Introduction

Complex regional pain syndrome (CRPS) is a type of chronic pain syndrome.  CRPS was formerly called reflex sympathetic dystrophy (RSD) and/or shoulder-hand syndrome.  CRPS causes severe burning pain and possible eventual deterioration of an affected arm or leg.  The cause of CRPS is unknown, but it can develop following an injury, stroke, or heart attack.  Prompt treatment is associated with the best outcomes.  If untreated, CPRS can cause irreversible extremity deterioration.

Anatomy

The sympathetic nervous system is a part of the complex system that regulates involuntary bodily functions.  These are bodily functions that run automatically and are necessary for life.  Your sympathetic nervous system speeds up your heart rate, constricts your blood vessels, sends blood to your vital organs, raises your blood pressure, raises your blood sugar level, and increases sweating.  It energizes your body for immediate action in response to an emergency or “flight or fight” situation.

Causes

The exact cause of CRPS is unknown.  Researchers suspect that changes in the sympathetic nervous system lead to poor regulation of blood flow, sensation, and temperature.  This contributes to problems involving the skin, nerves, blood vessels, bones, and muscles.  Another theory is that it may be related to an immune response.  CRPS can develop after an injury or infection in the arm or leg.  It can occur after heart attacks, cancer, nerve compression, and strokes.

Symptoms

The symptoms of CRPS vary from person to person.  Severe burning pain, joint stiffness, and swelling are hallmark symptoms of CRPS.  It can affect an arm or leg.  CRPS is characterized by three stages.  Not all people progress through all three of the stages.  Some people may stay in the first stage indefinitely, and others may skip a stage.

Stage I occurs at the onset of CRPS and can last about three months.  You may feel burning pain, stiffness, increased sweating, and warmth in your affected limb.  Your nails and hair may grow faster than usual.  Your skin may become dry, thin, and change color.

Stage II CRPS lasts from three to twelve months.  You may experience an increase in swelling.  Your skin may become cooler and more sensitive to touch.  Your pain may become more widespread.  Your joints and muscles may become stiffer.

Stage III occurs from one year on.  Changes in Stage III may be irreversible and permanent.  The pain may spread to your entire limb.  Your joints may be very stiff and very difficult to move.  You may experience muscle wasting and contractures.

Diagnosis

Early diagnosis of CRPS is important for the best treatment results.  Your doctor can diagnose CRPS by reviewing your medical history and conducting a physical examination.  You should tell your doctor about your symptoms and their progression.  Your doctor will examine your limb for skin changes, swelling, changes in blood flow, and loss of mobility.  Your doctor may order tests such as X-rays, bone scans, or nerve studies.  There is no test, however, that can diagnose specifically CRPS.

Treatment

To ensure the best outcome, it is important to start treatment as soon as possible.  CRPS is treated with medications, therapy, injections and surgery.  There is no true cure for CRPS, but treatments in the early stages can prevent the disease from progressing, and cause symptoms to regress.  Treatment goals during the advanced stages are aimed at symptom relief and improving function.

Your doctor can prescribe medications to help ease your symptoms.  A combination of medications may be used including pain relievers, antidepressants, certain blood pressure medications, and steroids.  Injected pain relieving medications, spinal cord stimulation, and implanted medication delivery pumps may provide pain relief for longer periods of time.

You may be referred to rehabilitation, including aquatic therapy.  Participating in rehabilitation will help ease symptoms and improve function in your limb.  Your therapists may use modalities, such as application of hot and cold treatments or a transcutaneous electrical stimulation (TENS) unit.  Desensitization techniques may be helpful for hypersensitivity.  Additionally, aquatic therapy can provide a warm and supportive environment for you to safely exercise.  In many cases treated with injections, therapy should immediately follow an injection, to take advantage of the relief the injection may provide.

Surgery is rarely indicated for CRPS.  For those cases in which the syndrome is caused by nerve injury or compression, surgery to resolve the problem can help relieve symptoms.

Recovery

CRPS that is treated in the early stages has the best outlook.  If treated early, CRPS can go into an inactive state and function is optimized.  If CRPS is not diagnosed and treated promptly, irreversible changes can occur in the involved extremity.

Prevention

There is no known prevention for CRPS.  Prompt treatment may prevent the progression of symptoms.