Complex regional pain syndrome, also called CRPS, is a disorder which may occur following peripheral nerve injury, sprains or fractures, and even soft tissue injuries. The primary characteristic of the syndrome is chronic pain, which is typically experienced at the site of injury but may also be more widespread. Complex regional pain syndrome was formerly known as reflex sympathetic dystrophy syndrome and causalgia.
The causes of complex regional pain syndrome are not well understood, and there are several different theories which attempt to explain how the disease is triggered. Up to 90% of people with CRPS do not sustain any prior nerve injury. Only a relatively small fraction of people sustain an injury which causes damage to peripheral nerves or the central nervous system. Another complicating factor is that CRPS can develop following a stroke or heart attack.
The fact that such a large proportion of people do not sustain any nerve damage means it is particularly difficult to explain how CRPS develops. One theory is that the brains of people who develop the disorder have somehow created abnormal connections in the area of the brain which controls pain perception. This theory is borne out by evidence suggesting that the white matter of the brain, where neuronal connections are formed, does undergo some changes in people with CRPS.
The most common symptom of the syndrome is pain, which can be experienced at other locations in the body in addition to the site of prior injury. Many people have allodynia, meaning that they feel pain in response to a stimulus which is not ordinarily painful. Another type of pain which may be experienced is hyperalgesia, which means the pain is much greater than that which would normally be associated with the prior injury. Often, movement or cold weather exacerbates the pain. If the syndrome is not diagnosed and treated, possible complications include loss of strength and muscle tone, osteoporosis, and depression.
There is no cure for CRPS, but if the disease is diagnosed and treated early enough it is possible to induce remission. Medical complex regional pain syndrome treatment typically concentrates on pain relief and reducing inflammation. For some people, over-the-counter medications such as non-steroidal anti-inflammatory drugs can reduce pain and inflammation, but many require stronger medications to relieve their symptoms.
Medications usually prescribed for pain management include analgesics and opioids. Antidepressants are an often-used treatment for CRPS, as some types can reduce pain which is caused by nerve damage. Steroids may also be prescribed to reduce inflammation. Long-term use of steroids can cause other complications such as reduced immune system function, however, meaning that steroids are usually only prescribed for short-term use.
Many people find that certain types of natural complex regional pain syndrome therapy can provide relief from their pain. Acupuncture and physical therapy can both help reduce pain. Physical therapy is also useful to help prevent loss of muscle strength and to improve a person’s range of motion. Transcutaneous electrical nerve stimulation, in which electrical impulses are applied to the affected area, can be particularly effective for reducing pain in some people with complex regional pain syndrome.