Reflex sympathetic dystrophy (RSD) is a chronic pain syndrome complex which develops as a complication, usually after a traumatic injury. The hallmark of RSD is pain that is out of proportion to the initial injury.

The incidence rate of RSD in the general population, and more specifically among workers in the United States, is underdetermined because the condition often is not recognized. However, it seems to be relatively prevalent, particularly among women in their 30s. Midwest Occupational Health Associates, for example, sees 5-10 cases of RSD per month from among 1,500 patient encounters.

From the employer's perspective, RSD can be a particularly troublesome and costly condition, primarily because it is not well understood. It is not uncommon for a patient to see numerous physicians before an accurate diagnosis is made and appropriate treatment is rendered. In addition, RSD, as a condition, is potentially ripe for workers' compensation fraud.

What is RSD?

RSD is associated with vasomotor and neurologic changes that alter the appearance of affected tissues. Patients typically describe the pain as burning, intense and constant. The pain commonly occurs following an injury (often a minor injury), more often in upper extremities that in lower extremities. RSD involves hard and soft tissues: bones, nerves, muscles, joints, skin and fascia.

Weir Mitchell, a Civil War-era surgeon, first recognized RSD in soldiers with war-related nerve injuries who developed burning pain and shiny fibers. Mitchell coined the term "causalgia" translated from two Greek words for burning and pain. The term reflex sympathetic dystrophy was adopted in 1947. RSD has also been known as algoneurodystrophy, chronic traumatic edema, posttraumatic pain syndrome, reflex algodystrophy, Sudek's atrophy, shoulder-hand syndrome, and sympathetic-mediated pain.

Causes of RSD

The exact mechanisms that cause RSD have not been identified. Reflex sympathetic dystrophy occurs when a triggering event, sometimes a direct trauma and other times a minor event, leads to short-circuiting of the sympathetic nervous system. This event leads to a chronic pain syndrome because the body loses control of pain and temperature function. There is debate about exactly how the sympathetic nervous system goes haywire to cause RSD.

The sympathetic nervous system is one of two divisions of the autonomic nervous system which unconsciously controls body functions such as sweating, digestion, and heart rate. The sympathetic nervous system has fibers that connect to the central nervous system via a chain of ganglia close to the spinal cord.

In addition to traumatic injuries, RSD has been linked with heart attacks, cancer, degenerative joint disease, frostbite, and as a complication of cumulative trauma disorder or surgery. Often the precise cause cannot be pinpointed.

The clinician should also be aware of risk factors that may predispose a patient to develop RSD. These include secondary gain issues, dependent personality types, and genetic factors that are currently under investigation.

Symptoms

Symptoms of RSD include:

• burning pain in a non-anatomical pattern;
• swollen tissues;
• nail changes (trophic changes)
• hypersensitivity to touch (allodynia)
• hair growth changes (trophic changes)
• skin changes: mottled appearance in early and middle stages, shiny appearance in late stages;
• changes in temperature of the affected tissue/limb, from warmer to much cooler; limited range of motion in the affected limb; The clinical course of RSD is variable and depends on how quickly it is recognized. If treated appropriately, early cases can be completely resolved. However, the condition can last for several years, and in some cases, be permanently disabling.

Long-term complications associated with RSD include the potential for addiction to narcotics such as codeine. RSD can cause extreme contractures of tendons, causing a "claw hand" appearance, and it can lead to the wasting away of calcium in bones of the affected limb.

The Stages of RSD:

RSD:

WHAT ARE THE VARIOUS STAGES OF RSD?

• Early (Stage I)
• Middle (Stage II)
• Late (Stage III)

RSD:

The early acute stage (I):

• Onset of severe, burning pain closely limited to site of injury within days or weeks
• Lasts around three months if left untreated
• Localized swelling

The early acute stage (I) (cont,):

• Stiffness and limited mobility
• Vascomotor changes with initial warming of affected limb, followed by cold, clammy, phase with mottled appearance to skin
• Excessive sweating is noted

Stage II (Development of Dystrophy Phase:

• Limb becomes ""brawny""
• Pain becomes more diffuse and severe
• Skin becomes shiny
• Hair becomes scant and nails are brittle
• Increased thickness of joints

REFLEX SYMPATHETIC DYSTROPHY (RSD)

DAVID J. FLETCHER, MD, MPH

Clinical Assistant Professor - University of Illinois, College of Medicine Medical Director, MOHA - Decatur, Illinois RSD WHAT IS IT?

