ABSTRACT
Complex regional pain syndrome, type I (CRPS I) (formerly known as reflex sympathetic dystrophy [RSD]) and complex regional pain syndrome, type II (CRPS II) (formerly known as causalgia) are symptom complexes that evoke a great deal of confusion. Very often, physicians do not recognize that these are separate and distinct entities, and commonly assume that they are disorders of the same etiology, as well as responsive to the same treatment. Clinically, this has not proven accurate. CRPS, type I is a group of symptoms and clinical signs that usually follows a minor injury to a limb. In contradistinction, CRPS, type II is usually associated with peripheral nerve injury, classically from a bullet wound or some other partial nerve damage. Throughout this chapter, for the sake of consistency, earlier references that used the terms of reflex sympathetic dystrophy (RSD) are referenced or quoted as CRPS, type I, despite the original nomenclature. This same approach is used for references using the term causalgia, which are changed for the sake of continuity, to CRPS, type II. In a very fine review article, Payne (1986) clearly defined the distinction between CRPS, type I and CRPS, type II, although at the time he called them RSD and causalgia, respectively. This has been further expanded by the International Association for the Study of Pain in a supplement edited by Merskey (1986) (Table 20.1). A further expansion of this comparison is offered by Baron, Blumberg, and Janig (1996) (Table 20.1A).
