Dr. Sunita Lawange
– Dr. Sunita Lawange


DEFINITION: A variety of painful conditions which occur after
the injury with regional distribution having a distal predominance of abnormal findings,
which exceed in intensity and duration of expected clinical course of the inciting

Complex regional pain syndrome (CRPS) comprises of variety of
clinical presentations in which severe pain is associated with vasomotor changes
and dysfunction in response to the injury. It was earlier named as causalgia, reflex
sympathetic dystrophy (RSD). The term CRPS was coined by Robley Dunglison from the
Greek words for heat and for pain in a special consensus workshop at Florida in
1999. The International Association for the Study of Pain (IASP) changed the name
of reflex sympathetic dystrophy to CRPS I and causalgia to CRPS II, because not
all pain in this spectrum are sympathetically maintained.


The highest incidence of CRPS is between 50-70 years , though it can occur at
any age with higher incidence in females F: M= 3-4: 1 Incidence in upper limb is
60% and in lower limb about 40%CRPS is a diagnosis seen with increasing frequency
in injured workers but it can occur after surgery or any vascular event.


  • Trauma
  • Post-surgical factors
  • Neurologic injury
  • Carcinoma
  • Burns

IASP Diagnostic Criteria for CRPS (1994)

  1. The presence of an initiating noxious event
  2. Continous pain, allodynia or hyperalgesia
  3. edema, changes in skin blood flow or abnormal sudomotor activity in the
    region of pain.

Modified IASP research diagnostic criteria for CRPS: Budapest Criteria

  1. Continuous pain disproportionate to the inciting event.
  2. Must report at least one of the following symptom in each of the four following

    1. sensory: reports of hyperesthesia/ allodynia
    2. Vasomotor: temperature asymmetry/skin colour changes/ skin colour asymmetry
      in the affected region.
    3. Sudomotor/ Edema: edema and / or sweating changes/asymmetry in the affected
    4. Motor/ trophic: decreased ROM/ motor dysfunction and / trophic changes
      {hair, nail. Skin}
  3. must have at least one sign at the time of evaluation in two or more categories:
    1. Sensory: evidence of hyperalgesia and or allodynia to light touch/deep
      pressure and /or joint movement.
    2. Vasomotor: evidence of temperature asymmetry and / or skin colour changes
      and / or symmetry.
    3. Sudomotor/ edema: evidence of edema and /or sweating changes and / sweating
    4. Motor/ Trophic: evidence of decreased range of motion and / or motor
      dysfunction and /or trophic changes.
  4. There is no other diagnosis that better explains the signs and symptoms.


It purely remains a clinical one. Detailed medical history, Development, time, course, distribution and characteristic of pain, general neurological examination, detection of swelling, sweating, trophic, temperature and motor abnormality in the disturbed area is important. The diagnostic tools to confirm the diagnosis are:

  • Bone scintigraphy
  • Radiography
  • Quantitative sensory testing(QST)
  • Autonomic functions
  • Thermography
  • Sudomotor testing
  • All these investigations can be used to follow the progress of the
    condition and the response to the treatment.

Stages of CRPS

Stage one: ACUTE

  • Edema
  • Severe burning pain, paresthesia
  • Muscle spasms
  • Joint stiffness
  • Restricted mobility
  • Rapid hair and nail growth
  • Increased sweating (hyperhidrosis)


  • Intense pain
  • Swelling spreads
  • Hair growth diminishes
  • Nails become cracked, brittle, grooved, and spotty
  • Osteoporosis
  • Joints thicken
  • Muscles wasting

Stage Three: ATROPIC

  • Irreversible changes in the skin and bones
  • Pain may envolve entire limb
  • Marked muscle atropy
  • Severe restricted range of movement
  • Flexor tendon contracture
  • Marked bone softening and thinning

Pathophysiology of CRPS

  1. Autonomic nervous system mediated
  2. Inflammation
  3. Autoimmune etiology
  4. Central mechanism
  5. Psychological factors
  6. Role of HLA system
  7. Complex disease of peripheral and central nervous system


The targeted therapy in management of CRPS include:

  • Minimization of pain and distress
  • Restoration of function
  • Improvement of quality of life
  • Severity of disease determines the therapeutic regime. A
    methodical patient approach to pharmacotherapy is essential in CRPS. The
    various mechanisms targeted by the pharmacological agents are:

    Inflammatory process: nsaids, corticosteroids, immunoglobulins. Monoclonal
    antibodies such as anti TNF –alpha antibodies
  • Sensitization of pain: intrathecal baclofen, capsaicin, carbamazepine,
    anticonulsants, NMDA receptor blocker, Sodium channel blocker, Opioids and
  • Sympatholytic agents: alpha 2 agonist, guanithedine
  • Free radical scavengers: DMSO, NAC, vitamin C
  • Bisphosphonates
  • Intranasal Calcitonin


Minimally Invasive Therapies:

  • Sympathetic nerve blocks
  • Intravenous regional nerve blocks
  • Somatic nerve blocks

More invasive therapies:

  • Epidural and plexus blocks
  • Neuro-stimulation: SCS and PNS
  • Continuous intrathecal pump implantation

Surgical and Experimental Therapies:

  • Sympathectomy
  • Endoscopic thoracic sympathectomy
  • Motor cortex stimulation
  • Mirror therapy
  • Psychological interventions
  • Pulsed Radiofrequency Neurolysis


CRPS is a severe debilitating heterogeneous pain disorder that results in physical as well as emotional burden to the patients. It is associated with significant disability, anxiety and depression. The pathophysiology of CRPS is yet not fully known. The diagnosis of CRPS is purely clinical and the use of diagnostic tests has not been validated.

Management of CRPS needs a multimodal and multidisciplinary approach with the inclusion of medical, psychological, physical and rehabilitation interventions. The treatment should be aimed at remodulating, normalizing, disrupting or preventing the progression of abnormalities in pain processing. No single drug or drug combination works for these patients. Spinal cord stimulation, neuraxial route of analgesia, motor cortex stimulation are very promising modalities for managing patients with intractable CRPS. Overall these guidelines help but a holistic approach encompassing constant assurance, ongoing support, compassion and flexibility is essential for successful treatment of CRPS.