Complex Regional Pain Syndrome (CRPS)
What is complex regional pain syndrome (CRPS)?
Complex regional pain syndrome (CRPS), formerly known as reflex sympathetic dystrophy syndrome (RSDS), is a condition that causes pain; swelling; changes in skin color, texture and temperature and other symptoms. It usually affects your extremities – an arm, leg, hand or foot – but can affect any part of your body.
Most cases of CRPS start after a soft tissue injury (such as a sprain), fracture or surgery. The pain can be intense and is much more than what would be expected during recovery from an injury, fracture or surgery.
Experts believe that CRPS occurs as a result of dysfunction in the central or peripheral nervous systems. Your central nervous system consists of your brain and spinal cord. Your peripheral nervous system relays information from your brain and spinal cord to your organs, arms, legs, fingers, and toes. The abnormal functioning results in an overreaction to pain signals that the nervous system can’t shut off.
CRPS is not widely known by many doctors and is not well understood, so it’s often misdiagnosed. Many patients receive the wrong treatments or no treatment at all.
Who gets complex regional pain syndrome (CRPS)?
Complex regional pain syndrome (CRPS) appears to peak around age 40. The syndrome also can occur in children. It affects women more often than men.
Symptoms and Causes
What causes complex regional pain syndrome (CRPS)?
How CRPS is caused is not totally understood. Scientists think it might be a combination of factors that produce similar symptoms. They think CRPS is the result of general inflammation, inflammation of the nerves and perhaps even changes in a person’s perception of pain in the brain and spinal cord (the central nervous system).
Researchers have found certain signs of inflammation – certain substances and chemicals – in the affected tissue, blood and spinal fluid of patients with CRPS. They have also found evidence of the release of certain pain- and inflammation-producing compounds in nerves in the affected area. There may also be dysfunction in the messaging between nerves at the site of injury. There are also signs of other substances and chemicals being released at the affected site, which results in an overreaction or oversensitivity to the sensation of pain in response to the injury. Autoimmune and genetic causes may also play a role in the development of CRPS. Researchers continue to look for and further understand causes of this condition.
What are the symptoms of complex regional pain syndrome (CRPS)?
How severe and how long symptoms of complex regional pain syndrome (CRPS) lasts varies from person to person. Pain is usually the leading and most disabling symptom.
Signs and symptoms of CRPS include:
- Continuous pain that gets worse over time.
- Pain that is out of proportion to the severity of your injury.
- Extreme sensitivity to pain such that a very light touch to your skin produces severe pain.
- Pain that spreads. (For example, pain from an injury to a finger or toe spreads to your entire arm or leg. Also, pain that travels to the opposite extremity.)
- “Burning” pain or a feeling that the affected limb is being squeezed.
- Skin swelling. Swelling in your affected limb that may come and go or remain constant.
- Decreased range of motion/loss of function, tremor. Decreased ability to move your affected limb and/or increased stiffness. Difficulty placing pressure on your affected limb or joint.
- Changes in skin temperature. The skin on your affected extremity feels warmer or cooler compared to the opposite extremity.
- Changes in skin color, appearing as blotchy, pale, purple/bruised or red.
- Changes in skin texture, becoming shiny and thin or excessively sweaty.
- Changes in nail and hair growth. There may be rapid hair growth or no hair growth.
Symptoms of CRPS typically start within four to six weeks after the injury, fracture or surgery.
Diagnosis and Tests
How is complex regional pain syndrome (CRPS) diagnosed?
There is no specific test to diagnose complex regional pain syndrome (CRPS). CRPS is diagnosed mainly through careful history, physical examination and review of your symptoms. Your healthcare provider will ask you if you’d had a recent injury (such as a sprain), fracture or surgery.
They will look for:
- A change in the appearance, temperature, and texture of your skin in the affected area.
- A higher-than-expected amount of pain from an injury.
- Any other disease or conditions that could cause your pain, changes in your skin or other symptoms.
