60. | Manual of Rheumatology and Outpatient Orthopedic Disorders (LB Spiral Manuals)

Chapter 53 Reflex Sympathetic Dystrophy

Manual of Rheumatology and Outpatient Orthopedic Disorders

Chapter 53 Reflex Sympathetic Dystrophy

James Halper and Michael Rubin

Introduction
Clinical presentations
Etiology
Pathophysiology
Diagnosis
General treatment concepts
Specific treatment modalities
Reflex sympathetic dystrophy of the knee

I. Introduction

Definition. Reflex sympathetic dystrophy (RSD) is a disorder in which an inciting noxious eventmost often an injury to an extremity , a visceral disorder such as myocardial infarction, or a brain insult such as cerebrovascular accident is followed by the development of a constellation of signs and symptoms in a regional distribution. These include the following:
1. Pain (both spontaneous and in response to ordinarily non-noxious sensory stimulation).
2. Swelling and stiffness.
3. Vasomotor and sudomotor changes.
4. Trophic skin changes.
5. Marked functional disability that initially results from pain, edema, and stiffness but later from less reversible changes (e.g., soft- tissue atrophy, osteopenia, and capsular-ligamentous joint changes).
  An abbreviated definition of RSD is a syndrome associated with (a) pain, (b) autonomic changes, (c) trophic changes, and (d) functional impairment that are not attributable to a discrete nerve injury and are out of proportion to the apparent precipitating noxious event.
Localization and variants. Hands and feet are typically affected, although it becoming increasingly appreciated that RSD may occur in other areas, particularly the knee. There are also localized variants (i.e., segmental forms) limited to individual rays of the hand or foot or parts of joints (e.g., patella, femoral condyle, or hip). The manifestations of RSD may spread to affect contiguous and even contralateral areas. Movement disorders and psychiatric disturbances frequently develop. Other disorders that have been proposed to be variants of RSD include transient regional osteoporosis, migratory regional osteoporosis, and palmer fasciitis, but the appropriateness of including these under the rubric of RSD remains controversial .
Diagnostic criteria. Advances in the understanding of and treatment of RSD have been hampered by a lack of consistent laboratory findings associated with the disorder and the absence of a standardized set of diagnostic criteria accepted by the many specialties that deal with this type of pain syndrome. A given patient may vary in presentation within a short time scale (minutes to hours), reflecting reactive increases and decreases of different autonomic functions, or during a longer term as the picture evolves through the stages discussed below. Heterogeneity also results from the fact that that a multiplicity of neuropathic mechanisms, involving both sympathetic and somatic nerves, can cause different components of RSD or simultaneously contribute to a single manifestation. This has led to the appreciation that RSD is associated with both sympathetically and nonsympathetically maintained pain, the relative importance of which fluctuates over time. Thus, although amelioration of signs and symptoms by sympathetic blockade has been held by some to be an important criterion for RSD, this is too restrictive a criterion because of the potential for technical factors to cause false-negative results and also because of the natural history of the illness .
The International Association for the Study of Pain has proposed that RSD, as defined by items 1 through 5 above, should be named type 1 complex regional pain syndrome. Causalgia, a disorder in which similar symptoms, especially pain, are found in a distribution that can be attributed to a neuroanatomically defined nerve injury, is classified as type 2 complex regional pain syndrome. Either type of complex regional pain syndrome may be associated with sympathetically mediated and nonsympathetically mediated pain. At present, RSD is probably both underdiagnosed and overdiagnosed.

II. Clinical presentations

Cardinal signs and symptoms
1. Pain and an exaggerated, painful response to sensory stimuli
  1. Pain is variously described, but commonly used adjectives include constant, burning, aching, tearing , and intense , and the pain is characteristically out of proportion to the initiating injury. Patients also report subjective stiffness and a feeling of coldness in the affected region.
  2. Response to sensory stimulation
    1. Hyperalgesiaan exaggerated response to a painful stimulus.
    2. Allodyniapain resulting from a stimulus that does not normally cause pain.
    3. Hyperpathiapersistent delayed pain, especially following repetitive stimuli.
    4. Marked sensitivity to thermal stimuli.
    These pathologic sensory responses may contribute to the lancinating paroxysms of pain that may follow the slightest movement of or touch to the affected area. Joint movement may be particularly capable of inducing these paroxysms. Spontaneous paroxysms also occur.
    
