Myofascial pain and fibromyalgia: Diagnosis and treatment

Myofascial pain syndrome (MPS) and fibromyalgia (FM) are common muscular pain syndromes. They are both characterized by tenderness, but MPS is further characterized by the myofascial trigger point that has a taut band and causes referred pain. FM can be either primary (idiopathic) or secondary. MPS is always secondary to some muscle stressor. The diagnosis of these conditions is generally made by physical examination. Algometry can quantify the tenderness. EMG of the trigger point and diagnostic ultrasound can provide objective evidence of the trigger point. Biochemical markers and other phenomena associated with FM have not yet been shown to be either specific or sensitive enough to use as clinical indicators of the condition. Tryptophane is low in the serum and spinal fluid of FM patients, whereas substance P is elevated in the spinal fluid. Treatment of MPS is effective when the trigger point is inactivated and underlying mechanical or medical perpetuating factors are corrected. Treatment of fibromyalgia is more difficult as the drugs commonly used, such as the tricyclic antidepressants, which have uncertain benefits; and exercise, which clearly shows a short-term benefit, fail to provide long-lasting relief at 4 years.