Abnormal Pain Modulation in Patients with Spatially Distributed Chronic Pain: Fibromyalgia

摘要

Many chronic pain syndromes including fibromyalgia, irritable bowel syndrome, chronic fatigue syndrome, migraine headache, chronic back pain, and complex regional pain syndrome are associated with hypersensitivity to painful stimuli and with reduced endogenous pain inhibition. These findings suggest that modulation of pain-related information may be related to the onset and/or maintenance of chronic pain. Although pain sensitivity and pain inhibition are normally distributed in the general population, they are not useful as reliable predictors of future pain. The combination of heightened pain sensitivity and reduced pain-inhibition, however, appears to predispose individuals to greater risk for increased acute clinical pain (e.g., postoperative pain). It is unknown at this time whether such pain processing abnormalities may also place individuals at increased risk for chronic pain. Psychophysical methods, including heat sensory and pressure pain testing have become increasingly available and can be used for the evaluation of pain sensitivity and pain inhibition. However, long-term prospective studies in the general population are lacking which could yield insight into the role of heightened pain sensitivity and pain disinhibition for the development of chronic pain disorders like fibromyalgia.