Overview

Reflex sympathetic dystrophy (RSD) or complex regional pain syndrome (CRPS), is a chronic, painful, and progressive neurological condition that affects skin, muscles, joints, and bones. The syndrome usually develops in an injured limb, such as a broken leg, or following surgery. However, many cases of RSD involve only a minor injury, such as a sprain. And in some cases, no precipitating event can be identified.

Pain may begin in one area or limb and then spread to other limbs. RSD/CRPS is characterized by various degrees of burning pain, excessive sweating, swelling, and sensitivity to touch. Symptoms of RSD/CRPS may recede for years and then reappear with a new injury.

Types

Two types of RSD/CRPS have been defined:

• Type 1 - without nerve injury
• Type 2 (formerly called causalgia) - with nerve injury

Both types share the same signs and symptoms.

Incidence and Prevalence

Millions of people in the United States may suffer from this chronic pain syndrome. RSD/CRPS affects both men and women, and also occurs in children. It can occur at any age, but usually affects people between the ages of 40 and 60 years.

The National Institute of Neurological Disorders and Strokes (NINDS) reports that 2% to 5% of peripheral nerve injury patients and 12% to 21% of patients with paralysis on one side of the body (hemiplegia) develop reflex sympathetic dystrophy as a complication. The Reflex Sympathetic Dystrophy Syndrome Association of America (RSDSA) reports that the condition appears after 1% to 2% of bone fractures.

Causes and Risk Factors

RSD/CRPS appears to involve the complex interaction of the sensory, motor, and autonomic nervous systems, and the immune system. It is thought that brain and spinal cord (central nervous system) control over these various processes is somehow changed as a result of an injury.

Causes associated with the onset of RSD/CRPS include the following:

• Cerebral lesions
• Heart disease, heart attack
• Infection
• Paralysis on one side of the body (hemiplegia)
• Radiation therapy
• Repetitive motion disorder (e.g., carpal tunnel syndrome)
• Spinal cord disorders
• Surgery
• Trauma (e.g., bone fracture, gunshot and shrapnel wounds)

In 10% to 20% of cases, no direct cause can be found. Injury that precedes the onset of RSD/CRPS may or may not be significant.

Original article.