Early recognition of four sign and symptom factors determines success
Pain modulation includes multiple techniques, patience, and perseverance
Treatment avoids pain provocation
Practical approach to treatment based on four factors
Ultimate aim is functional restoration-holistic approach
Complex regional pain syndrome (CRPS) types I and II is one of the greatest clinical challenges presented to the hand therapist. Treatments require the concerted effort of and close communication among the physician, therapist, and patient to obtain an optimal functional outcome. Historically, various categorizations of the syndrome have been formulated under the designation reflex sympathetic dystrophy (RSD). The term reflex sympathetic dystrophy implies that the sympathetic nervous system is causally involved and considers the clinical presentation the result of reflex activation of sympathetic neurons. This may not be the case, however, because these implied mechanisms have not been proven.
Classically, RSD has been divided into five separate patient subtypes: minor causalgia, minor traumatic dystrophy, shoulder-hand syndrome, major causalgia, and major traumatic dystrophy. Betcher and Casten, in 1955, proposed a grading system progressing from grade 3 to 1, based on severity. More recently, Janig proposed three groups of RSD patients: 1, algodystrophy (a full-blown syndrome); 2, sympathetic dystrophy (RSD) without pain; and 3, sympathetic maintained pain (SMP), in which pain is the only overt manifestation. RSD had also been divided into three stages based on time frames and associated signs and symptoms with each stage. This staging has some merit; three distinct subgroups are recognized: (1) a limited syndrome predominated by neuropathic pain and sensory changes, (2) a limited syndrome predominated by vasomotor signs, and (3) “a florid CRPS syndrome similar to classical RSD descriptions.”
As established by the International Association for the Study of Pain (IASP), the current recommended nomenclature is CRPS types I and II. CRPS I corresponds to RSD, and CRPS II designates causalgia that presents similarly but occurs with injury to a peripheral nerve or nerve branch. Within the CRPS categories, pain is regarded as sympathetically independent pain (SIP), occurring in the initial onset of the syndrome. SMP, by contrast, is defined as “a symptom of CRPS and not a clinical entity” occurring after a period of time of the onset of the syndrome. CRPS has strict inclusion criteria that do not encompass the presence or absence of SMP. The IASP diagnostic criteria for CRPS are listed in Box 116-1 .
Presence of an inciting noxious event or a cause of immobilization.
Continuing pain, allodynia, or hyperalgesia with which pain is disproportionate to any inciting event.
Evidence at some time of edema, changes in skin blood flow or abnormal sudomotor activity in the region of pain.
This diagnosis is excluded by the existence of a condition that would otherwise account for the degree of pain and dysfunction.
In an effort to further validate the clinical diagnosis of CRPS, a factor analysis was performed. As a result of this research new diagnostic criteria have been proposed. In addition to pain, four symptom and sign factors were identified: sensory, vasomotor, sudomotor–edema, and motor–trophic. The patient must report the presence of at least three of the symptom factors, and at least two of the sign factors must be evident at the time of examination. This would result in a sensitivity of .85 and specificity of 0.69. The symptom and sign factors are highlighted in Table 116-1 .
|Hyperesthesia/Allodynia||Hyperalgesia (pin prick), allodynia (light touch, movement, deep somatic pressure)|
|Edema, sweating changes/asymmetry|
This chapter is devoted to the therapist’s recognition and management for CRPS. In the interest of clarity, discussion refers to CRPS I and II in place of RSD, unless referring to specific literature. The therapist must possess an in-depth understanding of the multiple components of this complex process on which to establish realistic goals, formulate appropriate treatment, and prognosticate the likelihood of successful functional outcome. This chapter emphasizes a problem-solving approach based on the patient’s presenting signs and symptoms as related to pain and the above four factors.
