Reflex sympathetic dystrophy (RSD) is also referred to as Complex Regional Pain Syndrome (CRPS), and typically occurs in the upper or lower extremities. There are two types of CRPS, CRPS 1, and CRPS 2. CRP1 occurs when pain stems from an initial painful event that may or may not be traumatic. CRPS 2 occurs when pain stems from an identifiable painful event or nerve injury. Both CRPS 1 and CRPS 2 cause continuous, intense pain out of proportion to the severity of the injury. Some common symptoms include drastic changes in the temperature and color of the skin over the affected limb or body part. The pain can be accompanied by severe burning, skin sensitivity, sweating, and swelling. Some other key features of CRPS include hyperalgesia, which is an increased sensitivity to painful stimuli, and allodynia, a painful response to a typically non-painful stimulus.
Diagnosis
CRPS is a very complex pain disorder, which can be very difficult to treat. CRPS often begins in the hand or the foot, and spreads to the affected arm or leg. CRPS can also spread to the opposite arm or leg. The cause of CRPS is unclear. There are no specific tests to diagnose CRPS, but testing can be done to rule out other diagnoses that may explain the symptoms. Blood testing can be ordered to rule out other inflammatory or rheumatologic conditions. Nerve conduction studies can also be ordered to rule out peripheral neuropathy or nerve entrapment conditions. Finally, a magnetic resonance imaging (MRI) can be ordered to rule out any soft tissue causes for the patient’s neuropathic symptoms. The diagnosis of CRPS is made in the absence of these other possible causes for the patient’s pain.
Treatment
The typical treatment for CRPS includes nerve blocks for pain reduction, desensitization treatments with a physical therapist, and medications that help with neuropathic pain. Some nerve blocks for upper extremity pain include stellate ganglion blocks, cervical epidural steroid injections, and interscalene blocks, followed by physical therapy. Injections for lower extremity CRPS include lumbar sympathetic nerve blocks, lumbar epidural steroid injections, and femoral sciatic nerve blocks, followed by physical therapy. Some medications used for CRPS include gabapentin, pregabalin, duloxetine and amitriptyline. If a patient does not respond to the physical therapy or medications, spinal cord stimulation may also be considered.
References:
- Reflex Sympathetic Dystrophy – PainDoctor.com
- Farouzanfar, T., Kemler, M., and Weber, W., et al (2004). Spinal Cord Stimulation in Complex Regional Pain Syndrome: Cervical and Lumbar Devices are Comparably Effective.
- British Journal of Anaesthesia, 2004. Kim, Philip (2004). Advanced Pain Management Techniques: An Overview of Neurostimulation. Retrieved February 16, 2010 from:
- National Institute of Neurologic Disorders and Stroke (2009). NINDS Complex Regional Pain Syndrome Information Page. Retrieved December 4, 2009 from:
- Rho R., Brewer R., and Lamer T., et al. (2002). Complex Regional Pain Syndrome. Mayo Clinic Proceedings, 2002; 77: 174-180.