Complex regional pain syndrome: recent updates

Abstract

Complex regional pain syndrome (CRPS) may be defined as a painful and disabling disorder affecting one or more extremities showing signs of vasomotor (relating to the constriction and dilatation of blood vessels), sudomotor (stimulation of sweat glands), inflammatory, and trophic changes (changes brought about in tissues from interruption or destruction of nerve, blood supply or both) in the affected extremity. CRPS can occur after even trivial injury and, on occasion, can develop spontaneously. It was first described as a spectrum of symptoms during the American Civil War by Silas Weir Mitchell and colleagues in their book entitled Gunshot Wounds and Other Injuries of Nerves, and named it causalgia. The gamut of symptoms stretches from a self-limiting mild condition to a severe, debilitating condition affecting the quality of life and having a high impact on activity. Owing to the varied manifestation, the patient can present to any specialty be it orthopaedics, rheumatology, neurology, dermatology, or pain medicine. Pain is an early presenting feature and can be the most prominent of symptoms. A high index of suspicion is needed as early diagnosis and treatment may prevent the progression of symptoms and prevent disability. It has been known by many names in the past, including reflex sympathetic dystrophy, algodystrophy, algoneurodystrophy, Sudeck’s dystrophy, and causalgia. In 1994, the International Association for the Study of Pain (IASP) came up with a standardized set of criteria to diagnose CRPS. Until then, numerous different diagnostic and clinical criteria were used. As IASP criteria lacked specificity, a new set of diagnostic criteria were adapted at a closed conference of leading experts from around the world in the Fall of 2004 in Budapest, Hungary—these were called the ‘Budapest criteria’ (Table 1). The Budapest criteria were compared with the former IASP criteria and found to have a higher specificity while maintaining sensitivity, and were validated. Clinical presentation