Dear Doctor Column, April 4, 2005

Treatments Offered for Chronic Pain Syndrome

Question:

I was diagnosed with RSDS by doctors 4 years ago. Since moving back home, my physicians here say I don't have RSDS. How do I know for sure if I have it or not?

Answer:

Reflex sympathetic dystrophy syndrome (RSDS), also called causalgia and complex regional pain syndrome, is a chronic condition characterized by severe burning pain, pathological changes in bone and skin, excessive sweating, tissue swelling, and extreme sensitivity to touch.

Although the cause is unknown, RSDS can occur as a result of injury to nerves, bones, joints, muscles, tendons or ligaments, particularly injuries from high-velocity impacts such as those from bullets or shrapnel. However, RSDS may occur without apparent injury: Other triggers include infections, cancer, diabetes, disorders of neck and lower back, thyroid disorders, lung disease, stroke or heart attack, and use of certain medications.

The pain patients with RSDS report is out of proportion to the severity of the injury, and the pain gets worse, rather than better, over time. Eventually, joints become stiff from disuse, and skin, muscles, and bone atrophy.

RSDS can strike at any age but is more common between age 40 and 60 years, although the number of RSDS cases among adolescents and young adults is increasing, according to the National Institute of Neurological Disorders and Stroke (NINDS), www.ninds.nih.gov.

RSDS is primarily diagnosed through observation of symptoms. Some physicians use thermography to detect changes in body temperature that are common in RSDS. X-rays also may show changes in bone.

One of the most frustrating problems with RSDS is that for many years doctors told patients their pain was psychological, not physical. It was not until recently that RSDS was understood as a serious and very real problem caused by an injury to the body's nervous system.

Good progress can be made in treating RSDS if treatment is begun early, ideally within 3 months after symptoms first appear. Early treatment often results in remission. If treatment is delayed, however, the disorder can quickly spread to the entire limb, and changes in bone and muscle may become irreversible. In 50% of RSDS cases, pain persists for 6 months to years.

Treatment includes taking drugs to halt inflammation and relieve pain, while undergoing intensive physical therapy that includes exercises to preserve motion and muscle strength. Heat therapy, gentle massage of the affected area, and transcutaneous electrical nerve stimulation (TENS) frequently helps.

TENS involves delivering a small amount of electrical current to the skin in the area to block transmission of pain impulses. If pain persists, the doctor may recommend injections into and around the affected nerves to suppress pain impulses. Short courses of cortisone-like drugs to halt inflammation, and sometimes drug infusions of medications to dilate narrowed blood vessels, help some people. In severe cases, surgery may be recommended to permanently sever nerves to the involved area, eliminating pain.

People with RSDS are often referred by their doctor to a pain center to work with physicians and therapists trained in the management of problems that cause long-lasting and difficult-to-relieve pain. Pain-management specialists stress an early diagnosis and aggressive management of RSDS is mandatory for a successful outcome.

Investigators at NINDS are studying new approaches to treat RSDS and intervene more aggressively after traumatic injury to lower a patient's chances of developing the syndrome. Scientists are studying how signals of the sympathetic nervous system cause pain in RSDS patients. Using a technique called microneurography, investigators record and measure neural activity in single nerve fibers of affected patients. By testing various hypotheses, researchers hope to discover the unique mechanism that causes the spontaneous pain of RSDS, and that discovery may lead to new ways of blocking pain.

For more information on RSDS, visit these Web sites: American Chronic Pain Association, www.theacpa.org; RSDS Association, www.rsds.org; American RSDHope Group, www.rsdhope.org; American Pain Foundation, www.painfoundation.org; and International Research Foundation for RSD/CRPS, www.rsdfoundation.org.