Fibromyalgia

By Bernard M. Abrams, MD

Posted: 10/31/2009

Fibromyalgia is a chronic pain disorder, which is characterized by generalized pain, multiple tender points in defined anatomical locations, fatigue, disturbed and nonrestorative sleep and numerous other somatic complaints. It affects 0.5% to 5% of the general population. This review is divided into two parts:
I. Definition, history, clinical characterization, and diagnostic criteria
II. Review of present treatment.

Definition, History, Clinical Characteristics, and Diagnostic Criteria

It should be stated at the outset of this review that fibromyalgia has been the subject of controversy in the past, and may, in cyclical fashion, expect to be a subject of controversy in the future. [1, 2] The absence of specific laboratory test abnormalities, the self reporting of pain and its severity, the lack of clear-cut etiology, and the subjective nature of complaints (word eliminated) upon which past diagnostic criteria have relied, have contributed to controversy. Also criticism by critics of the original studies who questioned the criteria for diagnosis [3] and decried the tautological aspects of selection of patients, then training observers, and then bringing the results into agreement with the examinations. [4]

History

In the 1700s, the distinction between articular and muscular rheumatism arose in Germany, Scandinavia, and Great Britain. [5, 6] Awareness was increased by the prevalence of massage for therapy and diagnosis. In 1815, William Balfour of Edinburgh described nodules in rheumatic muscles that he ascribed to inflammation in the connective tissue. In 1876, Helleday described a chronic myalgic condition, characterized by pain and nodules in the affected muscles. In 1904, Gowers first used the word “fibrositis” and described as one of his suggested treatments, deep hypodermic injection of cocaine, repeated daily, for 2 or 3 weeks! [7]

Stockman erroneously perpetuated the concept of inflammatory nodules, although he described edema without leukocytes, and inflammatory lesions. Moldofsky and others, in 1975, promulgated the concept of nonrestorative sleep syndrome. [8] The first reference to the tender area in muscle was “tender zone” and in 1939, Otto Steindler, Professor of Orthopedics at the University of Iowa, used the term trigger points and myofascial pain for the first time. The diagnosis of fibrositis was generally discarded when no inflammatory changes were found in muscle.

Fibromyalgia was the term advanced by Yunus and colleagues to replace fibrositis to acknowledge the lack of inflammation. [9] Using, Smythe’s description of fibrositis [10], he propounded initial criteria that reached fruition as the American College of Rheumatology criteria for the diagnosis of fibromyalgia published in February 1990. [3]

Clinical characteristics

Fibromyalgia has been described as one of a group of disorders, which have common somatic symptoms including chronic musculoskeletal pain, persistent fatigue, disturbed sleep, and cognitive difficulty. In reality, it is not a discrete disease, but rather is part of a continuum of psychological distress and chronic pain in the general population. As with other syndromes such as chronic fatigue syndrome, irritable bowel syndrome, and myofascial regional pain syndromes, it has symptoms that remain unexplained. Recently, there has been classification of these illnesses as central sensitivity syndromes. [11]

Pain is the overriding feature of fibromyalgia. The pain is usually described as deep and the patient's report that it is exhausting and intolerable. Allodynia and hyperalgesia are marked features. The patients' also experienced severe fatigue, insomnia, and depression.

A feeling of muscular weakness is prominent and nonrestorative sleep a constant feature. There may be prominent concentration and memory difficulties. The patients often describe a feeling of hurting all over and swelling of muscles and other soft tissues. Nonspecific neurological findings such as paresthesias and hyperactive reflexes are inconstant, but sometimes present. There is an association with other disorders. Headache, with unusual incidence of migraine, tenderness in all arteries, subjective dyspnea, irritable bowel syndrome, interstitial cystitis, hypotension, and increased, phonophobia, and photophobia, as well as odor and sensitivity are often described.

There is also an increased incidence in other collagen vascular disorders such as systemic lupus erythematosus rheumatoid arthritis and Sjogren's syndrome. Women are predominantly affected. Physical examination in uncomplicated fibromyalgia generally is normal, but many patients have signs of regional pain syndromes other than fibromyalgia that may confound the diagnosis.

Diagnosis

Historically, the American College of Rheumatology criteria for classification of fibromyalgia has relied on the following:

1. History of widespread pain
Definition: Pain is considered widespread one all of the following are present: Pain in the left side of the body, pain in the right side of the body, pain, above the waist, pain below the waist. In addition, axial skeletal pain (cervical spine or anterior chest or thoracic spine or low back) must be present. In this definition, shoulder, and buttock pain, is considered as pain for each involved side. “Low back” pain is considered lower segment pain. Thus, pain at 3 widespread sites (e.g. right arm, low back and left leg) will satisfy that criterion of widespread pain. [1]

2. Pain in 11 of 18 tender points sites on palpation
Definition: Pain (mild or greater) on digital palpation (force=4kg) must be present in at least 11 of the following tender point sites:

• Occipital: Bilateral, at the suboccipital muscle insertions

• Low cervical: Bilateral, at the anterior aspects of the intertransverse spaces at C5-7

