The history and definition of complex regional pain syndrome

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 RSD is due to the cardinal symptoms like pain and inherent skin conditions.

The cardinal symptoms of CRPS Type 1 are led by pain. (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 pain and swelling responses when the body does not reactively require it. In a sense therefore, one might also implicate the failure of the parasympathetic nervous system in bringing the body back to normal function. (Blumberg et al., 1997).

Progress of the Disease

CRPS Type 1 progresses in four stages. These are Dysfunction, Dystrophy, Atrophy, and Irreversible Failure of the Immune System. Because of the complexity and problems with misdiagnosis, many research panels have decided to avoid the process of staging. The disorder has been considered too complex to categorize. Incorrect categorization leads to significant problems for patients. Though RSD does not itself cause death, one has to be cautious of the problems with failure of the immune system and secondary effects.

Dysfunction or Stage I: This stage is also called early RSDS. Here, the pain is severe. But it is limited to the sight of injury. Patients often describe the pain to be of a burning and aching type. This pain often causes quality of life issues and emotional distress. A temperature reading often indicate that the local region where the pain is at either a higher or lower temperature than the rest of the body by up to one degree. Swelling is seen in the area of pain. Stage 1 is often characterized by abnormal hair or nail growth. Some changes in the bone mass or bone structure are also seen as a result of bone scans. This stage is also marked by muscle cramps. The skins color of the afflicted area changes from red to blue; the temperature changes from hot to cold. Stage 1 is marked by increases sweating. This is the best stage for treatment and complete recovery from RSDS. Unfortunately, depending upon the severity of the pain and associated symptoms, patients tend to ignore it or medical professional treat the pain as caused by other ailments, often prescribing incorrect treatment. It was mentioned earlier of the suggestion of eliminating suggestion. This is because of the variation in time associated with this stage. Typically, from the onset of the symptoms, the stage of dysfunction lasts for three months. In some however, it might last for shorter durations. In others, Stage 1 might last for several years. Research has shown that some patients never progress beyond this stage.

Dystrophy or Stage 2: This stage is also called the established stage. This stage is marked by increased severity of pain. The pain starts spreading at this stage, as does the swelling. The swelling also changes in character. The edematous tissue becomes indurate. In other words, it becomes hard to the touch, progressing from the soft swelling of the dysfunction stages. The excess growth of hair and nails is now replaced by falling hair and breakdown in nail-tissue giving rise to brittleness and cracks.

The dehydration from excess sweating causes dryness that it noticeable in the hands and palms. This is the stage when osteoporosis sets in. Bone scans or radiographs at this point are usually positive. Due to inactivity and reticence to move because of the pain, muscle tissue begins to waste away. The atrophy also extends to the skin and subcutaneous tissue. Once again, the severity and length of this stage are in dispute. In most patients however, the stage of dystrophy lasts between three months to a year.

Atrophy or Stage 3: The pain is still there and it is still severe. Occasionally, the pain diminishes but it is present. The pain also spreads to the entire limb. The spreading of the pain is also more significant. Studies have shown that the pain not only spreads proximally and laterally, there is a mirror affliction on the symmetrically opposite side of the body -- in some cases. (Maleki et al., 2000). The skin of the afflicted area becomes thin and shiny. This stage however, is marked by a lack of edema. Skin flare-ups and other problems occur spontaneously. Bone demineralization occurs. Muscle tissue is also often irreversibly damaged. Because of the progressive destruction of non-bony tissue such as muscles, ligaments and tendons, joint motion becomes severely restricted. Such joint motions are called contractures. In the atrophy stage, a small percentage of patients have generalized RSD. This means that it affects the entire body.

Stage Four: The fourth stage is when the disease becomes chronic enough and it is serious enough that the patient develops disturbance of immune system, hypertension, chest pain, stroke, and heart attack, and is at higher risk than the general population for high blood pressure and cancer. In the fourth stage, there is a high mortality due to suicide from secondary and psychosomatic effects. (Parillo, 2001).

Diagnosis

As has been mentioned previously in this work, diagnosing CRPS is very difficult because of the wide and varied nature of the symptoms. In believing that a patient has RSD, a potentially far more serious condition may be ignored. On the other hand, RSD symptoms may initially be ignored because the symptoms are not severe enough to warrant medication. Yet in some situations, the symptoms often correct themselves.

It is much easier to diagnose Type II CRPS because of the knowledge of occurrence of nerve damage from an identifiable injury. RSD is more difficult to detect; because of there is no known cause for the symptoms. (Aronoff et al., 2002).

The medical practitioner must adopt a more cautious approach in diagnosing RSD for the above-mentioned reasons. Practitioners aver that they should identify some symptoms more than other symptoms. These symptoms have been described earlier in detail. More often diagnosis can be easier if spreading occurs. On the other hand, in case of mirror afflictions, it is more difficult to identify the origin of the affliction, especially if the progress of the disorder has been slower.