    In general, both pain and sensitivity are decreased by elevation of the extremity and increased by physical loads, movement, emotional excitement, and temperature changes.
2. Edema. This is initially pitting but later becomes brawny. It may be more marked in periarticular regions , interfere with blood flow, and lead to pain from nerve compression and decreased mobility. These problems may then exacerbate the RSD.
3. Vasomotor and sudomotor changes. These reflect sympathetic activation and may vary dramatically between patients and with time and in location in the same patient. This is because RSD is associated with sympathetic instability and hyperreactivity rather than simply a statically increased sympathetic tone. Mediators released by nociceptors (e.g., substance P) also affect blood flow.
  1. Alterations in skin temperature. Skin temperature may be increased or decreased in comparison with the contralateral area, reflecting impaired thermoregulation. Initially, skin temperature is most commonly increased, but it often fluctuates over the affected area both spontaneously and in response to the triggering factors described above. As time passes , hypoperfusion with decreased skin temperature becomes more prominent. It should be noted that increased perfusion does not indicate an increase in nutrient blood flow, which is often decreased because of shunting and microcirculatory abnormalities.
  2. Alterations in skin color . Skin color, which also reflects blood flow, is similarly variable, ranging from red (hyperemia) to pale or cyanotic (diminished perfusion). These hyperemic and cyanotic alterations are usually associated with warmth and coldness of the affected areas, respectively. Marked local flow variations that lead to a livedoid, reticulated appearance are often seen.
  3. Hyperhidrosis, anhidrosis, and piloerection. Increased or decreased sweating and piloerection may occur, reflecting changes in autonomic tone.
  4. Trophic changes. Nails may be brittle, ridged, and abnormally colored and may show increased curvature. Hair may be coarse and increased. Skin may be thin and atrophied or hyperkeratotic. Atrophy or edema can lead to loss of skin folds , and finger pulp may be lost. Bony resorption is prominent from the onset and increases with disease duration.
  5. Functional impairment initially results from pain and swelling. This leads to disuse, which produces a synergistic effect with the pathophysiologic concomitant features of RSD, so that anatomic alterations and permanent functional impairment ensue. Such changes include severe atrophy of skin and other soft tissues, osteoporosis, nerve damage from compression, and joint capsular and ligamentous fibrosis.
Stages of reflex sympathetic dystrophy. The natural history of RSD is often divided into three stages (Steinbrocker classification). However, it should be noted that patients frequently may not demonstrate the full picture at each stage or an orderly progression from one stage to another.
1. Stage 1 (acute, months 1 to 3) is usually dominated by pain and tenderness, edema, and temperature changes, particularly increases. Patchy areas and periods of temperature decrease may, however, be seen. Sudomotor alterations, typically hyperhidrosis, tend to appear later in this phase. Signs and symptoms are initially limited to the region of injury or the surrounding areas but may spread to adjacent or even contralateral areas, reflecting changes at the spinal or even more central areas of the central nervous system.
2. Stage 2 (dystrophic). The pain usually extends beyond the area initially affected. Although still prominent, it may be either increased or decreased in comparison with pain in stage 1. Edema may take on a more brawny quality. Loss of hair and dystrophic nail changes become apparent, and muscle wasting and osteoporosis become more prominent. At this stage, a decreased range of motion (ROM) reflects capsular changes and contractures, in addition to pain and edema. The affected area is usually cool, pale, or cyanotic, reflecting a decrease in blood flow, although as usual marked fluctuations may occur.
3. Stage 3 (atrophic or chronic). Skin and soft-tissue atrophy, bony demineralization, and capsular thickening progress, as does functional impairment. The latter results from and leads to contractures, decreased passive movement, and apparent stiffness of joints. In extreme cases, a claw hammer hand or frozen shoulder may result.
  The importance of staging in treatment is controversial, at least in regard to stages 1 and 2. However, patients who have reached stage 3 are clearly distinct in that they have suffered irreversible damage and will respond poorly to any modality.
Movement disorders. Movement disorders become more prominent in the advanced stages (e.g., stages 2 and 3) and may even initially present after pain has subsided. Rarely, they may precede other changes. Abnormalities include tremor with resting, postural, and action components; spasms; myoclonus; focal dystonias; and an inability to initiate movements and complete complex movements that may develop into apraxia.
Hyperreflexia and decreased strength may cause or result from the guarding postures commonly assumed by the patient. However, the dysphasia and difficulty in swallowing that may be found in RSD affecting the upper extremities indicate cortical changes. The neglect reported to account for some cases of movement disorder in RSD is also consistent with cortical involvement. This is characterized by delayed, slowed, low-amplitude movements and a decrease in spontaneous movements. The patient feels disconnected from the involved region and may even refer to the affected extremity as it.

Movement disorders may interfere with physical therapy or become independent causes of morbidity. Dystonias, for example, may lead to total loss of hand function and the development of pressure sores in the clenched-fist syndrome, or problems of ambulation resulting from inversion and an equine position of the foot.

Movement disorders result from sympathetic hyperactivity and from plastic changes at spinal and peripheral neurons and muscle spindles induced by sympathetic activity and products of nociceptors. Cortical changes are also involved.
Psychiatric disorders. Affective disorders (e.g., depression or anxiety) and behavioral disturbances (e.g., social withdrawal, physical inactivity, chronic invalidism) are extremely common both in patients with RSD and in those with causalgia. It has been suggested that psychological features may be involved in the initiation of the disorder, but this is controversial. However, it is widely agreed that psychological disturbances commonly occur secondary to the pain and disability associated with the disorder. Both adjustment disorders (subsyndromal presentation of depressive or anxiety symptoms felt to occur as a reaction to stress) and major depressive disorders (full syndrome felt to be precipitated by the stress of the illness) may occur. Suicidal thoughts may occur in either instance.
Demoralization and frustration with the medical system (because of the not uncommon delays in the diagnosis of RSD and minimization of the significance of this poorly understood illness) on top of chronic pain may make the patient argumentative and otherwise difficult to deal with. This leads to patterns of escalating negative interactions with health care professionals and family members. The family members may be similarly difficult.

Thus, the relationship between RSD and psychological symptoms is complex and variable. However, regardless of the etiology, the psychological concomitant features of RSD must be addressed early in the treatment because psychological factors, such as tolerance of pain, methods of coping with stress and pain, and beliefs and expectations, have a major effect on the patient's willingness and ability to (a) tolerate often painful treatments , (b) avoid the extremes of too much mobilization and too much immobilization, and (c) cope with transient or permanent functional impairments.

The clinical observation that emotional stress may cause disease exacerbations and data linking flares with elevation of catecholamines further underscore the importance of dealing with psychological issues.

Addiction is often overdiagnosed but sometimes does occur.
Complications. In a small but significant number of patients, infections, ulcers, and chronic edema may develop. Unrecognized or resistant infections may be diagnosed as refractory RSD or even malingering. Severe dystonias have been discussed above. It has been suggested that complications and motor disorders may be more common in younger female patients with multiple involved sites in the lower extremities and in patients who present initially with decreased blood flow (cold presentation).
On the other hand, rarely, ulcerative lesions and infections have been the result of self-mutilation.
Possible atypical variants of reflex sympathetic dystrophy.
1. Transient regional osteoporosis.
2. Transient migratory osteoporosis. They are marked by a sudden onset of pain that is intensified by weight bearing . As the names imply, transient regional osteoporosis is limited to a single joint or part thereof. Hip pain in middle-aged men or in women in the third trimester of pregnancy is a common presentation of transient regional osteoporosis. Transient migratory osteoporosis most often affects the knee, ankle, and foot. As the name implies, it attacks a variety of joints, most often sequentially but occasionally with some temporal overlap. These conditions present with prominent focal areas of osteoporosis, unexplained severe pain (particularly on motion and weight bearing), positive findings on bone scans , and occasionally dependent rubor and muscle atrophy (from disuse). Thus, they may be diagnosed as RSD and have been considered by some authorities to be atypical forms of the disorder. However, a relation to an inciting insult can rarely be documented and physical changes are usually absent, as are the manifestations of neuropathic pain. Most importantly, neither transient regional nor transient migratory osteoporosis has a protracted course. Although there are scattered reports of responses to treatment with steroids, calcitonin, biphosphonates, estrogen, and even sympathetic blocks, there is no convincing body of evidence that these treatments actually alter the typically self-limited course of these entities. Hence, most authorities distinguish these disorders from RSD. It has been recently suggested that because of their association with characteristic changes on magnetic resonance imaging (increased intensity on T ₁ -weighted MRI and decreased intensity on T ₂ -weighted scans), bone marrow edema may be responsible for these syndromes. It is important to exclude infections (particularly tuberculosis), osteonecrosis, stress fractures, and neoplasms of bone and joints as cause of the complaints. Treatment is focused on reassurance, rest and crutch use, medications noted above, and gentle ambulationa very different approach from that taken with RSD.

