CRPS-I is a syndrome characterized by a continuing (spontaneous and/or evoked) regional pain that is seemingly disproportionate in time or degree to the usual course of pain after trauma or other lesion. The pain is regional (not in a specific nerve territory or dermatome) and usually has a distal predominance of abnormal sensory, motor, sudomotor, vasomotor/oedema and/or trophic findings. The syndrome shows variable progression over time. CRPS-I occurs after any form of trauma, particularly a fracture or soft tissue lesion. CRPS-II occurs after nerve damage.