• Trapezius: Bilateral, at the mid point of the upper border

• Supraspinalis: Bilateral, at the origins above the scapular spine near the medial border

• Second rib: Bilateral, at the second costochondral junctions. Just lateral to the junctions on the upper surfaces

• Lateral epicondyles: Bilateral,2cm distal to the epicondyles

• Gluteal: Bilateral, and upper, outer quadrants of products in the anterior fold of muscle

• Greater trochanter: Bilateral, posterior to the trochanteric prominence

• Knee: Bilateral, at the medial fat pad, proximal to the joint line. (1), (3)

• Digital palpation and with a force of 4 kg (enough to blanch the fingernail bed of a normotensive examiner) should produce complaints of pain.

Recently, Wilke has suggested that the symptom intensity score can be used to identify and quantify fibromyalgia syndrome. [12] The symptom intensity scale questionnaire is filled out by the patient and contains a list of 19 anatomic areas in which the patient is asked if he or she feels pain. The total number of yes answers constitutes the regional pain scale score. The visual analogue scale for her fatigue is then diagrammed by the patient on a horizontal axis and the length of the line is measured in centimeters. The regional pain scale is divided by two and added to the fatigue visual analogue scale. The sum is then divided by two. A score of 5 on the fatigue visual analogue scale is “probably consistent with a diagnosis of fibromyalgia syndrome”. [12] A score of greater than 5.75 is diagnostic and differentiates fibromyalgia syndrome from other rheumatic conditions. [12]

The advantage of the scale is that it can detect fibromyalgia syndrome in patients with other diseases. It is stated “fibromyalgia syndrome is more common in patients with chronic rheumatic or arthritic diseases, with a frequency ranging from 5% in osteoarthritis to 47% in Sjogren's syndrome.” [12, 13] While the author purports the scale to be an advantage because of the ability to diagnose intercurrent disease and the fact that the patient can fill it out in two minutes or less, it is not yet recognized by the American College of Rheumatology as part, or whole of the classification for criteria for fibromyalgia. The present author feels that it should be incorporated into the workup and observed as a parallel study while it awaits further validation.

Differential Diagnosis

The differential diagnosis of fibromyalgia includes rheumatoid arthritis SLE, polymyalgia rheumatica, spondyloarthropathy, inflammatory myopathy, hypothyroidism, osteomalacia, and hemochromatosis. Regional pain syndromes, and numerous neurological, entities must be ruled out. Chronic infections, endocrine disorders, occult neoplasms, and psychiatric disorders also enter into the differential diagnosis. A plea has been made to make a diagnosis of fibromyalgia based on inclusionary rather than exclusionary criteria. However, the differential diagnosis requires a workup, which should be obvious according to each diagnostic entity.

Conclusion

A useful working set of criteria for fibromyalgia includes the ability to separate it from other conditions and to evaluate it as an entity distinct enough to evaluate treatment and prognostic outcomes. Treatment will be the subject of part 2 of this review.

References

1. Abrams BM Tutorial 36: Myofascial Pain Syndrome and Fibromyalgia Pain Digest 1998 8:264-272

2. Bohr T problems, with myofascial pain syndrome, and fibromyalgia syndrome Neurology 1996; 46: 593-597.

3. Wolfe F, Smythe H, Yunus M, Et al. The American College of Rheumatology 1990 criteria for the classification of fibromyalgia: Report of the multicenter criteria committee. Arthritis Rheum 1990; 33:160-172

4. Cohen M, Quintner J Fibromyalgia, syndrome, a problem of tautology. Lancet 1993; 342:906-909

5. Simons DG Muscle pain syndromes (in two parts) AM J Phys Med Rehabil 1775 ; 54 :289-311 ; 1976 ;55 :15-42

6. Reynolds MD The development of the concept of fibrositis J Hist Med Allied Sci 1983; 38:5-35.

7. Gowers WR lumbago: Its lessons and analogues Br Med J 1904;1:117-121

8. Modlofsky H Scarisbrick P England R et al. Musculoskeletal symptoms and non-REM sleep disturbance, and patients with “fibrositis syndrome” and healthy subjects Psychosom Med 1975; 37:341-351.

9. Yunus M Masi AT Calabro JJ et al. Primary fibromyalgia (fibrositis): Clinical study of 50 patients with matched normal controls. Semin arthritis Rheum 1981; 11:151-171.

10. Smythe HA Fibrositis as a disorder of pain modulation. Clin Rheum Dis 1979;5:823-832

11. Yunus MB The concept of central sensitivity syndromes. The, fibromyalgia, and other central pain syndromes. Wallace DJ Clauw CJ, Eds. Lippincott, Williams, and Wilkins. Philadelphia 2005 p29

12. Wilke WS New developments in the diagnosis of fibromyalgia syndrome: Say goodbye to tender points? Cleveland Clinic Journal of Medicine 2009;76:345-352

13.  Wilke WS The clinical utility of fibromyalgia J Clin Rheumatol 1999;5:97-103.