The Pain of Fibromyalgia

Brain-scan study finds it’s real

When fibromyalgia patients say they’re in pain, they aren’t kidding. A new brain-scan study found that a gentle finger squeeze produced measurable pain signals in the brains of people diagnosed with fibromyalgia. Twice the squeezing force was required before healthy people felt the same levels of pain.

The study is the first to compare what fibromyalgia patients report they feel and what's happening in their brains when they feel it. The findings were published in the
May 2002 issue of Arthritis & Rheumatism, the journal of the American College of Rheumatology.

Lead authors Richard Gracely, Ph.D., professor of internal medicine and neurology in the U-M Medical School, and Daniel Clauw (M.D. 1985), U-M professor of internal medicine, conducted the study at Georgetown University Medical Center and the National Institutes of Health. They are now continuing their work at the University of Michigan Health System. In an accompanying editorial, Clauw and Leslie Crofford, M.D., an associate professor of internal medicine in the Medical School, stressed the importance of research on fibromyalgia.

Patients and many physicians say fibromyalgia is a specific, diagnosable chronic disease. It affects more than two percent of Americans, particularly women of childbearing age, and is characterized by tenderness and stiffness as well as fatigue, headaches, gastrointestinal problems and depression. Skeptics say fibromyalgia is rooted more in psychological and social factors than in physical, biological ones. Their argument has been bolstered by the failure to find a clear cause, an effective treatment or a non-subjective way of assessing patients.

The new study confirms scientifically what patients have been telling skeptics in the medical community for years. “The brain scan technology gave us an opportunity to look at the neurobiology of tenderness, the hallmark of fibromyalgia,” says Clauw. “These results, combined with work done by others, 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.”

Gracely and Clauw used a super-fast form of MRI brain imaging called functional MRI (fMRI) to test 16 fibromyalgia patients and 16 people without the disease while a device applied precisely calibrated, rapidly pulsing pressure to their thumbnails. Fibromyalgia patients reporting pain from mild pressure had increased activity in 12 brain areas, while the control subjects feeling the same pressure had increased activity in only two areas of the brain.

The study was supported in part by the National Fibromyalgia Research Association, the U.S. Army and the National Institutes of Health.

—KG

For more details, read the complete press release at:
www.med.umich.edu/opm/newspage/2002/fibromyalgia.htm
To learn more about fibromyalgia, visit:
www.med.umich.edu/1libr/topics/muscle15.htm or www.arthritis.org