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Complex Regional Pain Syndrome

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Complex Regional Pain Syndrome, Reflex Sympathetic Dystrophy, RSD, Sudeck's Atrophy, Causalgia, Shoulder-Hand Syndrome, Post-traumatic Pain Syndrome

  • Definitions
  1. Complex Regional Pain Syndrome (CRPS, previously Reflex Sympathetic Dystrophy)
    1. Severe, Chronic Pain and Disability of a limb (part or whole)
  • Pathophysiology
  1. Unclear mechanism
  2. Post-Traumatic inflammatory changes are present in CRPS
  3. Genetic component is likely
    1. Another family member with CRPS is not uncommon
  • Epidemiology
  1. Incidence: 26 per 100,000 patients
  2. Female predominance
  3. Peak Incidence age 61-70 years old
  • Types
  1. Type I Complex Regional Pain Syndrome (CRPS1)
    1. Not attributable to a specific nerve lesion
  2. Type II Complex Regional Pain Syndrome (CRPS2) or Causalgia
    1. Attributable to a specific nerve lesion
    2. However, resulting Allodynia and hyperalgesia does not follow a single nerve
  • Risk Factors
  1. Local Trauma
  2. Myocardial Infarction
  3. Routine surgery
  4. Diabetes Mellitus
  5. Malignancy with paraneoplastic syndrome
  • Causes
  • Precipitating events
  1. Precipitating injury (most common)
    1. Limb Fracture
      1. Colles Fracture (28% develop CRPS)
      2. Distal Radius Fracture (3-5% develop CRPS)
    2. Stab or Puncture Wound
    3. Animal Bite
  2. Shoulder-Hand Syndrome
    1. Myocardial Infarction
    2. Cerebrovascular Accident
  • Symptoms
  1. Limb pain
    1. Upper limb is affected in 60% of cases
  2. Onset 4-6 weeks after a mild to moderate limb injury
    1. See precipitating injuries above
  • Signs
  1. Pain
    1. Burning ache in a non-Dermatome pattern (early)
    2. Hyperalgesia (disproportionate pain to inciting event) develops
    3. Pain does not follow a single nerve innervation pattern (even when the initial cause was nerve related)
  2. Trophic Changes
    1. Early Changes
      1. Local edema
    2. Progressive Changes
      1. Skin thins
      2. Hair coarsens
      3. Nail thickens
    3. Late Changes
      1. Muscles shorten and atrophy
      2. Joints ankylose moving distal to proximal
  3. Autonomic instability (Late)
    1. Limb cool and sweaty
    2. Sympathetic hyperactivity
  4. Sensory Abnormalities
    1. Allodynia (exquisite sensitivity to slight touch)
    2. Hyperpathia (severe pain from gentle pressure)
  5. Bony changes
    1. Patchy Osteopenia
  • Stages
  1. Mild (Days to weeks)
    1. Burning pain worse with movement
    2. Edema
    3. Muscle spasm
    4. Patchy Osteopenia may occur
    5. Usually self limited
  2. Moderate: weeks to months
    1. Pain of local hyperesthesia
    2. Muscle wasting
      1. May radiate up extremity
      2. May affect contralateral extremity
    3. Skin cold and pale
    4. Abnormal bone scan
    5. Requires aggressive treatment
  3. Severe: weeks to months
    1. Pain from cold and from touch of additional clothing
    2. Loss of mobility of several joints
    3. Psychiatric changes
    4. Aggressive management may be too late
  • Imaging
  1. XRay (Changes in 85% of cases)
    1. Diffuse Osteopenia in 69% of cases (non-specific)
  2. Abnormal bone scan in 50-85% of cases
  • Differential Diagnosis
  • Management
  1. Active range of motion ("Move it OR lose it")
    1. Aggressive physical therapy with pain control
    2. Avoid immobilization (e.g. splints, slings)
  2. Physical therapy
    1. Isotonic stength
    2. Passive range of motion
    3. Aerobic Exercises
    4. Pool Exercises
    5. Ergonomic adjustments
  3. Analgesics
    1. NSAIDS (e.g. Ibuprofen or Naprosyn )
    2. Acetaminophen
  4. Antiinflammatory
    1. Oral Corticosteroids
  5. Neuropathy agents
    1. Gabapentin (Neurontin)
    2. Pregabalin (Lyrica)
    3. Tricyclic Antidepressant (e.g. Amitriptyline, Nortriptyline)
  6. Topical Medications
    1. Topical Lidocaine Patch (Lidoderm 5% or the OTC Lidocare 4%)
    2. Topical Dimethyl sulfoxide cream (50%) applied for 2 months
      1. May act as free radical scavenger
  7. Novel medications (consult pain management specialists or rheumatology)
    1. Bisphosphonates (e.g. Pamidronate 60 mg IV for 1 dose)
    2. Intravenous Immunoglobulin
      1. Goebel (2010) Ann Intern Med 152:152-8 [PubMed]
      2. Goebel (2013) Rheumatology 52 (11): 2091-3 [PubMed]
    3. Lidocaine infusion
      1. Initial: 1.5 mg/kg (1-3 mg/kg) IV over 20-30 min
      2. Later: 0.2 to 2 mg/kg per hour
      3. Wallace (2000) Anesthesiology 92(1):75-83 [PubMed]
      4. Ferrini (2004) J Support Oncol 2(1): 90-4 [PubMed]
  8. Invasive measures (pain management procedures)
    1. Spinal cord stimulation
    2. Intrathecal Baclofen Pump
    3. Sympathetic Nerve block (Stellate Ganglion, Brachial Plexus, lumbar)
      1. Temporary relief
  9. Other measures
    1. TENS Unit (questionable efficacy)
    2. Mental health counseling for patient and family
  • Prognosis
  1. Longterm Disability is common
    1. Only 20% can participate in prior activities (pain is the limiting factor in >70%)
    2. Schwartzman (2009) Clin J Pain 25(4): 273-80 [PubMed]