ABSTRACT The complex regional pain syndromes (CRPS I and CRPS II), also known as reflex sympatheticThe complex regional pain syndromes (CRPS I and CRPS II), also known as reflex sympathetic dystrophy and causalgia, have been recognized for the past 2,500 years and believed in for the past 150, but they have yet to be understood. These syndromes can be characterized by discrete sensory, motor, a...