For years, fibromyalgia sufferers have been telling sometimes skeptical doctors about their pain. (See our earlier article.) Now, new research confirms that their pain is all too real.
Researchers at the University of Michigan Health System, led by Richard Gracely, Ph.D., and Daniel Clauw, M.D., are using a new, faster MRI technique called fMRI to examine changes inside the brain that are associated with pain. fMRI scans can detect differences in how much pain different people feel when, say, their finger is squeezed.
"The fMRI technology gave us a unique opportunity to look at the neurobiology underlying tenderness, which is a hallmark of fibromyalgia," says Clauw. "These results, combined with other work done by our group and others, have convinced us that some pathologic process is making these patients more sensitive. For some reason, still unknown, there's a neurobiological amplification of their pain signals."
Published in the June 2002 issue of Arthritis & Rheumatism, the journal of the American College of Rheumatology (ACR), these findings may offer the best proof yet that fibromyalgia has a physical, rather than a psychological, origin.
With the fMRI technique, the researchers were able to record what occurs in the brain of FMS patients at the precise moment they feel pain. The doctors found that it only took a mild pressure to produce feelings of pain in the FMS patients, while the control subjects tolerated the same pressure with little pain.
"In the patients, that same mild pressure also produced measurable brain responses in areas that process the sensation of pain," says Clauw. "But the same kind of brain responses weren't seen in control subjects until the pressure on their thumb was more than doubled."
For decades, patients and some physicians have built a case that fibromyalgia is a specific, diagnosable chronic disease, characterized by tenderness and stiffness all over the body as well as fatigue, headaches, gastrointestinal problems and depression. Skeptics, however, have continued to debate the very existence of fibromyalgia, citing the lack of a known cause and the failure of researchers to find a a non-subjective way of assessing patients.
Next, on the to-do research list, is to find out why FMS patients are more sensitive to pain signals.