NOTE: I especially want to call your attention to the following quotations, which are from the article ( below ):
1.) "It is important to note that nerve entrapment syndromes are similar to a number of the symptoms of RSD."
2.) "One of the best ways to differentiate a patient with RSD from one suffering from a nerve entrapment syndrome is to determine whether or not the affected limb is extremely sensitive to temperature."
3.) "In some cases, a patient will have both RSD and peripheral nerve entrapment. More importantly, in my experience, between 75 percent and 85 percent of the time, a patient diagnosed with RSD will actually have a nerve entrapment syndrome."
4.) "It is important to establish whether or not there is associated nerve entrapment syndrome, along with RSD. The National Institute of Health reports indicate that even if properly treated for RSD, a patient will not improve unless any concomitant nerve entrapment syndrome is also treated. Therefore, it is essential to determine whether nerve entrapment syndromes co-exist with RSD. Treatment of one injury, without treatment of the other, results in treatment failure."
Reflex Sympathetic Dystrophy: Clearing Up The Misconceptions
Nelson Hendler, M.D., M.S. Reflex sympathetic dystrophy (RSD) is becoming well-known to many employers as RSD claims are on the rise in the nation's workplaces. What starts out as a simple sprain or soft tissue injury develops into a crippling, painful condition that leaves victims unable to work or even to function normally.
There is much confusion associated with RSD. What are the symptoms? Why is it so easily misdiagnosed? How can it be treated? Will the injured employee be able to return to work? This article attempts to clear up some of the misconceptions regarding RSD and educate the employer on the proper diagnosis and treatment.
WHAT IT IS
RSD is actually a cluster of symptoms. A syndrome is a disease that has many parts to it, just like a completed jigsaw puzzle is made up of many pieces. Each symptom represents a piece, and by itself may be unrecognizable. Only when put together into a "symptom complex" is the picture of the disease apparent. Unfortunately, unlike many syndromes, RSD suffers from additional problems.
The name of the disease has changed over the past 100 years, and the types of symptoms that would be included in the diagnosis of the disease have also changed. In part, the confusion has been created by newer diagnostic studies which have allowed physicians to refine the definition of some of the signs. On the other hand, some of the signs and symptoms have remained constant through the years.
The incidence (number of new cases that appear in a year) of RSD is unknown. Reports have ranged from 100,000 to up to a million new cases a year. Likewise, the prevalence (number of cases that are outstanding at any given point in time) of RSD is unknown. The prevalence of RSD has been estimated between 500,000 and 6 million cases at any given time within the United States.
CAUSES OF RSD
RSD can be caused by a variety of injuries, but very often, the injury is minor. Types of injuries that produce RSD range from accidentally striking the hand against the wall, to wearing tight nursing shoes, to twisting an ankle.
There are two major branches of the nervous system in the body: the voluntary nervous system and the autonomic nervous system. The voluntary nervous system can be divided into motor nerves (which move muscles) and sensory nerves (which transmit the sensation of pain, pressure, temperature, etc.). In the autonomic nervous system, the division is between sympathetic and parasympathetic nerves.
The sympathetic nerves control functions in the body, related to the "flight or fight" phenomena (a set of reactions which would prepare an organism to fight an attacker or run away). Therefore, the sympathetic nerves control pupil dilation, blood vessel diameter in the muscles, heart rate, the force of contraction of the heart, the diameter of the bronchioles in the lungs and certain sphincter activities.
The parasympathetic nervous system controls "vegetative" functions related to slowing down the heart rate, increasing stomach acid secretion and digestive functions. The sympathetic nervous system can be further divided into the alpha and beta sympathetic nervous system, which can both be divided into alpha I or beta 1, and alpha 2 and beta 2 receptors.
Note that sympathetic fibers cross the midline outside the spinal cord, which explains why the symptoms of RSD can cross from one leg or one arm to the other. Also, the fact that the sympathetic chain exists along the entire spinal cord explains why the symptoms may spread from one arm to a leg on the same side.