The key aspects of diagnosis are first, pain that is not proportionate to the injury. Additionally, other abnormal manifestations of the sympathetic nervous system, movement disorder, dystrophy and atrophy of the soft and hard tissue as evidenced by X-rays or three-phase bone scans are also diagnostic tools. Since afflicted areas are characterized by difference in temperatures, thermograms are also used to identify RSD. Experts believe that identifying one symptom is sufficient to make an initial diagnosis of CRPS.

Treatments

In treating CRPS symptoms, considering that it is not a disease, treatment is often done for the symptoms. A difficult or wrong diagnosis is often followed by incorrect treatment to the detriment of patient welfare. For example, placing the afflicted region in an immobilizing cast can cause further atrophy. Experts believe that caution is warranted and education of the patient is paramount. Practitioners are cautioned to encourage normal usage of limb. Treatment modalities often start with efforts to minimize pain. A determination of the contribution of the sympathetic nervous system to the pain is also important. (Stanton-Hicks et al., 1998).

In treating pain, different types of pains are identified and the medication prescribed is different for each of them. (Low et al., 1995). Muscle cramps associated with spasms and dystonia are treated with clonazepam and baclofen. The same medication is often used to treat muscle stiffness. The latter allow the proper use of limbs and muscles preventing atrophy.

Physical therapy is called for to use muscles thus preventing disuse. Therapy is beneficial but patients are strongly cautioned to obtain the supervision of a qualified medical practitioner who is aware of the needs of CRPS patients. Ganglia transmit sympathetic nerve impulses. Deadening the pain impulses is carried out by an anesthetist using nerve blockers injected directly into the ganglia. The center for this injection, if the points of affliction are in the upper extremities is, in the region along the windpipe. If the lower extremities are afflicted, then the injection is delivered in the lumbar region.

The sympathetic nerves that innervate the afflicted area can be deadened by surgical procedures called sympathectomies. (Kemler et al., 2000). This disrupts the traveling of the pain impulse. TENS-like gadgets might also be implanted in the patient so that a constant low impulse electrical stimulus can be delivered. Alternatively, the spinal cord can also be stimulated by placing electrodes in the affected area. (Barolat, Schwartzman, & Woo, 1989). These electrical signals replace pain with pleasant sensation creation stimuli. Intrathecal drug pumps are directly implanted in the patient to release doses of pain killing opioids directly into the spinal fluid. (Paice, Penn, & Shott, 1996).

Prognosis

The best chance of treating the diseases is if it is identified in the early stage, with a treatment success rate of more than eighty percent. Three months is a reasonable time to make an accurate diagnosis. If treatment is delayed, severe atrophying can result in irreversible damage to the tissues. In fifty percent of the cases, the pain persists from six months to several years. Research in the area led and financially supported by the NINDS has allowed researchers to understand the etiology and associated characteristics of CRPS better with passing time. This research is conducted at the NIH laboratories in Bethesda, Maryland. NIH-funded research is also taking place in research and academic institutions all over the world

Secondary Effects of the Disease

Quality of life is seriously affected due to constant pain, even in the early stages of the illness. Suicidal tendencies rise especially in the later stages of the disorder. Depression and anxiety are the result of the pain, immobility and progressing disease and symptoms. Psychological factors are not identified as symptoms of CRPS. (Ciccone, Bandilla, & Wu, 1997). It is essential that a psychological profile be established along with other factors related to the family situation.

Additionally, the potential for drug abuse and the threshold for pain are important considerations. Education of the patient is important. Knowledge of the treatment protocol can help the patient be focused. Also important is that the patient be properly motivated to follow the treatment regimens.

Since the patient is in constant pain, it is difficult for those around the person. Family life suffers significantly. There is an inability to work. Legal issues are also very important in terms of treating patients. Studies have shown that some patients who suffer from RSD symptoms only seek treatment because they need compensation or other legal recourse. In addition to typical treatment, other pain reducing modalities such as relaxation, breathing and hypnosis are also called for.

Resources Available

Though CRPS remains a disease that is complex at every step from diagnosis to treatment, there are several resources available to patients. The NINDS has made a pamphlet available "Pain: Hope through research." The NINDS website (NINDS, 2004). also informs about aspects of RSD. Since treatment of pain is considered the most important aspect of RSD, this website also gives contact information for different associations that deal with pain. A few examples are American Chronic Pain Association (ACPA), National Chronic Pain Outreach Association (NCPOA), Mayday Fund [For Pain Research], International Research Foundation for RSD/CRPS.

Other websites such as RSDSA website offers comprehensive information ranging from daily activities to resources to current clinical trials and relevant research. (RSDS, 2004).