Primary fibromyalgia syndrome: current concepts.

PFS is a characteristic and clinically recognizable rheumatologic syndrome. It is a very common condition, but only recently has investigational interest grown in this interesting syndrome. PFS should be diagnosed by its own characteristic features and not merely by excluding other conditions. Pathophysiology of PFS is not well understood at this time and needs further study. Sleep EEG studies in PFS have revealed disturbed non-REM sleep, and normal volunteers deprived of non-REM sleep develop many features of non-REM sleep develop many features of PFS, including musculoskeletal aching, tenderness, and fatigue. Psychologic studies have shown that only a subset of PFS patients have shown that only a subset of PFS patients are significantly disturbed as determined by MMPI scores, and PFS patients as a group are more stressed than RA patients and normal controls as measured by Holmes-Rahe Life Events Inventory. It appears that chronic anxiety-stress causes muscle spasm that can be appreciated clinically in some patients and indirectly, possibly by electron microscopic findings of muscle biopsy. Likely role of other factors, e.g., constitutional, trauma, posture, and weather are also discussed. Biochemical transmitters of pain remain to be studied in PFS. Lack of a specific physical or laboratory finding should not deter acceptance of PFS as an entity, since such specific findings are absent in other similar and well-accepted conditions, e.g., irritable bowel syndrome, with which PFS shares many other common features, including muscle tenderness and spasm. PFS is different from psychogenic pain, and any implication by a physician that it is "all in the head" is certain to perpetuate chronic pain and disability.(ABSTRACT TRUNCATED AT 250 WORDS)