History
The typical clinical picture of CRPS consists of disproportionate extremity pain, swelling, and autonomic (sympathetic) and motor symptoms. The condition can affect the upper or lower extremities, but it is slightly more common in the upper extremities.
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Pain:
Pain is reported in more than 90% of patients.
Most patients describe worsening of pain or other symptoms after exercising the affected limb.
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Edema:
Vascular abnormalities (often abnormal vasodilation and skin warming in the early phase and vasoconstriction in later stages) are characteristic symptoms of RSD/CRPS I.
Typically, patients with CRPS I exhibit a warm and vasodilated affected extremity in the early stages and cold and pale skin in the later stages.
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Alteration in motor function:
Although the IASP did not include motor dysfunction within their formal criteria for diagnosing RSD (because it is not universal), they acknowledged that such dysfunction is common. The abnormal motor symptoms that are reported most classically in RSD include the following:
Inability to initiate movement
Weakness
Tremor
Muscle spasms
Dystonia of the affected limb
In one study, weakness was reported in 95% of patients, tremor of the affected limb in 49%, and muscular incoordination in 54% of patients. In chronic RSD, severe spasms were present in 25% of patients.
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Alteration in sensory function - Although the IASP also decided not to include sensory dysfunction within their formal criteria for diagnosing RSD (due to variability), such symptoms, including hypo-esthesia, hyperesthesia, and allodynia, may occur.
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Psychological dysfunction - Although psychological dysfunction is often seen in patients with RSD, the IASP decided not to include it within their formal criteria for diagnosing the condition, due to ongoing debate as to whether psychological dysfunction increases the risk of RSD or whether the psychological dysfunction is actually a result of the RSD. Psychological disturbances may include anxiety, hopelessness, and/or depression.
Physical
See the list below:
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The common characteristic features of RSD (CRPS I) are spontaneous pain, hyperalgesia, impairment of motor function, swelling, changes in sweating, and vascular abnormalities in a single extremity. An overt nerve injury is not detectable:
Various sensory symptoms have been observed.
Allodynia (mechanical and thermal)
Hyperalgesia (mechanical and thermal)
Hyperpathia
Hypo-esthesia
Hypothermesthesia
Proprioception and anesthesia dolorosa (sensibility to touch is absent, while severe pain is present in the anesthetic area)
Dissociated sensory pattern (on rare occasions)
In a study by Veldman, discoloration of the skin was reported in 91% of cases, altered skin temperature in 92%, edema in 69%, and limited active range of motion (AROM) in 88% of cases.
Hyperhidrosis may be seen in more than 50% of cases (with warm or cold skin temperature).
Dystrophic changes may present in skin, subcutaneous tissue, muscles, and bone.
Changes in the growth pattern of hair or nails on the affected limb can be commonly observed.
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Complex regional pain syndrome:
Based on the IASP consensus conference, there are 2 types of CRPS, namely CRPS I (RSD) and CRPS II (causalgia). These 2 types are differentiated mainly based upon whether the inciting incident included a definable nerve injury.
CRPS I (RSD) – Occurs after initial noxious event other than a nerve injury
CRPS II (causalgia) – Occurs after nerve injury
In most other ways, CRPS I and CRPS II are quite similar. Features common to CRPS types I and II include the following:
Pain, whether spontaneous or evoked, may include allodynia (painful response to a stimulus that is not usually painful) and/or hyperalgesia (exaggerated response to a stimulus that is usually only mildly painful).
Pain that is disproportionate to the inciting event (eg, years of severe pain after an ankle sprain)
Regional pain that is not limited to a single peripheral nerve distribution
Evidence of autonomic dysregulation (eg, edema, alteration in blood flow, hyperhidrosis)
Diagnosis is excluded if another condition could account for the degree of pain and dysfunction.
Typically, CRPS I is subdivided into the following 3 phases:
Acute stage - Usually warm phase of 2-3 months
Dystrophic phase - Vasomotor instability for several months
Atrophic phase - Usually cold extremity with atrophic changes
These stages may be variable and often are not clear cut.
In CRPS I, 3 different kinds of spread patterns (ie, contiguous, independent, mirror-image) have been described. According to Maleki and colleagues, CRPS I may be due to aberrant CNS regulation of neurogenic inflammation. [7]
Causes
Various insults that may lead to RSD include the following:
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Trauma (eg, sprain, dislocations, fractures, surgery, burns, crash injury)
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Neurologic disorders (eg, stroke, tumor, syringomyelia)
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Herpes zoster infection
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Myocardial infarction
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Musculoskeletal disorder (shoulder rotator cuff injury)
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Malignancy
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Spontaneous/idiopathic
A study by Veldman and colleagues reported that in 65% of cases, RSD followed trauma (mostly a fracture); in 19% of cases, it followed an operation; and in 2% of cases, it followed an inflammatory process. [6] In 4% of cases, onset of symptoms followed various other precipitating factors, such as injection, intravenous infusion, or cerebrovascular accident. In 10% of cases, no precipitant could be identified. CRPS II (causalgia) has been reported after automated laser discectomy and cervical epidural injection.
In a study of 124 persons with CRPS, Peterlin et al reported evidence that migraine may be a risk factor for the condition and may also be associated with an increased severity of CRPS. [8] The study's results suggested that migraine is 3.6 times more likely to occur in individuals with CRPS than it is in members of the general population, and that chronic daily headache (CDH) is twice as likely to occur. The investigators also found that in subjects who had migraine or CDH, the mean age at which CRPS developed was lower and the number of limbs affected by CRPS was higher than they were in persons with CRPS who either had no headaches or who suffered from tension-type headaches.
In a retrospective study of adult patients with RSD, using the National (Nationwide) Inpatient Sample database, Elsharydah et al found that a higher rate of the disease was associated with female gender, Caucasian race, depression, headache, drug abuse, a greater median household income, and the use of private insurance (as opposed to Medicaid). A lower rate of RSD was linked to the presence of diabetes, obesity, hypothyroidism, and anemia. [9]
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A 29-year-old woman with reflex sympathetic dystrophy in the right foot demonstrates discoloration of the skin and marked allodynia.
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This photo shows the same patient as in the above image, following a right lumbar sympathetic block. Marked increase in the temperature of the right foot is noted, with more than 50% pain relief.
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A 68-year-old woman with complex regional pain syndrome type II (causalgia).
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A 36-year-old woman with right arm reflex sympathetic dystrophy and dystonic posture (movement disorder).
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Normal laser Doppler study of the upper extremities. When the patient performs inspiratory gasp repeatedly during laser Doppler image acquisition, the transient capillary flow decreases are displayed easily and dramatically (as dark bands) in the pseudocolor image.
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Laser Doppler study of the upper extremities in a patient with right hand reflex sympathetic dystrophy.
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Laser Doppler study of the lower extremities in a 25-year-old woman with reflex sympathetic dystrophy in the right foot.
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Algorithm for the management of chronic regional pain syndrome (CRPS). Resolution of this syndrome does not commonly occur, and the patient will need chronic pain management.