Lankford described the optimal treatment principle as follows: “Early diagnosis and concomitant early intervention of treatment is the most important factor in the eventual outcome of this disabling condition.” The hand therapist often is the first clinician to identify early onset, which may be precipitous and require immediate intervention. This point is supported by Birklein and associates, who noted that the early initiation of therapy after onset is important before structural changes occur in the affected limb that may compromise pain relief and function. Early recognition of CRPS will also help prevent exacerbation of the condition by the therapist and the patient. Finally the therapist must be mindful that recurrence has been reported to be 1.8%. This recurrence may occur spontaneously or 53% of the time may be related to a second traumatic incident. A delay in the diagnosis and treatment may also add to recurrence.
CRPS may present after a seemingly minor injury, and the presentation will exceed the normally expected reaction and clinical characteristics. Examination should be ongoing and as thorough but as nonprovocative as possible; pain exacerbation must be avoided even if this necessitates delaying some aspects of the examination. It is necessary to rule out any underlying conditions or inciting lesions that would otherwise account for the degree of pain and dysfunction and to establish the presence of the diagnostic criteria listed in Table 116-1 .
CRPS signs and symptoms are dynamic (complex), extend beyond the area of injury (regional), always include disproportionate continuing (pain), and occur in variable combinations (syndrome). The diagnosis of CRPS is primarily clinical; however, predictive value of the symptoms has been reported. In a study of 155 CRPS assessments, Perez and colleagues evaluated the sensitivity and specificity of the diagnostic criteria. They determined that a Visual Analog Scale (VAS) > 3 cm, McGill Pain Questionnaire with more than 6 words, a checked temperature difference of more than 0.4°C, hand volume difference greater than 6.5%, and active range of motion (AROM) limitation greater than 15% could be used as diagnostic indicators for the presence of CRPS I. In addition, the VAS has diagnostically demonstrated a positive correlation with volumetrics, AROM, and joint pain in patients with CRPS.
Pain has two basic components: sensory discriminative and affective-motivational. The physiologic component refers to strength and intensity; this may be neurogenically or non-neurogenically mediated by chemicals released in the body. Examples of neurogenic pain mediators are neuropeptides such as substance P and calcitonin gene-related peptides, which are also strong vasodilators. Non-neurogenic pain mediators such as bradykinins, certain antihistamines, prostaglandins, and leukotrienes are the result of connective tissue dysfunction. Dysesthetic pain results from damaged or regenerating nociceptive afferent fibers, which may also affect sympathetic function. The affective-motivational component is the emotional dimension, which allows pain to be perceived as pleasant or unpleasant. It is also the most likely source of variability of response to pain.
Pain assessment includes spatial representation, intensity, and qualitative and temporal components. Chapter 114 provides detailed information on the components of pain assessment. Clinical evaluation should include use of a body diagram indicating areas and types of pain ( Fig. 116-1 ). This can be augmented by the McGill Pain Questionnaire for qualitative evaluation. Quantification of pain intensity can be accomplished with a verbal or visual analog scale. It is important to apply the scale or scales to each area and type of complaint the patient has delineated. The relationship of pain over time, progression since onset, and whether it is constant versus intermittent, also must be addressed. In a study of 145 CRPS patients, Birklein et al. reported that spontaneous pain was present in 75% of the patients. Pain was amplified in 93% of the patients by dependent position, striking, or AROM of the affected limb, greater at night, and with environmental temperature changes. Common descriptors were tearing, burning, stinging, and squeezing. The location was deep (63%), superficial (30%), and continuous (60%) and lancinating (27%).
Evaluation of pain provides an important baseline for measuring progress and helps determine whether the pain is sympathetic, dermatomal, peripheral nerve, or referral related, as from myofascial trigger points. Joint tenderness can be quantified with a four-point scale based on palpation (see Fig. 116-1 ). Gradl and Schurmann reported that sympathetic dysfunction occurs early in CRPS and normalizes with time. Therefore, early identification of vasomotor changes in conjunction with pain may lead to early diagnosis.
Pain examination in the future may be more objective, using specific tests such as: heat-induced hyperalgesias, low- and high-threshold mechanical allodynia, transcutaneous electrical nerve stimulation, or monofilament testing in slow temporal summation of mechanical allodynia. Patients in whom temporal summation occurred with these tests were found to have more intense spontaneous pain than those who did not. It may be possible to predict which patient’s neural pain threshold may be low, indicating hyperalgesia or allodynia. With evaluative measures, the therapist may be able to intervene earlier, possibly avoiding increased pain occurring with temporal summation or even being able to predict the potential for developing CRPS.
