Complex regional pain syndrome is also known as Causalgia, Reflex sympathetic dystrophy. -ed.
In this clinical article, Dr. Steven Horowitz of the University of Vermont and Massachusetts General Hospital discusses complex regional pain syndrome (CRPS), a consensus-defined clinical neuropathic pain syndrome with an illustrious history and fascinating ever-elucidating pathophysiology. CRPS presents with pain, hyperalgesia, and allodynia as well as motor, vasomotor, sudomotor, and trophic changes, most often induced by trauma or immobilization. It is likely that peripheral nerve injury produces neuroinflammation peripherally, and centrally in the dorsal horn, thalamus, and elsewhere, resulting in peripheral and central sensitization, enhancement of symptomatology, and spread to other anatomical areas. Multiple cortical changes have been demonstrated on fMRI when symptoms are most manifest, which seem to return to normal with clinical improvement. Treatment is based on restoration of limb function and relief of pain and other symptoms.