UF Researchers Discover Abnormal "Pain Memory" Is Key In Fibromyalgia

November 2, 2000

GAINESVILLE, Fla. — The constant, intense pain of fibromyalgia may result from a central nervous system that “remembers” painful sensations for an unusually long time, University of Florida researchers have discovered. The findings may provide a foundation for developing new therapies to treat the disorder, which causes pain in muscles and soft tissues throughout the body, sleep problems and fatigue.

“The findings provide evidence that fibromyalgia patients have an abnormal central nervous system pain mechanism, or pain memory, that results in sensations that linger much longer than usual and require much less stimulation to produce,” said Dr. Roland Staud an associate professor of medicine in the division of rheumatology and immunology at UF’s College of Medicine.

Staud will present the findings Friday (Nov. 3) at the American Pain Society conference in Atlanta. He also presented them Monday at the American College of Rheumatology scientific meeting in Philadelphia.

The research is part of ongoing studies by UF scientists to shed light on the puzzling disease. The American College of Rheumatology estimates that 6 million Americans — primarily women of childbearing age — have fibromyalgia. There is no known cause, and current treatments do little to relieve the chronic pain associated with the disease. Blood tests and scans fail to detect the anomalies associated with fibromyalgia, which has led to some skepticism that the pain is real.

Using an instrument heated to 51.5 degrees Celsius (about 125 degrees Fahrenheit), the researchers applied a series of brief heat pulses to various sites on the skin of the hands of 59 people with fibromyalgia and 65 matched controls who were unaffected by the disease. The contact lasted for .7 seconds and the interval between the pulses within each series varied from two seconds to five seconds. Each patient was trained to numerically rate the magnitude of pain sensations they experienced following contact with the instrument, and the ratings of each group were compared.

The scientists found that pain accumulated in those with the disorder rather than dispersing quickly. In addition, the pain endured in people with fibromyalgia for an abnormally long time. The researchers also found sufferers of the disorder experienced the residual pain throughout their bodies, not limited to the area where the heat had been placed.

“These findings have significant implications not only for developing future therapies to target the abnormality, but also because it provides hope and credibility for patients who previously had no tangible basis for their pain,” Staud said.