SYMPTOMS: RAPID AND PROFOUND CHANGES
It is important to remember that at any given time, the symptoms associated with RSD may change. One month, the patient may have a swollen limb, overgrowth of hair or nails, and discolored skin. The next month, the patient may have hair loss, heat in a limb that had previously been cold (or vice versa), or a change in bone scan results. Not all patients will have all of the symptoms. As mentioned, the symptoms may spread from one limb to the other, or from one side of the body to the other. Indeed, RSD has been called a "chameleon disease" because the symptoms change so rapidly and so profoundly.
It is important to note that nerve entrapment syndromes are similar to a number of the symptoms of RSD. In one study, my colleagues and I found that 25 percent of the patients referred with RSD actually had nerve entrapment syndromes. In another series, 10 patients diagnosed with RSD were referred by the Worker's Compensation Commission of Nevada to Mensana Clinic. Eight of the ten were found to have nerve entrapment syndromes instead of RSD.
One of the best ways to differentiate a patient with RSD from one suffering from a nerve entrapment syndrome is to determine whether or not the affected limb is extremely sensitive to temperature. Patients with nerve entrapment syndrome very often do not have exquisite sensitivity to temperature, while RSD patients very often do suffer from extreme sensitivity to either heat or cold. However, patients with both nerve entrapment syndromes and RSD have, to some variable degree, sensitivity to light touch.
DIAGNOSTIC STUDIES AND THEIR COSTS
Since early diagnosis and treatment is essential to provide a cure for RSD, the appropriate use of diagnostic studies is important. Any delay in treatment will result in a disorder that is markedly resistant to treatment and can become permanent. An injured employee suffering from RSD must receive proper testing and treatment before the injury turns into a permanent disability. At the same time, the employer should be aware of the different types of diagnostic testing and treatment available, as well as their costs, to choose the best course of action to take. Often, the most expensive tests and treatments aren't necessarily the most effective.
Thermography: Thermography, one of the easiest, cheapest and most reliable diagnostic tools, has been virtually eliminated because of the abuses by certain physicians, as well as the refusal of a number of insurance carriers to pay for it. While thermography was misapplied to a number of diseases, it was an excellent early diagnostic tool for RSD. Unfortunately, the baby was discarded with the bath water, so it is difficult to find thermography readily available. The cost of thermography is approximately $64 for the test and $150 for the interpretation. (Keep in mind that costs vary throughout the country.)
Bone Scan: Another relatively cheap and simple test is a bone scan. But, bone scans have a unique property. Early in the course of RSD, they show increased uptake in the affected limb, while later in the course of RSD, they show reduced uptake. A bone scan has value, because it is basically a physiological test, rather than an anatomical test (it reveals what is happening to the blood supply of the bone, rather than just taking a picture). The cost for a whole body three phase bone scan is between $250 to $400.
Intravenous Phentolamine Injection: Intravenous phentolamine injection is another simple, relatively inexpensive test. This determines whether or not the patient's pain is maintained by the sympathetic nervous system. Here, the drug phentolamine, which blocks the sympathetic receptors from receiving circulating norepinephrine and epinephrine, will show whether or not a patient's symptoms will disappear when these receptors are blocked. The test is quite simple, since an intravenous injection of a drug does not require great medical skill.
The real skill comes from testing properly (using an adequate dosage of the drug and controlling for placebo responses) and interpreting the test. The cost is $50 for the injection and $250 for the interpretation of the results.
Drop and Swipe Test: Perhaps one of the simplest and most readily available diagnostic tests is the Mensana Clinic Alcohol Drop and Swipe Test. Since the diagnosis of RSD requires both thermal (temperature) and mechanical (touch) hyperalgesia (supersensitivity to a stimulus), the test fills both of these criteria.
An alcohol swab is opened and squeezed so that the alcohol drops from the swab onto the affected limb. The examiner waves his or her hand over the area to facilitate evaporation of the alcohol. In 10 to 60 seconds, the examiner asks the patient what he or she is feeling. If the patient reports that the pain has increased dramatically, is burning and has become unbearable, or if the patient withdraws his or her limb and responds with increased pain, then the patient is experiencing thermal hyperalgesia: a hypersensitivity to temperature stimulation caused by the evaporation of the alcohol which cools the limb at the spot where the alcohol is applied and reproduces the symptoms of RSD. If the patient just reports that the area feels cold, then the patient has a normal response to temperature and does not have thermal hyperalgesia.
