What Is Reflex Sympathetic Dystrophy Syndrome (RSD)?

Reflex Sympathetic Dystrophy (RSD) is referred to by several other names, including:

• Reflex Sympathetic Dystrophy Syndrome—RSDS
• Complex Regional Pain Syndrome
• Shoulder-Hand Syndrome
• Causalgia
• Sudeck's Atrophy

Causes

According to the National Institute of Neurological Disorders and Stroke (NINDS), RSD is "a chronic pain condition that is believed to be the result of dysfunction in the central or peripheral nervous systems." According to MedicineNet, RSD involves "irritation and abnormal excitation of nervous tissue, leading to abnormal impulses along nerves that affect blood vessels and skin."

Animal studies indicate that norepinephrine, a catecholamine released from sympathetic nerves, acquires the capacity to activate pain pathways after tissue or nerve injury, resulting in RSD. Another theory suggests that RSD, which follows an injury, is caused by triggering an immune response and symptoms associated with inflammation (redness, warmth, swelling). RSD is not thought to have a single cause, but rather multiple causes producing similar symptoms.

Triggers

There can be numerous triggers for RSD, including:

• Injury or trauma
• Surgery
• Degenerative arthritis of the neck
• Shoulder problems
• Heart disease
• Stroke
• Diabetes
• Cancer
• Infection
• Brain diseases
• Thyroid disorders
• Carpal tunnel
• Shingles
• Certain medications

In an estimated one-third of patients with RSD, there is no associated trigger.

Symptoms

RSD usually affects one of the extremities (arm, leg, hand, or foot). The primary symptom of RSD is intense, continuous pain. According to NINDS, the list of symptoms associated with RSD includes:

• Burning pain
• Increased skin sensitivity
• Skin temperature changes (warmer or cooler than opposing extremity)
• Skin color changes (blotchy, purple, pale, red)
• Skin texture changes (shiny, thin, sweaty)
• Changes in nail and hair growth patterns
• Stiffness and swelling in affected joints
• Decreased ability to move affected extremity

Pain can spread to a wider area (i.e. from finger to entire arm) and can spread to the opposite extremity (i.e., from left arm to right arm). Emotional stress can cause symptoms to worsen.

Some experts suggest there are three stages of RSD, during which progressive changes occur in the skin, muscles, joints, ligaments, and bones of the affected area. The progression has not been confirmed by clinical studies, though.

Stages 

Stage 1

• Lasts 1 to 3 months
• Severe, burning pain
• Muscle spasm
• Joint stiffness
• Rapid hair growth
• Skin color and temperature changes

Stage 2

• Lasts from 3 to 6 months
• Pain which becomes more intense
• Swelling
• Decreased hair growth
• Nails which are cracked, brittle, grooved, spotty
• Softened bones
• Stiff joints
• Weak muscle tone

Stage 3

• Irreversible changes to skin and bone
• Pain is continuous
• Muscle atrophy
• Severely limited mobility
• Contractions of muscles and tendons (limbs may be twisted)

Diagnosis

A patient's clinical history (signs and symptoms) are the major factor in diagnosing RSD. The diagnosis is made difficult because many of the symptoms overlap with other conditions.

There is no specific blood test or other diagnostic tests for RSD. X-rays may show thinning of bones (osteoporosis) and nuclear bone scans may show characteristic uptake patterns which help diagnose RSD.

Treatments

Treatment focuses on relieving painful symptoms associated with RSD. Treatment can include:

• Physical therapy and exercise
• Psychotherapy to relieve stress, anxiety, and depression
• Sympathetic nerve blocks
• Surgery including sympathectomy (considered controversial)
• Spinal cord stimulation
• Intrathecal drug pumps
• Medications including, topical analgesics, anti-seizure drugs, antidepressants, corticosteroids, or opioids

Is Enbrel Commonly Used to Treat RSD?: Enbrel is among the TNF blockers used to treat rheumatoid arthritis. When asked if it is used to also treat RSD, rheumatologist Scott Zashin M.D. commented, "Enbrel is not FDA approved to treat RSD. Studies have shown some benefit in treating nerve inflammation. Since RSD is felt to have a neurological component, it might be beneficial and worth a try. This condition may sometimes be difficult to treat with standard therapies."

Celebrity Announces Battle With RSD: Former American Idol judge and celebrity Paula Abdul announced that following a 25 year battle with chronic pain, precipitated by a cheerleading accident when she was 17 years old, she has been diagnosed with RSD.

The media attention is given to Abdul's medical struggle temporarily placed RSD on front pages and magazine covers. RSD is among the 100 types of arthritis and rheumatic diseases. It is estimated that there are 50,000 new cases of RSD every year in the United States.