What is Complex Regional Pain Syndrome?

Complex Regional Pain Syndrome, also known as Reflex Sympathetic Dystrophy Syndrome, is a chronic pain condition that affects one of the limbs, typically after an injury or trauma to that limb. This can occur after a car accident, a slip-and-fall accident, a workplace injury, or another instance of trauma.

Causes of Complex Regional Pain Syndrome

Scientists believe Complex Regional Pain Syndrome is caused by damage to the peripheral and central nervous systems (or a malfunction of one of these systems). The brain and spinal cord make up the central nervous system, and the peripheral nervous system involves signals between the nerves, the brain, and the spinal cord.

In more than 90 percent of CRPS case, the condition is triggered by a clear incident of injury or trauma. Most commonly, these injuries include fractures, strains, sprains, soft tissue injuries, limb immobilization, or surgical or medical procedures. Complex Regional Pain Syndrome amplifies the effects of the injury, and in some cases, causes people to respond excessively to a trigger that would not bother others.

There is no single means of diagnosis for CRPS. Typically, a medical professional will use the individual’s medical history and symptoms to match the definition of Complex Regional Pain Syndrome. It is important for doctors to examine the patient closely as symptoms may mimic those of other conditions. Testing can also help rule out other conditions, including arthritis, Lyme disease, clotted veins, and muscle diseases.

Types of CRPS

There are two main types of Complex Regional Pain Syndrome: CRPS-I and CRPS-II. CRPS-I, called reflex sympathetic dystrophy syndrome, is the term for Complex Regional Pain Syndrome that does not involve nerve injury. CRPS-II, previously known as causalgia, is the term for CRPS with confirmed nerve injuries.

CRPS can strike at any age, but the average age of individuals affected by CRPS is 40. It is not uncommon in teenagers, but it is quite rare in children under 10.

Symptoms of CRPS

The main symptom of Complex Regional Pain Syndrome is prolonged or excessive pain. Certain individuals report it feeling like a “pins and needles” or burning sensation, and others report feeling like someone is squeezing the affected body part. Even if the initial injury was only to a finger or toe, the pain can spread to the entire arm or leg in many cases. The pain may even travel to the opposite extremity (i.e. from the right leg to the left leg). Most individuals affected by CRPS experience increased sensitivity in the affected area, making even light touch or contact painful.

Other common symptoms may include:

  • Changes in skin texture on the affected area (may appear shiny and thin)
  • Abnormal sweating pattern in the affected area
  • Changes in nail and hair growth
  • Stiffness in affected joints
  • Problems coordinating muscle movement
  • Decreased ability to move the affected body part
  • Abnormal movement in the affected limb
  • Fixed abnormal posture (called dystonia)
  • Tremors or jerking of the affected limb

Symptoms of CRPS vary in duration and severity. In some cases, the victim recovers gradually over time and the pain is mild, but in other cases, the victim may never recover and will suffer long-term disability.