LET for Fibromyalgia

At enrollment, participants will complete a baseline assessment including collection of demographic information (age, race/ethnicity, BMI, employment status, duration of symptoms, smoking history), past/current medical history, and current medications. The primary outcome measure of severity and functional impact of fibromyalgia symptoms will be collected using the Fibromyalgia Impact Questionnaire Revised (FIQR) at baseline, at each of the four treatment sessions, and one month after the last treatment. The following secondary outcome measures will be collected at baseline, immediately after the first treatment session, and before and after the fourth treatment session: 1. Pressure pain threshold (PPT), 2. temporal summation (TS) to pin prick, and 3. Autonomic cardiovascular function and conditioned pain modulation (CPM) during cold pressor test (CPT). Thirty-six participants will be randomized at the baseline testing session to receive 4 weekly treatments of active (n=18) or sham (n=18) LET. Opaque, sealed envelopes containing equal quantities of the number "1" or "2" will be placed into a container. On the first day of the study, participants will select an envelope that will only be opened by the treating clinician. The number "1" will designate participants to the active LET group, with the number "2" designating to the sham LET group. The treating clinician will record the participant's group assignment in order to administer the correct treatment throughout the study. The Aria LET Elite Instrument (Arcturus Star, Cortez, Colorado) will be utilized for the intervention and sham groups. The active device has two treatment wands that emit electrostatic energy, and give off a perceptible light and sound when they come in contact with the skin of the participant. The sham LET device used for the control group will also use two wands that emit a light and sound similar to the active LET device, but will not emit electrostatic energy waves. The device intensity ranges from 0-10 units which correlates to an amplitude of 12.9-38.25 microamps. Frequency ranges from 0-1000 units with a nonlinear correlation between 41-260 Hz. In the active treatment group, for session 1, the machine's intensity will be set to 3 units and a frequency of 300 units. For treatment session 2, the intensity and frequency will increase as tolerated to 4 units and 400 units, respectively. For treatment session 3, the intensity and frequency will increase as tolerated to 5 units and 500 units, respectively. For treatment session 4, the intensity and frequency will increase as tolerated to 6 units and 600 units, respectively. In the unlikely event that participants report an increase in fibromyalgia-related symptoms for more than two days after a treatment session, the treating clinicians will maintain (not increase) the intensity and frequency settings between visits. The treatment will utilize both wands contacting the skin of the participant and will progress in this treatment landmark order: terminus, jugulodigastric, parotid glands/sinuses, axilla, abdominal region, inguinal, lower/upper back. The clinicians will spend about 3 minutes on each landmark, spending more time in areas that exhibit more soft tissue resistance (detected through the wand), but staying within a total treatment time of 25 minutes. The control group will receive treatment using the same parameters, landmark progression, and treatment time on the sham device. All treatment parameters and participants' responses to treatment (treatment effect) will be documented at each visit. Additional measures will include a Blinding Fidelity Question administered at the end of the first and fourth treatment visit.

Using fibromyalgia as a target condition, the following aims will be tested:

1. Evaluate within- and between- group changes in severity and functional impact of fibromyalgia symptoms using the Fibromyalgia Impact Questionnaire-Revised (FIQR) 2. Evaluate within- and between- group changes in quantitative sensory testing (QST) and autonomic cardiovascular testing (ACT). 3. Correlate FIQR to QST and ACT values.

• Change quantitative sensory testing (QST) as assessed by PPT immediately after treatment 1 [Time frame: Baseline, week 1 post treatment]
• Change in quantitative sensory testing (QST) as assessed by PPT immediately after treatment 4 [Time frame: Week 4 pre-treatment, week 4 post-treatment]
• Change in quantitative sensory testing (QST) as assessed by PPT at week 4 post treatment from baseline [Time frame: Baseline, week 4 post- treatment]
• Change in quantitative sensory testing (QST) as assessed by temporal summation (TS) to pin prick immediately after treatment 1 [Time frame: Baseline, week 1 post treatment]
• Change in quantitative sensory testing (QST) as assessed by temporal summation (TS) to pin prick immediately after treatment 4 [Time frame: Week 4 pre-treatment, week 4 post-treatment]
• Change in quantitative sensory testing (QST) as assessed by temporal summation (TS) to pin prick at week 4 post treatment from baseline [Time frame: Baseline, week 4 post treatment]
• Change in quantitative sensory testing (QST) as assessed by CPM score immediately after treatment 1 [Time frame: Baseline, week 1 post treatment]
• Change in quantitative sensory testing (QST) as assessed by CPM score immediately after treatment 4 [Time frame: Week 4 pre treatment, week 4 post treatment]
• Change in quantitative sensory testing (QST) as assessed by CPM score at week 4 post treatment from baseline [Time frame: Baseline, week 4 post treatment]
• Change in autonomic cardiovascular testing (ACT) as assessed by Heart rate change during cold pressor task (CPT) immediately after treatment 1 [Time frame: Baseline, week 1 post treatment]
• Change in autonomic cardiovascular testing (ACT) as assessed by Heart rate change during cold pressor task (CPT) immediately after treatment 4 [Time frame: Week 4 pre treatment, week 4 post treatment]
• Change in autonomic cardiovascular testing (ACT) as assessed by Heart rate change during cold pressor task (CPT) at week 4 post treatment from baseline [Time frame: Baseline, week 4 post treatment]