Complex regional pain syndrome requires aggressive rehabilitation
Saturday, April 30, 2005
Over the last few weeks, this column has featured a variety of chronic pain conditions, including lower back pain, pelvic pain and fibromyalgia. They increasingly are recognized by health-care providers as common disorders that significantly interfere with our ability to function.
An intriguing but less common cause of chronic pain is called “complex regional pain syndrome,” previously known as “reflex sympathetic dystrophy” or “causalgia.” This condition originally was described during the Civil War, when soldiers experienced continuous, often burning, pain long after their gunshot wounds or stabbing injuries had healed.
Unlike conditions such as arthritis, which affect many parts of the body simultaneously, CRPS usually begins in one limb. It occurs three times as often in women than men and can occur at any age, even in children.
In CPRS, patients generally experience persistent pain in an arm or leg, often with a burning or aching quality. The skin of the affected limb can change color, from white to blue to a mottled reddish color. The skin is extremely sensitive to touch; even a gentle breeze or light brush from clothing will produce intense pain. This excessive sensitivity is called allodynia, and makes even everyday events such as putting on clothing painful.
If untreated, the affected limb may become stiff and swollen. It may sweat more than the limb on the other side. Since moving the limb makes the pain worse, patients protect the arm or leg from movement, which leads to weakness and atrophy of the muscle, which results in even less mobility.
CRPS often occurs after trauma to an extremity. The injury does not have to be severe. Even a seemingly mild event, such as a sprained ankle or a bruised thumb, can result in this chronic, painful condition. Even vaccinations have been reported to produce it. The pain outlasts the injury, persisting long after the original condition has healed. Even when the original site of the trauma is small, the pain can spread to the entire extremity.
There are two types of CRPS: Type I occurs after an injury, illness or surgery that didn’t directly damage the nerves of the limb. Type II follows a direct trauma to the nerve itself and is less responsive to treatment than Type I.
Fortunately, the incidence of CRPS is very low. According to a review article in the Archives of Neurology, only 2 percent to 14 percent of nerve injuries to limbs result in this syndrome. However, about 10 percent of patients seen in pain clinics are diagnosed with this disorder.
The main therapy for CRPS is what most patients would rather not do: movement. Moving an affected arm or leg initially worsens the pain, but immobility can lead to permanent bone and joint changes and loss of muscle bulk. At its worst, CRPS can result in a useless limb.
Early treatment is imperative, before muscle wasting and joint stiffness occur. An aggressive physical therapy and rehabilitation program focuses on the return of function to the arm or leg. Therapists use desensitization techniques to “train” the skin to become less sensitive to touch or pressure. They start with a light cotton touch and, gradually, move to more rough materials stroked on the skin.
Medications for CRPS include simple analgesics such as acetaminophen and anti-inflammatory agents. Topical pain relievers such as Aspercreme and Ben-Gay often are well-tolerated. Anti-inflammatory drugs such as corticosteroids are used cautiously, as they may have risky side effects over the long term. Some steroid preparations are available in creams and gels, which are safer than ingesting them orally. Many patients find that the prescription Lidoderm Patch, a local-anesthetic, provides effective relief.
Long-term medicines include those that act directly on the nerves – in the affected limb or in the brain – that carry and receive pain signals. Tricyclic antidepressants, serotonin-active drugs and muscle relaxants help many individuals. Blocking the nerve signals at their source is accomplished with sympathetic nerve blocks, which often can give immediate and long-lasting relief.
In severe cases, narcotics and local anesthetics can be infused directly into the space surrounding the spinal cord and spinal cord stimulators, which are tiny electrodes placed near the nerves of the spine.
Mind-body treatments, therapeutic touch and reiki healing help individuals with chronic pain increase function and diminish the effect pain has on everyday activities. There is also evidence that acupuncture can increase the release of chemicals called endorphins that block the brain’s perception of pain. Since many acu-points are near nerves, the stimulation of these nerves from acupuncture needles activates the nerve’s muscle, sending a signal to the brain to release these endorphins, which act much like morphine to dull pain.
The most successful treatment for CRPS, much like other chronic pain syndromes, entails a combination approach. Short and long-term medications, nerve blocks or spinal cord stimulators can allow an individual with CRPS to break the cycle of the pain and permit vigorous participation in a supervised exercise program to prevent immobility and ultimate disuse of the affected limb.
Women (or the men who care about them) who have a question about women’s health can send their questions to Tucker via e-mail to AskDrTucker@aol.com or mail them to Ask Dr. Tucker, The Plain Dealer Features Department, 1801 Superior Ave., Cleveland, OH 44114. Tucker is a clinical associate professor of neurology at Case Western Reserve University School of Medicine and is directing medical-student education at the American Headache Society.