A specific number of the symptoms described in this article must be present to confirm a diagnosis of CRPS. This diagnostic criteria is called the Budapest criteria (see reference section at end of article for a link to learn more ).
Other tests: Other tests may be ordered to rule out other conditions that cause similar symptoms. For example, an electromyography (EMG) may reveal other causes of neuropathy, which may result in some similar pain scenarios.
Management and Treatment
How is complex regional pain syndrome (CRPS) treated?
There is no cure for complex regional pain syndrome (CRPS). The goal of treatment is to decrease your pain and other symptoms, restore function to the affected limb, and maintain the quality of your life.
It’s important to start treatment early in the course of CRPS. This is because CRPS can cause the affected limb to stiffen over time, the pain usually worsens without treatment, and movement becomes more and more difficult.
Treatment of CRPS requires a combination of approaches carefully managed by physicians and therapists who are experienced in this complex condition.
Treatment methods include:
Physical therapy and occupational therapy: A physical therapist can help improve blood flow to your affected limb as well as increase your flexibility, strength, muscle tone and function. An occupational therapist can teach you new ways to accomplish everyday tasks.
Mirror therapy: This treatment technique uses a mirror to trick your brain into perceiving movement in the affected limb without pain. Looking at the reflection of movement of your unaffected limb in a mirror fools your brain into thinking you are moving two normal limbs.
Desensitization: This technique involves touching the affected area with materials of different textures and weights and even placing the affected limb into water of warmer and cooler temperatures. By exposing the affected area/limb to different sensations slowly over time, your brain adjusts to the sensations and pain begins to lessen.
Psychotherapy: Having CRPS increases anxiety, depression and stress, which can increase pain. Psychotherapy (“talk therapy”) involves learning ways to better cope with these and other factors that contribute to your pain and disability.
Medications: No medications are specifically approved for CRPS in the U.S. However, many drugs from different drug classes can be tried. Topical analgesic creams and patches (such as lidocaine) might help relieve pain. Other anesthetic medications and/or medications that have pain-reducing effects include ketamine, dextromethorphan, opioids, some antidepressants (such as amitriptyline and duloxetine [Cymbalta®]), anti-seizure drugs (such as gabapentin [Neurontin], pregabalin [Lyrica®], topiramate [Topamax®]), nonsteroidal anti-inflammatory drugs (such as aspirin, ibuprofen [Advil®, Motrin®], naproxen), bisphosphonates (such as alendronate [Fosamax®]) and botulinum toxin injections.
Choice of medication(s) to begin with varies from patient to patient. Your healthcare provider will consider such factors as your age, other existing health conditions, any current medications you are taking, and the potential for medication side effects or interactions with the current medications you are taking.
If your CRPS has not responded well to the medications mentioned above or you have severe pain or ongoing CRPS, the following more invasive treatments can be tried:
- Sympathetic nerve blocks: These blocks can provide significant pain relief for some people. One kind of block involves injecting an anesthetic next to the spine to directly block/interrupt the pain signal.
- Intrathecal drug pumps: This treatment involves using an implanted catheter to send pain-relieving drugs, such as ziconotide (Prialt®), right into the spinal fluid.
- Spinal cord stimulation: This treatment involves surgically implanting a pulse generator device under your skin in your abdomen or buttock and electrodes near your spinal cord. The device, which is similar to a pacemaker, sends low level electrical current to the spinal cord. Electrical pulses stimulate the nerves where your pain is felt. These pulses interfere with the pain signal being sent to the brain. This treatment is usually considered only if you are in severe pain and all other treatment methods have failed to reduce your pain.
- Dorsal root ganglia stimulation: This treatment is similar to spinal cord stimulation except that the electrodes are implanted on the dorsal root ganglion, which is a cluster of neurons in the root of the spinal cord. The stimulation is a more targeted therapy that concentrates stimulation where doctors think the pain originates. Again, like spinal cord stimulation, it is usually considered only if you are in severe pain and all other treatment methods have failed to reduce your pain.
