History of RSD The history and the discovery of RSD (Reflex Sympathetic Dystrophy) Syndrome and its symptoms have typically been associated with wars. While there is no doubt that RSD from physical stress and injury existed earlier, it was left up to war physicians to assign pathology to it. Silas Weir Mitchell, an army doctor during the Civil War, described the symptoms of "burning pain" left in soldiers long after the bullets have been removed. He attributed these residual and long lasting pains to major nerve injury. Weir was the first to call RSD causalgia (currently, specifically known as CRPS-2), which is Greek for "burning pain." He wrote that, "Under such torments, the temper changes, the most amiable grow irritable, the soldier becomes a coward, and the strongest man is scarcely less nervous than the most hysterical girl." Weir accurately reflected the symptoms. (PARC, 2004). Mitchell accurately described the symptoms associated with the disorder as feeling of heat in the afflicted area where the skin tone changed to a glossy, rash-like appearance. He also described, very accurately, the secondary, psychological symptoms of the disease.

World War I, army surgeon Rene Leriche first treated causalgia by administering numbing medication to the parasympathetic nerve endings associated with the region of pain. This was the first time the parasympathetic nervous system was implicated in the disorder. Later, William Livingstone, also working with the defense services described the symptoms of RSD with greater accuracy. He also identified, in injured soldiers, the spread of the symptoms -- mirror pains on the opposite side of the body. This proved that there the origins of the disorder are at higher centers in the brain.

The history and the discovery of RSD can also be traced, parallelly to other countries. Sudeck and Keinbock found and confirmed the symptoms of RSD and also showed that disuse of parts of the body due to pain could cause osteoporosis. In France, in 1890, the physician Charcot, attributed the symptoms of RSD to psychosomatic origins. We know now that this is not true. Nonetheless, Charcot contributed a great deal to the school of thought in accurately describing the symptoms of RSD. In 1947, Steinbrocker named RSD, "shoulder-hand" syndrome. (PARC, 2004).

Definition of RSD

While RSD Regional Sympathetic Dystrophy has been readily named after earlier attempts based on the symptoms of the condition, identifying a specific cause of the disease and treating it effectively has been very difficult. This is because the incidence of RSD is difficult to pinpoint. The symptoms vary in severity. The aftereffects are also largely varied. Though RSD is often caused by injuries from high velocity impact such as bullets and shrapnel, on occasion it arises from no known injury. Treatment is difficult because the symptoms are usually masked and misdiagnosis occurs often. (Schwartzman & McLellan, 1987).

RSD has been better defined by the acronym, CRPS (Complex Regional Pain Syndrome). There are two types of CRPS. CRPS Type 1 is also known as RSD. For the purpose of this, only CRPS Type 1 will be explored. CRPS Type 2 is known as causalgia. The two types should not be used interchangeably. Though the symptoms are most often the same within internal variations in severity and aftereffects, what distinguishes RSD (CRPS 1) from Causalgia or CRPS 2 is that the former is due to no identifiable nerve injury and the latter is due to a severe nerve injury as was identified in soldiers.

The precipitating causes of RSD are difficult to identify because even remote innervations to the sympathetic nervous system can cause symptoms. Causative factors are even more difficult to identify because the sympathetic nervous system coordinates and controls many of the involuntary functions necessary to sustain life. The most easily identifiable cause is trauma. The difficulty here is that a minor injury, which most patients ignore when the initial pain goes away, may also trigger symptoms of RSD. Heart disease and myocardial infarctions are other known causes, as are cervical spine- and other spinal cord disorders. Infections and trauma from surgery may also cause RSD. Cerebral lesions are difficult to identify externally, though they have been implicated. Repetitive motion disorders such as carpal tunnel syndrome can also cause symptoms of RSD. (Bonica, 1988).

Both types of CRPS are associated with cardinal and secondary symptoms. Very often, psychological factors such as depression are directly attributed to the disorder. (Ciccone, Bandilla, & Wu, 1997). To date however, there has been no identifiable psychological symptom for RSD. Researchers have concluded that depression that arises from...

