Reflex sympathetic dystrophy syndrome is a severe, chronically painful condition usually involving one arm or leg. This condition has been called many other names, including algodystrophy, causalgia, shoulder-hand syndrome, Sudeck's atrophy and transient osteoporosis. In 1995, the name was changed officially to complex regional pain syndrome, or CRPS, although this name change has not been accepted universally.

Reflex sympathetic dystrophy syndrome is characterized by severe, constant, burning pain in the affected limb. The lightest touch over the limb, even a brush of clothing or a breeze, can be excruciatingly painful. The pain sometimes is accompanied by severe swelling, color changes, temperature changes (usually cooler, sometimes warmer) and increased sweating. Skin can become thinner, and nails can grow faster or become thickened or brittle. As the pain worsens, patients have difficulty moving the limb, which can lead to stiffness and more pain.

Reflex sympathetic dystrophy syndrome appears to be triggered by damage to nerve fibers in tissue that was injured in some way. These nerves then become hypersensitive to incoming sensory signals. Painful signals become more painful, and common stimuli such as light touch and temperature changes also are experienced as pain.

This condition usually starts after an injury or event, such as trauma, a fracture, an infection, surgery, a stroke or wearing a plaster cast. Often, the injury that triggers reflex sympathetic dystrophy syndrome is very mild compared with the pain that follows it. In addition, the pain is often not localized to the area that was injured. The earliest described cases were among Civil War soldiers in whom a gunshot wound that eventually healed was followed over days to weeks by severe pain in arms or legs.

This condition can occur at any age. It is most common in people between the ages of 40 and 60, but it is being diagnosed more frequently in children and adolescents. Researchers estimate that 12 percent to 21 percent of adults with paralysis on one side of the body (hemiplegia) and about 5 percent of adults with nerve injuries will suffer from reflex sympathetic dystrophy syndrome

In children with RSDS, girls are affected about five times more often than boys. Female dancers, competitive athletes and gymnasts are at greater risk of RSDS.

Symptoms of RSDS include:

• Intense pain, throbbing, burning and swelling, usually in the hand or foot
• Shiny, thin skin around the affected area
• Initially increased but later diminished hair over the affected area
• Brittle, thickened nails
• Dry and withered skin

The condition can progress through three stages, although not everyone goes through every stage. In the earliest stage, days to weeks after the precipitating injury, the limb can become dry, hot, red and painful. Even the lightest touch or the slightest movement can cause pain. Your doctor may not clearly identify reflex sympathetic dystrophy syndrome at this point because it can be mistaken for rheumatoid arthritis, infection, gout or another disorder.

Over the next few weeks to months, the skin can become shiny, thin and cool. The limb becomes mottled and purplish. There is considerable swelling. Pain worsens. The nails become brittle and can grow faster. As the limb becomes difficult to move, you may experience increased pain further up the limb. This might be related to muscle stiffness and soreness. Some people experience other movement problems, including weakness, spasm and tremor. An affected limb can become permanently flexed or bent, a condition called contractures. Finally, in some people, the skin can become drawn, dry and shriveled. The bones can become brittle from disuse. The skin, muscles and joints stiffen so that the affected area cannot be moved. Some patients have less pain at this point. Once the disease reaches this point, it is extremely difficult to treat.

Your doctor will ask questions about your medical history and will examine you. RSDS is diagnosed when all these symptoms are present: burning, spontaneous pain, hypersensitivity, swelling, temperature changes and sweating. In the earliest stages, before many of these features develop, diagnosis is difficult or impossible.

In later stages, X-rays sometimes show bone loss, especially around the joints. A bone scan can help to confirm the diagnosis, but the condition cannot be diagnosed with a bone scan alone. Two tests that evaluate nerve function electromyography and nerve conduction studies may be ordered to look for nerve damage or another cause of your symptoms.

Your doctor also may order a diagnostic sympathetic block. This is an injection in the neck or low back that reduces pain in some but not all patients. If the block is effective, this can help confirm the diagnosis.

Some physicians use thermography to help diagnose this condition. A thermogram is a color-coded scan that shows the amount of blood in various areas of the body. In a person with RSDS, a thermogram may show abnormal blood flow to the painful area.

Some people with RSDS improve without treatment, but getting early treatment improves your chances of pain relief. About half of people with RSDS are still experiencing pain six months after treatment was started.

There is no known way to prevent RSDS because the cause is not clear.

Physical or occupational therapy, together with supervised exercises, will be recommended. Maintaining movement is an important goal of treatment. Once a reasonable degree of movement is restored, an exercise routine will help strengthen muscles and joints and maintain functioning.

Medications can help manage pain. Corticosteroids and physical therapy can help ease pain during an acute episode, but long-term results are mixed. Medications that may help include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) and other pain relievers
• Capsaicin (a cream or ointment thought to interrupt pain signals)
• Certain antidepressants used in nerve pain treatment (called tricyclic antidepressants, including amitriptyline (Elavil))
• Blood pressure medications that affect the sympathetic nervous system, including prazosin (Minipress), propranolol (Inderal) and guanethidine (Ismelin)
• Bisphosphonates for example, alendronate (Fosamax) medications that reduce bone loss

A small device called a transcutaneous electrical nerve stimulator (TENS) unit sometimes can help relieve pain. The battery-operated device is thought to work by blocking nerve impulses. Biofeedback also can help control pain, blood flow and skin temperature.

Simple measures such as applying heat or cold are controversial. Applying cold might relieve pain temporarily, but some experts suggest that ice worsens the symptoms of reflex sympathetic dystrophy syndrome later on. The response to heat also varies.

When all else fails, your doctor may recommend an injection of a numbing agent near the affected nerves or alongside the spinal column to block the sympathetic nervous system (a sympathectomy). This procedure usually is done as a series of three to five injections given over seven to 14 days. If the numbing is effective, a more permanent procedure called a sympathectomy may be done. In this procedure, the nerves are destroyed with chemicals or by surgery.

Newer treatments include implanting a device that stimulates the spinal cord, and infusing a medication called baclofen (Lioresal) into the spinal fluid. Baclofen usually is used for muscle spasms. These treatments are considered invasive, do not always work and may be associated with complications. But for severe cases that have not responded to other treatments, the benefits may exceed the risks.

Contact your physician if you experience the symptoms of RSDS.

The earlier the condition is diagnosed, the better the prognosis. If treatment is started early, symptoms can disappear after as early as three months. Delayed treatment can lead to irreversible bone and muscle changes. The overall response to treatment is poor. In about 50 percent of cases, people with RSDS are still in pain months and even years later.

American Chronic Pain Association
P.O. Box 850
Rocklin, CA 95677
Toll-free: (800) 533-3231
Fax: (916) 632-3208
E-Mail: ACPA@pacbell.net
http://www.theacpa.org/

National Institute of Neurological Disorders and Stroke
P.O. Box 5801
Bethesda, MD 20824
Toll-Free: (800) 352-9424
http://www.ninds.nih.gov/