Examination of peripheral nerve function should include threshold (monofilament) and innervation density (two-point discrimination) tests to identify areas of altered response. Care must be exercised, because monofilament testing may increase allodynia. If the patient displays extreme hypersensitivity, testing should be delayed. Areas of tactile or mechanical allodynia and hyperalgesia should be carefully assessed and have been reported to occur in 88% of the patients. Sensory testing for these symptoms would include noting the distribution of the symptoms and the response to pinprick and light touch. Sensory examination may be used to serially chart changes in allodynia and may also help identify inciting lesions. Examination of peripheral nerve also includes neurodynamic assessment, patient resting posture, and any active or passive motion dysfunction. See Chapter 118 for more information on the assessment of adverse neural tension.
Systematic review should focus on the four sign factors. Changes such as fibrosis of the skin, connective, and skeletal tissue and vasomotor status should be determined, including comparison with the contralateral extremity. The observations of the skin, color, texture, temperature, hair growth, and other trophic changes should be noted. Sudomotor changes such as hypohidrosis or hyperhidrosis should be observed for any asymmetry. While taking the patient history, the therapist should inquire as to whether any diagnostic tests such as three-phase bone scan have been performed.
Vasomotor changes, whether vasodilated (hot, red, edematous), vasoconstricted (cold, pale), or mixed/fluctuating, should be assessed. Bilateral baseline circumferential and volumetric measurements should be obtained, and the type of edema (brawny or pitting) should be noted. The thoracic spine should be evaluated, considering the sympathetic chain from T2 to T6 and its relationship to the upper extremity. Note that sympathetic innervation does not correlate with dermatomes.
Decreased ROM, motor weakness, or movement dysfunction may be present. As patient tolerance permits, the entire skeletal system and articular structures from the cervical spine throughout the upper extremity should be examined. Manual muscle testing should be performed to ascertain muscle strength, integrity, innervation status, or the presence of any altered motor response. This, as with the pain evaluation, may uncover underlying precipitating lesions. Grip dynamometer and standard pinch meter testing will provide additional baseline data if the patient is able to tolerate testing. Connective tissue status should be assessed with palpation for fibrosis and joint tenderness. A careful screen for the presence of myofascial trigger points should also be performed, as this has been linked to CRPS.
Goniometric measurement of AROM and passive range of motion (PROM) and assessment for arthrofibrosis, extrinsic, and intrinsic tightness provide additional information about level of involvement and effect on function. Any dystonia (abnormal posturing or movements), tremors, or akinesia/bradykinesia while attempting active motion should be noted. History taking should also determine the preexistence of any central movement disorders or predisposing factors. A “typical” RSD patient is depicted in Figure 116-2 .
The history, pain and physical examination will establish the level of tissue irritability or sensitivity that creates the guidelines for formulating a treatment plan. The patient’s signs and symptoms may be dynamic, variable, and widespread. Clinical reasoning, ongoing observation, and assessment of tissue status and response to treatment determines the plan for care. Figure 116-3 is a diagrammatic representation of the clinical reasoning and the treatment options available to the therapist.
There is a paucity of any randomized controlled trials examining the effectiveness of therapy intervention. Regardless of this fact, almost every piece of literature on CRPS cites the use or need for therapy intervention. There have been multiple case reports that reported the successful treatment of CRPS with therapy intervention. However, these reports lacked the use of patient self-report outcome measures other than a pain analog scale and ROM measurements. The only prospective randomized clinical study of CRPS was reported in a series of four articles. In this series 145 patients with CRPS I with symptom duration less than 1 year were each randomly assigned to one of three treatments: physical therapy (PT), occupational therapy (OT), and control therapy (counseling by social worker; CT). Oerlemans and associates reported no difference in impairment percentages after 1 year ; however, PT and OT resulted in a significant and more rapid improvement in the impairment level sum score, PT resulted in a more rapid decrease in pain and was superior to OT and CT for increasing AROM ; and PT was more cost-effective. Specific interventions were not described but were defined based on the goals of each discipline. In a randomized clinical trial on the efficacy of spinal stimulation that included PT intervention, the effectiveness of PT was extrapolated, and it was reported that PT did not influence functional parameters in chronic (>1 year) CRPS I. The authors did, however, report that patients with lower pain scores and less motor and/or strength involvement responded better with the PT intervention.
