Miscellaneous Pain Disorders that Affect Multiple Areas of the Body

Miscellaneous Pain Disorders that Affect Multiple Areas of the Body

Complex Regional Pain Syndrome (Formerly Known as Reflex Sympathetic Dystrophy or Causalgia)

Complex regional pain syndrome (CRPS) is defined as a syndrome of diffuse limb pain, often burning in nature, usually a consequence of injury or painful stimulus. CRPS was first described in 1864 during the Civil War. Most soldiers went through a normal recovery period from superficial gunshot wounds, but for some a chronic pain syndrome developed. The pain was characterized by a severe burning sensation. These soldiers would go on to have painful limbs with marked dysfunction. The distribution of pain was inconsistent, not representing a single dermatome or peripheral nerve, distinguishing it from a single-nerve injury. Skin, hair, and nail changes developed in affected limbs.1

CRPS can occur after a major event such as knee surgery or after a minor event such as bumping your shoulder. Some common precursors include trauma, surgery, inflammation, nerve injury, stroke, and immobilization. CRPS is divided into two types: Types I and II. CRPS Type I, formerly known as reflex sympathetic dystrophy, occurs when there is no known preceding nerve damage—for example, an ankle sprain. No correlation exists between the severity of the injury and the resulting painful syndrome.1 In 5% to 10% of patients, there is an absence of any painful event. Type I is more common than Type II. CPRS Type II, formerly known as causalgia (literally “hot pain”), occurs when there is apparent preceding nerve damage. The incidence after known peripheral nerve injury ranges from 1% to 14% in different series.

CRPS frequently occurs in young adults and is more common in females than males. No specific psychological factor or personality trait has been identified that predisposes individuals to the development of CRPS.

There is no definitive agreement among clinicians regarding the pathophysiology of CRPS. One of the main theories postulates that after a painful stimulus the body normally sends out a sympathetic discharge. If that discharge were to continue aberrantly without shutting down, this could lead to a sympathetic hyperdynamic state.2 A continued sympathetic hyperdynamic state would cause peripheral tissue damage, generating further sympathetic discharge and perpetuating the vicious cycle (Fig. 7-1).
Eventually this leads to both peripheral and central nervous system (CNS) changes that exist independent of the sympathetic state. In recent years, the concept of a sympathetic cause has been challenged because a subset of patients with presumed CRPS do not respond at all to sympathetic block. This led to the name change from reflex sympathetic dystrophy to CRPS.

Figure 7-1 Complex regional pain syndrome (CRPS), formerly known as reflex sympathetic dystrophy. Suspected vicious pain cycle.

Aug 29, 2016 | Posted by in Uncategorized | Comments Off on Miscellaneous Pain Disorders that Affect Multiple Areas of the Body
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