III. Etiology. RSD results from conditions that cause (alone or together) regional tissue damage, pain and immobilization, and direct injury to the central nervous system. Local or central nervous system injury and immobilization lead to long- lasting changes at both the peripheral and central nervous system level in pain processing and control of sympathetic function. This neural plasticity explains the severity and persistence of the signs and symptoms that comprise the disorder.

Inciting events include local trauma, particularly fractures and or improper casting. Colles' fracture is a common cause of RSD of the hand, and this association is a good example of how RSD may affect an area adjacent to but not totally overlapping the site of injury. Other precipitants include apparently minor injuries (sprains); arthroscopic procedures and surgery (arthroplasty and carpal tunnel release); painful peripheral conditions (burns, herpes zoster); diseases of the spinal cord or brain (stroke); visceral disorders associated with pain and immobilization (myocardial infarction); local effects of metastatic cancer (which also may cause RSD as a paraneoplastic syndrome); pregnancy; and certain medications (phenobarbital, ergotamine, cyclosporine, and isoniazid) (Table 53-1). However, up to one-third of patients may not recall an inciting event.

Table 53-1. Precipitating factors and diseases associated with reflex sympathetic dystrophy

As alluded to above, the lack of agreement on standard diagnostic criteria has hampered precise quantification of the overall incidence of RSD and its association with the different conditions thought to trigger it.

The potential for development of RSD after surgery is greater in patients who have had previous episodes of RSD, diabetic neuropathy, or depression, or in whom secondary gain may be important.

IV. Pathophysiology.

Nervous system insult. The initial insult, including local tissue injury, pain, and immobilization, is thought to cause functional and structural alterations at peripheral, spinal, and even cortical levels of the nervous system, resulting in spontaneous pain and exaggerated painful responses to mildly noxious or non-noxious stimuli. Changes at the spinal level include a decrease in descending inhibitory influences, hyperexcitability, increase in size of receptive fields of neurons, and reorganization of pain reflexes, including those involving sympathetic neurons. An alteration of a wide range of dynamic neurons has been proposed as an important occurrence, resulting in their signaling pain in response to ordinarily non-noxious stimuli. The decrease in normal sensory input resulting from the decreased activity of the affected region opens the gate to ongoing pain and leads to further neural reorganization.
In the peripheral nervous system, nociceptors begin to generate ectopic or exaggerated discharges. These may result from microscopic injury and alterations in the milieu, including edema, decreased nutrient flow, and release of products by activated sensory neurons themselves (e.g., substance P).

The sympathetic nervous system, which is normally linked to pain by spinal and more central reflexes, assumes a more prominent role in pain generation and becomes less able to regulate vascular tone, sweating, and other functions normally. One component of sympathetically mediated pain is the development in nociceptors of a -adrenergic receptors and synaptic connections with sympathetic neurons, so that they become inappropriately activated by sympathetic neuronal activity and circulating catecholamines.
Sympathetic dysfunction. Sympathetic function, including sudomotor and vasomotor activity, may be both increased and decreased abnormally (i.e., the key abnormality is instability and dysregulation). Periods of sympathetic hypofunction may lead to receptor hypersensitivity. This is why, in most patients, the affected region may at different times be warm and red (hypervasular), blue and cold (hypoperfused), or mottled. It should be noted that even in areas of hypervascularity nutrient flow will often be diminished (because of dysregulation of microvasculature and arteriovenous anastomoses), which contributes to pain and weakness. These changes explain both the effectiveness of treatments designed to decrease sympathetic nervous activity and the variability of the response.
Edema occurs when venous outflow is compromised either mechanically or in response to the products of sympathetic or sensory neurons (e.g., prostaglandins, substance P). Edema itself can cause pain through nerve compression, interference with blood flow and diffusion of nutrients, and interference with motion. All of these in turn can further increase edema and lead to dystrophic changes.
The synergistic effects of substance P and prostaglandins with abnormal blood flow patterns cause the rapid development of osteopenia. Atrophic changes result from the above abnormalities and disuse.
Movement disorders result from the effects of sympathetic hyperactivity and of neuropeptides released by nociceptors on motor neurons in the spinal cord and preganglionic sympathetic nerves. These, in turn, affect muscle spindles and muscle itself and nociceptor function in the affected region. Tremor is the movement abnormality most tightly linked to sympathetic activity. Changes at the cortical level may also play a role, particularly in neglect.
Mechanical derangements. The injury triggering RSD or the changes resulting from RSD can lead to mechanical derangements and secondary nerve injuries (e.g., compression and neuromas); these cause pain and further perpetuate the disorder.
A major and still unanswered question is why RSD develops in a particular personin other words, what is the diathesis? Psychiatric components have been suggested but have never been convincingly demonstrated. It has been suggested that sympathetic reactivity as evidenced by a personal history of vasomotor instability, blushing or blanching, palmar perspiration in response to emotions, or a family history of Raynaud's syndrome may be a marker of susceptibility, but this remains to be firmly established.

V. Diagnosis. The diagnosis is clinical and based primarily on the development of the symptoms and signs described above in an appropriate temporal relation to an inciting event. The time required for symptoms to develop ranges from a day or two to 2 weeks or longer. In the early phase, the excessive pain may be attributed to the injury, whereas in the delayed presentation, the original injury may have been forgotten, especially if minor. Because the early signs and symptoms are vague and nonspecific, the clinician must have a high index of suspicion for RSD in the setting of conditions associated with it.

There are no diagnostic tests specific for RSD. Levels of acute-phase reactants are abnormal only if they are secondary to an associated illness. Hence, they may alert the clinician to consider alternative diagnoses. Radiographs and technetium bone scans are the modalities most commonly used in routine clinical practice. Increasing attention is being given to the incorporation of more sophisticated tests of blood flow and sympathetic function.

Most series emphasize the frequency with which diagnosis is delayed. The earlier the treatment is initiated, the better the response, because neural changes and osteopenia may take a while to reverse and RSD is perpetuated by the vicious cycle of pain and immobilization. There is some uniformity in the marked decrease in response to treatment after RSD has been present for a year or even 6 months.