Next, the alcohol swab is lightly stroked over the affected area. If the patient responds with increased pain, or withdraws the limb, or tells the examiner to stop, then the area is experiencing mechanical hyperalgesia: a supersensitivity to mechanical stimulation. Since most RSD patients experience both thermal hyperalgesia as well as mechanical hyperalgesia, this quick and inexpensive test allows an examiner to rapidly determine whether or not the patient is a candidate for additional, expensive testing. If the patient experiences only mechanical hyperalgesia, without the thermal hyperalgesia, more likely than not the patient has a nerve entrapment syndrome, but probably does not have RSD. The cost of this test? A half a cent.
Sympathetic Block: Older types of testing, such as sympathetic blocks, are based on blocking the sympathetic ganglion, which is the cluster of sympathetic nerves outside the spinal cord. These types of blocks, if done on a repetitive basis early in the course of the disease, may actually cure the patient. However, blocks require a skilled anesthesiologist or other physician trained in the administration of these blocks, and they can produce some painful side effects. Moreover, there is always the possibility that the physician providing the block might miss the sympathetic ganglia and not give an adequate block. Additionally, with repetitive blocks (greater than 25 to 30), there is a risk of scarring around the ganglia, thereby reducing the effectiveness of future blocks. The cost of a single sympathetic block ranges from $350 to $600.
Epidural Block: One test that defies rational diagnostic criteria is the epidural block. In this test, an anesthetic agent is instilled into the spinal canal in the area of the affected limb. However, since a local anesthetic agent (such as a numbing agent, similar to what a dentist would use), is applied, all nerves that come in contact with this agent become numb. Also, the sympathetic nerves lay outside the area of the epidural because they are outside the spinal canal, although their origin occurs inside the thoracic spinal canal. Therefore, an epidural block will block motor nerves, sensory nerves and sympathetic nerves all at once, and does nothing to provide a diagnosis that helps differentiate between RSD, radiculopathy, or peripheral nerve entrapment syndromes. The cost of an epidural block ranges from $700 to $900.
Peripheral Nerve Block: On the other hand, peripheral nerve blocks into specific nerves do help differentiate RSD from nerve entrapment syndromes. These tests are useful if there is a positive response, because they will indicate that the nerve block is contributing to the production of the pain. In some cases, a patient will have both RSD and peripheral nerve entrapment. More importantly, in my experience, between 75 percent and 85 percent of the time, a patient diagnosed with RSD will actually have a nerve entrapment syndrome. Therefore, peripheral nerve blocks are quite useful in differentiating between the two. The cost of a single nerve block ranges from $250 to $500.
3D-CT: 3D-CT (three-dimensional CT scanning) is a useful tool. It is not unusual for patients with bone injuries to have hidden fractures that do not show on bone scans, X-rays or regular CTs. In fact, a recent study determined that in 100 patients with back pain, but with normal CT, myelograms, MRIs, Xrays and bone scans, 56 percent of the time, the 3D-CT was able to find a bony lesion that had been missed by these other tests. For that reason, a patient with RSD might need a 3D-CT of the site of injury to help determine whether or not there is a hidden fracture that had been missed by regular examination. The cost of a 3D-CT runs between $800 to $1,000.
EMG Nerve Conduction: This study is useful in the differentiating of RSD from nerve entrapment syndromes. Here, the speed of conduction of a nerve is measured by inserting needles along the nerve and measuring how long an electrical impulse takes to traverse the nerve. Likewise, activity within a muscle measured by electromyographic studies shows the integrity and strength of a muscle. The cost of an EMG nerve conduction test is $800 to $1,200, depending on the number and complexity of the nerves.
However, EMG nerve conduction studies are limited, especially if the patient's complaint is purely pain. For this reason, diagnostic studies that are designed specifically to measure sensory nerves, such as current perception threshold testing, will help differentiate which type of pain fibers are damaged by the disorder. The current perception threshold can measure the three types of pain fibers that carry the message of pain: the A beta fiber, the A delta fiber, and the C fiber. As this fine degree of differentiation is not available with EMO nerve conduction velocity studies, this is a better test for sensory nerve. The cost is approximately $75 per nerve (six nerves are tested), or $450 total.
