Complex regional pain syndrome: diagnostic controversies, psychological dysfunction, and emerging concepts.

Complex regional pain syndromes (CRPS) types I and II are neuropathic pain disorders that involve dysfunction of the peripheral and central nervous system. CRPS type I and type II were known formerly as reflex sympathetic dystrophy and causalgia, respectively. Most experts believe that a multidisciplinary approach including pharmacotherapy, physiotherapy, and psychotherapy is warranted. Historically, there has been considerable controversy regarding this disease entity. In particular, the precise mechanism of the sympathetic dysfunction as well as the nature of the psychological dysfunction commonly observed in patients with CRPS has been the subject of considerable debate. Current strides in our understanding of the pathophysiology of this disease have improved treatment options.