reflex sympathetic dystrophy
about reflex sympathetic dystrophy syndrome
Reflex sympathetic dystrophy syndrome (RSDS), also known as complex regional pain syndrome, is a rare disorder of the sympathetic nervous system that is characterized by chronic, severe pain. The sympathetic nervous system is that part of the autonomic nervous system that regulates involuntary functions of the body such as increasing heart rate, constricting blood vessels, and increasing blood pressure. Excessive or abnormal responses of portions of the sympathetic nervous system are thought to be responsible for the pain associated with reflex sympathetic dystrophy syndrome.
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The symptoms of reflex sympathetic dystrophy syndrome typically begin with burning pain, especially in an arm, finger(s), palm of the hand(s), and/or shoulder(s). In some individuals, RSDS may occur in one or both legs or it may be localized to one knee or hip. Frequently, RSDS may be misdiagnosed as a painful nerve injury. The skin over the affected area(s) may become swollen (edema) and inflamed. Affected skin may be extremely sensitive to touch and to hot or cold temperatures (cutaneous hypersensitivity). The affected limb(s) may perspire excessively and be warm to the touch (vasomotor instability). The exact cause of RSDS is not fully understood, although it may be associated with injury to the nerves, trauma, surgery, atherosclerotic cardiovascular disease, infection, or radiation therapy.
signs and symptoms
The symptoms of reflex sympathetic dystrophy syndrome most commonly affect an arm and/or shoulder, and sometimes a leg and/or hip. The onset of symptoms can be slow, often beginning with gradual stiffness, discomfort, a burning sensation, and/or weakness in the affected area. However, in some cases, the symptoms appear suddenly and consist of severe pain, stiffness, and extreme sensitivity (hyperesthesia) of the affected area.
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Pain and swelling associated with reflex sympathetic dystrophy syndrome may occur at the site of a previous injury (causalgia), surgery, trauma, or radiation therapy. Pain may extend beyond the original area of the injury and is more severe than the original trauma. Eventually, the entire limb may become involved and, in some cases, symptoms can spread to other areas of the body. Touching or covering the affected area with clothing or bed sheets may cause profound pain. Other early symptoms of this syndrome include redness of the skin, tenderness, excessive localized sweating (hyperhidrosis), and/or limited mobility of the affected extremity. Warm temperatures may intensify pain in some people with RSDS.
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The symptoms of RSDS may worsen after 3 to 6 months. Pain generally becomes more intense and range of motion may become more restricted. Muscle weakness is also common during this stage of the disease. The skin over the affected areas may be pale or have a “pitted” appearance with an abnormal blue coloration (cyanosis) due to the lack of adequate blood supply to the area.
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In some cases, a later stage of reflex sympathetic dystrophy syndrome may be associated with a decrease in pain. In other late cases, the pain may become constant (intractable). Only mild pain relief may be achieved with most treatment options. Muscle tremors and spasms may be present and muscle mass may diminish in size (atrophy). Strength in the affected limb may also be greatly reduced. Joints (e.g., shoulder) may become “frozen” or fixed in place (tendon contracture); sometimes, these joint changes are permanent. Bone mass may also diminish (osteoporosis), skin lesions may develop (i.e., atrophic changes), and grooves may appear in the nails.
affected populations
RSDS/CRPS can occur at any age but is most common between the ages of 40 and 60. It occurs slightly more often among females than among males. It has been reported in children and young adults.
related disorders
Some disorders may be very limited in their functional effects, while others may involve substantial disability and support needs. The degree of ability or disability may vary over time and across different life domains. Furthermore, continued disability has been linked to institutionalization, discrimination and social exclusion as well as to the inherent effects of disorders. Alternatively, functioning may be affected by the stress of having to hide a condition in work or school etc., by adverse effects of medications or other substances, or by mismatches between illness-related variations and demands for regularity.
u.s. mental disorder statistics
Symptoms of the following disorders can be similar to those of reflex sympathetic dystrophy syndrome (RSDS). Comparisons may be useful for a differential diagnosis:
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Erythromelalgia is a rare vascular disorder that affects the skin of the feet and/or hands and is characterized by episodes of sudden widening of the blood vessels (paroxysmal vasodilatation) in these areas. Symptoms may include episodes of intense burning pain in the feet and sometimes in the hands. The skin over the affected areas is typically bright red, swollen, and hot to the touch. Symptoms generally become worse during the hot weather and gradually become more severe over time. An acute episode of symptoms can be brought on by a combination of warm temperatures and exercise. Primary erythromelalgia is inherited as an autosomal dominant genetic trait. Secondary erythromelalgia can occur as the result of an underlying disorder such as polycythemia vera, thrombocythemia, or lupus. (For more information on this disorder, choose “Erythromelalgia” as your search term in the Rare Disease Database.)
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Thalamic syndrome, also known as Dejerine-Roussy syndrome, is a rare neurological disorder that occurs because of damage to the thalamus, which is that part of the brain responsible for mediating sensation. The disorder is characterized by pain and the loss of sensation. Different parts of the body may be affected, especially the face, arms, and/or legs. Intense pain, which is exaggerated by touch or cold temperatures, may occur in affected areas. A slow tremor of the hand, arm, foot, or leg may be present and becomes more intense during voluntary movement. (For more information on this disorder, choose “Thalamic” as your search term in the Rare Disease Database.)
