Pain
Conditions
Brief summary
This study will use using fMRI (functional Magnetic Resonance Imaging) to elucidate how contextual learning/expectation relieves or aggravates pain experience in the same cohort of subjects and the same study session.
Interventions
DEVICEHeat pain applied using TSA or CHEPS
TSA-2001 Thermal Sensory Analyzer (Medoc LTD Advanced Medical Systems) or the Pathway Medoc (CHEPS model, Contact Heat-Evoked Potential Stimulator, Medoc LTD Advanced Medical Systems)
Sponsors
Massachusetts General Hospital
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
21 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* a) Healthy male and female adults aged 21-50 * b) No contraindications to fMRI scanning * c) Right handed
Exclusion criteria
* a) Current or past history of major medical, neurological, or psychiatric illness * b) Pregnancy or breast feeding, menopause, and irregular menstrual cycles (length of cycle must be within 26 to 32 days) * c) Claustrophobia * d) History of head trauma * e) History of impaired elimination * f) Instability of responses to experimental pain (see Study Procedures Section) * g) Use of psychotropic drugs, hormone treatments (including hormonal birth control) within 1 year * h) Non-fluent speaker of English
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Subjective Response to Pain (0-20 Visual Analogue Scale) | Weeks 1-3 | Subjects received heat pain before and after the application of a neutral cream (told one application of neutral cream was lidocaine, one was capsaicin, and one was neutral) and rated pain intensity on a 0-20 Visual Analogue Scale (0-no pain, 20-intolerable pain). We only measure this outcome measure in session 3. The pain intensity for each cream was averaged amongst all participants for both the pre and post treatment in session 3. Subjects have up to 3 weeks to complete the 3 sessions. |
| fMRI Signal Changes in the Dorsal Anterior Cingulate Cortex | Week 4 | We used fMRI to investigate the signal changes associated with administration of identical pain stimuli before (pre) and after the treatment (post) with different creams in session 3. It is important to note that the subjects had multiple weeks to complete the study, but this measure was only taken during one session. The change was calculated from two time points as the value at the later time point (post treatment) minus the value at the earlier time point (pre treatment). |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Heat Pain There is only one cohort in this study. All subjects receive the same intervention, the application of heat pain using TSA or CHEPS.
Heat pain applied using TSA or CHEPS: TSA-2001 Thermal Sensory Analyzer (Medoc LTD Advanced Medical Systems) or the Pathway Medoc (CHEPS model, Contact Heat-Evoked Potential Stimulator, Medoc LTD Advanced Medical Systems) | 24 |
| Total | 24 |
Baseline characteristics
| Characteristic | Heat Pain |
|---|---|
| Age, Continuous | 26.5 years STANDARD_DEVIATION 6.7 |
| Sex: Female, Male Female | 11 Participants |
| Sex: Female, Male Male | 13 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 38 | 0 / 38 |
| other Total, other adverse events | 1 / 38 | 0 / 38 |
| serious Total, serious adverse events | 0 / 38 | 0 / 38 |
Outcome results
Primary
fMRI Signal Changes in the Dorsal Anterior Cingulate Cortex
We used fMRI to investigate the signal changes associated with administration of identical pain stimuli before (pre) and after the treatment (post) with different creams in session 3. It is important to note that the subjects had multiple weeks to complete the study, but this measure was only taken during one session. The change was calculated from two time points as the value at the later time point (post treatment) minus the value at the earlier time point (pre treatment).
Time frame: Week 4
Population: The neutral cream is omitted from the data table below because we were only concerned about the direct comparison between positive expectancy (Lidocaine) and negative expectancy (Capsaicin) conditions. Data were only collected for the Lidocaine and Capsaicin creams.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Heat Pain | fMRI Signal Changes in the Dorsal Anterior Cingulate Cortex | Lidocaine | 0.2 Post-Pre treatment peak beta | Standard Deviation 0.18 |
| Heat Pain | fMRI Signal Changes in the Dorsal Anterior Cingulate Cortex | Capsaicin | 0.3 Post-Pre treatment peak beta | Standard Deviation 0.3 |
Primary
Subjective Response to Pain (0-20 Visual Analogue Scale)
Subjects received heat pain before and after the application of a neutral cream (told one application of neutral cream was lidocaine, one was capsaicin, and one was neutral) and rated pain intensity on a 0-20 Visual Analogue Scale (0-no pain, 20-intolerable pain). We only measure this outcome measure in session 3. The pain intensity for each cream was averaged amongst all participants for both the pre and post treatment in session 3. Subjects have up to 3 weeks to complete the 3 sessions.
Time frame: Weeks 1-3
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Heat Pain | Subjective Response to Pain (0-20 Visual Analogue Scale) | Pre-treatment placebo Lidocaine | 10.7 units on a scale | Standard Error 2.4 |
| Heat Pain | Subjective Response to Pain (0-20 Visual Analogue Scale) | Pre-treatment placebo capsaicin | 11 units on a scale | Standard Error 1.8 |
| Heat Pain | Subjective Response to Pain (0-20 Visual Analogue Scale) | Pre-treatment neutral | 11.2 units on a scale | Standard Error 2 |
| Heat Pain | Subjective Response to Pain (0-20 Visual Analogue Scale) | Post-treatment placebo lidocaine | 8.1 units on a scale | Standard Error 3 |
| Heat Pain | Subjective Response to Pain (0-20 Visual Analogue Scale) | Post-treatment placebo capsaicin | 12.2 units on a scale | Standard Error 2.6 |
| Heat Pain | Subjective Response to Pain (0-20 Visual Analogue Scale) | Post-treatment neutral | 10.8 units on a scale | Standard Error 2.3 |