Through the examination, the therapist can determine the irritability of the patient’s involved tissues and formulate a treatment plan. If the therapist fails to make an accurate assessment of the patient’s signs and symptoms, in many instances he or she becomes the “pain terrorist.” Even with accurate assessment, there is no recipe for treating these patients. Treatment program development requires clinical reasoning, frequent if not daily observation of the patient, assessment of the patient’s response to previous treatments, and assessment of the patient’s level of irritability. The therapist must clinically decide at each visit the vasomotor state of the patient’s extremity. There is no support in the literature to suggest an appropriate dosage or duration for treatment. It is only through this ongoing evaluation process that these parameters can be determined and modified.
The Practical Approach—“Treat the Signs and Symptoms”
The therapist should choose a practical approach based on the major presenting signs and symptoms, within the context of the four factors previously discussed. Before the IASP classification of CRPS, the teachings and descriptions of RSD stages led the practitioner to believe that the patient is vasodilated at certain stages (stages 1 and 2) and vasoconstricted at other stages (stages 2 and 3). It is now recognized that CRPS is an ongoing vasomotor instability problem. The patient may be vasodilated, vasoconstricted, or a combination of both at any given time. In light of this unstable vasomotor tone, the therapist should clinically attempt to identify the current vasomotor state (at each treatment session) and avoid exacerbating the tone identified. A patient with a hot, red, swollen hand may be vasodilated. The therapist should choose treatment methods that will not accentuate the vasodilatation. In contrast, the patient with a cool and pale extremity may be vasoconstricted. The vasoconstriction may be assisting in perpetuating the syndrome, and treatment should use methods that create vasodilatation and avoid vasoconstriction.
The pursuit of a practical treatment approach should be individually geared toward treating the pain and accompanying four sign and symptom factors of sensory, vasomotor instability, sudomotor/edema, and motor/trophic changes. The therapist must recognize the emotional and psychological aspects of the RSD patient. Hardy and Merritt found that compared with non-RSD patients, RSD patients were significantly different in somatization, depression, interpersonal sensitivity, and anxiety but that pain scores showed no significant difference between the two groups. In contrast Ciccone et al. found no difference in psychological dysfunction between CRPS, chronic low back pain, and neuropathic pain patients.
Pain-related fear of physical activity or re-injury has been identified in chronic pain and CRPS patients. This pain-related fear can often be more disabling than pain itself. Pain-related fear has led to the model of fear-avoidance, where “confrontation” and “avoidance” are the extremes of the response. Confrontation may lead to reductions in fear over time. As a result, a treatment model of graded exposure has been recommended. The application of graded exposure was studied by deJong et al. in a single-case experimental ABCD design of eight patients diagnosed with CRPS I. The program consisted of education to the fear avoidance model to increase willingness to move (exposure) and graded exposure to those movements or situations that provoked pain-related fear. They found this program decreased pain-related fear, pain intensity, disability, and physiologic signs or symptoms related to autonomic and vasomotor disturbances. The important point is that the treatment environment and the therapist also should address the psychological needs of the patients.
Every health-care professional treating patients with CRPS should consider the impact of this disease on their quality of life. This fact alone supports the need for therapeutic intervention. It has been demonstrated in acute and chronic (>3 years) CRPS that there is a marked decrease in the use of the involved extremity, especially in the case of involvement of the dominant hand. The greater the impairments in ROM and strength, the greater the limb activity was decreased especially in sitting. Patients with CRPS also tend to be less active overall with less intensity. This decrease in limb activity tended to correlate with disability and handicap. Geertzen and associates reported that 62% of their patients were limited in activities of daily living (ADLs) and these patients were significantly more handicapped as measured by the Groningen Activity Restriction Scale and RAND-36 (SF-36) questionnaire. Similar findings of reduced quality of life as measured with the Neuropathic Pain Scale, Modified Brief Pain Inventory, and a self-report questionnaire were reported by Galer et al. Both of these research groups confirmed that pain also played a major role in quality of life.
