Complex regional pain syndrome

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at August 4, 2016
StartDiseasesComplex regional pain syndrome

Complex regional pain syndrome (CRPS) is a disorder involving chronic pain that typically occurs as a result of trauma to the limbs. This rare condition affects anywhere from 200,000 to 1.2 million people in the Unites States.


Definition & Facts

CRPS is a neurological disorder that is believed to be the result of damage to the peripheral nervous system and central nervous systems. The average age of onset is 40. It is more common in children over the age of 10 than in younger children. Females are three times more likely to experience the disorder.

There are two very similar types of the condition: CRPS-I and CRPS-II. Both have identical symptoms and are treated in the same way. However, CRPS-I has no confirmed evidence of nerve injury, while CRPS-II has a clear indication of nerve damage. 

Symptoms & Complaints

The number one symptom of complex regional pain syndrome is excessive, persistent pain that might be unbearable for some people. In many cases, patients claim that the pain from CRPS is more severe than the pain from the injury that caused it. There is a range of other symptoms that can help to pinpoint whether or not the pain is connected to CRPS. Common symptoms may include:

Persons might not experience all symptoms. Symptoms and complaints may also come and go frequently. 


In over 90 percent of cases, people with this condition have a history of limb trauma. Trauma may have been in the form of a sprain, bone fracture, deep wound or laceration, surgery, or other type of severe injury. The condition is believed to be caused by some form of damage to the nerves in the central and peripheral nervous system as a result of any of the traumas.

The central nervous system consists of the brain and spinal cord, while the peripheral nervous system involves nerves throughout the body that sense input and deliver the message of that stimuli to the central nervous system as well as nerves that run from the brain to other parts of the body. This disorder is a result of both systems malfunctioning.

Complex regional pain syndrome also affects the immune system, which contributes to the redness or swelling in the affected limb. There is some speculation that CRPS might be hereditary, since there have been some cases implicating family history as a factor.

Diagnosis & Tests

A visit to the doctor is recommended if severe, unwavering pain is experienced, or if there is difficulty in movement or paralysis of the limb occurring. No specific diagnostic path has been taken for this condition. Clinical examination and laboratory tests are typically conducted to rule out any other cause of the symptoms being experienced by the patient.

The patient’s medical history is also taken into account, especially whether or not they have had previous trauma to the limb. Also, the patient’s ability to move the limb may be assessed to see the extent to which the symptoms affect them. Magnetic resonance imaging (MRI) is used to see the condition of the bone in the case of a fracture. This is because CRPS can indicate a breakdown in the bone which causes excessive levels of calcium into the blood.

Tests are made to measure the temperature of the patient’s skin and to see the level of blood flow to the affected limb in comparison to another limb. If there are significant differences between the two, then a diagnosis might be made.

Since only a few medical practitioners are aware of complex regional pain syndrome, there may be difficulty in diagnosing the condition. This means that individuals may go undiagnosed or some may receive a diagnosis without actually having the disorder. 

Treatment & Therapy

There is a range of treatments to complex regional pain syndrome, and these may include the administering of medication, physical therapy, and psychological approaches.

Medications may be used to manage the pain of the condition. There are a number of drugs that may assist depending on the level of pain experienced by the patient. Doctors may recommend nonsteroidal anti-inflammatory drugs such as ibuprofen or naproxen.

Corticosteroids help with inflammation as well, and these may include prednisone or methylprednisolone. N-methyl-D-aspartate (NMDA) receptor antagonists including dextromethorphan or ketamine may be administered. For deep bone pain, calcitonin is typically prescribed. Topical local anesthetic creams such as lidocaine may also be used.

Other treatments include spinal cord stimulation, where stimulating electrodes are placed into the spine with a needle. Sympathetic nerve block is another form of treatment that is used to destroy and reduce the number of bad nerves that misfire signals.

Rehabilitative physical therapy is recommended. Therapy will focus on increasing circulation, which in turn reduces pain and improves function. Psychotherapy for CRPS patients may be necessary, since painful and disabling conditions are often associated with psychological symptoms. Patients may develop depression, posttraumatic stress disorder (PTSD), or other mental disorders, which may heighten the pain. Therapy may be able to mitigate such symptoms and complications.

Prevention & Prophylaxis

Taking proper safety precautions during activities that commonly cause traumatic injury - such as extreme sports and driving a motor vehicle - is encouraged. It is also recommended to consume adequate amounts of calcium and vitamin C-rich food in order to prevent bones from easily fracturing or severe fractures.

It is recommended that patients complete physical therapy after experiencing trauma such as bone fractures or sprains. Increased mobility such as the regular exercise of a limb that has undergone trauma is suggested in order to increase blood flow. There are no definite ways to prevent CRPS since the response of the nervous systems to certain traumas is not typically predictable.