A new study has revealed that we may hold the key to understanding fibromyalgia in the palms of our hands – literally! Published in the June issue of the journal Pain Medicine, the study details the first physically detectable pathology providing a logical rationale for the debilitating symptoms of fibromyalgia.
This breakthrough discovery, made by scientists at Integrated Tissue Dynamics LLC (INTiDYN), a biotechnology company housed and supported at the University at Albany’s East Campus in Rensselaer, New York, provides a biological rationale for fibromyalgia.
"Instead of being in the brain, the pathology consists of excessive sensory nerve fibers around specialized blood vessel structures located in the palms of the hands," said Dr. Rice, President of Intidyn and the senior researcher on the study. "This discovery provides concrete evidence of a fibromyalgia-specific pathology which can now be used for diagnosing the disease, and as a novel starting point for developing more effective therapeutics."
Study Design and Results
To analyze the nerve endings, the researchers used microscopic technology, referred to as ChemoMophometric Analysis (CMA), to study small skin biopsies (less than half the size of a pencil eraser) collected from the palms of 24 fibromyalgia patients and 14 controls. The study was limited to women, who have over twice the occurrence of fibromyalgia than men.
What the team uncovered was an enormous increase in sensory nerve fibers at specific sites within the blood vessels of the skin. These critical sites are tiny muscular valves, called arteriole-venule (AV) shunts, which form a direct connection between arterioles and venules (see diagram).
Dr. Rice describes their function, "We are all taught that oxygenated blood flows from arterioles to capillaries, which then convey the deoxygenated blood to the venules. The AV shunts in the hand are unique in that they create a bypass of the capillary bed for the major purpose of regulating body temperature."
Regulating Temperature and Blood Flow
In humans, these types of shunts are unique to the palms of our hands and soles of our feet which work like the radiator in a car. Under warm conditions, the shunts close down to force blood into the capillaries at the surface of the skin in order to radiate heat from the body, and our hands get sweaty. Under cold conditions, the shunts open wide allowing blood to bypass the capillaries in order to conserve heat, and our hands get cold and put on gloves.
"The excess sensory innervation may itself explain why fibromyalgia patients typically have especially tender and painful hands," said researcher Dr. Phillip J. Albrecht. "But in addition, since the sensory fibers are responsible for opening the shunts, they would become particularly active under cold conditions, which are generally very bothersome to fibromyalgia patients."
Although they are mostly limited to the hands and feet, the shunts likely have another important function which could account for the widespread deep pain, achiness, and fatigue that occurs in fibromyalgia patients.
"In addition to involvement in temperature regulation, an enormous proportion of our blood flow normally goes to our hands and feet. Far more than is needed for their metabolism," noted Dr. Rice. "As such, the hands and the feet act as a reservoir from which blood flow can be diverted to other tissues of the body, such as muscles when we begin to exercise. Therefore, the pathology discovered among these shunts in the hands could be interfering with blood flow to the muscles throughout the body. This mismanaged blood flow could be the source of muscular pain and achiness, and the sense of fatigue which are thought to be due to a build-up of lactic acid and low levels of inflammation fibromyalgia patients. This, in turn, could contribute to the hyperactivity in the brain."
Dr. Albrecht also points out that alterations of normal blood flow may underlie other fibromyalgia symptoms, such as non-restful sleep or cognitive dysfunctions. "The data do appear to fit with other published evidence demonstrating blood flow alterations to higher brain centers and the cerebral cortex of fibromyalgia patients,"he stated.
Senior Research Chair of the Alan Edwards Center for Pain Research at McGill University, Dr. Gary Bennett, commented after seeing the results. "It is exciting that something has finally been found," he remarked. "We can hope that this new finding will lead to new treatments for fibromyalgia patients who now receive little or no relief from any medicine."
This discovery of a distinct tissue pathology demonstrates that fibromyalgia is not "all in a patient’s head," which should provide an enormous relief to those suffering with fibromyalgia, while changing the clinical opinion of the disease and guiding future approaches for successful treatments.
Not being a scientist myself, I have to admit I don't fully understand everything about this study, nevertheless, I do find it fascinating. The temperature-regulating aspect is particularly interesting since so many of us with FM are hyper-sensitive to cold or heat or both. I trust this will be the first of many studies exploring this new avenue for FM research that may finally provide answers about the cause of this enigmatic disease.
Albrecht, P. J., et al. (2013). Excessive peptidergic sensory innervation of cutaneous arteriole–venule shunts (AVS) in the palmar glabrous skin of fibromyalgia patients: Implications for widespread deep tissue pain and fatigue. Pain Medicine, 14(6), 895-915. doi: 10.1111/pme.12139.
University at Albany's East Campus Biotech Company Makes Major Fibromyalgia Discovery. News release. University at Albany, June 20, 2013.