FRIDAY, Oct. 27 (HealthScout)The elusive cause of fibromyalgia could be linked to a central nervous system that in some people remembers pain for an abnormally long time, new research shows. The findings should prompt researchers to pursue treatment that targets abnormal central pain mechanisms, says lead investigator Dr. Roland Staud, associate professor of medicine at the University of Florida in Gainesville.
A disorder that affects an estimated 2 percent of the U.S. population, fibromyalgia is a syndrome characterized by chronic and widespread pain, stiffness, fatigue and sometimes flu-like symptoms. There is no cure, and the cause is unknown. But evidence is growing that the disease is related to amplified pain sensation in the brain and spinal cord. Fibromyalgia sufferers who took part in Staud's study reported more pain than did a control group when heat was applied to their hands, he reports. Unlike a control group, those with fibromyalgia experienced residual pain after the stimulus was removed. And the pain was widespread, rather than limited to a single area of the body, the study found. "Our findings provide evidence for abnormal central nervous system mechanism of pain in fibromyalgia patients, and have significant implications for future therapies," Staud says in a press release from this week's Annual Scientific Meeting of the American College of Rheumatology.
The findings may explain the cause of fibromyalgia in most patients, says Dr. I. Jon Russell, associate professor of medicine and director of the University of Texas' Clinical Research Center. Russell is one of the country's leading researchers in fibromyalgia and co-author of The Fibromyalgia Helpbook. "I am impressed with Dr. Staud's work because it is insightful, systematic and focused logically on a region of the central nervous system where the majority of fibromyalgia patients are likely to be processing pain signals abnormally," Russell says. "The mechanical methodology he is developing will pioneer new ways of viewing the process of pain in fibromyalgia and other disorders of chronic pain," he says. "I think we will increasingly attempt to correct abnormalities that we know are there, rather than to blindly try one class after another of analgesic drugs in hopes of finding something that may work," Russell says. "All of fibromyalgia management, however, begins with believing the patients when they describe their pain. Pain is always a personal experience that cannot be proven or disproven. We have no choice but to believe our patients and do our best to help them," Russell says.
The hypothesis that fibromyalgia is linked to the central nervous system is the most widely accepted, says Tyler Cymet, assistant professor of internal medicine at The Johns Hopkins School of Medicine. He also has a family medicine practice in Baltimore, where he is helping about 40 patients manage fibromyalgia. Those with fibromyalgia often have lower levels of biochemical substances such as serotonin, norepinephrine and dopamine, Cymet says. The criteria for fibromyalgia are chronic pain lasting more than three months in the upper and lower body, both on the left and right sides. And the pain is in at least 11 of 18 specific points called "tender points," according to the American College of Rheumatology. "We're still in the beginning phases of [studying fibromyalgia]," Cymet says. "Fibromyalgia is a disease where the patients came to us and said, 'We have this disease.' Fifty percent of people with fibromyalgia can tell you the date and time [the symptoms] started." Often, Cymet says patients trace symptoms back to an event years earlier, such as an injury, but the pain has since spread to the whole body. Most doctors treat fibromyalgia with two drugs, amitriptyline, a tricyclic anti-depressant, and cyclobenzaprine, a muscle relaxant, Cymet says. He recommends everything from medications to T'ai Chi. "Fibromyalgia has so many different presentations that I think it's important to see how it's affecting the person most, and then set achievable goals," Cymet says