Recognition of the biopsychosocial aspects of CRPS has led to the concept of functional restoration, which advocates, as have I, for the treatment of the signs and symptoms of which therapy plays a major role. Stanton-Hicks and associates state that therapy must include five aspects: neuromodulation of pain, movement and muscle activation, isometric strength and stress load, and functional recovery. The dynamic nature of CRPS necessitates that each program is individually based and allows flexibility in the plan of care.
Clinical Treatment of Signs and Symptoms
The management of pain is of primary importance, especially in the early onset of CRPS. Before any progress can be achieved, pain must be decreased. Pain modulation may include modalities as an adjunct and may be obtained by managing tissue changes, which may allow improvement in movement dysfunction. It is of the utmost importance that the therapist not exacerbate the patient’s pain during treatment To determine a meaningful reduction of pain in patients with CRPS I, Forouzanfar and associates studied 52 patients and measured their responses on the VAS and Perceived Global Effect Score. The authors determined their patients’ defined meaningful reduction in pain to be at least a 50% reduction and an absolute 3-cm change on the VAS. Furthermore, it is necessary to have this level of pain reduction for patients to report a successful treatment.
Electroanalgesia or Transcutaneous Electrical Nerve Stimulation
There is little evidence at this time that supports the use of transcutaneous electroanalgesia in the management of patients suffering with CRPS. The reader is referred to Chapter 114, “Pain Management: Principles of Therapist’s Interventions ,” and Chapter 117, “The Use of Physical Agents in Hand Rehabilitation ,” for a more in-depth discussion on the use of electroanalgesia and physical agents for pain modulation.
Other Modalities and Procedures
Active exercise may contribute to decreasing the patient’s discomfort through activation of large-diameter afferent fiber stimulation or through opioid stimulation. The use of thermotherapy to treat pain has been reported. Ultrasound is delivered over the affected area or the accompanying peripheral nerves. The reader is referred to Chapter 117 on physical agents for a more in-depth discussion on the use of physical agents as an adjunct to treatment intervention.
Mirror Visual Feedback
Mirror visual feedback (MVF) has been advocated for the treatment of CRPS to assist in somatosensory cortex reorganization. The technique utilizes a mirror to simulate movement of the affected limb by using the unaffected limb’s reflection while performing specific movements ( Fig. 116-4 ). McCabe and associates in a descriptive study of eight patients treated with MVF reported a “striking reduction” in VAS during and after treatment in five patients suffering with CRPS for less than 2 years. Repeated use of MVF four to nine times per day resulted in progressive extension of the analgesic effect. In a pilot study, Tichelaar et al. treated three CRPS patients with MVF combined with a cognitive behavioral therapy and reported some success in decreasing the VAS and improving motion in two of the patients with symptoms of 8 and 30 months in duration. There was no change in the other patient, whose symptoms had been present for 9 years. A more in-depth discussion on MVF will occur later in this chapter and can also be found in Chapter 46, “Sensory Reeducation .”
As discussed earlier many patients with CRPS demonstrate pain-related fear behavior. Use of graded exposure to the pain-related fear has been used successfully to treat patients with chronic low back pain. Recently deJong and colleagues treated patients with chronic CRPS I utilizing a graded exposure to overcome pain-related fear using a single-case experimental ABCD design. The treatments consisted of educating the patients on the fear avoidance model, then developing an individual graded exposure plan to the situations the patients described as dangerous. The patients agreed to expose themselves to these fearful activities until anxiety had decreased. The therapist gradually withdrew from the program. Although a relatively low study population (eight patients), self-reported pain-fear, pain intensity, disability, and physiologic signs and symptoms all improved.
