HealthyNCT04485689
The Effect of Capsaicin-induced Pain on Homeostatic Plasticity in Healthy Human Participants
A study testing Capsaicin Topical - alone and Capsaicin Topical - ice in people with Healthy, run by Aalborg University at 1 site in Denmark.
Trial summary
People suffering from chronic pain exhibit changes in the way the central nervous system processes pain. Some of the changes in the central nervous system are associated with how the brain adapts to the process of different stimuli. Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Capsaicin Topical - alone and Capsaicin Topical - ice
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 24 participants
- Where
- 1 siteDenmark
- Study dates
- 1 Jul 2020to Dec 2020
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy, aged between 18-60 years, right-handed and can speak and understand English.
Who cannot join
- Lack of ability to cooperate
- Chili allergy
- History or present chronic pain or current acute pain
- Pregnancy
- Drug addiction defined as the use of cannabis, opioids or other drugs
- Present and previous neurological disorders such as epilepsy, Alzheimer's disease,
Show all 14Show fewer
- dementia, stroke, migraine and other headache disorders, multiple sclerosis,
- Parkinson's disease, neuroinfections, brain tumors and head trauma.
- Present or previous musculoskeletal disorders such as tendonitis, degenerative disc disease, mechanical back syndrome, and ruptured/herniated disc.
- Present or previous mental illnesses such as depression, bipolar disorder, and schizophrenia.
- Current use of medications that may affect the trial (e.g. analgesics, anti- inflammatories, anti-depressives)
- Contraindications to TMS application (history of epilepsy, metal implants in head or jaw, etc.)
- Failure to pass the tDCS screening questionnaire
- Failure to pass the "TASS questionnaire"
Trial locations and contacts
1 site in 1 country.
Denmark1 site, 1 recruiting
- Recruiting
Aalborg University
Aalborg, 9220
Priscilla G Wittkopf, PhD, +4531539979, pgw@hst.aau.dk
About this study
People suffering from chronic pain exhibit changes in the way the central nervous system processes pain. Some of the changes in the central nervous system are associated with how the brain adapts to the process of different stimuli. There are several physiological mechanisms that regulates how the brain adapts to changes and one of these mechanisms is called homeostatic plasticity (or equilibrium plasticity ). In healthy participants homeostatic plasticity mechanisms have been tested and considered normal, whereas in patients with chronic conditions, such as low back pain, this mechanism was shown to be dysfunctional. However, it is unknown when this difference in the pain system develops. It is possible that homeostatic mechanism becomes impaired during early stages of pain. This experiment will investigate the effect of capsaicin-induced pain on homeostatic plasticity in healthy participants.
Read the detailed description
The aim of this study is to investigate the effect of capsaicin-induced pain on homeostatic plasticity.
A randomised crossover design will be used to evaluate the effect of capsaicin-induced pain on homeostatic plasticity using cathodal transcranial direct current stimulation (tDCS). Each participant will take part in four experimental sessions during which homeostatic plasticity and corticomotor excitability will be induced and measured in the left primary motor cortex. Participants will receive - in randomised order - capsaicin or placebo patch placed on the dorsal part of the right hand.
Each participant will attend four sessions, being two consecutive sessions separated by two weeks (i.e. wash-out period). During the experiment, participants will be seated comfortably with hands and arms at rest. First, the electromyography electrodes will be placed at the right first dorsal interosseous muscle to be used for assessing the corticomotor excitability by recordings of motor evoked potentials by transcranial magnetic stimulation (TMS) on the left primary motor cortex. Then, the cap for tDCS on the left primary motor cortex will be mounted. The optimal scalp position (hot spot) for TMS stimulation will be identified and marked with a pen on the cap for standardisation. A 5 x 7 cm capsaicin/placebo patch will be placed on participants' right hand. After 30 minutes of patch application, baseline measures of pain and motor-evoked potentials will be taken. Then, the homeostatic plasticity induction process will take place followed by motor-evoked potentials recordings every 15 minutes up to 45 minutes post protocol. Participants will be divided in 2 groups, one group will receive ice over the patch as to reduce pain intensity to minimum of 1 in a numeric rating scale; the other group will proceed without ice. Homeostatic plasticity will be induced and measured as previously described. The patch will be left in place for 24 hours, at which point participants will return to the laboratory and homeostatic plasticity will once again be induced and measured. After a wash-out period of two weeks, participants will go through an identical process but at this time with a different patch.
