What is reflex sympathetic dystrophy/complex regional pain syndrome?

RSD/CRPS is a chronic condition characterized by severe burning pain, pathological changes in bone and skin, excessive sweating, tissue swelling, and extreme sensitivity to touch. The syndrome is a nerve disorder that occurs at the site of an injury (most often to the arms or legs). It occurs especially after injuries from high-velocity impacts such as those from bullets or shrapnel. However, it may occur without apparent injury.

The condition called “causalgia” was first documented in the 19th century by physicians concerned about pain that Civil War veterans continued to experience after their wounds had healed. Doctors often called it “hot pain,” after its primary symptom. Over the years, the syndrome was classified as one of the peripheral neuropathies, and later, as a chronic pain syndrome. Currently, there are two types of CRPS that are differentiated-type I and type II. Both types share the same basic set of symptoms, but have one distinct difference: type I (previously referred to as RSD) describes cases in which there is no nerve injury, while type II (formerly called causalgia) refers to cases in which a distinct nerve injury, for example from a gunshot wound, has occurred

What are the symptoms of RSD/CRPS?

The symptoms of RSD/CRPS usually occur near the site of an injury, either major or minor, and include: burning pain, muscle spasms, local swelling, increased sweating, softening of bones, joint tenderness or stiffness, restricted or painful movement, and changes in the nails and skin. One visible sign of RSD/CRPS near the site of injury is warm, shiny red skin that later becomes cool and bluish.

The pain that patients report is out of proportion to the severity of the injury and gets worse, rather than better, over time. It is frequently characterized as a burning, aching, searing pain, which may initially be localized to the site of injury or the area covered by an injured nerve but spreads over time, often involving an entire limb. It can sometimes even involve the opposite extremity. Pain is continuous and may be heightened by emotional stress. Moving or touching the limb is often intolerable. Eventually the joints become stiff from disuse, and the skin, muscles, and bone atrophy.

The symptoms of RSD/CRPS vary in severity and duration. However, there are usually three stages associated with RSD/CRPS, and each stage is marked by progressive changes in the skin, nails, muscles, joints, ligaments, and bones. Stage one lasts from 1 to 3 months and is characterized by severe, burning pain at the site of the injury. Muscle spasm, joint stiffness, restricted mobility, rapid hair and nail growth, and vasospasm (a constriction of the blood vessels) that affects color and temperature of the skin can also occur.

In stage two, which lasts from 3 to 6 months, the pain intensifies. Swelling spreads, hair growth diminishes, nails become cracked, brittle, grooved, and spotty, osteoporosis becomes severe and diffuse, joints thicken, and muscles atrophy.

As the patient reaches stage three, changes in the skin and bones become irreversible, and pain becomes unyielding and may now involve the entire limb. There is marked muscle atrophy, severely limited mobility of the affected area, and flexor tendon contractions (contractions of the muscles and tendons that flex the joints). Occasionally the limb is displaced from its normal position, and marked bone softening is more dispersed.

What causes RSD/CRPS?

RSD/CRPS was originally thought to be the result of malfunctioning nerves of the sympathetic nervous system-the part of the nervous system responsible, for example, for controlling the diameter of blood vessels. This idea has been called into question and the mechanism remains controversial.

Since RSD/CRPS is most often caused by trauma to the extremities, other conditions that can bring about RSD/CRPS include sprains, fractures, surgery, damage to blood vessels or nerves, and cerebral lesions. The disorder is unique in that it simultaneously affects the nerves, skin, muscles, blood vessels, and bones.

Who gets it?

RSD/CRPS can strike at any age, but has usually been more common between the ages of 40 and 60. Recent reports show that the number of RSD/CRPS cases among adolescents and young adults is increasing. It affects both men and women, but is most frequently seen in women.

Investigators estimate that two to five percent of those with peripheral nerve injury and 12 to 21 percent of those with hemiplegia (paralysis of one side of the body) will suffer from RSD/CRPS.

How is RSD/CRPS diagnosed?

RSD/CRPS is often misdiagnosed because it remains poorly understood. Diagnosis is complicated by the fact that some patients improve without treatment. A delay in diagnosis and/or treatment for this syndrome can result in severe physical and psychological problems. Early recognition and prompt treatment provide the greatest opportunity for recovery.

RSD/CRPS is diagnosed primarily through observation of the symptoms. However, some physicians use thermography — a diagnostic technique for measuring blood flow by determining the variations in heat emitted from the body — to detect changes in body temperature that are common in RSD/CRPS. A color-coded “thermogram” of a person in pain often shows an altered blood supply to the painful area, appearing as a different shade (abnormally pale or violet) than the surrounding areas of the corresponding part on the other side of the body. An abnormal thermogram in a patient who complains of pain may lead to a diagnosis of RSD/CRPS. X-rays may also show changes in the bone.

What is the prognosis?

Good progress can be made in treating RSD/CRPS if treatment is begun early, ideally within 3 months of the first symptoms. Early treatment often results in remission. If treatment is delayed, however, the disorder can quickly spread to the entire limb and changes in bone and muscle may become irreversible. In 50 percent of RSD/CRPS cases, pain persists longer than 6 months and sometimes for years.

What is the treatment?

Physical therapy is the mainstay of therapy. Physicians use a variety of drugs to treat RSD/CRPS, including corticosteroids, vasodilators, and alpha- or beta-adrenergic-blocking compounds. Elevation of the extremity may be helpful. Injection of a local anesthetic, such as lidocaine, is sometimes used. Injections are repeated as needed. TENS (transcutaneous electrical stimulation), a procedure in which brief pulses of electricity are applied to nerve endings under the skin, has helped some patients in relieving chronic pain.

In some cases, surgical or chemical sympathectomy-interruption of the affected portion of the sympathetic nervous system-has been used to relieve pain. Surgical sympathectomy involves cutting the nerve or nerves, destroying the pain almost instantly. But surgery is controversial and may also destroy other sensations.

Are there any other disorders like RSD/CRPS?

RSD/CRPS has characteristics similar to those of other disorders, such as shoulder-hand syndrome, which sometimes occurs after a heart attack and is marked by pain and stiffness in the arm and shoulder; Sudeck’s syndrome, which is prevalent in older people and in women and is characterized by bone changes and muscular atrophy, but is not always associated with trauma; and Steinbrocker’s syndrome, which affects both sexes but is slightly more prevalent in women, and includes such symptoms as gradual stiffness, discomfort, and weakness in the shoulder and hand.

What research is being done?

The National Institute of Neurological Disorders and Stroke (NINDS), a part of the National Institutes of Health (NIH), supports and conducts research on the brain and central nervous system. Some studies are conducted at the Institute’s own laboratories and clinics located in Bethesda, Maryland, on the NIH campus, while others are funded through grants to major medical institutions across the country. NINDS-supported scientists are studying new approaches to treat RSD/CRPS and intervene more aggressively after traumatic injury to lower the patient’s chances of developing the disorder. Other studies to overcome chronic pain syndromes are discussed in the pamphlet ” Pain: Hope Through Research,” published by the NINDS.

Is help available?

The unrelenting pain from RSD/CRPS has caused many patients much physical and emotional misery. Family, friends, coworkers, and, regrettably, physicians themselves, may regard the patient as a complainer, thereby increasing the patient’s distress. To meet the needs of individuals with RSD/CRPS and other conditions causing chronic pain, the following voluntary health agencies promote research, provide information, and may offer advice on coping. For information, write or call: