Stress and Chronic Pain

March 1, 2006 Fibromyalgia is a condition that is characterized by serious, widespread chronic joint and muscle pain. The pain is often described as shooting, throbbing, aching, burning or twitching. The intensity of the pain varies and may be worse in the early morning, or after exposure to cold or humid weather, excessive activity and stress and anxiety. The pain and tenderness associated with fibromyalgia is most severe at 18 specific areas of the body, called tender points. Those tender points are located in the area of the neck, elbows, hips and knees. Although there is no specific test for fibromyalgia, the condition is considered when other causes of the pain have been ruled out, pain persists for at least three months, and patients experience pain in at least 11 of the 18 tender points. Fibromyalgia also causes several other symptoms. Patients can experience severe, debilitating fatigue, numbness or tingling in parts of the body, sensitivity to odors, bright lights or loud noises, sleep problems, headaches, digestive problems, impairment in memory and concentration, dry eyes, restless legs syndrome, dizziness, pelvic pain (in women), problems with coordination and depression. According to the National Fibromyalgia Association, up to six percent of Americans have fibromyalgia. About 80 to 90 percent of patients are women. The condition can occur at any age, but is most commonly diagnosed between 20 and 50. The cause is unknown. However, patients with rheumatic diseases (like rheumatoid arthritis, lupus, and ankylosing spondylitis) appear to be at higher risk for the condition. Fibromyalgia also tends to run in families, but researchers are uncertain if genetics or environmental factors play a role in the increased risk. The Role of Stress Researchers at the University of Alabama at Birmingham recently conducted a study to determine the role of stress on pain perception in patients with fibromyalgia. Patients with the condition may respond differently to stress than healthy people. Investigators recruited 120 patients with fibromyalgia and 60 healthy control patients. In the first part of the study, participants were asked to image a stressful or neutral event from their past. Then a heat stimulus was applied to the skin of the arm for a few minutes. Researchers measured heart rate, blood pressure and cortisol levels (a stress hormone) in the blood. Patients also rated the intensity and unpleasantness of the pain. In the second part of the study, researchers repeated the same testing conditions with the heat stimulus. But this time, images of the brain were taken. The images allow investigators to study the differences in blood flow to the brain during periods of stressful and nonstressful pain. Laurence Bradley, Ph.D., a Chronic Pain Researcher at the University of Alabama at Birmingham, says pain has both a sensory component and an emotional component. Sometimes our emotional response to pain has a great influence in how we perceive the pain. Preliminary results from the study show patients with fibromyalgia tend to rate the heat stimulus as much more unpleasant than healthy control subjects. Bradley says, if the results show that emotions play an important role in pain perception for those with fibromyalgia, doctors may want to consider treating depression in patients with higher levels of the emotional symptoms. That may help some fibromyalgia patients gain better control over their pain symptoms. The researchers are now performing a second study to find out if brothers and sisters of patients with fibromyalgia also have a greater sensitivity to pain than brothers and sisters of healthy control subjects. The information may help doctors determine if genetic factors may be related to the development of fibromyalgia. AUDIENCE INQUIRY For information on fibromyalgia: American College of Rheumatology, http://www.rheumatology.org Arthritis Foundation, http://www.arthritis.org National Fibromyalgia Association, http://www.fmaware.org National Institute of Arthritis and Musculoskeletal and Skin Diseases, http://www.niams.nih.gov BIBLIOGRAPHY "About Fibromyalgia," Orange: National Fibromyalgia Association, downloaded from website (http://www.fmaware.org), January 1, 2006. Conte, Paola, et al., "Temperament and Stress Response in Children With Juvenile Primary Fibromyalgia Syndrome," Arthritis and Rheumatism, October 2003, Vol. 48, No. 10, pp. 2923-2930. Cook, Dane, et al., "Functional Imaging of Pain in Patients with Primary Fibromyalgia," The Journal of Rheumatology, February 2004, Vol. 31, No. 2, pp. 364-378. 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Maquet, D., et al., "Pressure Pain Thresholds of Tender Point Sites in Patients with Fibromyalgia and in Healthy Controls," European Journal of Pain, April 2004, Vol. 8, No. 2, pp. 111-117. Mease, Philip, "Fibromyalgia Syndrome," The Journal of Rheumatology, August 2005, Vol. 75, Suppl., pp. 6-21. Montoya, P., et al., "Altered Processing of Pain-related Information in Patients with Fibromyalgia," European Journal of Pain, June 2005, Vol. 9, No. 3, pp. 293-303. Montoya, Pedro, et al., "Influence of Social Support and Emotional Context on Pain Processing and Magnetic Brain Responses in Fibromyalgia," Arthritis and Rheumatism, December 2004, Vol. 50, No. 12, pp. 4035-4044. Nampiaparampil, Devi, M.D., and Robert Shmerling, M.D., "A Review of Fibromyalgia," The American Journal of Managed Care, November 2004, Vol. 10, No. 11, Pt. 1, pp. 794-800. Petzke, F., et al., "Differences in Unpleasantness Induced by Experimental Pressure Pain Between Patients with Fibromyalgia and Healthy Controls," European Journal of Pain, June 2005, Vol. 9, No. 3, pp. 325-335. "Questions and Answers About Fibromyalgia," Bethesda: National Institute of Arthritis and Musculoskeletal and Skin Diseases, downloaded from website (http://www.niams.nih.gov), February 1, 2006. Sandberg, M., et al., "Different Patterns of Blood Flow Response in the Trapezius Muscle Following Needle Stimulation (Acupuncture) Between Healthy Subjects and Patients With Fibromyalgia and Work-related Trapezius Myalgias," European Journal of Pain, October 2005, Vol. 9, No. 5, pp. 497-510. "What is Fibromyalgia?" Bethesda: National Institute of Arthritis and Musculoskeletal and Skin Diseases, downloaded from website (http://www.niams.nih.gov), February 1, 2006. Research compiled and edited by Barbara J. Fister