Differential diagnosis includes the large number of conditions that in themselves cause pain, immobility, and swelling with or without inflammation . These include injuries (crush wounds, fractures, stress fractures, osteonecrosis); infections of both bone and soft tissue, which, like RSD, may result from injuries; thromboangiitis obliterans; Raynaud's syndrome; and inflammatory disorders, including crystal-induced and other arthritides. Pain and swelling may of course result from an injury per se, but their duration and severity and the associated vasomotor and sudomotor changes help in the differentiation. Thoracic outlet syndrome and cervical or thoracic spine disorders must be considered. It has been suggested that the former, particularly if associated with prominent subclavian stenosis, may be associated with true RSD. RSD may also be confused with scleroderma in cases that initially present with skin changes late in stages 2 or 3.
Radiography and laboratory tests
1. Radiographs reveal osteopenia with various patterns of bone loss, including patchy, bandlike periarticular loss, irregular cortical outlines, cortical tunneling and striation, scalloping of inner cortical surfaces, surface erosions of subchondral and subarticular surfaces, and other subchondral changes. These may occur late and are nonspecific. Joint spaces are preserved until late in the course.
  Quantitative bone density studies such as dual-energy x-ray absorptiometry indicate that substantial bone loss may occur early. Much of this is irreversible, at least in adults.
2. Technetium bone scans. The third (delayed, static) phase of the bone scan is considered the most useful study in the investigation of RSD. Diffuse bony uptake with periarticular accentuation is generally considered the most characteristic finding. Although this pattern has been quite specific (>90%) and sensitive (>90%) in some series, it is considered neither necessary nor sufficient for the diagnosis. However, if present, it may provide corroborative evidence, and if absent, it may prompt reexamination of the diagnosis. The blood flow (immediate) component of the scan and the blood pool (early phase) are often asymmetric when the affected limb is compared with the normal one. As expected from blood flow and autonomic variability, the affected area may show either an increase or decrease in uptake.
3. Measures of autonomic function. Results will vary, as one might expect from the autonomic variability discussed above. Thermography and other techniques to measure temperature are most commonly employed and are often used to assess the efficacy of therapeutic manipulations (e.g., sympathetic blockade). Again, asymmetry is the most typical finding. Sudomotor function can be assayed by galvanic skin resistance (GSR), resting output, or quantitative sudomotor axon reflex test (QSART); these have been advocated both for diagnosis and for following response to treatment modalities.
  Certain specialized centers emphasize the importance of stress tests of autonomic function to uncover the degree of autonomic hyperreactivity or the specific stimuli most relevant to a particular patient.
  
  Inclusion of at least a semiquantitative assessment of sweating and some measurement of temperature is strongly recommended whenever sympathetic blocks are performed.
4. Measures of pain are required to follow a patient's response to treatment. At a minimum, these should include (a) a semiquantitative assessment of pain (e.g., Visual Analog Scale, with pain intensity graded on a scale of 1 to 10) for spontaneous pain and allodynia in response to gentle touch with a cotton swab; (b) a test of temperature sensitivity (e.g., to cold produced by evaporation of a drop of acetone placed on the skin); and (c) a rough map of the distribution of abnormalities. More quantitative measures, such as filaments and algometers, may be useful.
5. Synovial biopsy is no longer used except to rule out other diagnoses, as it reveals only nonspecific findings, including subsynovial fibrosis, synovial proliferation , and occasionally mild inflammatory changes.
6. Response to sympathetic blockade as a criterion for diagnosis. Although many earlier series made a response to diagnostic sympathetic blockade a sine qua non for the diagnosis of RSD, the role of this procedure has been reconceptualized. It is now employed to identify the contribution of sympathetically mediated pain in a given patient and to assess the utility of sympathetic blockade and related modalities for treatment. Thus, rather than being a diagnostic tool, sympathetic blocks are considered more of a therapeutic trial. As is the case for any test, misleading negative and positive results can occur. For example, failure to respond may result from the dominance of nonsympathetically mediated pain at the time the block was performed or the effect of high levels of circulating catecholamines (which may be increased in response to pain, depression, and anxiety). These will continue to induce sympathetically mediated pain even when local catecholamine release is blocked. False-negative results can also be caused by technical problems. In the case of stellate ganglion block for RSD of the upper extremity, it must be remembered that Horner's syndrome may occasionally result from blocks that fail to affect the sympathetic nerves controlling the upper limb. Thus, stellate ganglion blocks must be evaluated by a careful assessment of autonomic function of the relevant area, even when Horner's syndrome is noted. False-positive results can occur through the placebo response. It should also be remembered that some sympathetic blocks may affect somatic nerves (i,e., pain relief may reflect anesthesia of somatic afferents). This leads to a false-positive result from the perspective of assessment of the importance of sympathetically mediated pain and the decision regarding whether to continue treatment targeted at the sympathetic nervous system. Criteria for a successful blockade vary between centers (which vary in the sophistication of assessment of pain and a utonomic function). At the minimum, evaluation should include a semiquantitative assessment of pain (e.g., on the Visual Analog Scale of 1 to 10, both spontaneous and in response to gentle pressure with a cotton swab), measurement of skin temperature, and global estimation of sweat production function, which demonstrate substantial pain relief and reversal of autonomic features. This is indicated by elevation of fingertip temperature by more than 1 to 3F, venous engorgement, dryness of the skin, and a subjective feeling of warmth. Doppler fluxometry may be particularly informative.
  When the diagnosis of RSD is strongly suspected, the effects of several blocks on pain that meet the above criteria for technical adequacy should be assessed before any decision regarding treatment is made. This is because a large number of patients who fail to respond to one (technically successful) block may do so after three or occasionally more are performed. Implications of partial and brief responses are discussed below.
  
  It has recently been suggested that high-dose IV phentolamine (an a -adrenergic receptor antagonist) infusions with demonstration of adequate a -adrenergic receptor blockade may be particularly useful for the demonstration of sympathetically mediated pain. Blockade of a -adrenergic receptors will antagonize the effects of circulating catecholamines not affected by sympathetic block as well as those released by the neurons innervating the area. Because this is a technically easier and less invasive procedure than sympathetic blockade, it is more suitable for placebo-controlled trials and for repeated trials followed by careful quantitative assessment of spontaneous and laboratory-induced pain and autonomic function in individual patients. Although well tolerated, blood pressure and electrocardiographic monitoring should be performed during and after the procedure, and the procedure should be performed in an area capable of handling cardiovascular emergencies. An absent or partial response indicates the presence of a nonsympathetically mediated pain component, a b -adrenergic component, or both. Some proponents stress the importance of high-dose (1 mg/kg) phentolamine and advocate inclusion of b -adrenergic blockers.

VI. General treatment concepts. It is hard to provide a treatment protocol for a disorder in which a consensus regarding either diagnostic criteria or etiology has not yet been reached and that is associated with so much variability between and within individual patients. Many outcome studies, particularly those using invasive procedures, have been poorly controlled. Interpreting the findings of other studies and applying their recommendations to an individual patient is complicated by the inclusion of subjects with different presentations. This refers not only to the Steinbrocker stages (which are relatively stable over time) but also to day-to-day fluctuations and region-to-region variations.

