Blunted touch perception in fibromyalgia
Fibromyalgia is a chronic condition that is characterized by severe pain in the body. Scientific researchers still have very limited knowledge on what causes fibromyalgia. However, recent research has revealed one interesting aspect of fibromyalgia that there is a definitive link between fibromyalgia and the central nervous system.
The findings of the study revealed that there is abnormal processing of signals in C-type skin nerves which are associated with the perception of touch in fibromyalgia. The researchers from the National Center for Complementary and Integrative Health in Bethesda, Maryland looked into, if the fibromyalgia patients rated the perception of touch differently than healthy individuals. The study also looked into the opioid signaling in fibromyalgia.
Previous research has found that fibromyalgia sufferers have a smaller count of opioid receptors in the brain, which aid in pain signaling and mediate feelings of reward to natural behaviors. The study enrolled 24 fibromyalgia patients and 28 healthy controls. The researchers used slow or fast moving brushes along the participants’ forearms to explore the effects of perception. Participants were asked to rate pleasure and intensity of the strokes. Normal controls rated slow brush strokes as more pleasurable but less intense. This is an expected result, as the C-type nerves are better activated by a slow touch. Fibromyalgia patients, on the other hand, rated both fast and slow brush strokes as equally pleasurable and intense.
Participants received either a drug that blocks opioid receptors or the placebo. Under the influence of the drug, healthy controls rated both slow and fast touch to be slightly more pleasurable, but fibromyalgia patients did not notice any change, but rated both fast and slow brush strokes as less intense compared to those individuals on a placebo.
The results indicate that the fibromyalgia patients have abnormal touch processing and altered opioid signaling. Additional research is required to determine, if these findings may help to uncover the underlying cause of fibromyalgia.