Factor 1: Sensory Hyperesthesia–Allodynia
Treatment requires the patient’s diligent performance of a desensitization program incorporated into the clinic and home program. The desensitization program should be specifically outlined for the patient, including duration and frequency of each stimulus throughout the day. Desensitization should be initiated after determining the patient’s baseline hypersensitivity and the amount and type of tactile stimulation he or she is capable of tolerating without exacerbation of pain. Desensitization may include the use of textures, percussion, pressure, and vibration.
The therapist should initiate desensitization outside of the area of hypersensitivity and progressively work toward the area of greatest sensitivity. As previously discussed, Price et al. demonstrated the capability of some tactile stimuli to create temporal summation of mechanical allodynia. Intermittent tactile stimuli applied at intervals of 3 seconds have been found to increase the patient’s discomfort. In the clinic, the intermittent or cyclic application of tactile stimuli such as percussion or intermittent skin contact with desensitization modalities actually may increase the patient’s allodynia. Every effort should be made to maintain contact of the stimulus with the skin and avoid cyclic stimulation, as occurs when the therapist removes his or her hands with each stroke of retrograde massage.
Vibration is a component of desensitization. Bin et al. found that vibration of 200 Hz performed directly over the projected area of pain was most effective in relieving the pain produced by electrical stimulation of cutaneous fascicles of the median nerve. Pressure, cooling, and warming also were compared with vibration for the relief of this discomfort and were found to be less effective. Lundenberg treated 267 pain patients using 100-Hz vibration with a 60- and 200-cm probe. He found after 3 months of vibration that 50% of the patients reported more than 50% pain relief. After 6 months, 75% still using the device were reporting pain relief. In general, he found that the use of vibration decreased as the months progressed and relief was greatest in the musculoskeletal patients as compared with the neurogenic pain patients. Vibration used for a 45-minute period twice a day at 100 Hz also was found to be most effective for pain relief when compared with various vibratory rates from 50 to 600 Hz. In general, the greater the relief, the longer the relief lasted after vibration, and this relief was directly related to the amount of time vibration was applied. Finally, investigators found that stimulation of greater than 200 Hz caused radiation of discomfort. From the results of these experiments, vibration treatments at 100 Hz for periods of 20 to 45 minutes each for a total of 90 minutes per day with continuous modest pressure using a 6-cm square padded probe appears most effective in relieving pain and hypersensitivity. The benefits of vibration have been reported by Gay and associates. In a nonrandomized study with 11 subjects the authors utilized 14 points of stimulation on the hand that caused “kinesthetic illusions” at a frequency of 86 Hz for 1 minute in 4 15-second periods; this was repeated once and performed 5 days per week for 10 weeks. The authors reported a 50% reduction in pain as measured on the VAS and a 30% improvement in wrist and finger ROM following the 10-week treatment session.
A 10-step hierarchy program for desensitization has been advocated by Barber. For the CRPS patient, every attempt should be made to include desensitization as part of the AROM and functional activity program. Initially, desensitization may make up the major component of the treatment program to gain control of hypersensitivity. As hypersensitivity improves, the necessity for desensitization will diminish. The therapist should determine the tactile stimulus that just provokes the threshold response. Only after the patient accommodates to this stimulus is the patient progressed to the next stimulus in the hierarchy.
Retrograde massage performed for edema control is also part of a desensitization program. In most cases the patient should be encouraged to perform desensitization with the established modality for 20 to 45 minutes at a time, totaling 90 minutes per day. Desensitization often fails as a result of early abandonment of the program, inadequate time spent with each individual modality to produce sensory accommodation to the stimulus, or inappropriate stimulus choice. In those patients who cannot tolerate desensitization on the affected extremity, stimulating the identical area on the unaffected extremity may assist in decreasing sensitivity and assisting in cortical reorganization. This can be combined with MVF.
When desensitization fails, the therapist may need to provide protection to areas that are hypersensitive to enable the patient to perform ADLs and occupational requirements. Use of protective orthotic positioning, elastomer inserts, and padded gloves or garments may be the only alternative available to protect the hypersensitive area from environmental stimuli ( Fig. 116-5 ).