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Carpal tunnel syndrome is a neurological disorder characterized by compression of the median nerve, which passes through the carpal tunnel inside the wrist (peripheral nerve entrapment). Symptoms of this disorder affect the hand and wrist and may include pain, numbness, loss of feeling in the finger tips, and/or unusual sensation such as burning or “pins and needles”. Many people with carpal tunnel syndrome are awakened during the night by a burning discomfort in the wrist and/or fingers. This pain can usually be relieved by vigorously shaking or flexing the affected wrist and fingers. This is a classic sign of carpal tunnel syndrome. The thumb, index, middle, and part of the ring finger are most commonly involved. Carpal tunnel syndrome may be caused by occupational or sports activities (repetitive stress injury or RSI) or may occur as the result of another underlying disorder. (For more information on this disorder, choose “Carpal Tunnel” as your search term in the Rare Disease Database.)
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Tarsal tunnel syndrome is a neurological disorder characterized by compression of the posterior tibial nerve, which passes through the ankle toward the foot (peripheral nerve entrapment). Symptoms may include painful burning, tingling, or numbness in the foot. The pain is often most intense at night and may be relieved by moving the foot. The exact cause of tarsal tunnel syndrome is not fully understood, although it may be the result of a past injury or fracture. (For more information on this disorder, choose “Tarsal Tunnel” as your search term in the Rare Disease Database.)
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Peripheral neuropathy is a term used to describe a group of neurological conditions that affect the nerves outside the central nervous system (i.e., arms and legs). Most frequently, the hands and feet are affected. Peripheral neuropathy can produce symptoms that relate to sensory, motor, and/or autonomic malfunction. A single nerve may be involved (mononeuropathy), or many nerves may be affected (polyneuropathy). Symptoms may include weakness, pain, numbness, and/or burning or tingling sensations, especially in the hands and feet. Trauma, fracture, penetrating injuries, and/or an underlying disease process may cause peripheral neuropathy. (For more information on this disorder, choose “Peripheral Neuropathy” as your search term in the Rare Disease Database.)
diagnosis
The diagnosis of RSDS may be confirmed by a thorough clinical evaluation that includes a complete history of symptoms and a comprehensive physical examination. Other specialized tests (e.g., skin temperature readings, x-rays, thermographic studies, and bone scans) may also suggest the diagnosis. A positive response to sympathetic blockade (see below) confirms the diagnosis of reflex sympathetic dystrophy syndrome.
treatment
Although no standard treatment for RSDS has been developed, prevention and early treatment of symptoms are recommended. In most cases, the earlier that treatment begins, the more effective it is likely to be.
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Daily physical therapy should begin when the diagnosis of RSDS is confirmed. Whirlpool and paraffin wax baths are sometimes beneficial to help maintain mobility. Ice or heat applications should be avoided in most cases because they may result in overstimulation of nerve endings, leading to increased discomfort. Splinting of the affected area while the patient is at rest may help to prevent muscle contraction deformities (contractures), especially in the hand.
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A special device known as a transcutaneous electrical nerve stimulator (TENS) may be used to treat people in the early stages of this syndrome. TENS treatment may also be added to an existing therapy program. The device alters nerve transmissions and helps to block the nerve impulses that cause pain.
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Local or systemic glucocorticosteroid drugs (e.g., prednisone) may be effective for the treatment of some cases of reflex sympathetic dystrophy syndrome. However, they must be used with caution. Side effects are rarely seen with the lower doses recommended for the treatment of RSDS, but weight gain, swelling of the face (moon facies), and digestive upset have been reported. Other drugs that relieve pain (i.e., analgesics), including nonsteroidal antiinflammatory medications (e.g., ibuprofen or ketorolac) and muscle relaxants, sometimes help to relieve the symptoms of the disorder.
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Some people with reflex sympathetic dystrophy syndrome may be treated with other drugs that block nerve function such as intravenous infusion of the drug guanethidine (an orphan drug). Propranolol (a beta blocker), nifedipine (a vasodilator), phenytoin (an anticonvulsant), and tricyclic drugs (antidepressants) have also been used with occasional success to treat people with reflex sympathetic dystrophy syndrome. Drugs that reduce the activity of the sympathetic nerves (sympatholytic agents), such as phenoxybenzamine, have also been used to treat RSDS. Electroacupuncture has had some success in treating people with early, mild cases of RSDS.
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A specialized procedure known as a sympathetic blockade can be helpful for the treatment of intractable pain associated with RSDS. This procedure should be done as early in the course of the disease as possible since those treated earlier seem to experience better pain relief. During this procedure, drugs (e.g., lidocaine, buflomedil, or bupivacaine with epinephrine) are injected directly into the site of the suspected group of overactive nerve fibers. When the pain is located in an arm or shoulder, a stellate ganglion block is used. When pain is in a lower extremity, a lumbar sympathetic block is performed. The block is considered successful if blood circulation to the affected area is improved and if the patient reports a significant reduction in pain. These treatments can be given in a series or as indicated by the relief of symptoms. Sympathetic blocks have a unique advantage in that, when successful, they can confirm the diagnosis as well as provide rapid pain relief in many cases.
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If blockade is not successful in reducing the symptoms of reflex sympathetic dystrophy syndrome, some people may then undergo a procedure known as a sympathectomy. During a pharmacologic (chemical) sympathectomy, nerves that control the constriction of blood vessels are destroyed by the injection of certain drugs. This allows the blood vessels to widen (dilate), allowing more blood to flow to the affected area and reducing pain. In a surgical sympathectomy, sympathetic nerves surrounding certain blood vessels (sheath) are surgically removed. The risks associated with a surgical sympathectomy are usually greater than those of a chemical sympathectomy.
Other treatment for RSDS is symptomatic and supportive.
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An interdisciplinary committee of the Reflex Sympathetic Dystrophy Syndrome Association has written practice guidelines for the diagnosis, treatment, and management of RSDS. The guidelines, written in English and Spanish, are available on the organization's web site at http://www.rsds.org.