Homeostatic plasticity will be induced in the left primary motor cortex using tDCS applied for 7 minutes followed by an interval of 3 minutes and another block of 5 minutes of stimulation. A constant current of 2mA will be transmitted through the tDCS system, using two 25 cm2 electrodes placed into holes of a cap over the hot spot and right supraorbital area.
A sample size calculation was conducted using α of 0.05, β of 0.80 and effect size of 0.29 based on motor evoked potential (MEP) analysis of previous studies resulting in a target of 22 participants. To account for differences in designs 24 participants will be included, being 12 in each group.
Data distribution will be assessed using the Shapiro-Wilk test. A mixed analysis of variance (ANOVA) will be conducted on mean MEPs: within factors Intervention (Capsaicin and Placebo), Time (baseline, 0 min, 15 min, min, 30 min, 45 min), Time with pain (immediate, post pain relief post prolonged pain); and between factor (ice , no ice). A Greenhouse-Geisser correction will be used if Mauchly's test shows that sphericity cannot be assumed. Adjustments will be made for multiple post-hoc comparisons using the Bonferroni correction. Results will be interpreted according to the level of statistical significance p≤0.05.
- Conditions
- Healthy
- Being tested
- Capsaicin Topical - alone, Placebo - alone, Capsaicin Topical - ice, Placebo - ice
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Capsaicin Topical - aloneDrug
5x7 cm2 capsaicin patch applied on the dorsal area of the hand and left in place for 24 hours
Placebo - aloneDrug
5x7 cm2 patch applied on the dorsal area of the hand and left in place for 24 hours
Capsaicin Topical - iceDrug
5x7 cm2 capsaicin patch applied on the dorsal area of the hand and left in place for 24 hours. Ice will be applied on top of the patch 1.5 hrs post patch application and left in place for 1 hr.
Placebo - iceDrug
5x7 cm2 patch applied on the dorsal area of the hand and left in place for 24 hours. Ice will be applied on top of the patch 1.5 hrs post patch application and left in place for 1 hr.
| Study group | Role | What they receive |
|---|---|---|
| Capsaicin - alone | Experimental | 5x7 cm2 capsaicin patch Receives: Drug: Capsaicin Topical - alone |
| Placebo - alone | Placebo comparator | 5x7 cm2 placebo patch alone Receives: Drug: Placebo - alone |
| Capsaicin - ice | Experimental | 5x7 cm2 capsaicin patch - plus ice Receives: Drug: Capsaicin Topical - ice |
| Placebo - ice | Placebo comparator | 5x7 cm2 placebo patch - plus ice Receives: Drug: Placebo - ice |
What is being measured
The primary outcome is the main question the study is designed to answer.
Conspiratorial excitability
Corticospinal excitability measured as motor evoked potentials amplitude induced by transcranial magnetic stimulation.
Measured: [Time Frame: 0 minutes post homeostatic plasticity induction]
Conspiratorial excitability
Corticospinal excitability measured as motor evoked potentials amplitude induced by transcranial magnetic stimulation.
Measured: [Time Frame: 15 minutes post homeostatic plasticity induction]
Conspiratorial excitability
Corticospinal excitability measured as motor evoked potentials amplitude induced by transcranial magnetic stimulation.
Measured: [Time Frame: 30 minutes post homeostatic plasticity induction]
Conspiratorial excitability
Corticospinal excitability measured as motor evoked potentials amplitude induced by transcranial magnetic stimulation.
Measured: [Time Frame: 45 minutes post homeostatic plasticity induction]
Secondary outcomes (1)
Pain intensity
Pain intensity measured using an 11-point numeric rating scale where 0= no pain and 10 = worst imaginable pain.
