Complex regional pain syndrome

Dr Henry Knipe and A.Prof Frank Gaillard et al.

Complex regional pain syndrome (CRPS), also known as Sudeck atrophy, is a condition which can affect the extremities in a wide clinical spectrum.

Two types of CRPS have been described 8:

  • type 1: no underlying single nerve lesion (formerly known as reflex sympathetic dystrophy)
  • type 2: underlying nerve lesion identified (formerly known as causalgia)

Patients present after an initiating event (see causes below) with symptoms such as oedema, changes in skin blood flow, abnormal motor activity, allodynia or hyperalgesia. Symptoms are often out of proportion to the initiating event and not limited to a single peripheral nerve 8.  

  • trauma: often minor
  • idiopathic: immobilisation
  • unknown in many cases
  • CNS disorders
  • myocardial infarction

Occurs in hands and feet distal to the injury.

  • severe patchy osteopenia particularly in the periarticular region
  • soft tissue swelling, with eventual soft tissue atrophy
  • subperiosteal bone resorption
  • preservation of joint space

It is important to differentiate this from disuse osteopaenia hence clinician could start aggressive physical therapy.

  • soft tissue oedema and enhancement, skin thickening
  • muscle atrophy in later stages
  • patchy bone marrow oedema signal (particularly subcortical)
  • there is increased uptake on all three phases
  • diffusely increased juxta-articular activity around all joints of hand or foot on delayed images is the most sensitive indicator

In most cases, a multidisciplinary approach is required and various treatments may be employed such as physical therapy, medications either systemic or regional, surgery such as sympathectomy or spinal cord stimulation, or psychotherapy. Interventional radiology can offer pain relief by peripheral nerve block procedures. 

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Article information

rID: 1154
Section: Syndromes
Synonyms or Alternate Spellings:
  • Reflex sympathetic dystrophy
  • Sudeck atrophy
  • RSD
  • Reflex sympathetic dystrophy (RSD)
  • Sudeck's atrophy
  • Sudeck dystrophy
  • Sudeck osteodystrophy
  • Causalgia

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Cases and figures

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    Case 4: type 2
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