Complex Regional Pain Disorder

1. What are the clinical features of CRPS?
2. What are the clinical stages of CRPS?
3. What are the radiographic findings of CRPS?
4. What is the treatment of CRPS?
*5. What are four tests used to determine if the pain is sympathetically mediated?

Answers:
1. Pain, deep burning exacerbated by movement, allodynia, hyperalgesia. local edema and vasomotor changes (initially warm and red, then becomes cool and cyanotic), muscle weakness, dystrophic changes.
2. Acute (pain, hypersensitivity, swelling, vasomotor changes), dystrophic (atrophic skin changes, decreased temp, hyperhidrosis), atrophic (atrophy, contractures, skin glossy, cool, and dry).
3. Sudeck's atrophy shows up on plain radiographs as patchy osteopenia. Three-phase bone scan is non-specific in first two phases, in third phase is abnormal with enhanced uptake in peri-articular structures.
4. Immediate mobilization, pain control. Corticosteroids for two weeks then gradual taper. Sympathetic ganglion block.
5. Sympathetic block with local anesthetic, guanethidine test (inject distal to suprasystolic cuff --> positive if pain reproduced after injection and relieved after cuff released), pentolamine test (reprod pain with IV pentolamine), ischemia test (inflation of suprasystolic cuff decreases pain).