Fibromyalgia, Pain
Conditions
Brief summary
Fibromyalgia (FM) patients have increased windup (WU). However, WU of FM patients is only quantitatively but not qualitatively different from healthy controls (HC). Thus WU abnormalities of FM patients could be the result of supra-spinal and not the result of spinal pain mechanisms. The study team will test this hypothesis by sensitizing FM patients with topical capsaicin.
Detailed description
The study team hypothesizes that at baseline the slopes of sensitivity adjusted WU of FM patients are not statistically different from HC. However, after capsaicin application, the slopes of sensitivity adjusted WU will be significantly different from baseline and greater than those of HC, suggesting central sensitization. This would imply that FM patients are sensitive to heat pain but not sensitized.
Interventions
DRUGCapsaicin Patch 8% or 0.1% Capsaicin Cream
0.1 ml of 8% capsaicin topical patch or 0.1% capsaicin cream
OTHERVehicle Patch
Control patch will be the same topical solution but will not contain capsaicin.
Sponsors
University of Florida
Study design
Observational model
CASE_CONTROL
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* individuals diagnosed with fibromyalgia will have pain of duration \> 6 months and meeting the 1990 Research Diagnostic Criteria for FM (ACR). * healthy, pain-free age matched controls without chronic pain
Exclusion criteria
* Allergy to red chili peppers; * Pregnant; * Significant hearing loss; * Presence of chronic disease (e.g. cancer, cardiovascular disease, liver disease, kidney disease, diabetes, etc.). * FM patients must be willing to discontinue or hold their FM related medications for at least 5 half-lives.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Progression of Temporal Summation of Second Pain | 2 hr | A Peltier device (Pathway, Medoc) will be used to tap the skin surface with a 3 cm x 3 cm probe. The Peltier device will be used to provide very brief, repetitive, thermal stimuli (for approx. 1s) to the skin using computer controlled temperatures. Heat stimuli at intervals of 2.5 sec produce sensations of increasing pain (temporal summation), depending on the number of stimuli presented. The late sensations of warmth are delayed in onset by approximately 1.5 sec after the probe touches the skin, because the sensation depends upon stimulation of slowly conducting unmyelinated peripheral afferents. |
Countries
United States
Outcome results
None listed