Optimized tDCS for Fibromyalgia: Targeting the Endogenous Pain Control System

Purpose

This trial aims at understanding the mechanisms of optimized transcranial direct current stimulation (tDCS) (16 tDCS sessions combined with exercise)] on pain control. Optimized tDCS can lead to stronger engagement of the endogenous pain regulatory system that will ultimately lead to increased pain relief in patients with fibromyalgia (FM). Therefore, the investigators designed a 2x2 factorial mechanistic trial [tDCS (active and sham) and aerobic exercise (AE) (active and control)] to evaluate the effects of 4 weeks of tDCS coupled with exercise on the endogenous pain regulatory system assessed by conditioned pain modulation (CPM) and central sensitization as assessed by temporal slow pain summation (TSPS), and compared to either intervention alone and to no intervention.

Condition

  • Fibromyalgia

Eligibility

Eligible Ages
Between 18 Years and 65 Years
Eligible Genders
All
Accepts Healthy Volunteers
No

Inclusion Criteria

  1. Age range 18-65 years, 2. Diagnosis of FM pain according to the ACR 2010 criteria (existing pain for more than 6 months with an average of at least 4 on a 0-10 VAS scale) without other comorbid chronic pain diagnosis, 3. Pain resistant to common analgesics and medications for chronic pain such as Tylenol, Aspirin, Ibuprofen, Soma, Parafon Forte DCS, Zanaflex, and Codeine, 4. Must have the ability to feel sensation by Von-Frey fiber on the forearm, 5. Able to provide informed consent to participate in the study.

Exclusion Criteria

  1. Clinically significant or unstable medical or psychiatric disorder, 2. history of substance abuse within the past 6 months as self-reported (if subject reports a history of substance abuse, we will confirm using DSM V criteria), 3. Previous significant neurological history (e.g., traumatic brain injury), resulting in neurological deficits, such as cognitive or motor deficits, as self-reported, 4. Previous neurosurgical procedure with craniotomy, 5. Severe depression (If a patient scores >30 on the Beck Depression Inventory, one will obtain clearance. If one does not pass the medical clearance, one will not be included in the study) 6. Pregnancy (as the safety of tDCS in pregnant population (and children) has not been assessed (though risk is non-significant), the investigators will exclude pregnant women (and children). Women of child-bearing potential will be required to take a urine pregnancy test during the screening process and at every week of stimulation), 7. Current opiate use in large doses (more than 30mg of oxycodone/hydrocodone or 7.5mg of hydromorphone (Dilaudid) or equivalent), 8. Patients will be excluded when they have increased risk for exercise

Study Design

Phase
N/A
Study Type
Interventional
Allocation
Randomized
Intervention Model
Factorial Assignment
Primary Purpose
Other
Masking
Triple (Participant, Investigator, Outcomes Assessor)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Active tDCS and Active Exercise 		Active tDCS for 20 min Active exercise (60-70% max HR) for 30 min
  • Device: Active tDCS
    Active tDCS: A 1x1 Low-intensity DC Stimulator will be used to deliver direct current through rubber electrodes in saline soaked sponges. The anode will be placed over the left primary motor cortex (M1) while the cathode will be placed over the contralateral supra-orbital area. 20 minutes of tDCS will be applied.
    Other names:
    • tDCS
  • Procedure: Active Exercise
    Participants will walk briskly in a treadmill (as to keep at 60-70% maximum heart rate) for 30 minutes
    Other names:
    • Aerobic Exercises
Active Comparator
Sham tDCS and Active Exercise 		Sham tDCS for 20 min Active exercise (60-70% max HR) for 30 min
  • Procedure: Active Exercise
    Participants will walk briskly in a treadmill (as to keep at 60-70% maximum heart rate) for 30 minutes
    Other names:
    • Aerobic Exercises
  • Device: Sham tDCS
    Active tDCS: A 1x1 Low-intensity DC Stimulator will be used to deliver direct current through rubber electrodes in saline soaked sponges. The anode will be placed over the left primary motor cortex (M1) while the cathode will be placed over the contralateral supra-orbital area. Only 30 seconds of current will be applied for the sham condition.
    Other names:
    • Placebo tDCS
Active Comparator
Active tDCS and Sham Exercise 		Active tDCS for 20 min Sham exercise (within 10% baseline HR) for 30 min
  • Device: Active tDCS
    Active tDCS: A 1x1 Low-intensity DC Stimulator will be used to deliver direct current through rubber electrodes in saline soaked sponges. The anode will be placed over the left primary motor cortex (M1) while the cathode will be placed over the contralateral supra-orbital area. 20 minutes of tDCS will be applied.
    Other names:
    • tDCS
  • Procedure: Sham Exercise
    Participants will walk in a treadmill (as to keep at 10% within their baseline heart rate) for 30 minutes.
    Other names:
    • Placebo Aerobic Exercise
Sham Comparator
Sham TDCS and Sham Exercise 		Sham tDCS for 20 min Sham exercise (within 10% baseline HR) for 30 min
  • Device: Sham tDCS
    Active tDCS: A 1x1 Low-intensity DC Stimulator will be used to deliver direct current through rubber electrodes in saline soaked sponges. The anode will be placed over the left primary motor cortex (M1) while the cathode will be placed over the contralateral supra-orbital area. Only 30 seconds of current will be applied for the sham condition.
    Other names:
    • Placebo tDCS
  • Procedure: Sham Exercise
    Participants will walk in a treadmill (as to keep at 10% within their baseline heart rate) for 30 minutes.
    Other names:
    • Placebo Aerobic Exercise

More Details

Status
Active, not recruiting
Sponsor
Spaulding Rehabilitation Hospital

Study Contact

Detailed Description

Recent evidence has suggested that FM pain can be related to deficits in pain endogenous regulatory control and that novel non-pharmacological interventions, such as tDCS can modulate this system and, consequently, reduce pain intensity. Widespread pain in FM is thought to represent enhanced pain sensitivity that is maintained by central mechanisms. This suggests changes in the descending pain control mechanisms and a possible relationship with the central sensitization phenomenon. Recent evidence has suggested that pain inhibitory pathways are affected in FM; thus, further understanding these pathways' role can significantly change how the treatment of this condition. In this study the investigators will test the effects of two interventions -tDCS and aerobic exercise - on the modulation of the endogenous inhibitory pain system in fibromyalgia.