Generalized Hypersensitivity in Patients With Fibromyalgia Syndrome

Study Overview
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Brief Summary
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Fibromyalgia (FM) is a chronic musculoskeletal pain disorder with unknown causes. Our previous studies showed abnormal sensations of second pain (wind-up), indicating central hypersensitivity as an important mechanism of FM. Triggering events have been implicated as the cause of central hypersensitivity.

Detailed Description
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Increasing evidence has shown that the hypersensitivity of FM is not limited to painful stimuli but seems to extend to non-painful stimuli as well. These stimuli include smell, taste, touch, light, and sound. This study will provide detailed QST examinations of FM subjects and controls' responses to light using visually evoked potentials (VEP). In addition, careful characterization of experimental pain responding across multiple sensory modalities will be examined.

Official Title
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Generalized Hypersensitivity in Patients With Fibromyalgia Syndrome

Conditions
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Fibromyalgia

Intervention / Treatment
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* Behavioral: Paced Auditory Serial Addition task (PASAT)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Individuals diagnosed with FM will have pain of > 3 months and meet the 1990 and 2011 Diagnostic Criteria for FM (ACR) Healthy, pain-free age and sex matched controls without chronic pain Exclusion Criteria: 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 a minimum of one day prior to the visit. Significant vision loss not corrected by eye wear Family history of photosensitive epilepsy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Interventional Model Description: Participants sensitivity to pressure, heat, and light will be modulated by an attention task.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Effects of PASAT on Sensory Testing<br>After baseline evaluation of light and pain sensitivity FM subjects and controls will undergo the PASAT task. This task consists of responding to a rapid presentation of numbers by ear phones. Subjects are asked to add each 2 consecutive numbers and provide a response each time the sum is equal to 13. This test will last several minutes and delivered at increasing speed. | Behavioral: Paced Auditory Serial Addition task (PASAT)<br>* Single and double digits are presented at intervals between 2 and 3 seconds and the participant must add each new digit to the one immediately prior to it. The participants will be asked to indicate by electronic button press whether the sum of the addition is 13 or not. The duration of the PASAT will be two 12-min tasks.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Verbal Pain Ratings of Painful Heat and Pressure Stimuli using a Numerical Pain Scale from 0 - 100 | FM and control subjects will provide verbal ratings of experimental pain stimuli. For this purpose a numerical ratings scale (0-100) will be used ranging from no sensation to the most intense sensation possible. All measures will be obtained in triplicates and the averages will be used for statistical comparisons. | 1 hour | 
| Visual Evoked Potentials (VEP) During Flicker | FM and control subject will focus on a light source while VEPs are obtained. EEG tracings will be evaluated by special software to detect VEP. For intensity ratings of the flicker stimulus a numerical ratings scale (0-100) will be used ranging from no sensation to the most intense sensation possible. All measures will be obtained in triplicates and the averages will be used for statistical comparisons. | 1 hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Response to 2011 Fibromyalgia Criteria Questionnaire | FM and control subjects will complete the 2011 FM Questionnaire. The answers of this questionnaire will be added to obtain the wide-spread pain index and the somatic symptom score. The scores will be combined to obtain the final score. Scores of >12 fulfill the Criteria for Fibromyalgia | 0.5 hours | 
| Response to the Center for Epidemiological Studies (CES-D) Depression Questionnaire | FM and control subjects will complete the CES-D. The answers of this questionnaire will be combined to obtain a final score. Total scores of >15 are consistent with the diagnosis of major depression. | 0.5 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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central sensitization, peripheral sensitization, visual evoke potentials (VEP), quantitative sensory testing