General concepts of therapy. Despite these caveats, agreement has been reached regarding certain general features of treatment. These include the following:
1. Early diagnosis.
2. Aggressive multimodal treatment by a multidisciplinary treatment team, including an anesthesiologist and physical therapist in addition to the orthopedist or rheumatologist.
Educational and psychological modalities. Gaining the confidence of patients is key because they will have to participate in a long and grueling program. This is best accomplished by devoting time to education, reassurance, and the assessment of maladaptive coping mechanisms, sleep disturbances, psychiatric disorders, and issues of compensation and litigation. On occasion, a psychiatrist or psychologist should be consulted. Treatment is focused on restoring functioning as rapidly as possible while avoiding an increase in pain, which will merely perpetuate the cycle of pain, neuronal change, dysfunction, and more pain. The severe pain and exquisite sensitivity of the affected area to touch and movement together with the necessity for early mobilization and functional restoration puts the treatment team between Scylla and Charybdis. The patient and family are often frustrated and frustrating, but they must be enlisted as part of the team at the very onset of therapy.
Priority must be given to treating pain and edema. This in turn will allow ROM and strength to be addressed. In addition, it must always be kept in mind that RSD is a dynamic disorder with rapid fluctuations in autonomic tone and tolerance to manipulations. Modalities that were used yesterday to reduce blood flow in a hyperemic hand may have no place for today's cold, vasoconstricted hand. Procedures that a patient tolerated the day after a successful block can be excruciating as the block wears off. Thus, treatment requires sensitivity and flexibility, which in turn require careful ongoing assessment and utilization of a myriad of modalities, either sequentially or in combination. As so pithily put by Ficat and Hungerford, It [RSD] is not a disease to be beaten into submission but to be gently seduced. The patient must be fully informed and convinced of the rationale behind the often painful modalities, and the patient should participate in the development of discrete and well-defined goals.
Monitoring progress or lack thereof. Progress should be carefully monitored . Whereas some centers attempt to quantify parameters as described above, others rely on more subjective descriptions. However, whatever method is used, the measurement of such milestones must be consistently and regularly applied.
Pain control and physical therapy. Occasionally, early cases will respond to simple analgesics, local measures such as transcutaneous electrical nerve stimulation (TENS), judicious use of heat and cold, elevation, and active ROM exercises.
Use of sympathetic blocks as initial treatment. This is indicated if (a) no improvement is seen in 1 to 4 weeks, (b) patients cannot tolerate even the most gentle application of these measures, or (c) a patient presents after 6 months of symptoms, a time at which the window of opportunity is rapidly closing. A recommended approach is shown in Fig. 53-1.

FIG. 53-1. Pain following injury (which may be trivial) to bone, soft tissue, or peripheral nerve; an approach to the diagnosis and treatment of the reflex sympathetic dystrophy syndrome. (From Payne R. Neuropathic pain syndromes with special reference to causalgia and reflex sympathetic dystrophy. Clin J Pain 1986;2:59.)

VII. Specific treatment modalities

Pain control
1. Nonsteroidal antiinflammatory drugs and analgesics are often insufficient for pain control (although the combination of ketorolac and amitriptyline may be efficacious). There has been an increase in the use of narcotics, including opioids, by either the oral or parenteral route. As is always the case, once a decision regarding these medications has been made, they should be given in adequate doses and at appropriate intervals. Transdermal fentanyl also has been found useful. Exercises should be coordinated wit h the pain medication . The early use of sympathetic blockade may be indicated if opioid/narcotic tolerance appears to be developing.
2. TENS is used in many centers for pain control, and according to some authorities, it may also be helpful with vasomotor phenomena. Stimulus parameters (frequency, pulse width, and amperage) and site of application must be chosen for tolerability and efficacy. Although stimulation to the site of discomfort is often most efficacious, patients frequently cannnot tolerate this location, and proximal or even contralateral sites may be initially employed. Acupuncture or trigger points have also been used.
Physical therapy. Physiotherapists/physiatrists experienced in this disorder are key because of the delicate balance required between appropriate mobilization of the affected region and pain relief. Allodynia may make certain manipulations (e.g., splinting) particularly difficult. Small, defined goals should be set and shared with the patient, and specific physical efforts should be prioritized. Initial focus is on pain and edema because their control allows increased focus on ROM (both active and passive). This then allows strengthening exercises and functional restoration.
1. Desensitization. This must be carried out in a graded fashion and, when possible, in a functionally relevant way. Patients may be encouraged to rub their hand on the back of a couch while watching television. Vibration has also been advocated.
2. Exercise as tolerated may help by gating out pain, leading to release of opioids peripherally and stabilization of the autonomic nervous system. It may also increase the general sense of well-being of these often deconditioned patients.
3. Thermal modalities
  1. Heat. Heat may be useful during the times when the affected region is cold and vasoconstriction predominates. Many authorities discourage the use of a whirlpool because the dependent position of the affected area tends to increase edema. Paraffin and fluidotherapy are useful alternatives, and it is useful to combine them with stretching and ROM exercises. The often exquisitely increased sensitivity of these patients to heat must be kept in mind. Some patients may be able to tolerate application of heat only to remote areas. This may lead to vasodilation of the affected areas if thermoregulatory reflexes are even partially preserved.
  2. Cold. The application of cold packs may be useful for the warm, hyperemic limb, with caveats similar to those for the use of heat. Again, remote cooling may be useful.
  3. Contrast baths. When careful attention is given to determining tolerated temperature, these may be useful in the treatment of pain and edema and may be taken at home.
4. Elevation, decongestive massage, and intermittent Jobst pneumatic compression. These techniques are useful for edema, and the massage also provides desensitization. Again, many patients will have difficulty tolerating massage and compression because of allodynia and hyperpathia. For some patients in whom temporal summation of pain is prominent, pain can be minimized if care is taken to ensure continuous rather than intermittent contact during massage. It has been suggested that deep massage may lead to histamine release and increased inflammation.
  For patients who tolerate Jobst compression, this modality should be not be allowed to interfere with mobilization. Compressive garments and wraps if tolerated are advantageous with respect to motility .
5. Range of motion. Movement is necessary to prevent contractures, reduce edema, gate out pain, help restore normal neuronal architecture, and strengthen muscles . The necessity of the potentially painful exercises should be explained, and the therapist needs to monitor the patient's response constantly. The exercises should be coordinated with pain treatment and performed at appropriate intervals after pain medication. Failure to tolerate exercise even after that may be an indication for more aggressive treatment, including sympathetic blockade. A stress-loading approach involving compression and distraction while joint movement is minimized has been found to be particularly useful (e.g., scrub and carry for the upper extremity and standing with graduated weight bearing for the lower).
  Generally, active and assisted active ROM exercises are emphasized . On those occasions, when it is deemed that passive ROM exercises are indicated, it should be remembered that these are more likely to lead to pain and interference by allodynia. The ideal ROM exercises are those relevant to activities of daily living (e.g., walking with crutches for RSD of the lower extremity).
6. Splinting. Static and dynamic splinting may be useful, but only if employed judiciously. Too many or too complicated splints will overwhelm the patient. Static splints may be necessary to prevent contractures and may be useful at night to prevent joint motion from disturbing sleep. It may also help position the affected areas to allow appropriate strengthening exercises. Of course, they will also contribute to the undesirable sequelae of immobilization if overused . Dynamic splinting, if carefully crafted, may decrease pain through stimulation of large afferents, reduce edema, and maintain ROM. Static progressive splinting is indicated when ROM is limited by contractures and stiffness and pain is relatively quiescent.
7. Ultrasound may be helpful by providing pain relief and inducing vasodilation.
8. Biofeedback may be useful for vasomotor instability and movement abnormalities, including hypertonicity, spasticity, and dystonias.
Treatment of movement disorders. Interventions that decrease sympathetic function may be useful in the treatment of tremor but have inconsistent effects on dystonias. Benzodiazepines may be helpful for spasms. Visual and verbal cues may be helpful in cases in which features of neglect are prominent.
Psychiatric and psychological interventions. Many patients with RSD present with a history of mistaken diagnoses, perceptions (which may or may not be accurate) that their pain has been dismissed (by professionals and family), irritability, demoralization, and sleep deprivation because of pain. These often lead to anger at the medical system and strained relations between the patient and family members. Stress, anxiety, and depression, which are common in these patients, are well-known to exacerbate pain from any cause, and because of their effects on the autonomic nervous system (association with increase or dysregulation of circulating catecholamines), they also may play a more specific role in RSD.
Many psychological interventions can be performed by any member of the multidisciplinary team. These include developing a supportive relationship; carefully educating the patient about pain, including explicitly acknowledging its disabling effects and adverse effects on interpersonal relationships; and making the patient aware of the interaction of pain with mood. Certain antidepressant drugs that may be used for sleep and pain also have adrenergic-blocking effects.

