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Fibromyalgia Has Much in Common with CFS

Two of the presentations [given at the AACFS Conference, October 10-12, 1998] explored the relationship between CFS and fibromyalgia. Keynote speaker Robert Bennett, noted the two syndromes first share the common perception by many physicians that they are mythical or imaginary conditions. They also share similar profiles - pain and fatigue that are related in severity, predominance of women, disability, psychological stress, poor sleep, sensitivity to food and chemicals, etc.

Dr. Bennett, professor of medicine and head of the Division of Arthritis and Rheumatic Diseases at the Oregon Health Sciences University, placed fibromyalgia on a spectrum of pain conditions and noted that the same could be done with CFS and fatigue states.

The criteria for CFS differ from that for fibromyalgia in that CFS requires recent onset. Also, symptoms such as impaired memory, sore throat, new headaches, post-exertional malaise, and muscle or multi-joint pain are included in CFS while they are not part of the definition of fibromyalgia. The CFS definition also has exclusions, which are not considered in fibromyalgia. If you have the positive criteria for fibromyalgia, you have it, regardless of whatever else you might have. Many patients with conditions like rheumatoid arthritis, lupus and Sjogrens also have fibromyalgia, and that may explain the difference in prevalence between the two conditions (about 2% of the population has fibromyalgia, about four times the prevalence of CFS).

Dr. Bennett suggested that a fundamental feature of the two syndromes may be disordered sensory processing, in which the pain activation and modulation systems are not functioning properly. This may be caused by substances in the brain that activate or block neurotransmitters at pain channels and may prolong the sensation of pain. Chronic pain also activates the limbic system, which controls the psychological stress or suffering response to pain.

Areas of mutual interest to fibromyalgia and CFS research-ers are positive table tilt tests, low levels of growth hormone, the role of infections and other environmental triggers, activated cytokine production, and disorders in the body's neuroendocrine system.

Don Goldberg, chief of rheumatology at Newton-Wellesley Hospital in Massachusetts, also discussed common ground between fibromyalgia and CFS in a presentation at the patient conference. He noted that the clinical overlap is so great that a patient's diagnosis may depend on what she tells her doctor, the patient's perception of the illness, the apparent trigger for onset (flu or accident), or type of doctor the patient sees.

Dr. Goldenberg noted numerous similarities in studies of physiology, sleep abnormalities, cognitive difficulties, psychiatric co-morbidity, blood flow in the brain, growth hormone and other hormone systems, the HPA axis, stress and more. He also noted that many treatments, such as low doses of antidepressants, have similar responses in both conditions.