Reflex Sympathetic Dystrophy
RSD, more properly known since 1993 as CRPS (complex regional pain syndrome) usually with SMP (sympathetically mediated pain) is a complicated neurologic disorder of the autonomic nervous system. The autonomic nervous system is distinct from the central nervous system (brain) and peripheral nervous system (spinal cord and peripheral nerves). The sympathetic portion of this system is located alongside the spinal column and exists as chains of ganglia (like bunches of bait worms) and is responsible for the spontaneous constriction of blood vessels in response to certain stimuli such as heat, cold, fear, etc.
Rarely, and for unknown reasons, a stimulus can cause an abnormally vigorous and sustained response, leading to a cold, clammy, sweaty, swollen, blue extremity with searing or burning pain. Usually starting distally, e.g., in a finger or toe, and if unrecognized or untreated early, this dystrophic response can spread throughout the extremity. Via certain neurons in the spinal cord this process can spread to other extremities. Some unfortunate patients can become totally disabled with advanced RSD in one or more extremities.
The most common causes are minor injuries such as contusions, lacerations, or burns. Other causes include repetitive trauma, medical procedures, or heart attacks. Early diagnosis is essential to avoid the development of the condition.
The medical literature contains abundant peer accepted references. Treatment is difficult and not always successful. What is agreed upon in the world's literature is that if any success is to be obtained, treatment must be instituted within the first weeks or months. Treatment may consist of steroids, vasodilators, opioids, injections, or nerve blocks, and ultimately, may require surgery to sever the sympathetic connections.