Fibromyalgia

The classification of fibromyalgia is based on the criteria of the American College of Rheumatology. For diagnostic reasons autonomic disturbances and mental features have to be considered, The distinction between fibromyalgi a (tender points) and myofascial pain syndrome (trigger points) is essentia l. Internal and neurological disorders as a primary cause of fibromyalgia h ave to be excluded. The aetiology and pathogenesis of fibromyalgia still re main uncertain, The myopathological patterns in fibromyalgia are non-specif ic: type-II-fiberatrophy, a slight increase in lipid droplets, a proliferat ion of mitochondria and a slightly elevated incidence of ragged red fibers. Biochemically alterations of the serotonin system and high levels of subst ance P in the cerebrospinal fluid of fibromyalgia patients are important, A nimal experiments showed that the central stimulation by nociceptor input f rom muscles is exaggerated in skeletal muscle pain conditions, suggesting c entral hyperexcitability. The diagnosis of fibromyalgia requires a thorough exclusion of other rheumatologic and neurologic disorders. The differentia l diagnosis is complicated by an overlap to other chronic somatoform pain d isorders.