(Veldman et al., 1993). The pain felt is usually intense and burning. The area of affliction may also be at a higher temperature (or sometime at a lower temperature). The pain, with time, travels across the extremity. The pain occurs long after the wounds from the injury are healed. In case of minor injuries, the pain is often incommensurate with the severity of the injury. With RSD, hyperpathia and allodynia are found. The first is about pain felt long after the pain stimulus is removed. The second is pain at even the slightest touch. Pain from RSD increases with movement. It also increases in cold weather. Slight climatic changes in pressure can exacerbate the pain.
In addition to the pain, edema or swelling of afflicted area due to fluid retention also occurs. The skin takes on glossy tones and there is significant discoloration in hues ranging from red, blue, purple and gray. There is also muscle stiffness.

Due to the patient's reticence to move, which worsens the pain, osteoporosis and atrophy often occurs. There is a breakdown of skin tissue. If RSD afflicts the hand, there is thickening in the palmar fascia. Reddening of the skin occurs due to the dilation of capillaries (erythema). One of the secondary characteristics of RSD is hyperhidrosis or excessive perspiration. This often results in dehydration. (Lankford & Thompson, 1977).

CRPS is unique and complex. It can affect the blood vessels, bones, muscles and nerves with varying severity. The complexity of the disorder points to the fact that it might be associated with the sympathetic and parasympathetic nervous system. The mammalian nervous system consists of the central nervous system and the autonomic nervous system. The Central Nervous System consists of the brain and the spinal cord. The autonomic nervous system consists of sympathetic and parasympathetic nervous system. The autonomic nervous system consists of nerves that run from the hypothalamus (sympathetic) and the medulla oblongata (parasympathetic) and the nether regions of the body. These are sensory and motor nerves. The motor nerves control muscle function. The pre-ganglion motor neurons of the sympathetic nervous system arise from the spinal chord. They pass into the ganglia that are on either side of the spinal chord. These pre-ganglion motor neurons then synapse with post-ganglion neurons. These then pass into the spinal nerves, which innervate the extremities up to the outer dermis of the skin. This is the mechanism that is most closely associated with RSD. It explains some of the symptoms.

Additionally, (but not of any specific relevance here), the sympathetic nervous system is also associated with the involuntary functions such as the raising of the heartbeat and blood pressure, dilation of pupils, controlling peristalsis in the gastro intestinal tract, dilating the trachea, stimulation of the conversion of glycogen to glucose in the liver (and vice versa). In a sense therefore, the sympathetic nervous system trains the body to react. (Bakewell, 1995).

The parasympathetic nervous system works in conjunction with the sympathetic nervous symptoms. Briefly described, the parasympathetic nervous system returns the body to the normal state. For example, if the sympathetic nervous system raises the heart rate or dilates the pupils, the parasympathetic nervous system lowers the heart rate and constricts the pupils back to normal. RSD is thought to be a result of excitation of peripheral nerve elements with an abnormal and severe sympathetic response resulting in the pain and signs and symptoms of RSD. (Bakewell, 1995).

From a mechanistic standpoint, it is important to understand how the sympathetic nervous system plays a role the cause of RSDS. The sympathetic nervous system is often associated with the "fight or flight" aphorism. This means that it triggers an involuntary reaction mechanism to protect the body from violence or unwanted stimuli. Muscle vibrations cause shivering, which is a warming mechanism against cold. Or, firing of sympathetic nerves causes blood vessels in the skin to contract, forcing blood deep into muscle and enabling the victim to use his muscle to get up after an acute injury and escape from further danger. Also the decreased supply of blood to the skin reduces blood loss through superficial injuries that may occur on the surface of the body. The role of the sympathetic nervous system is therefore to function for a short period of time. The parasympathetic nervous system then takes over to bring the body back to normal. In RSD/CRPS, the sympathetic nervous system functions abnormally. It fires, with…