Measured: Every 10 minutes post capsaicin application
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Jul 2020
- Study start1 Jul 2020
- Primary completionDec 2020 (estimated)
- Study completionDec 2020 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for HealthyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Model description
- This is a within-between subjects comparisons study.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 24 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Aalborg University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Priscilla G. Wittkopf, Aalborg University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04485689
- Sponsor's protocol ID
- N-20190069/2
- Status last verified
- Aug 2020
- First submitted
- 13 Jul 2020
- Last updated
- 31 Aug 2020
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Thapa T, Graven-Nielsen T, Chipchase LS, Schabrun SM. Disruption of cortical synaptic homeostasis in individuals with chronic low back pain. Clin Neurophysiol. 2018 May;129(5):1090-1096. doi: 10.1016/j.clinph.2018.01.060. Epub 2018 Feb 9.
PubMed 29472134Thapa T, Schabrun SM. Test-Retest Reliability of Homeostatic Plasticity in the Human Primary Motor Cortex. Neural Plast. 2018 Jun 10;2018:6207508. doi: 10.1155/2018/6207508. eCollection 2018.
PubMed 29983706Karabanov A, Ziemann U, Hamada M, George MS, Quartarone A, Classen J, Massimini M, Rothwell J, Siebner HR. Consensus Paper: Probing Homeostatic Plasticity of Human Cortex With Non-invasive Transcranial Brain Stimulation. Brain Stimul. 2015 May-Jun;8(3):442-54. doi: 10.1016/j.brs.2015.01.404. Epub 2015 Apr 1.
PubMed 26050599Fricke K, Seeber AA, Thirugnanasambandam N, Paulus W, Nitsche MA, Rothwell JC. Time course of the induction of homeostatic plasticity generated by repeated transcranial direct current stimulation of the human motor cortex. J Neurophysiol. 2011 Mar;105(3):1141-9. doi: 10.1152/jn.00608.2009. Epub 2010 Dec 22.
PubMed 21177994Rossini PM, Burke D, Chen R, Cohen LG, Daskalakis Z, Di Iorio R, Di Lazzaro V, Ferreri F, Fitzgerald PB, George MS, Hallett M, Lefaucheur JP, Langguth B, Matsumoto H, Miniussi C, Nitsche MA, Pascual-Leone A, Paulus W, Rossi S, Rothwell JC, Siebner HR, Ugawa Y, Walsh V, Ziemann U. Non-invasive electrical and magnetic stimulation of the brain, spinal cord, roots and peripheral nerves: Basic principles and procedures for routine clinical and research application. An updated report from an I.F.C.N. Committee. Clin Neurophysiol. 2015 Jun;126(6):1071-1107. doi: 10.1016/j.clinph.2015.02.001. Epub 2015 Feb 10.
PubMed 25797650
Study at a glance
From the registry record, last updated by the sponsor on 31 Aug 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Capsaicin-induced Pain on Homeostatic Plasticity in Healthy Human Participants
- ClinicalTrials.gov ID
- NCT04485689
- Acronym / sponsor ID
- N-20190069/2
- Conditions
- Healthy
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 24 participants (estimated)
- Lead sponsor
- Aalborg UniversityUniversity, hospital or other
- Study start
- 1 Jul 2020 (actual)
- Primary completion
- Dec 2020 (estimated)
- Study completion
- Dec 2020 (estimated)
- First posted
- 24 Jul 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
People suffering from chronic pain exhibit changes in the way the central nervous system processes pain. Some of the changes in the central nervous system are associated with how the brain adapts to the process of different stimuli. There are several physiological mechanisms that regulates how the brain adapts to changes and one of these mechanisms is called homeostatic plasticity (or equilibrium plasticity ). In healthy participants homeostatic plasticity mechanisms have been tested and considered normal, whereas in patients with chronic conditions, such as low back pain, this mechanism was shown to be dysfunctional. However, it is unknown when this difference in the pain system develops. It is possible that homeostatic mechanism becomes impaired during early stages of pain. This experiment will investigate the effect of capsaicin-induced pain on homeostatic plasticity in healthy participants.
Detailed description
The aim of this study is to investigate the effect of capsaicin-induced pain on homeostatic plasticity.