Concerns about an associated depression or other psychiatric disorder that perhaps requires treatment with psychotropic agents , behavioral problems that severely compromise the treatment, or medical issues that complicate the use of an antidepressant may indicate the need for a more formal psychiatric consultation. This must be accomplished tactfully and after good rapport has been established (to the extent that this is not prevented by the psychological problems). Both patient and family may resist the suggestion of a psychiatric consult because, in addition to the usual stigma associated with such a consult , they may feel that this is another example of the dismissal of symptoms as being all in the head. Indeed, this might be a good starting place for psychological education to begin: Yes, pain is in your head, all of our feelings are in our head. Pain affects mood and mood affects pain. We all have heard stories of soldiers wounded in battle who do not feel the wound until the battle is over. On the other hand, we all know that minor pains (and I'm not talking about RSD) are 10 times more annoying when we're tired or upset. Another approach is to explain that the psychiatrist is a specialist in helping people deal optimally with stressful conditions and that many of the medications they use are effective in treating pain. The psychiatrist may also play a role as a neutral party in helping to monitor the use of narcotics, ensuring that the patient receives adequate dosage yet watching for inappropriate dosage escalation. Support groups may be useful for patient and family. Antidepressants are discussed below.
Therapies directed at the nervous system. The importance of factors other than sympathetic function in RSD has been discussed above. Nevertheless, interventions to decrease the activity of sympathetic neurons, such as ganglionic blocks and regional IV catecholamine depletion, still play an important role in assessment (see section V.B.6 ) and treatment. Again, it must be emphasized that only some of the adrenergic activity in a given region is caused by the local release of catecholamines, the target of these procedures. Circulating catecholamines (which may be increased in response to pain, depression, and anxiety), including norepinephrine released from sympathetic neurons in other regions and epinephrine from adrenal medullary activity, may stimulate the adrenergic receptors relevant to the manifestations of RSD.
a -Adrenergic blockade (e.g., phentolamine) will prevent the action of catecholamines, whether they are locally or systemically produced. Hence, a case could be made for the combined or sequential use of modalities. Somatic blockade may be required for patients in whom a major component of pain is nonsympathetic in origin.

