What is Complex Regional Pain Syndrome?


Published: 13 March 2017

Complex regional pain syndrome (CRPS) is a chronic pain condition that can last for months or even years. It is a syndrome that doesn’t discriminate, often occurring after an injury such as a fracture or sprain. It is believed to be the result of damage or malfunction to the peripheral and central nervous system. The average age of an individual with CRPS is 40 years old, with women more likely to be affected than men.
However, to discuss what CRPS is, we should first remind ourselves how the body processes pain. We as nurses come across pain constantly. Pain or nociception involves the transduction (defined as any process by which a biological cell converts one kind of signal or stimulus into another), transmission, perception and modulation of pain. Basically nociceptors respond to painful stimuli by transmitting an impulse to the spinal cord and from there to the brain stem—specifically, the thalamus. The pain impulses are processed by the brain, leaving the individual with a multidimensional experience of the pain. In CRPS, the pain impulses continue to be received by the brain regardless of whether a painful stimuli is present or not. This can make it difficult to nurse these patients as there is often no obvious cause for the pain they are experiencing. This in turn leaves the medical team at a loss for treatment options.

What Are the Symptoms of CRPS?

Pain pathways to the brain.

Nociceptors and nerve pathways to the brain.

The main symptom of CRPS is constant and relentless pain. People often describe this pain as a burning or pins and needle like sensation. It is common for the person to experience what is known as allodynia, where pain is received by a stimuli which does not normally provoke pain. Other symptoms to watch out for include:

  • Changes in temperature
  • Skin colour and swelling (caused by abnormal microcirculation from damaged nerves)
  • Loss of motor control
  • Tremors and spasms
  • Stiffness
  • Abnormal sweating pattern of the limb; and
  • Changes in nail and hair growth patterns.

How is CRPS Diagnosed?

Unfortunately, there is no diagnostic test currently available specifically for CRPS. Therefore, diagnosis is usually determined via a process of elimination. This would involve a review of the patient’s medical history and symptoms, as well as medical tests such as bone scans, CTs, and MRIs—which can also assist in diagnosis. This is where thorough pain assessments by nurses are invaluable, as it could lead to much earlier diagnosis of CRPS.

How is CRPS Treated?

It is important that an individual’s treatment encompasses a multidisciplinary approach, including input from allied health professionals. Pharmacological agents that can be used in the treatment of CRPS include:

  • Anti-inflammatory medications
  • Corticosteroids
  • Anti-convulsants
  • Anti-depressants
  • Opioids
  • NMDA receptor antagonists (e.g. ketamine)
  • Anti-hypertensive agents; and
  • A-Adrenergic antagonists (e.g. clonidine).

Individuals can also undergo spinal cord stimulation, a treatment based on the gate control theory of pain. This treatment is commonly used for a number of other conditions involving neuropathic pain. For severe CRPS, amputation can also be recommended, although this is infrequent and is not completely supported by evidence as a cure for CRPS. However, one study found that amputation positively contributed to the individuals’ lives with the risk of CRPS recurring being 24%.

Nurses have the greatest amount of contact with these patients and are subsequently in a unique position to manage the person’s pain through pharmacological and non-pharmacological methods.

CRPS Prognosis

Most adults will gradually recover from CRPS, however a small percentage of individuals continue to endure significant pain and disability for quite some time after their initial diagnosis. Children and teenagers, on the other hand, are far more likely to make a full recovery. Some studies have found that early treatment, which includes rehabilitation, is beneficial in the progression of CRPS, but more research is needed in this area.