A randomised crossover design will be used to evaluate the effect of capsaicin-induced pain on homeostatic plasticity using cathodal transcranial direct current stimulation (tDCS). Each participant will take part in four experimental sessions during which homeostatic plasticity and corticomotor excitability will be induced and measured in the left primary motor cortex. Participants will receive - in randomised order - capsaicin or placebo patch placed on the dorsal part of the right hand.
Each participant will attend four sessions, being two consecutive sessions separated by two weeks (i.e. wash-out period). During the experiment, participants will be seated comfortably with hands and arms at rest. First, the electromyography electrodes will be placed at the right first dorsal interosseous muscle to be used for assessing the corticomotor excitability by recordings of motor evoked potentials by transcranial magnetic stimulation (TMS) on the left primary motor cortex. Then, the cap for tDCS on the left primary motor cortex will be mounted. The optimal scalp position (hot spot) for TMS stimulation will be identified and marked with a pen on the cap for standardisation. A 5 x 7 cm capsaicin/placebo patch will be placed on participants' right hand. After 30 minutes of patch application, baseline measures of pain and motor-evoked potentials will be taken. Then, the homeostatic plasticity induction process will take place followed by motor-evoked potentials recordings every 15 minutes up to 45 minutes post protocol. Participants will be divided in 2 groups, one group will receive ice over the patch as to reduce pain intensity to minimum of 1 in a numeric rating scale; the other group will proceed without ice. Homeostatic plasticity will be induced and measured as previously described. The patch will be left in place for 24 hours, at which point participants will return to the laboratory and homeostatic plasticity will once again be induced and measured. After a wash-out period of two weeks, participants will go through an identical process but at this time with a different patch.
Homeostatic plasticity will be induced in the left primary motor cortex using tDCS applied for 7 minutes followed by an interval of 3 minutes and another block of 5 minutes of stimulation. A constant current of 2mA will be transmitted through the tDCS system, using two 25 cm2 electrodes placed into holes of a cap over the hot spot and right supraorbital area.
A sample size calculation was conducted using α of 0.05, β of 0.80 and effect size of 0.29 based on motor evoked potential (MEP) analysis of previous studies resulting in a target of 22 participants. To account for differences in designs 24 participants will be included, being 12 in each group.
Data distribution will be assessed using the Shapiro-Wilk test. A mixed analysis of variance (ANOVA) will be conducted on mean MEPs: within factors Intervention (Capsaicin and Placebo), Time (baseline, 0 min, 15 min, min, 30 min, 45 min), Time with pain (immediate, post pain relief post prolonged pain); and between factor (ice , no ice). A Greenhouse-Geisser correction will be used if Mauchly's test shows that sphericity cannot be assumed. Adjustments will be made for multiple post-hoc comparisons using the Bonferroni correction. Results will be interpreted according to the level of statistical significance p≤0.05.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 4
- Model description
- This is a within-between subjects comparisons study.
| Arm | Type | Receives |
|---|---|---|
| Capsaicin - alone | Experimental | Drug: Capsaicin Topical - alone5x7 cm2 capsaicin patch |
| Placebo - alone | Placebo comparator | Drug: Placebo - alone5x7 cm2 placebo patch alone |
| Capsaicin - ice | Experimental | Drug: Capsaicin Topical - ice5x7 cm2 capsaicin patch - plus ice |
| Placebo - ice | Placebo comparator | Drug: Placebo - ice5x7 cm2 placebo patch - plus ice |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Healthy, aged between 18-60 years, right-handed and can speak and understand English.
Key exclusion criteria (14 listed)
- Lack of ability to cooperate
- Chili allergy
- History or present chronic pain or current acute pain
- Pregnancy
- Drug addiction defined as the use of cannabis, opioids or other drugs
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Capsaicin Topical - alone5x7 cm2 capsaicin patch applied on the dorsal area of the hand and left in place for 24 hours | Drug | Capsaicin - alone |
| Placebo - alone5x7 cm2 patch applied on the dorsal area of the hand and left in place for 24 hours | Drug | Placebo - alone |
| Capsaicin Topical - ice5x7 cm2 capsaicin patch applied on the dorsal area of the hand and left in place for 24 hours. Ice will be applied on top of the patch 1.5 hrs post patch application and left in place for 1 hr. | Drug | Capsaicin - ice |
| Placebo - ice5x7 cm2 patch applied on the dorsal area of the hand and left in place for 24 hours. Ice will be applied on top of the patch 1.5 hrs post patch application and left in place for 1 hr. | Drug | Placebo - ice |
Primary outcome
Conspiratorial excitability
Time frame: [Time Frame: 0 minutes post homeostatic plasticity induction]
Corticospinal excitability measured as motor evoked potentials amplitude induced by transcranial magnetic stimulation.
