Complex Regional Pain Syndrome Diagnosis and Management

Diagnosis

The American College of Radiology recommends three-phase bone scintigraphy as the most useful imaging modality for CRPS, with a pooled sensitivity of 78% and specificity of 88% 1
Clinical Infectious Diseases guidelines suggest that CRPS does not demonstrate a placebo response except at very early time points (15-30 minutes), distinguishing it from other pain syndromes 2
The diagnosis of CRPS is primarily clinical, based on the Budapest Criteria, requiring symptoms present for at least 12 months to be considered chronic, with excruciating pain disproportionate to the initial injury that worsens with touch or stimulation 3

Pain characteristics of CRPS include excruciating, burning pain that gradually increases in intensity and spreads within the affected limb, sometimes extending to the contralateral limb 2, 3
Sensory abnormalities, such as allodynia and hyperalgesia, are hallmark features of CRPS 3
Autonomic dysfunction, including temperature dysregulation, skin color changes, and abnormal sweating patterns, is common in CRPS 3
Motor impairment, including functional limb weakness and decreased active range of motion, is a characteristic of CRPS 3
Trophic changes, such as hair loss, tissue changes, and skin discoloration, can occur in chronic CRPS 2, 3

The American College of Radiology recommends physical and occupational therapy as the cornerstone of CRPS treatment, with all other interventions serving to facilitate participation in rehabilitation 4
Gentle stretching and mobilization, active range of motion exercises, and sensorimotor integration training are essential components of physical therapy for CRPS 4
Analgesics, such as NSAIDs and acetaminophen, may be used to enable physical therapy participation 4
Oral corticosteroids may be used to reduce inflammation and edema in CRPS 4
Sympathetic nerve blocks, such as stellate ganglion blocks or lumbar sympathetic blocks, may be used for moderate to severe cases with sympathetic dysfunction 4
Spinal cord stimulation is a recommended treatment for refractory CRPS cases, requiring a trial before permanent implantation 4
Cognitive behavioral therapy and stepped psychological interventions can help reduce anxiety and avoidance behavior that perpetuate disability in CRPS patients 4

Delaying physical therapy waiting for pain to resolve can worsen outcomes through disuse and pain upregulation 4
Continuing sympathetic blocks indefinitely without documented progressive improvement and increasing duration of relief is not recommended 4
Using peripheral somatic nerve blocks for long-term treatment is not indicated 4
Using sympathetic blocks for non-CRPS neuropathic pain contradicts evidence-based guidelines 4
Failing to document objective functional outcomes beyond pain scores can justify continued interventional treatment 4

Evaluating CRPS patients at least twice annually by a specialist is recommended due to high recurrence risk 3

The American College of Radiology defines Complex Regional Pain Syndrome (CRPS) as two distinct types: Type I, which occurs without an identifiable nerve injury, and Type II, which occurs after a confirmed nerve injury 5
Type I encompasses reflex sympathetic dystrophy and similar conditions where no specific nerve lesion has been identified, despite thorough clinical evaluation 5
Type II is diagnosed when there is an identifiable nerve injury or lesion documented through clinical examination or diagnostic testing 5
The critical diagnostic distinction is documentation of nerve injury—its presence defines Type II, while its absence defines Type I 5

Three-phase bone scintigraphy demonstrates pooled sensitivity of 78% and specificity of 88% for CRPS diagnosis, though it cannot distinguish between Type I and Type II 5
MRI has higher specificity (91%) but lower sensitivity (35%) for CRPS-I, making it unsuitable as a screening test 5
For CRPS-II specifically, MRI may provide additional diagnostic value by directly visualizing nerve lesions and detecting denervation changes 5
High-resolution ultrasound and MRI may be particularly useful in Type II cases given their capability to directly visualize nerve pathology and detect signs of muscle denervation 5

The European League Against Rheumatism recommends hydrotherapy for fibromyalgia, with significant improvement in pain at end of treatment (effect size -0.78), but notes all trials were poor quality 6

The American College of Rheumatology suggests that hand therapy and physiotherapy, including therapeutic exercises, improve functionality and reduce pain in CRPS patients, with benefits lost during follow-up periods, emphasizing the need for continuous supervised therapy 7, 8
Manual lymph drainage is beneficial for hand function and quality of life in CRPS patients, according to the European League Against Rheumatism, with critical caveat that benefits are lost during follow-up periods 7, 8

The American College of Rheumatology states that manual therapy with exercise shows no additional benefit over exercise alone in other pain conditions, as reported in Arthritis and Rheumatology 9

For work compensation approval, the American Medical Association requires documentation of failure or inadequate response to current evidence-based therapies after adequate trial, typically 8-12 weeks, as well as specific functional goals and objective outcome measures 7, 8