Case 71 - CRPS

Question 1

What is CRPS?

Answer 1

• a continuous and sympathetically mediated pain usually due to an injury
• pain is severe, burning in nature.
• can see autonomic and trophic changes
• sensory and motor dysfunction

Question 2

CRPS 1 vs CRPS2?

Answer 2

CRPS 1 asa RSD

• unknown cause, minor injury

CRPS 2

• traumatic injury involving nerve

Question 3

What are some theories regarding etiology of CRPS?

Answer 3

• 3 main mechanisms: aberrant inflammatory response, vasomotor dysfunction, maladaptive nerve regeneration

Vasomotor dysfunction

• early period - affect limb warm than contralateral side
• late period - affect limb cold than contralateral side
  
  • temperature changes 2/2 vasoconstriction changes over time

Maladaptive nerve regeneration

• connection between somatic nervous system and autonomic nervous system
  
  • whether by chemical mediation or actual structural connectoin
• result - emotion, temp, weather reroute from sym system to somatic system –> Pain
  
  • light touch rerout from somatic to sym system –> uncoordinated sympathetic response

Question 4

What are the three different stages of CRPS?

Answer 4

1) Acute or Hyperemic

• days to weeks; sympathetic blockade
• severe burning
• skin is red, warm, dry
• hyperesthesia and allodynia

2) dystrophic

• weeks to months; sympathetic hyperexcitability
• skin is pale, cyanotic, and cool
• hyperesthesia + allodynia

3) atrophic

• months to years; prolonged vasoconstrict 2/2 incrased sympathetic discharge over time
• smooth glsasy skin, loss of hair, brittle nails, muscle atrophy, osteoperosis

Question 5

allodynia vs hyperesthesia

Answer 5

allodynia - pain to nonnoxius stimuli

hyperesthesia - exagerated response to stimuli

Question 6

what are s/sx of a successful sympathetic nerve block in dx of CRPS. What are risks of the procedure?

Answer 6

• stellate ganglion - dx of CRPS of upper extremity
  
  • level of TP of C6 - chaissagnac tubercle located
  • at this level, vertebral artery is anterior to TP at C7 and dives posteriorly into vertebral foramen
• successful block
  
  • hornor syndrome - ptosis, miosis, anhydrosis
  • vasodilation and increase temp of affected arm (symp blockade)
• Risks
  
  • vertebral A injection
  • pnuemo
  • bradycardia
  • diaphragamatic paralysis
  • neuraxial spread