eMedicine Specialties > Orthopedic Surgery > Trauma

Reflex Sympathetic Dystrophy

Author: Satishchandra Kale, MD, FRCS(Edin), FRCS Ed(UK), Dip Sports Med, Honorary Assistant Professor of Trauma and Orthopedics, University of Bombay; Consultant, Department of Orthopedics, Dr R N Cooper Hospital, Brahmakumaris Global Hospital, India
Contributor Information and Disclosures

Updated: Jul 2, 2008

Introduction

Background

Reflex sympathetic dystrophy (RSD) is a condition that is often described under various synonyms that point to its incompletely understood etiology. In 1864, Weir Mitchell coined the term causalgia to designate severe pain following nerve injury. In 1900, Sudeck described regional demineralization accompanying posttraumatic pain. In 1923, Leriche described vasomotor disequilibrium.¹ In 1947, Evans introduced the term reflex sympathetic dystrophy. In 1993, the International Association for the Study of Pain renamed algodystrophy complex regional pain syndrome (also known as chronic regional pain syndrome or CRPS).

Reflex sympathetic dystrophy, or RSD, is type 1 CRPS. RSD can be considered an excessive sympathetic reaction of joints and periarticular soft tissues to any insult, traumatic or unknown. This is quite different from causalgia (type 2 CRPS), in which the etiology is a partial nerve injury. RSD is characterized by pain, regional edema, joint stiffness, muscular atrophy, vasomotor disturbances (including temperature changes), trophic skin changes, and regional skeletal demineralization seen on radiographs. These changes are aggravated by activity and extend over a larger area than the primary injury or surgery, including the area distal to this focus.^2,3,4

Because pathognomonic criteria are lacking for RSD, a taxonomic system based on clear definitions and objective quantification is desirable. Therefore, the current terminology of CRPS is increasingly being used as an umbrella to replace the myriad empirical descriptions used previously. No apparent relationship exists between the degree of initial trauma and severity of RSD, but RSD generally is more frequent following minor trauma or operations.

eMedicine Related topics:
Complex Regional Pain Syndrome (Emergency Medicine)
Complex Regional Pain Syndromes (Physical Medicine and Rehabilitation)

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Pathophysiology

Reflex sympathetic dystrophy (RSD, algodystrophy, complex regional pain syndrome [CRPS]) usually follows minor trauma or surgery. It also has been associated with various clinical conditions (eg, diabetes, parkinsonism). RSD begins with spontaneous pain associated with vasomotor and sudomotor disturbances.

Bonica described the progress of severe cases in 3 stages.⁵ The acute stage of RSD is marked by pain, swelling, and warmth. Neurologic changes, such as hyperesthesia (glove and stocking distribution), incoordination, tremor, muscle spasms, and paresis, may be seen. The second dystrophic stage is characterized by cold skin with trophic changes. The final atrophic stage is manifested by muscle wasting and joint contractures. Symptoms usually are disproportionate to the cause and reflect disturbance of autonomic, sensory, and motor function.

Frequency

United States

According to various researchers, incidence of reflex sympathetic dystrophy (RSD) may be 2-17% following minor trauma or surgery. If causalgia is included in the broad definition, incidence can be as high as 32-35%. In the past, many subtle forms of RSD were missed, but with increased awareness of the condition, actual incidence may be much higher than initially thought.

International

There are no regions or population groups that have a predilection for reflex sympathetic dystrophy.

Mortality/Morbidity

Mortality associated with reflex sympathetic dystrophy (RSD) is negligible, though morbidity is extremely high. Despite good results following intravenous sympathetic blockade and intensive mobilization techniques, weakness of the extremity resulting from RSD is seen in almost 50-65% of patients, even 18-24 months following initial diagnosis. Full range of movement accompanying the above aggressive therapies is seen in 60-74% of patients. Prolonged morbidity is observed in about 50% of patients with psychiatric diathesis, workers' compensation claims, and lawsuits.⁶

Race

No particular race has a predilection for reflex sympathetic dystrophy.

Sex

Reflex sympathetic dystrophy is more common in women than in men; the male-to-female ratio is approximately 3:7. The ratio of upper extremity to lower extremity involvement is approximately 2:1. Even in children, girls are affected more frequently than boys, but peculiarly, the lower extremity is involved more frequently than the upper extremity.⁷

Age

Most patients with reflex sympathetic dystrophy (RSD) are aged 30-55 years, and the mean age is 45 years. With increasing awareness, RSD is being diagnosed in children more often; however, no studies exist pointing to a particular age distribution.

Clinical

History

Patients with reflex sympathetic dystrophy have a history of trauma, minor rather than major (eg, Colles fracture), in about 50-65% of cases. The condition may also follow a surgical procedure.

Physical

• Symptoms and signs of reflex sympathetic dystrophy
  • Pain, described as burning, throbbing, shooting, or aching
  • Hyperalgesia
  • Allodynia (perception of pain with normally innocuous stimuli, characteristic of sympathetically mediated pain [SMP])
  • Hyperpathia
• Trophic changes - Changes within 10 days of onset of RSD in 30% of the extremities affected
  • Stiffness and edema
  • Atrophy of hair, nails, and/or skin
• Autonomic function
  • Abnormal sweating, either excess or anhydrosis
  • Heat and cold insensitivity
  • Redness or bluish discoloration of the extremities

Causes

Iatrogenic causes of reflex sympathetic dystrophy (RSD) following surgery, such as carpal tunnel decompression or Dupuytren release, can be diagnosed easily.⁸ No clear etiology (including trauma) can be identified in 25-35% of cases. A detailed history can be useful to pinpoint uncommon causes of RSD.

• Potential causes of RSD
  • Trauma (about 60-65% of cases), minor (eg, Colles fracture, fracture of the metacarpals) rather than major in a significant number of cases
  • Minor surgery (eg, release of carpal tunnel for median nerve compression, release of Dupuytren contracture [see Image 1])
  • Treatment with antituberculous drugs or phenobarbital
  • Atypical causes such as pregnancy or postpartum causes, diabetes mellitus, malignant tumors, parkinsonism or other CNS disorders
• Possible contributory causes
  • Persistent mechanical irritation of peripheral nerves
  • Incomplete regeneration of the peripheral nerves
  • Abnormal neurotransmitter activity⁹
  • Nutritional deprivation secondary to abnormal arteriovenous shunting
  • Central pain imprinting
  • Genetic or familial predisposition (suggested but not proven)¹⁰
• Statistically significant associations
  • Cigarette smoking has been associated with RSD.
  • Patients frequently show high scores on schizophrenia or depression scales. Investigating and treating the so-called diathesis is worthwhile.
  • Incidence of RSD is high in wartime casualties.

Related Medscape topics:
Resource Center Schizophrenia
Resource Center Depression

Related eMedicine topics:
Carpal Tunnel Syndrome
Dupuytren Contracture
Schizophrenia
Depression

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