RSD refers to a chronic pain syndrome complex which develops as a complication usually after a traumatic injury. The patient experiences burning pain, most commonly in an extremity.

What Characterizes RSD?

RSD is associated with vasomotor and neurologic changes that changes the appearance of the affected tissue Patients describe the pain as burning, intense, and constant that usually occurs after an injury, often times a very minor injury.

What Does It Affect?

It affects hard and soft tissues: bones, nerves, muscles, joints, skin & fascia

Three Stages

RSD occurs in three stages, each characterized by the following:

Stage I - Early Stage:

• onset of severe, burning pain closely limited to the site of the injury within days or weeks;
• pain lasting about three months if left untreated;
• localized swelling;
• stiffness and limited mobility;
• vasomotor changes with initial warming of affected limb, followed by cold, clammy phase with mottled appearance to skin;
• excessive sweating.

Stage II - Development of Dystrophy Phase:

• limb becomes ""brawny"";
• pain becomes more diffuse and severe;
• skin becomes shiny;
• hair becomes scant and nails are brittle;
• joint thickness increases;
• phase may last three to six months;

Stage III - Atrophic:

• marked trophic changes become irreversible;
• atrophy a muscles;
• contracture of flexor tendons and sublucations of joints;
• bone demineralization becomes marked and diffuse.

Diagnosis

A clinician should have a high index of suspicion of RSD when characteristic early clinical signs are present and there is a subjective compliant of burning pain out of proportion to the initial injury.

Diagnostic tests include:

(1.) X-ray studies to compare the affected limb with the unaffected limb, looking for osteoporosis.

(2).Triple-phase bone scan, cited by some authorities as one of the best diagnostic tools, with a high predictive value.

(3). Thermogram, considered one of the most effective early tests to confirm local abnormality of skin temperature regulation.

(4). Diagnostic stellate ganglion block, in which a needle is inserted in the neck into sympathetic nerve system ganglia in the affected side. A decrease in pain and warming of the affected limb within 30 minutes is diagnostic. If the test, is effective, the patient's eye should droop (Horner's Syndrome.)

(5). Intravenous phentolamine.

(6). Cold stressor test, in which the affected limb is placed in ice.

Treatment

The primary treatment for RSD involves directly blocking the sympathetic nervous system via a nerve block, or by surgically removing the involved ganglia tissue. There are four sympathetic blocks that may be used to treat RSD: regional, differential spinal paravertebral and epidural. A paravertebral block is the most commonly used technique. Other treatment methods include localized physical therapy, such as diadynamic electrotherapy, which desensitizes the sympathetic ganglion. Use of a TENS unit may also be effective in controlling burning pain.

The state of Minnesota has adopted treatment guidelines which have proven effective in diagnosing and treating RSD. (The citation for the RSD treatment parameters is STAT AUTH: MS 176.103; 176.83 HIST: 19 SR 1412.)

Prognosis and Prevention

RSD itself cannot be prevented, as it is an unintended consequence of trauma, but early intervention and recognition can prevent its devastating effects. The prognosis for RSD depends on the stage during which it is recognized. About 75 percent of patients get better within two years, but the remainder continue to suffer.

A support group, the Reflex Sympathetic Dystrophy Syndrome Association, has been established for patients and their families to help them better understand and cope with the condition. The RSDSA recognized the frustration faced by patients and the many problems and unanswered questions that health care professionals, adjusters, human resource personnel and attorneys may have in dealing with the disorder. To contact the RSDSA, write to PO Box 821, Haddonfield, NJ 08083, or call 609-858-6553.

David J. Fletcher, M.D., M.P.H. is director of MidWest Occupational Health Associates, (Now SafeWorksIllinois of Champaign) Decatur, IL and clinical assistant professor at the University of Illinois, College of Medicine.