10 indicates the worst imaginable pain. The outcome will be expressed as the change in pain intensity from pre- to post-application of topical capsaicin cream.

    Time frame: From baseline through completion of the experimental session, an average of 2 hours

  3. Change in Intracortical Facilitation

    Intracortical facilitation will be assessed using paired-pulse transcranial magnetic stimulation over the primary motor cortex, with electromyographic recordings from the first dorsal interosseous muscle. A subthreshold conditioning stimulus set at 80% of resting motor threshold will be followed by a suprathreshold test stimulus set at 120% of resting motor threshold, with an interstimulus interval of 15 ms. Fifteen conditioned trials will be recorded for this measure. The outcome will be expressed as the change in conditioned motor evoked potential amplitude relative to the unconditioned test response from pre- to post-application of topical capsaicin cream.

    Time frame: At baseline (before capsaicin cream application); at pain stabilization (after capsaicin cream application)

  4. Change in Long-Interval Intracortical Inhibition

    Long-interval intracortical inhibition will be assessed using paired-pulse transcranial magnetic stimulation over the primary motor cortex, with electromyographic recordings from the first dorsal interosseous muscle. A suprathreshold conditioning stimulus set at 120% of resting motor threshold will be followed by a suprathreshold test stimulus set at 120% of resting motor threshold, with an interstimulus interval of 100 ms. Fifteen conditioned trials will be recorded for this measure. The outcome will be expressed as the change in conditioned motor evoked potential amplitude relative to the unconditioned test response from pre- to post-application of topical capsaicin cream.

    Time frame: At baseline (before capsaicin cream application); at pain stabilization (after capsaicin cream application)

  5. Change from baseline in corticospinal excitability

    Corticospinal excitability will be assessed using single-pulse transcranial magnetic stimulation applied over the primary motor cortex, with electromyographic recordings from the first dorsal interosseous muscle. Single magnetic pulses of increasing intensity will be delivered to construct input-output recruitment curves for each participant. Stimulation intensity will be increased in 5% steps, and 10 stimuli will be delivered at each intensity level. Motor evoked potentials will be recorded using surface electromyography. Input-output curves will be modeled using a Boltzmann sigmoidal function, and the slope, plateau, and S50 parameters will be extracted. The outcome will be expressed as the change in these input-output curve parameters from pre- to post-application of topical capsaicin cream.

    Time frame: At baseline (before capsaicin cream application); at pain stabilization (after capsaicin cream application)

Other outcomes

  1. Kinesiophobia

    Kinesiophobia will be assessed using the French-Canadian version of the Tampa Kinesiophobia Questionnaire (EKT-CF). It takes the form of a self-reported questionnaire of 17 items using a Likert scale ranging from 1 (strongly disagree) to 4 (strongly agree), with an acceptable degree of internal consistency (Cronbach's alpha = 0.71), satisfactory construct validity, and high sensitivity to change (intra-class correlation coefficient \> 0.7). The total score is obtained by adding the value of the responses and is between 17 and 68. The value of 37/68 is considered as the threshold value at which kinesiophobia becomes significant.

    Time frame: Baseline

  2. Pain catastrophizing related to pain

    Pain catastrophizing will be assessed using the French-Canadian version of the Pain Catastrophizing Scale (PCS-CF), a self-report questionnaire designed to measure catastrophic thoughts related to pain. The PCS-CF includes 13 items rated on a Likert scale from 0 ("not at all") to 4 ("all the time"), covering three dimensions: rumination, magnification, and helplessness. Item scores are summed to yield a total score ranging from 0 to 52, with higher scores indicating greater pain catastrophizing. A total score ≥30 has been proposed to identify clinically relevant levels of pain catastrophizing.

    Time frame: Baseline

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Study locations

1 site
  • Université de Sherbrooke - Campus de la santé
    Sherbrooke, Quebec J1H 5H3, Canada
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jul 7, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT07688525
Responsible party
Guillaume Léonard (Principal Investigator, Université de Sherbrooke) — Principal investigator
First posted
Jul 7, 2026
Start date
Aug 1, 2026 (estimated)
Primary completion
Nov 30, 2026 (estimated)
Completion
Dec 31, 2026 (estimated)
Last update
Jul 7, 2026

Study contacts

Guillaume Léonard, Ph.D.
Contact
guillaume.leonard2@usherbrooke.ca
819-821-8000
Adrien Nourry
Contact
adrien.nourry@usherbrooke.ca
+33611074458
Guillaume Léonard, Ph.D.
principal investigator · Université de Sherbrooke

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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Studies of the drug tested here: Capsaicin

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