Again, choice of treatment, length of treatment, how soon to try these more invasive treatments will vary from patient to patient. Discuss these options with your healthcare provider and ask if any are appropriate for you (if needed).
Outlook / Prognosis
What outcome can I expect if I have been diagnosed with complex regional pain syndrome (CRPS)?
Each person’s experience with CRPS is different. Symptoms in some people go away (remission), remain the same or lessen. In others, CRPS will get worse and even spread to other areas of the body. Each person’s outcome is difficult to predict.
The most important goals are to relieve pain and restore movement and strength in the affected limb. By achieving pain relief, you increase the odds of improving function and quality of life. Carefully selected medications allow some patients with CRPS to successfully manage their pain and lead active lives. Other patients require additional interventions, such as nerve blocks or spinal cord stimulators to relieve pain.
The promising news is that there are many treatment options and many combinations of options that can be tried.
Because of the complexity of this condition and the fact that it is often misdiagnosed, seek out – or ask your healthcare provider to refer you to – a pain management specialist or a specialty pain center with knowledge of CRPS if:
- You think you have symptoms of CRPS.
- You believe your symptoms are getting worse.
- Your condition has not responded to other treatment methods.
The earlier CRPS is diagnosed and treatment is started, the better the chance that your symptoms will not worsen and that your symptoms will respond to treatment.
Can complex regional pain syndrome (CRPS) recur?
Yes, complex regional pain syndrome (CRPS) recurs in about 10% to 30% of patients. Most recurrences are due to unknown reasons; the remainder are associated with a new injury or surgery.
Does stress increase the pain level of complex regional pain syndrome (CRPS)? If so, what are some suggestions for relieving stress?
Yes, stress plays a direct role in pain levels. Stress from any cause such as worry, pain and financial concerns may all affect the part of the brain that is responsible for the autonomic nervous system. This system does not work properly in patients with complex regional pain syndrome (CRPS). Helpful stress-reducing methods include yoga, pilates, meditation, hypnosis and psychotherapy.
Can complex regional pain syndrome (CRPS) spread from its original body site to a distant site?
Yes it can. For example, complex regional pain syndrome (CRPS) can spread from a primary site, such as a hand, to a distant site, such as the leg or foot.
If treated early, spinal cord stimulation may prevent spread to another site. Spinal cord stimulation can be effective for CRPS affecting either the upper or lower extremity. In some cases, it can be used to treat CRPS affecting both upper and lower extremities at the same time. Spinal cord stimulation is reserved for patients whose condition has not responded to medications and/or other therapies.
Does complex regional pain syndrome (CRPS) affect organ function?
Possibly. For example, there are several cases in the medical literature of patients with longstanding lower limb CRPS who have problems with the function of their bladder and bowel and also have abdominal pain. Even though it may start at one site like the foot, CRPS is a chronic condition that involves the entire nervous system. It often causes the autonomic nervous system (the nervous system that looks after internal organs) to react and not function properly like they should.
What is full body complex regional pain syndrome (CRPS)?
Full-body complex regional pain syndrome (CRPS) may be the result of more than one disease. If CRPS starts in one limb, for example, and then spreads to involve another limb or even all four limbs, this will impact all of the trunk muscles. While this is not necessarily CRPS, the muscle pain may produce what people call “full body” CRPS. Treatment of this involves gradually sorting out muscle groups individually until all of the muscle pain is under control. This requires months of treatment and requires physical therapy, occupational therapy and behavioral medicine all working together.
What is the difference, if any, between fibromyalgia and complex regional pain syndrome (CRPS)?
Fibromyalgia and complex regional pain syndrome (CRPS) are considered different syndromes. They don’t have the same symptoms and there is no evidence they are caused by similar changes in body chemistry or function.
Some helpful resources for complex regional pain syndrome (CRPS) include:
- Support group and education: Reflex Sympathetic Dystrophy Syndrome Association (RSDSA).
- Clinical trials: Clinicaltrials.gov.