Complex Regional Pain Syndrome Type 1 (Reflex Sympathetic Dystrophy)

Introduction

Essentials of Diagnosis

• Burning or aching pain of greater severity and longer duration than expected following trauma to an extremity.
  
• Manifestations of localized vasomotor instability are generally present.

General Considerations

The syndrome is characterized by burning or aching pain in an injured extremity that is more severe than would be expected given the inciting trauma. It occurs in all age groups and equally in both sexes and can involve either the arms or the legs. The degree of trauma is in some cases surprisingly minor (phlebotomy), but most cases follow crushing injuries with lacerations and soft tissue destruction. Closed fractures, simple lacerations, burns (especially electric burns), elective operative procedures, and myocardial infarction with referred left arm pain are other reported causes.

Clinical Findings

In the early stages, the pain, tenderness, and hyperesthesia are localized to the injured area, and the extremity is warm, dry, swollen, and red or slightly cyanotic. With time, muscle spasm and joint stiffness limit mobility, and the nails may become ridged. In advanced stages, the pain is more diffuse, and nocturnal pain may become extreme; the extremity becomes cool and clammy and intolerant of temperature changes (particularly cold); and the skin becomes glossy and atrophic. The patient's dominant concern is to avoid external stimuli, particularly in trigger point areas. Pain and disuse lead to loss of function. Radiographs reveal asymmetric osteopenia more severe than anticipated from immobility alone.

Prevention

Trauma to peripheral nerves during surgery is avoided by knowledge of their anatomy and careful mobilization by handling of the perineural tissue only. Splinting and adequate analgesia followed by early mobilization of an injured extremity minimize the occurrence of reflex sympathetic dystrophy.
Treatment & Prognosis

A. Conservative Measures
Early recognition and treatment are essential to preserve function of the limb. In the early stages, when major secondary changes have not yet developed, physical therapy involving active and passive exercises combined with a mild anxiolytic (diazepam, 2 mg twice daily, or alprazolam, 0.125-0.25 mg twice daily) may relieve symptoms. Opioids have been a mainstay of treatment; recently, however, gabapentin (beginning at 200 mg twice daily) has been used with success. Sympathetic blocks (stellate ganglion or lumbar) can be combined with intensive physical therapy for cases refractory to more conservative treatment. Protection from further injury and avoidance of irritating stimuli are imperative.