This would appear, by definition, to represent an inflammation or other affection of the fibrous tissues of the muscles, fascia, and aponeuroses. Unfortunately, the pathologic basis of this state remains obscure. Only some clinical facts can be stated. During the first movements after a period of inactivity, a muscle or group of muscles may become painful and tender, particularly after exposure to cold, dampness, or minor trauma, but often for no reason that can be discerned. One looks in vain for signs of tendinous, muscular, or arthritic disease. The neck and shoulders are the most common sites. Tender areas, up to several centimeters in diameter, can be palpated within the muscles (“fibrositic nodules” by experts), and active contraction or passive stretching of the involved muscles increases the pain—points said to be of diagnostic value, but disputed. Often, symptoms such as mental and physical fatigue, insomnia, and headache are associated and raise the suspicion of an anxiety state or depression. In a few instances the condition clears up in a few weeks; local heat and massage and local injections of anesthetics or steroids are found to give comfort while symptoms are present, but most often it becomes a chronic condition.
The chronic form of fibromyalgia presents far greater problems, usually disabling the patient and causing a change in accustomed habits and employment as discussed in Chap. 10. It has become one of the prime diagnoses made by rheumatologists and physiatrists, but the patient may first come to the attention of a neurologist. Most definitions of the syndrome have been circular or somewhat arbitrary. Those now in general use are similar to the one proposed by a committee of the American College of Rheumatology. The basis for diagnosis is the presence of widespread pain, including focal areas of pain (trigger points) that can be produced by 4 kg of digital pressure in 11 of 18 typical locations over muscles, tendons, or bone—these are concentrated around the shoulders and paraspinal regions—and there is no requirement for the presence of the several common systemic complaints that accompany the illness in most patients (fatigue, difficulty concentrating, sleeping difficulty, or anxiety). In the past, similar pains were associated with cases of irritable bowel or irritable bladder syndromes, dysmenorrhea, chronic headache, and cold intolerance. Depending on how broad a definition one allows for the widespread pain and painful trigger points, most or all patients in our experience manifest many of the same complaints as those with the chronic fatigue syndrome, which is discussed in Chap. 24. Writers on the subject, however, have pointed out that in the majority of patients, formal assessment by modern criteria fails to confirm the presence of depression, and that when depression coexists with the muscular complaints, the two are discordant temporally and in severity. While we acknowledge that antidepressants often give disappointing results and that in our practice there have been a number of patients with fibromyalgia who appeared to be psychologically sound and lacked depression, they have been the exceptions. The literature eschews the use of corticosteroids for treatment of the pain, but we have had occasion to see patients whose symptoms were relieved when these medications were used for other purposes.
Fibromyalgia remains a problematic illness, defined largely by a pattern of pain that justifies its name. Despite attempts to objectify the physical symptoms, psychiatric factors should not be overlooked. This condition is a favorite illness with physiotherapists, who claim that their physical measures are helpful, as they may well be. Rarely, a similar syndrome is the forerunner of what proves, after some days, with the onset of neurologic signs, to be a radiculitis, brachial neuritis, or outbreak of herpes zoster.