Important note: Any pain relief provided by sympathetic or somatic blockade should be followed immediately by intensive mobilization and other physical therapy modalities.
1. Sympathetic ganglion blockade. Sympathetic blocks with local anesthetic agents are used for both diagnostic and therapeutic purposes. Stellate ganglion block is utilized for the upper extremities. However, as stated above, care must be taken to ensure that blockade of sympathetic nerves to the arm has actually been accomplished, even in the presence of Horner's syndrome. This is indicated by elevation of fingertip temperature by 1 to 3F venous engorgement, dryness of the skin, and a subjective feeling of warmth. Although many use lidocaine for the initial treatment, bupivacaine block may last considerably longer than lidocaine block. Lumbar (L-2 through L-4) blocks are used for the lower extremities. It is generally agreed that the procedure should be repeated at least three times within 7 to 10 days before it should be considered to have failed. It is often performed even more frequently (every other day) and tapered when the response has plateaued, typically after six to 12 successful blocks.
2. Epidural block. The epidural route is also useful, particularly for the lower extremity, because of the technical difficulties and pain associated with lumbar ganglionic block. Further, the ease and safety of placement of epidural catheters make it an attractive procedure. Continuous epidural blocks may relieve pain even when repeated lumbar blocks have failed to do so. They can be performed quite selectively with respect to level and nature of neurons (sympathetic, somatic, or both). Some groups advocate initial infusion with local anesthetic followed by agents such as narcotics or ketamine; in this way, motor function is left intact so that active ROM exercises can continue. On the other hand, sparing of motor fibers is not as important when this procedure is used to cover passive ROM exercises or manipulations. Of course, epidural blocks also have their side effects, including hypotension, urinary retention, and rarely seizures or infection. Respiratory depression is rare unless morphine is used. Recently, epidural clonidine has been used alone and in combination with other agents because its a ₂ -adrenergic agonism will inhibit the release of norepinephrine.
3. Intravenous regional chemical sympathectomy. In the past, IV regional chemical sympathectomy was recommended for patients in whom sympathetic or somatic ganglion block and epidural block were contraindicated (hypersensitive or on anticoagulants). Additionally, it represented an alternative to surgical sympathectomy in high-risk patients. In chemical sympathectomy, an IV infusion of agents depletes noradrenaline from sympathetic terminals. The agents are confined to the affected region by placement of a blood pressure cuff or other compressive device inflated above systolic pressure proximal to the site of injection. After a period of time, during which the agents are taken up by the sympathetic nerve terminals, the tourniquet is released. However, the place of this procedure in the modern armamentarium remains undefined. As is the case for so many modalities used in RSD, enthusiastic reports are counterbalanced by negative ones. This variability may result from patient heterogeneity and technical factors. Review of the studies indicates variation in the rigor with which sympathetic blockade was demonstrated. Guanethidine and to a lesser extent reserpine were used in virtually all the studies, and these agents are no longer routinely available in the United States. However, bretylium, another catecholamine-depleting agent, has been reported to be safe and efficacious. With respect to technical factors, the simplicity of the technique is more apparent than real. Because of the possibility of side effects (e.g., hypotension) resulting from systemic leakage before and after the cuff is released, this procedure should be carried out with continuous monitoring of vital signs. Electrocardiographic equipment in a suite equipped for resuscitation is mandatory, and a well-functioning IV line should be placed in an uninvolved area. In addition, application of the tourniquet may be quite painful and cause phlebitis.
  These regional catecholamine depletion techniques do not relieve pain caused by circulating catecholamines. This problem has been addressed by the use of regional blockade of a -adrenergic receptors. The reversible antagonist phentolamine may be infused regionally in patients who cannot tolerate the marked autonomic side effects accompanying systemic infusion. The use of IV phenoxybenzamine, an irreversible antagonist that should in theory have a longer duration of action, was reported recently. Although the results were positive, the study must be considered preliminary.
4. Intravenous a -adrenergic blockade is the simplest technique to block the effects of circulating and locally produced catecholamines. Infusion of phentolamine and phenoxybenzamine has been used more often as a diagnostic technique than as an ongoing treatment because of the autonomic side effects of these drugs when administered systemically rather than regionally. Brief but reproducible and perhaps partial responses to abrogation of sympathetic activity may be indications to consider more permanent and invasive approaches to abrogating sympathetic function.
5. Role of surgical sympathectomy or chemical sympatholysis. Short-lived or partial responses to the above measures have in the past been considered indications for sympatholytic procedures, such as injection of phenol or alcohol into ganglia or surgical sympathectomy. Recently, radiofrequency ganglionic ablation has been reported. These techniques can be guided with imaging. However, their role is controversial because of technical considerations, because the results are irreversible (particularly in the case of surgical procedures), and because pain may paradoxically recur or even increase (sympathalgia). The latter may reflect aberrant regeneration or receptor hypersensitivity. Reliance on surgical sympathectomy and sympatholysis has decreased because of the availability of techniques for more continuous sympathetic blockade, the development of newer concepts regarding the importance of nonsympathetic pain in RSD, and the realization that the plasticity of the nervous system allows it to remodel in response to normalization of function and diminution of pain resulting from even temporary interruption of the pain cycle.
6. Somatic blocks. Patients in whom suboptimal pain relief is obtained with the above modalities may have an important nonsympathetic component to their pain and hence may benefit from somatic blocks. For them, continuous infusions may be considered, either directly into the relevant plexus or the epidural space. Again, this procedure is often used to facilitate physical therapy, so it is crucial to coordinate the modalities with respect to timing and technique. For example, lower concentrations of anesthetic (0.125% to 0.25% rather than 0.5% bupivacaine) to minimize motor block are used if active exercises are to be undertaken following the block.
7. Oral adrenergic receptor antagonist. a -Adrenergic blockers (prazosin, phentolamine, phenoxybenzamine, terazosin) have been reported to be useful, although no controlled trials have been performed. Side effects include hypotension, reflex tachycardia, and impaired sexual function. b -Adrenergic blockers (with concern for their well-known side effects) may be used to treat the reflex tachycardia or occasionally alone (propranolol).
8. Clonidine. Clonidine decreases norepinehrine release through its agonist effect on inhibitory a ₂ -autoreceptors. Oral, transdermal, and epidural routes have been recommended. Aside from its potential to decrease peripheral catecholamines, it is also anxiolytic through a central effect. Hypotension and sedation are major side effects.
9. Anticonvulsants. Carbamazepine (Tegretol) has been used for RSD. Although carbamazepine has been extensively studied in neuropathic pain, it is difficult to use because of its narrow therapeutic margin, profile of side effects (most notably central nervous system, liver, and blood; rarely, syndrome of inappropriate secretion of antidiuretic hormone, or SIADH), and myriad drug interactions (it is a potent enzyme inducer). Its quinidine-like properties must be remembered in patients with heart disease who are taking anti-arrythmics and related compounds . Gabapentin (Neurontin) is a more recently introduced anticonvulsant that does not have these disadvantages but has not been as extensively used in the treatment of pain. Phenytoin and valproate have been used. As is typical for RSD, reports are anecdotal.
10. Antidepressants. It should be noted that tricyclic antidepressants, which may be used to treat depression and relieve pain while also leading to a transient increase in norepinephrine, may cause a decrease in norepinephrine turnover and hence be considered sympatholytic. Indications for their use in RSD include treatment of depression, insomnia, and pain per se. A fuller description of their use in depression may be found in Chapter 49. Tricyclics have been shown to be effective in neuropathic pain, with amitriptyline being the most frequently prescribed agent. The dosages for pain are usually but not always lower (25 to 75 mg) than those for depression (150 mg and higher); their effects are also evident more quickly (days rather than weeks). Even at these lower doses, side effects, including orthostatic hypotension, anticholinergic actions, and electrocardiographic (quinidine-like) abnormalities, make these drugs problematic . The sedative effects of amitriptyline and doxepin may be helpful with regard to sleep. The selective serotonin receptor inhibitors [Zoloft (sertraline hydrochloride), Prozac (fluoxetine hydrochloride), and Paxil (paroxetine hydrochloride)] are easier to use and hence are first-line drugs in the treatment of depression. However, their efficacy in the treatment of pain has not been as well demonstrated as that of the tricyclics. Trazodone (Desyrel), a heterocyclic antidepressant, is advocated by some because of its sedative effects and because it is a potent a -adrenergic blocker. However, it may cause severe gastrointestinal distress, hypotension, and rarely priapism.
Corticosteroids. The use of corticosteroids is controversial. Advocates claim that they are especially useful when joint involvement is prominent or bone scans show increased uptake. One protocol consists of 4 days of 60, 40, 30, 20, 15, 10 (in divided doses for the first six doses), and 5 mg. Relapsers may be re-treated with low-dose steroids or a second tapering course with the above doses but with 8 days at each dose. The risks of steroids, particularly the 8-day schedule, must be carefully considered in the light of the paucity of controlled trials regarding their benefit. There have been reports of benefit from regional IV corticosteroids.
Miscellaneous. Calcium channel blockers such as nifedipine (10 to 30 mg three times daily) were beneficial in one uncontrolled trial in 7 of 11 patients. Presumably they act by reducing vascular myogenic hyperactivity. Calcitonin has been given, based on the marked degree of osteoporosis in some stages of RSD. Thus, it has been suggested that calcitonin would be particularly useful in the presence of marked bony changes or increased hydroxyproline excretion. Human recombinant calcitonin (0.5 to 1 g daily) is a first-line treatment in many European centers. Some advocates feel that intranasal calcitonin is markedly less effective.
Note: Although oral preparations of local anesthetic agents have been suggested, they are associated with potentially dangerous side effects and cannot be generally recommended.
Surgery. Surgery may be required in patients with RSD, but only for carefully defined indications, as there is no such thing as minor surgery. These patients have already demonstrated a diathesis for overreaction to injury, and in some cases, it was surgery that led to their RSD. However, under certain circumstances, surgery is indicated. As RSD resolves, it becomes evident that a previously obscured mechanical problem requires surgical correction, or that deformities (requiring capsulotomy, tenolysis) have arisen as a sequela of the RSD. Alternatively, mechanical pain triggers or triggers resulting from nerve injuries, including neuromas and nerve compression, may develop as a sequela of fibrosis and edema and serve to perpetuate the pain cycle. In the case of deformities and mechanical derangements, surgery should be delayed until the RSD is in remission. However, pain triggers will perpetuate RSD and must be addressed as soon as the treatment team is convinced that the RSD has plateaued and further improvement is unlikely to occur unless the pain triggers are addressed.
Surgery should be performed under sympathetic blockade, with particular attention to hemostasis and avoidance of mechanical stress on nerves. Postoperative pain control and elevation are critical, but a tourniquet effect from the overly zealous use of splints and casting should be avoided. Exercises (especially stress-loading exercises) should be started as soon as possible.
Refractory reflex sympathetic dystrophy. Potentially treatable, unrecognized causes of RSD, such as occult infection and triggers, must be identified and addressed. The potential contribution of secondary gain and associated noncompliance , in which the site is purposefully subjected to harmful stressors and even frank self-mutilation may be involved, also must be considered. Although amputation is fortunately rarely necessary and unpredictably useful in refractory cases, all too often it is associated with recurrence of RSD in the stump and poor tolerance of prosthesis or phantom limb pain. Neurosurgical interventions for pain, such as peripheral nerve stimulation and even cord or thalamic stimulation, may be successful.

