Complex regional pain syndrome

Abstract

Complex regional pain syndrome (CRPS) previously known as reflex sympathetic dystrophy is a chronic neurological disorder involving the limbs characterized by disabling pain, swelling, vasomotor instability, sudomotor abnormality, and impairment of motor function. CRPS is not uncommon after hand surgery and may complicate post-operative care. There is no specific diagnostic test for CRPS and the diagnosis is based on history, clinical examination, and supportive laboratory findings. Recent modifications to diagnostic criteria have enabled clinicians to diagnose this disease more consistently. This review gives a synopsis of CRPS and discusses the diagnosis, pathophysiology, and treatment options based on the limited evidence in the literature.

Keywords: Causalgia; Sudeck atrophy; complex regional pain syndrome; hand surgery; reflex sympathetic dystrophy; superficial radial nerve.

Conflict of interest statement

Conflict of Interest: None declared.

Figures

Figure 1

Silas Weir Mitchell (1829-1914)

Figure 2

A 45-year-old lady with Madelung deformity of both wrists presented with bilateral pain greater in the right wrist in May 2010. Her pre-operative visual analogue scale (VAS) pain score was 2/10. She underwent excision of the distal ulna (Darrach procedure) for the right wrist in June 2010. Post-operatively (July 2010), she continued to have severe pain (VAS: 9/10) and swelling in the wrist and hand. She described the pain as burning in nature. She also complained of numbness of all fingers, frequent colour changes in her hand (purplish hue), and a subjective feeling of objects feeling colder to touch with her right hand compared to the left

Figure 3

On examination, the right hand appeared pale, swollen, and with limited range of motion at all joints of the hand and wrist. Her motor power at the wrist and fingers (extension/ flexion) was diminished (grade 3) and skin temperature recordings showed the right side to be 34.2 °C and the left hand to be 33.6 °C. Nerve conduction studies were reported as normal. Patient was diagnosed to have CRPS I and started on gabapentin and oxycodone. On follow-up in August 2010, she did not report any improvement in symptoms and a diagnostic stellate ganglion block was done. She did not have any improvement following the sympathetic block

Figure 4

An infraclavicular brachial plexus catheter was placed for continuous patient controlled analgesia. Her pain score improved to 3/10 and she was able to participate in therapy. The catheter was removed in September and she has gradually made progress in her therapy and the medications were tapered. On her last follow-up in March 2011, she complained of intermittently pain (VAS 2-3/10), her range of motion was approximately 70-80% of the opposite limb, and she was able to return to work as a respiratory technician

Figure 5

Algorithm for the treatment of CRPS[38]