Complex Regional Pain Syndrome
What is it?
Complex Regional Pain Syndrome (CRPS) is a chronic pain problem which usually affects the arms or the legs. The affected body part has persistent pain which is often described by patients as a burning discomfort, a deep ache or sharp, stabbing pain. The affected body part can become very hypersensitive so that light touch, the feel of clothing on the skin, or even the wind blowing across the skin can cause excruciating pain.
In addition to pain, the limb has characteristic physical changes which may come and go. These include swelling, temperature change with the limb becoming very hot or very cold, color changes with the skin looking pale to bright red to deep purple or mottled. Hair and nails may grow more quickly or more slowly than usual. Sometimes there is excessive sweating only in the affected body part. The skin can become tight and shiny. Muscles may become difficult to control and soft tissues can become stiff resulting in lost range of motion. There can be loss of bone density in the affected limb.
People with this problem often stop using their limb because moving it is associated with so much pain.
What causes CRPS?
Most of the time, CRPS is preceded by an injury to the affected limb. The injury may be relatively severe such as a fracture. However, sometimes the injury is one that seems quite minor at the time, such as a sprain or contusion.
Prolonged immobilization after an injury increases the risk of developing CRPS. A nerve injury can also set off CRPS. CRPS caused by an injury that does not include a nerve injury is called CRPS type I. This has also been called Reflex Sympathetic Dystrophy. CRPS caused by a nerve injury is called CRPS type II, also known as Causalgia.
Scientists do not understand everything that happens in the body to cause an injury to produce chronic persistent pain. In the case of CRPS there seem to be changes in the central nervous system affecting the sympathetic nervous system as well as the part of the central nervous system that processes sensory information.
The sympathetic nervous system controls blood flow to the limbs and controls sweating. In CRPS the sympathetic nervous system can become hyperactive and unstable. As a result, blood flow to the limb is variable, leading to color and temperature changes as well as swelling.
Sensory processing also changes. Sensory stimulation which is not normally painful (light touch, pressure, movement) may be mistakenly transmitted through the pain pathways and is therefore felt as if it were a painful stimulus. The pain can cause motor inhibition making movement difficult.
How is CRPS treated?
As soon as CRPS has been diagnosed, it is important to provide treatment to try to normalize sympathetic nervous system activity, control pain and encourage normal movement. Initial treatment usually includes medications to control pain, injections to block the sympathetic nervous system, and physical therapy.
What we do to treat CRPS at RIW
When the initial treatment does not produce improvement, or early treatment is not provided, symptoms can become very severe and patients may completely abandon trying to use the affected limb. In these cases a more intensive treatment approach is necessary.
At RIW we join with the anesthesiologists from Virginia Mason Medical Center to combine anesthetic techniques for pain control with intensive therapy to help restore normal movement and function.
- Patients may have a temporary epidural catheter placed with a portable pump to provide pain control. Patients will be seen by an anesthesiologist at Virginia Mason daily, if necessary, to adjust the medication dose to maintain pain control.
- The patients participate in daily physical and occupational therapy focusing on regaining normal flexibility, movement patterns and strength.
- We work with the patients on desensitization techniques to diminish the hypersensitivity so common with this disorder.
- We use mirror box therapy to help retrain the brain to normalize sensory processing.
- Patients also benefit from the full treatment options available through the pain management program including psychological support, counseling and education.
The typical treatment program for a patient with CRPS starts with two weeks of daily OT and PT, the first week assisted by the epidural catheter, followed by the full 4 week pain management program. This process has produced some long term improvements in pain and function in many patients.