Clinical:Fibromyalgia

Fibromyalgia syndrome (FMS) is a chronic condition charaacterized by symptoms in multiple domains, including pain, fatigue, sleep disturbance, mood disturbance, function impairment, irritable bowel syndrome, tension and migraine headache, and cognitive dysfunction. Its pathophysiology is rooted in neural dysregulation in the spinal cord and brain.^[1]

FMS affects between 2% and 5% of the American population, primarily women. It may be associated with other painful conditions, such as arthritis and low back pain.

Diagnosis

The American College of Rheumatology (ACR) has established classification criteria that define FMS as a condition in which widespread pain has been present in at least 11 of 18 anatomically specific tender points for at least 3 months. This was intended to be used for research, and is problematic when used in clinical practice because the criteria lack specificity and exclude some patients with chronic widespread pain who do not experience pain in those specific tender points.

The ACR classification criteria were intended to be used for research studies, but increasingly they have been used as diagnostic criteria in practice. This is problematic. Although the tender point examination helps physicians discriminate FMS as a condition characterized by augmented tenderness, an increased number of tender points is associated with female sex and "distress." This criterion lacks high specificity and excludes some patients with chronic widespread pain who do not fulfill the tender point criteria

Treatment

Treatment should be customized to the symptom domains of the patient and should include both pharmacological and nonpharmacological approaches. Nonpharmacological approaches including education, exercise, and cognitive behavior therapy are the cornerstone of treatment. Many patients may try complementary/alternative therapies, although none has been shown effective.

The results of controlled trials suggest that several classes of medications may be effective, particularly neuromodulatory agents. The anti-epileptic agent pregabalin is the first medication to be approved by the FDA for FMS. In clinical trials it produced significant improvements in fatigue, sleep disturbance, pain, and quality of life.

A large proportion of FMS patients have comorbid depression, and antidepressants are often effective in this patient group. The mixed serotonin/ norepinephrine antidepressants (eg, duloxetine and milnacipran) are effective and generally well tolerated; for some patients, the older tricyclic agent amitriptyline may be helpful.

Analgesics (eg, tramadol) have shown benefit, although stronger opioid analgesics do not appear to be helpful, especially for long-term use.

References

1. ↑ Mease P and Seymour K, Fibromyalgia Syndrome: Guidelines for Effective Care. Consultant 48:7 (2008)