VIII. Reflex sympathetic dystrophy of the knee is described in a separate section because until recently it was insufficiently appreciated and rarely considered. It may present as unexpectedly severe knee pain on walking and weight bearing and stiffness and temperature sensitivity following minor injuries (including falls , sprains, or dashboard injuries). Vasomotor signs may be subtle. There may be relatively little limitation of motion, and gait disturbances are variable. The patellofemoral joint is invariably involved, and tenderness of the medial aspect of patellofemoral joint and medial capsule are characteristic. It has been suggested that severe knee pain and edema without effusions and mechanical allodynia along the margins of the patella and tibial joint lines either with or without a decreased ROM should alert the clinician to this diagnosis.

On the other hand, patients may present with locking and buckling knees because of mechanical derangements resulting from an injury. These may overshadow the RSD that has also resulted from the injury.

It has been suggested that not infrequently surgery or arthroscopy may be performed in cases of unrecognized RSD. This is liable to exacerbate the condition. On the other hand, RSD may be precipitated by knee surgical procedures ranging from arthroscopy to arthroplasty. It may be a common cause of stiff knee following arthroplasty. Prolonged pain (mistaken by the unwary for postsurgical pain but usually differentiated from that by the patient) and a poor response to rehabilitation after surgery are suggestive of RSD. Knee infections, meniscal tears, osteochondritiis dissecans, chondromalacia, and neuroma may be considered in the differential diagnosis of RSD or as precipitants of RSD.

This diagnosis must be considered whenever recovery from trauma or surgery is delayed for an unexpectedly long time. As with any type of RSD, the diagnosis is clinical. Increased uptake on the third phase of the bone scan provides corroborative evidence, but this may occur relatively late in the course. Interestingly, other joints in the lower extremities not infrequently show abnormalities. Osteoporosis develops after several weeks. It is diffuse, does not generally involve joint margins, and is often best seen on a skyline view of the patella. MRI is helpful in excluding other conditions. The role of sympathetic blockade in assessment is similar to its role in RSD affecting other locations. Treatment includes the modalities described above. Standing stress therapy and walking with crutches are frequently useful in patients who cannot tolerate other modalities (e.g., active or assisted active ROM exercises). Arthroscopy should be avoided unless it is required for correction of an underlying mechanical disturbance, and it should be delayed until patient is in remission. Arthroscopy, other surgery, or manipulations that may be required if capsular fibrosis occurs should be performed under the protection of sympathetic blockade.

Bibliography

Cooney, LA. Upper extremity pain dysfunction: somatic and sympathetic disorders. Hand Clin 1997.

Kozin F. Reflex sympathetic dystrophy syndrome [Editorial Review]. Curr Opin Rheumatol 1994;6:210.

O'Brien SJ, et al. Reflex sympathetic dystrophy of the knee: causes, diagnosis and treatment. Am J Sports Med 1995;23:655.

Payne R. Sympathetically maintained pain: diagnosis and treatment. Presented at the annual meeting of the American Academy of Neurology, Boston, April 2127, 1991.

Pierce PA, Brose WG. Causalgia/reflex sympathetic dystrophy. In: Yaksh T, et al., eds. Anesthesia: biologic foundations. Philadelphia: LippincottRaven Publishers, 1998:889.

Portenoy RK. Issues in the management of neuropathic pain. In: Basbaum A, Besson JM, eds. Towards a new pharmacotherapy of pain. New York: John:Wiley and Sons, 1989.

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Books@Ovid
Copyright 2000 by Lippincott Williams & Wilkins
Stephen A. Paget, M.D., Allan Gibofsky, M.D., J.D. and John F. Beary, III, M.D.
Manual of Rheumatology and Outpatient Orthopedic Disorders

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