Because
transcutaneous electrical nerve stimulation (
TENS) works by reducing central excitability and activating central inhibition pathways, we tested the hypothesis that
TENS would reduce
pain and
fatigue and improve function and
hyperalgesia in people with
fibromyalgia who have enhanced central excitability and reduced inhibition. The current study used a double-blinded randomized, placebo-controlled cross-over design to test the effects of a single treatment of
TENS with people with
fibromyalgia. Three treatments were assessed in random order: active
TENS, placebo
TENS and no
TENS. The following measures were assessed before and after each
TENS treatment:
pain and
fatigue at rest and in movement; pressure pain thresholds, 6-m walk test, range of motion; 5-time sit-to-stand test, and single-leg stance. Conditioned
pain modulation was completed at the end of testing. There was a significant decrease in
pain and
fatigue with movement for active
TENS compared to placebo and no
TENS. Pressure pain thresholds increased at the site of
TENS (spine) and outside the site of
TENS (leg) when compared to placebo
TENS or no
TENS. During active
TENS, conditioned
pain modulation was significantly stronger compared to placebo
TENS and no
TENS. No changes in functional tasks were observed with
TENS. Thus, the current study suggests
TENS has short-term efficacy in relieving symptoms of
fibromyalgia while the stimulator is active. Future clinical trials should examine the effects of repeated daily delivery of
TENS, similar to the way in which
TENS is used clinically on
pain,
fatigue, function, and quality of life in individuals with
fibromyalgia.