Early concepts and theories
The term fibrositis (suggesting inflammation of the fibrous muscle tissue) was coined by Sir William Gowers in 1904 to describe the muscle pain that he would commonly see in his clinics. The term fibromyalgia was applied by two Canadian physicians, Drs Harvey Modosfki and Hugh Smith of Toronto, in 1977. The term reflected the increasing lack of proof that the syndrome was due to muscle inflammation. In 1990 the American College of Rheumatology established research criteria and characterized FM as a condition of both chronic pain and tenderness. While these criteria aimed to promote research, they were indiscriminately applied to all patients and led to a number of misconceptions. Originally FM patients were diagnosed with the syndrome if they were positive for more than 11 out of the specific 18 tender points. By the late 80s several studies appeared showing beyond a shred of doubt that patients with FM have entire body tenderness including the thumbnails!
Drs Williams and Claw stated that the tender point requirements for the diagnosis misrepresent the nature of tenderness in patients seen in the community. While women with FM are 10 times more likely to have 11 or more tender points than men, when one accepts only the criterion of Chronic Widespread Pain in all 4 quadrants to the body (but NOT accessed by tender points), women are only 1.5 times more likely than men to experience Chronic Widespread Pain. Additionally, those with many tender points are specifically displaying a fair amount of emotional distress. At the end, tender points and high levels of distress represent only one sample of FM patients, which is more severely affected and is usually seen in specialty clinics (rheumatology and pain clinics), but not often in the offices of the family physicians.
FM, central pain and “sensory augmentation”
Today, research supports some involvement of one or more mechanisms within the central nervous system such as central pain processing abnormalities, disturbance of the hypothalamic pituitary adrenal axis and the autonomic nervous system. The most consistent research findings point to abnormalities in central mechanisms that “increase” pain or reduce the ability to “block” pain.
These findings have been supported by brain studies of FM in patients with functional imaging techniques that permit us to visualize brain structures involved in pain processing. Of importance are studies that show that FM patients are also more sensitive to noise and light. In summary, today there is some support for the notion that FM and related syndromes “might represent general neurobiological amplification of sensory stimuli”. In other words, people with FM and similar conditions seem to have some form of “in-brain amplifier” that increases the impact of different stimuli coming from our senses (touch, pain, sound, light etc).
In part II we will cover other factors involved in FM. I will also summarize my experience with this condition from tertiary care clinic point of view.
Read one of Doctor Mailis-Gagnon’s previous columns
Chronic Pain: The Elephant in the room that no one wants to see Read more