TREATMENTS: PROS AND CONS
Once the diagnosis of RSD has been more or less established, the easiest and simplest treatment is a series of sympathetic blocks for the affected limb. Usually, a patient will require no more than 12 blocks, which will help determine whether the patient has RSD, whether there is a slow progressive steady improvement after the blocks, or whether the symptoms return after the medication from the blocks wears off, necessitating sympathectomy (surgical removal of the entire sympathetic ganglia supplying the painful area).
Sympathectomy: There is great disparity, however, when reporting the effectiveness of sympathectomy. In a review of articles describing the benefits of sympathectomy, success rates ran from 12 percent to 92 percent. The confusion arising from this kind of outcome deals primarily with
(a) difficulty in accurate diagnosis of the disorder,
(b) definition of RSD versus causalgia, versus other types of neuropathic pain that may mimic RSD,
(c) the skill of the surgeon,
(d) the accuracy and honesty of the reports, and
(e) the criteria selected for "cure" or "improvement." The cost of a sympathectomy ranges from $2,000 to $5,000.
By and large, in an accurately diagnosed patient who has had a positive response to a series of sympathetic blocks, but no long-term improvement, sympathectomy is the treatment of choice. Since it is possible for RSD to spread from one side to the other, as discussed earlier, it is not unusual to require a bilateral sympathectomy in approximately 5 percent to 10 percent of the cases. (This is a general clinical impression, as there have been no published statistics to confirm this figure.)
Steroids and Exercise: A form of treatment that is best given in the early stages is a high dose of steroids, coupled with intense exercise. There are no well-documented cases about the efficacy of this approach in the later stages of RSD. Early and late-stage RSD is not determined by the amount of time that the patient has the disorder, but rather, by the types of symptoms that are present. Physical therapy can cost $45 to $90 a session, but the patient can get the same results by just going to the gym. Instead of wasting $45 to $90 a session for physical therapy five times a week for one month (20 x 45 = $900, at the low end), it would be cheaper for the employer to just to buy a gym membership for the employee at $30 to $45 a month.
Epidural Electrical Stimulation: Another treatment that held promise for a while was the use of epidural electrical stimulation, or dorsal column stimulation. In this type of treatment, an electrical wire is threaded above the spinal cord and the wires run through a receiver which has been planted underneath the skin. The transmitter then sends electrical impulses to the receiver, and electrical stimulation is passed onto the spinal cord. This does provide a symptomatic relief for RSD. However, there are reports that the efficacy of the dorsal column stimulator diminish over time, and that it loses its effectiveness in a large percent of the cases after two years. The cost is $7,000 to $10,000.
Morphine Pumps: Here, a catheter is inserted under the dura (the covering over the spinal cord) along the spinal cord, which then leads to a drug reservoir that has its own internal pump. This delivers a steady level of morphine directly to the spinal cord at dosages far below what is required by mouth.
In this fashion, the peripheral side affects of morphine can be eliminated, and the patient experiences relief due to the application of morphine directly to the spinal cord. Unfortunately, there are many instances of infection, difficulty with pumping mechanisms, and even fatalities if the wrong dosage of morphine is inserted into the reservoir. The reservoir needs to be filled every month by an external injection through the skin into the reservoir receiving port. The cost of implanted epidural morphine pumps is $10,000 to $15,000.
Medications: Medications are helpful to some degree, and are designed to treat specific symptoms such as intense muscle spasms controlled at a spinal cord level. The best drug to treat this is a central reacting muscle relaxant such as baclofen. Swelling in the limb is difficult to treat, although some minimal improvement may be achieved with the use of Diamox, which reduces the production of fluid in the limb. Patients may improve their sleep, which is usually disturbed with chronic pain, by the use of antidepressant drugs, which also alleviates the attendant anxiety and depression that very often comes with persistent pain.
Recently, some studies have suggested that gabapentin, an anti-convulsant, may reduce the perception of pain in approximately 50 percent of RSD cases. Additional studies to confirm the efficacy of this drug will need to be done. The use of oral morphine, or a drug similar to morphine which actually blocks the activity of morphine (Methadone), has been advocated by some clinicians. However, there are many attendant side affects, such as constipation, mental confusion, depression, irritability, etc., that may suggest this approach is not best suited for RSD. In fact, a number of studies report that narcotics have very little effect on "neuropathic" pain states, of which RSD is a prime example.