Conspiratorial excitability
Time frame: [Time Frame: 15 minutes post homeostatic plasticity induction]
Corticospinal excitability measured as motor evoked potentials amplitude induced by transcranial magnetic stimulation.
Conspiratorial excitability
Time frame: [Time Frame: 30 minutes post homeostatic plasticity induction]
Corticospinal excitability measured as motor evoked potentials amplitude induced by transcranial magnetic stimulation.
Conspiratorial excitability
Time frame: [Time Frame: 45 minutes post homeostatic plasticity induction]
Corticospinal excitability measured as motor evoked potentials amplitude induced by transcranial magnetic stimulation.
1 secondary outcome
Pain intensity
Time frame: Every 10 minutes post capsaicin application
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 31 Aug 2020.
- Background: PubMed 29472134Thapa T, Graven-Nielsen T, Chipchase LS, Schabrun SM. Disruption of cortical synaptic homeostasis in individuals with chronic low back pain. Clin Neurophysiol. 2018 May;129(5):1090-1096. doi: 10.1016/j.clinph.2018.01.060. Epub 2018 Feb 9.
- Background: PubMed 29983706Thapa T, Schabrun SM. Test-Retest Reliability of Homeostatic Plasticity in the Human Primary Motor Cortex. Neural Plast. 2018 Jun 10;2018:6207508. doi: 10.1155/2018/6207508. eCollection 2018.
- Background: PubMed 26050599Karabanov A, Ziemann U, Hamada M, George MS, Quartarone A, Classen J, Massimini M, Rothwell J, Siebner HR. Consensus Paper: Probing Homeostatic Plasticity of Human Cortex With Non-invasive Transcranial Brain Stimulation. Brain Stimul. 2015 May-Jun;8(3):442-54. doi: 10.1016/j.brs.2015.01.404. Epub 2015 Apr 1.
- Background: PubMed 21177994Fricke K, Seeber AA, Thirugnanasambandam N, Paulus W, Nitsche MA, Rothwell JC. Time course of the induction of homeostatic plasticity generated by repeated transcranial direct current stimulation of the human motor cortex. J Neurophysiol. 2011 Mar;105(3):1141-9. doi: 10.1152/jn.00608.2009. Epub 2010 Dec 22.
- Background: PubMed 25797650Rossini PM, Burke D, Chen R, Cohen LG, Daskalakis Z, Di Iorio R, Di Lazzaro V, Ferreri F, Fitzgerald PB, George MS, Hallett M, Lefaucheur JP, Langguth B, Matsumoto H, Miniussi C, Nitsche MA, Pascual-Leone A, Paulus W, Rossi S, Rothwell JC, Siebner HR, Ugawa Y, Walsh V, Ziemann U. Non-invasive electrical and magnetic stimulation of the brain, spinal cord, roots and peripheral nerves: Basic principles and procedures for routine clinical and research application. An updated report from an I.F.C.N. Committee. Clin Neurophysiol. 2015 Jun;126(6):1071-1107. doi: 10.1016/j.clinph.2015.02.001. Epub 2015 Feb 10.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Capsaicin Topical - alone and Capsaicin Topical - ice in people with Healthy, run by Aalborg University at 1 site in Denmark.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 31 Aug 2020. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Denmark. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Priscilla G Wittkopf, PhD (311539979, pgw@hst.aau.dk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Conspiratorial excitability (time frame: [Time Frame: 0 minutes post homeostatic plasticity induction]). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04485689, which also lists 5 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 31 Aug 2020.