REFLEX SYMPATHETIC DYSTROPHY (RDS) – A MYSTERIOUS PAIN EXPLAINED
An otherwise healthy patient presents to the emergency department of her local hospital after falling onto her out-stretched arms. She has an obvious deformity of her wrist. The ER physician consults an Orthopedic surgeon who successfully reduces her broken wrist and places a cast over her wrist and lower arm. The patient is discharged home in good condition. Several days later she returns to her Orthopedist for a check-up; she has no complaints and is doing well. She returns to her Orthopedist several weeks later and is complaining of a burning pain in her wrist and arm. The Orthopedist examines her and notes that her hand and arm are shiny, swollen and red. He diagnoses her with reflex sympathetic dystrophy (RSD) and begins her on physical therapy and anti-inflammatory medications. Months later, she continues with her pain even after undergoing multiple sympathetic blocks, medications, and even surgery. Years later she continues to have the burning pain, and her hand and lower arm are almost useless.
Unfortunately, the above patient has developed RSD following a fairly minor trauma, and she demonstrates the typical course and treatment for such a patient. In this article, I will discuss this puzzling pain syndrome and attempt to delineate its causes as well as its clinical presentation. More importantly, I will discuss its treatment and its prognosis. Hopefully, such a discussion will enlighten those patients with RSD as to their condition and future.
Reflex sympathetic dystrophy is generally considered a disease characterized by a group of signs and symptoms including pain, swelling, and vasomotor dysfunction (vascular instability) in a limb following a minor trauma or occurring spontaneously. In 1864, Weir Mitchell first described RSD in Civil War patients with limb and nerve injuries accompanied by intense, burning pain. In 1953, Dr. Bonica differentiated RSD from another pain syndrome – causalgia - based upon the severity of the signs and symptoms of the patient. Generally, causalgia is seen as the more severe of the two syndromes while RSD is generally not associated with a direct nerve injury. To further confuse the issues, in the 1990’s, a panel of experts recommended that the term complex regional pain syndrome (CRPS) be used instead of RSD. At the present time, both CRPS and RSD can be used to describe these types of pain patients
WHAT IS RSD AND WHO GETS IT?
As mentioned above, RSD is a pain syndrome characterized by a specific yet generalized set of signs and symptoms. Its exact cause is unknown, and RSD can occur spontaneously for unknown reasons. RSD is characterized by three stages: (1) the acute phase, occurring immediately after or several weeks following the traumatic event; (2) the dystrophic stage, occurring 3 to 6 months after the injury; and finally, (3) the atrophic stage, usually occurring 6 months or longer following the injury. The acute stage is characterized by aching or burning pain following the course of the blood vessels accompanied by swelling, redness, heat, and sweating of the affected limb. The dystrophic stage is characterized by a burning pain just above or below the injury, an incredible sensitivity to touch or temperature, swelling, hair loss, muscle wasting, joint stiffness, and bone loss. The atrophic stage is characterized by pain, decreased skin temperature, smooth, shiny skin, wasted muscles, fixed joints, and extreme bone loss. All these changes are permanent when seen during the third stage of RSD.
Most patients with RSD are between 30 and 60 years old, although RSD can occur in children. RSD demonstrates no racial or sexual predilection and occurs in about 5% of all patients who suffer some type of upper extremity trauma. RSD usually only occurs in one extremity but can occur in both extremities in about 25% of the cases. The cause of this bilateralism is unknown.
WHY DO PATIENTS CONTRACT RSD?
The bottom line is: NO ONE KNOWS!! RSD occurs following trauma or not; RSD occurs spontaneously or not; RSD can vanish with early treatment or not; RSD can be permanent or not; RSD can be disabling or not. The generally accepted theory with regard to the cause of RSD is based upon an unrestricted sympathetic response, the closing of blood vessels, to an injury. In a healthy person, an injury results in a sympathetic response including vasoconstriction designed to prevent swelling and bleeding. This sympathetic response soon is replaced by a vasodilatation, the blood vessels open, to allow increased blood flow, and increased delivery of nutrients designed to hasten tissue repair. In patients with RSD, the acute phase of the injury response goes unchecked; in other words, the blood vessels shut down depriving the area of blood, oxygen, and nutrients. The result is a swollen, stiff, painful, damaged limb. If not treated soon, the effects can be widespread and permanent.
WHAT IS THE TREATMENT FOR RSD?
The treatment for RSD can consist of a multitude of interventions ranging from anti-inflammatory medications and physical therapy to significant surgical procedures. The first and foremost rule for treating RSD, however, remains: the earlier the intervention, the better the outcome, in most cases. To begin early treatment, the patient must be diagnosed early in the course of the disease. A diagnosis of RSD or at least a suspicion of RSD should be entertained if a patient presents with any of the above signs or symptoms following any type of traumatic event. At that point, the physician should refer the patient to a specialist who will begin one of several interventions.
The first therapies usually include and begin with physical therapy coupled with anti-inflammatory medications. Some physicians, however, go directly to the use of sympathetic blocks – injections around the sympathetic nerves designed to reduce the nerve’s irritation and firing thus blocking their reactions to the traumatic event. In addition, as part of an early course of treatment, many physicians begin the use of drugs called sympatholytics that block the sympathetic nerves. If no single treatment modality is effective, all can be used in combination. Finally, if no treatment or combination thereof is effective, surgical procedures that destroy the involved sympathetic nerves should be instituted. If the patient has failed all the established therapies, they may be considered candidates for a spinal cord or peripheral nerve stimulator.
WHAT IS THE PROGNOSIS FOR PATIENTS WITH RSD?
The earlier the patient is diagnosed and the earlier treatment begins, the better the prognosis for that patient. The younger the patient at the age of first presentation and treatment, the better the prognosis for that patient. The cure rates for all the above treatment options range from 12 to 97% and thus a meaningful prediction as to prognosis is difficult at best. Unfortunately, however, once the patient’s pain becomes unresponsive to the above medications and procedures, the pain is probably lifelong and possibly disabling.
WHAT ARE THE MEDICO-LEGAL ASPECTS OF RSD?
Inasmuch as earlier diagnosis and treatment significantly affects prognosis, the clinician must be vigilant in diagnosing patients with RSD. Moreover, early appropriate treatment must be instituted promptly and in the most efficacious manner. Finally, referral to a specialist is a must. Failure to do any of those actions would be construed as malpractice.
RSD is a baffling pain syndrome characterized by three specific phases occurring after an injury or even spontaneously. It is characterized by an overactive sympathetic nervous system resulting in pain, skin, hair, bone, and muscle changes. Treatment consists of interventions designed to reduce the sympathetic outflow or its effects. Prognosis is better in those patients diagnosed and treated early in the course of the disease. Unfortunately, those not diagnosed or treated early generally demonstrate a poor prognosis with permanent pain.