Complex Regional Pain Syndrome (CRPS) in Adults

Complex Regional Pain Syndrome, or CRPS, is a chronic pain condition that affects a particular region of the body, usually a distal limb (a foot, hand, leg, or arm) or one that is beyond the region of the affected by the original trauma, and which usually appears weeks after a fracture, soft tissue injury, or surgery. The general consensus is that CRPS is caused by damage done to or a malfunction of the peripheral and central nervous systems. CRPS is characterized by allodynia (extreme pain from minor stimuli), swelling, limited range of motion, skin changes, hot flashes, and bone loss.

TWO TYPES OF CRPS

Type I, or reflex sympathetic dystrophy, is the most common – affecting 90 percent of those with CRPS. Patients with Type I CRPS do not show evidence of damage to the peripheral nerves.
Type II is characterized by peripheral nerve injury.

CRPS is also often categorized into either “warm” CRPS or “cold” CRPS. Warm CRPS is distinguished by increased skin temperature at the onset of symptoms, which is suggestive of inflammation. “Cold” CRPS is characterized by decreased skin temperature at the onset of symptoms.

ORIGIN AND DEVELOPMENT

There are three possible mechanisms by which CRPS develop:

• Classic inflammation, wherein there is an increase in cytokines (which facilitate inflammatory immune response) in the affected tissue, plasma, and cerebrospinal fluid.
• Neurogenic inflammation/central sensitization, whereby the central nervous system adapts to persistent pain and become more reactive/sensitive to stimuli.
• Maladaptive changes in pain perception resulting in enhanced sensitivity to stimuli.

EPIDEMIOLOGY

It is estimated that between 5 and 26 per 100,000 individuals are affected by CRPS per year. It is also more common in women, and the highest incidence is among postmenopausal women.

• Fractures
• Crush injuries
• Sprains
• surgery

SYMPTOMS

• Pain. This is the most prominent and debilitating symptom of CRPS. CRPS pain is described as a burning, stinging, or tearing sensation deep inside the affected limb; in some cases, the pain felt is superficial. The pain can either be continuous and undulating, or paroxysmal (recurs and intensifies suddenly). Pain may worsen at night, or with limb movement, contact, stress, and changes in temperature.
• Sensory. Some patients experience hypersensitivity to pain (hyperaglesia); extreme pain from minimum stimuli (allodynia); or a diminished capacity for skin sensation and, therefore, a diminished pain response to stimuli (hypesthesia). These sensory symptoms are often felt in an extremity.
• Motor. About two-thirds of CRPS patients have pain-related motor impairments. These include reduced muscle strength in handgrip or when tiptoeing; limited limb movement caused by edema, pain, or contractures; tremors; muscle spasms; abnormal fixed limb postures; or impaired initiation of movement.
• Autonomic. The affected area usually has a different temperature, skin color, amount of sweat, and level of edema than the rest of the limb.
• Trophic. CRPS patients may experience increased hair growth, increased or decreased nail growth, skin atropy, and contraction and thickening and scarring (fibrosis) of joints and connective tissue.

STAGES OF CRPS

• Stage 1 – Either after an event or without apparent cause, the patient develops pain in a limb. The essential features include burning, throbbing pain; diffuse, uncomfortable aching; sensitivity to touch or cold; and localized edema. A change in skin color and temperature of the affected area also occurs.
• Stage 2 – This is characterized by the progression of the edema; thickening of the skin and joint tissues; muscle wasting; and the development of brawny skin. These symptoms may last between three and six months.
• Stage 3 – This is the most severe stage and is characterized by limited movement, frozen shoulder, shortening and hardening of the finger muscles; waxy skin; brittle, ridged nails; and bone loss.

EVALUATION AND DIAGNOSIS

Diagnosis of CRPS is usually made when the symptoms develop within four to six weeks after limb trauma; when symptoms are no longer fully explained by the initial trauma; and when symptoms affect the distal (lower) limb, or go beyond the region involved in the trauma.

Criteria for CRPS Diagnosis

Continuing pain, usually weeks after the original trauma
The patient must report at least one symptom in three of the following four categories:

• Sensory: hyperesthesia and/or allodynia
• Vasomotor: temperature asymmetry and/or skin color changes and/or asymmetry
• Sudomotor/edema: edema and/or sweating changes and/or asymmetry
• Motor/trophic: decreased range of motion and/or weakness, tremor, involuntary muscle contractions and/or trophic changes (hair, skin, nail)
• During examination, the patient must display at least one sign in two of the four following categories:
• Sensory: hyperalgesia and/or allodynia
• Vasomotor: temperature asymmetry and/or skin color changes and/or asymmetry
• Sudomotor/edema: edema and/or sweating changes and/or asymmetry
• Motor/trophic: decreased range of motion and/or weakness, tremor, and involuntary muscle contraction, and/or trophic changes (hair, skin, nail)

All other diagnoses have been eliminated.

Diagnostic Tools

• Bone scintigraphy or bone scan
• Plain film radiography
• Autonomic testing
• Other tests and interventions

Differential Diagnosis.

Other conditions can have the same symptoms as CRPS:

• Infection of skin, muscle, joint, or bone, which is characterized by redness, swelling, warmth, and pain.
• Compartment syndrome, wherein there is increased pressure within a body’s compartment which results in reduced blood supply to the affected tissues.
• Peripheral vascular disease, which leads to decreased blood flow to the feet and legs, resulting in cold feet with discoloration, leg cramps, or pain that is worse with activity and better with rest.
• Deep vein thrombosis, or DVT, which can lead to swelling, redness, and pain of the involved extremity.
• Peripheral neuropathy, which is usually accompanied by hypersensitivity and dystrophy of the extremities (wasting away)
• Vascular thoracic outlet syndrome, characterized by discoloration of a hand, lack of color in one or more of the fingers or the entire hand, and arm pain. These may also be accompanied by swelling, paresthesia (a burning or prickling sensation in the hands, arms, legs, or feet), and erythema (skin redness).
• Rheumatoid arthritis
• Raynaud phenomenon, characterized by the hand’s and fingers’ extreme sensitivity to cold temperature and emotional stress. The skin of the fingers have sharply demarcated color changes when exposed to cold temperatures.
• Erythromelalgia, an acquire or (rarely) inherited condition characterized by intermittent occurrence of red, hot, painful extremities, usually the legs and feet.
• Conversion disorder, wherein neurologic symptoms are present but there is no diagnosis of a neurologic disease.
• Factitious disorder, or Munchausen syndrome, wherein a patient makes up their symptoms to assume a “sick role.”

TREATMENT

The treatment of complex regional pain syndrome involves a multidisciplinary team approach. Physical therapy and occupational therapy are important for maintaining function of the affected limb. In order to help decrease the pain, certain medications such as neuropathic pain medicines (Lyrica, Nortriptyline) may be initiated to help. In addition, interventional injections such as stellate ganglion block or a lumbar sympathetic block may be utilized.

If your pain does not resolve after a brief period, contact us so that we may help diagnose the problem and treat the underlying cause.  Do not let pain persist or else it may become chronic. If you are suffering with symptoms from complex regional pain syndrome, contact us to make an appointment and see our specialist to develop a plan that will restore your quality of life.