What Is Complex Regional Pain Syndrome?
Complex regional pain syndrome (CRPS) is a very common topic among pain science and in the rehabilitation field. CRPS refers to a condition which the pain experienced is disproportionate to the degree of tissue injury, as well the tissue healing process persists beyond the normal expected timeframe. This condition got its name because the pain does not follow a typical dermatomal (sensory) nerve pattern, rather, it is regional. It usually occurs at the distal extremities and could spread to more proximal (towards the trunk) or even the other (contralateral) side of the body. According to the literature, this condition occurs three to four times more common in women than in men. More common in the upper limbs, and mostly happen to individuals at 50-70 years of age.
What Causes CRPS?
The most common reason for someone to develop CRPS is after a fracture, which happens in more than 40% of CRPS cases. In addition, sprains, contusions, crush injuries, nerve trauma, and surgeries could also predispose individuals to CRPS. Although currently there is no support in the literatures that show that specific personality or psychopathology can predict CRPS, a significant psychological burden and/or poor coping mechanism may affect how a person perceive their pain.
Patients with CRPS may be referred for an electromyography (EMG) for muscle function or a nerve conduction test for their nerve condition. And each patient may experience different signs and symptoms e.g. pain when grabbing things, altered sensation when lower the arm below the heart. But in general, clinician can form a diagnosis if patients report at least one symptom in three out of the four following categories.
1. Sensory: patients report increased sensitivity to pain/stimuli (hyperalgesia), and/or feeling pain from non-painful stimuli (allodynia).
2. Vasomotor: patients report significant change in temperature and/or skin colour in the affected area that is different than in the opposite limb.
3. Sudomotor/edema: patients report sweating and/or swelling in the affected area that is different than in the opposite limb.
4. Motor/trophic: Patients report decreased range of motion / muscle weakness / tremor / significant changes in hair, skin or nails.
What Are the Treatment Options?
Complex regional pain syndrome can be managed best by an interprofessional care team. Referral to a pain management clinic with an onsite pain specialist is ideal. Physiotherapy and occupational therapy which include mirror therapy could also benefit the condition. Pharmacological treatment provided by a pharmacist also plays an important role in the recovering process. Lastly, cognitive behavioral therapy that is offered by social service could help the individuals cope with the pain and other related stressors!
References: Guthmiller, K. B., & Varacallo, M. (2020). Complex Regional Pain Syndrome. StatPearls [Internet].