Overview of complex regional pain syndrome and recent management using spinal cord stimulation.

Complex regional pain syndrome (CRPS) is an enigmatic disease process affecting the upper and lower extremities. It consists of various combinations of sensory, autonomic, and motor abnormalities, the pathogenesis of which is unclear. Formally known as reflex sympathetic dystrophy or causalgia, CRPS has a revised taxonomy since 1994. The International Association for the Study of Pain established 2 categories, type I and type II, based on precipitating events. This syndrome manifests in 3 progressive stages, displaying peripheral and central neurologic aberrancies. The exact triggering mechanism is unclear but appears to involve neurogenic inflammation from axonal damage to small-fiber distal nerves. Central sensitization independent of afferent input and central somatotopic reorganization may be contributory in successive stages. Treatment goals are twofold: management of pain and restoration of function. Time is critical, as therapeutic effectiveness is limited in the latter stage. Various treatment modalities, including medication regimens, sympathetic nerve blocks, and physical therapy have met with differing degrees of success. Recent advances in spinal cord stimulation are promising. Although initially costly, this may prove to be the least expensive and most effective treatment in the long-term.