Amputation: Amputation of the limb has been advocated in extreme cases, without much success. There have been documented instances where the RSD has spread either up or down, or across to the other side, after amputation.
It is important to establish whether or not there is associated nerve entrapment syndrome, along with RSD. The National Institute of Health reports indicate that even if properly treated for RSD, a patient will not improve unless any concomitant nerve entrapment syndrome is also treated. Therefore, it is essential to determine whether nerve entrapment syndromes co-exist with RSD. Treatment of one injury, without treatment of the other, results in treatment failure.
MISSED DIAGNOSES AND ABUSES
Certainly, RSD creates much confusion. Since the etiology is unknown, the treatment approach varies. However, there are some fairly obvious abuses that do occur that should be stopped. The most flagrant abuse is the overuse of sympathetic blocks. A series of 6 to 12 blocks is enough to determine if
(a) the blocks will provide a treatment by themselves,
(b) the blocks work only temporarily, and the patient needs a sympathectomy, or
(c) the blocks do not work, and the patient does not have RSD.
The most appalling abuse of blocks I have ever seen was in a case from Nevada. A woman, injured on the job, developed RSD and had 350 blocks and a sympathectomy for her right arm (all without benefit) before the Worker's Compensation Commission of Nevada referred her to Mensana Clinic. By the time she arrived at the clinic, over $450,000 had been spent for various treatments that had not worked. At the clinic, she was diagnosed as having RSD in the right arm, thoracic outlet syndrome and C3-C4 cervical disk. She underwent a C3-C4 fusion and a repeat sympathectomy at a lower level, and is awaiting her thoracic outlet surgery.
Unfortunately, the RSD has spread to her right leg, possibly due to the delay in treatment. Equally as egregious was an East Coast physician who diagnosed even the most minor nerve entrapments as RSD and began a series of sympathetic blocks without any diagnostic studies. Treatment should be determined by diagnosis, and administered only in a logical progression, not haphazardly applied. The later method is costly and inappropriate.
SOME RSD-RELATED CASES OF NOTE
Because of the nature of RSD, comp benefits have been denied in many cases. Employers, insurers, even physicians, have believed that claimants exaggerate or even fabricate injuries to obtain benefits.
For example, in Winterberg v. CNA Ins. Co. 868 F. Supp. 713 (E.D. Pa. 1994), the claimant injured her foot at work and developed RSD. She initially collected workers compensation benefits, but the insurer then attempted to discontinue her benefits and refused to pay for her medical treatment.
At the request of the insurer, the claimant was examined by a neurologist engaged by the insurer. During the examination, which was prior to the initiation of the present litigation, the doctor asked her if she had settled her lawsuit yet. He grabbed her foot immediately after she told him she couldn't bear even the light pressure of air blowing across the injury site. He insisted that she walk, and when she became unsteady, he refused to help her. She fell to the floor, and he told her, "I am not going to help you up. You are not an invalid and you have to get up yourself." The claimant suffered chin, neck and head injuries from the fall, and later attempted suicide. She ultimately filed suit against the insurer for the physician's abusive behavior which led to her injuries sustained in the doctor's office.
When little is understood about RSD, the following situation can happen: In Craver v. Dixie Furniture Co. 447 S.E.2d 789 (N.C. App. 1994), the claimant injured both her elbow and hand within a five-month period. Each time, the company nurse applied ice to the injured area. Two years later, she developed RSD in the affected areas and her employer filed for workers comp benefits. The insurer denied benefits, stating that the claim was filed too late.
The court found that since the claimant had given appropriate notice when initially injured, had her medical bills covered at the time, and had been told by the company nurses that her claim and resulting disability would be compensable, the claimant had been "lulled into inaction." It is interesting that the court's decision was not based on the fact that she had developed RSD from her work-related injuries.
SUMMARY
In summary, it is important to establish accurate diagnosis of RSD. The examiner must he certain that
(a) the disorder really is RSD,
(b) there are no other concomitant or associated nerve entrapment syndromes, and
(c) there are no other associated radiculopathies.
Early intervention and treatment is essential, starting with high dose steroids and exercise, progressing to sympathetic blocks, and then sympathectomy. Delays in treatment are disastrous, and will result in an employee who may have long-term or permanent disabilities which will impact on your workers compensation dollar.