What is complex regional pain syndrome?

Pain Management

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Complex regional pain syndrome (CRPS) refers to a rare condition causing unexplained pain on one side of the body that lasts 6 months or more in the hands, feet, legs or arms.

The most common type of complex regional pain syndrome typically occurs after an illness or injury. It’s referred to as type 1 or reflex sympathetic dystrophy syndrome. It affects nerves that were not directly impacted by illness or trauma.

Type 2 complex regional pain syndrome causes the same symptoms, but usually happens after the nerves in the affected area were injured.

There’s no known reason why complex regional pain syndrome begins. There could be an underlying condition causing miscommunication between the central nervous system (brain and spinal cord) and the peripheral nervous system (the nerves traveling down the arms and legs.) This malfunction creates an abnormal inflammatory response that results in pain.

Though rare, complex regional pain syndrome is most frequently diagnosed in women between the ages of 20 and 35. It seldom is seen in children and older populations.

What causes complex regional pain syndrome?

The most common causes of complex regional pain syndrome are fractures, crushing injuries, burns, cuts, and amputation.

It may also occur after a major illness or health condition such as heart attack, stroke or severe infection.

In some cases, even relatively small injuries such as a sprained ankle, bruises, injections or being in a cast can trigger the painful condition.

Medical specialists believe people at the highest risk of complex regional pain syndrome have less protein and fat insulating their nerve fibers, which control the blood vessels. When complex regional pain syndrome causes the blood vessels in the affected area to shut down or constrict, it causes skin changes and pain.

What are the symptoms of complex regional pain syndrome?

The symptoms of complex regional pain syndrome can be mild or debilitating depending on the progression of the condition. Most cases begin with visible changes in the affected area. Complex regional pain syndrome causes:

Barbed wire on the back illustrationMicrocirculation issues in the affected limb

  • Burning
  • Sensations of pins and needles
  • Feelings of constriction or squeezing
  • Changes in skin color, temperature, and texture
  • Touch sensitivities (allodynia)

An increase in the immune response

  • Swollen and stiff joints
  • Abnormal sweating in the affected area
  • Changes in nail and hair growth
  • Muscle spasms and tremors
  • Muscle weakness and sometimes muscle loss or atrophy

The microcirculation and immune response symptoms can occur at the same time. Once complex regional pain syndrome causes skin and nail changes, the condition may be irreversible.

How is complex regional pain syndrome diagnosed?

Pain management specialists use several tests to rule out conditions with similar symptoms such as Lyme disease, arthritis and other diseases affecting muscles, veins and nerves. Providers may use:

  • Bone scans to look for changes that can cause pain.
  • Nervous system tests to measure the response and reflexes of the arms and legs.
  • A physical exam to check for similar temperature, color, and swelling.
  • X-rays to track the amount of mineral loss in the bones.
  • Magnetic resonance imaging (MRI) to see changes in soft tissues.

Is there a cure for complex regional pain syndrome?

Since there’s no conclusive test that diagnoses complex regional pain syndrome, there’s not a definitive cure. Some people find the condition goes away on its own. Others learn pain management techniques to cope with chronic pain.

When complex regional pain syndrome is suspected, early treatment results in improvement and, often, remission.

When do you need to see a doctor?

If you experienced symptoms that get worse or last longer than 2 weeks, it’s time to make an appointment with your health care provider or pain management specialist.

For the best results and outcome, it’s important to start treating this nerve condition early to prevent or slow its progression.

Left untreated, complex regional pain syndrome can limit movement of your legs, arms, hands or feet. The inability to move often leads to breakdown and weakening of the skin, bones, and muscles affected by pain.

Who treats complex regional pain syndrome?

If you have symptoms of complex regional pain syndrome, make an appointment with a neurologist or a pain management specialist.

  • A neurologist can pinpoint the source of the pain.

  • A pain management specialist prescribes treatments to help you alleviate or cope with chronic pain.

How is complex regional pain syndrome treated?

A pain management specialist may choose several types of treatments depending on your symptoms and the results of your diagnostic tests.

Often providers start with conservative treatments, which are less invasive and produce fewer side effects. Your pain management specialist may use:

Over-the-counter (OTC) medications to reduce pain and inflammation.

If your condition does not respond to OTC pain relievers, your health care provider may prescribe corticosteroids along with other pain-relieving medications to decrease inflammation and increase movement. Before prescribing habit-forming medications like opioids, your provider may try antidepressants, anticonvulsants or anesthetics to interrupt or block the pain messages sent by damaged nerves.

Physical and occupational therapy can reduce pain, maximize motion, and ensure your ability to continue to care for yourself and return to activity. These non-invasive therapies also can slow the progression of complex regional pain syndrome.

Heating pads may ease movement.

Applying topical analgesics like capsaicin or lidocaine creams can reduce sensitivity to touch or temperature.

Biofeedback and graded-motor imagery use the power of your mind to help the body feel better.

Graded-motor imagery works like the visualization techniques athletes use to improve performance. Sitting in front of a mirror and moving the arm or leg not affected by chronic pain gives the brain the impression that the pain-filled arm or leg is moving. What the brain perceives it believes. In some cases, this simple therapy helps people increase mobility and decrease pain.

Biofeedback helps you recognize the feeling in your body and use relaxation techniques to relieve those feelings.

If your body does not respond to conservative treatments, your health care provider may recommend transcutaneous electrical nerve stimulation, spinal cord stimulation or an intrathecal drug pump.

Transcutaneous electrical nerve stimulation (TENS) disrupts electrical nerve impulses or deadens nerve endings to stop the pain response.

Your health care provider may refer you to a psychotherapist who can help you combat anxiety, depression, and/or post-traumatic stress disorder that often accompanies chronic pain conditions.

Can complex regional pain syndrome be prevented?

There are some things you can do to minimize your risk of developing the condition after an injury or illness. Studies suggest taking vitamin C after suffering a fracture may lower your risk of developing the condition.

Other providers recommend moving as soon as possible after injury or an illness such as stroke.

Your health care provider can tell you more about prevention.

For more information about complex regional pain syndrome or resources for living with the condition, visit https://rsds.org.

If you have unexplained chronic aches or pains in your arm, leg, hand or foot, request an appointment with one of Bone & Joint’s pain management specialists. 

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