by Nicole Berardoni M.D, Paul Lynch M.D, and Tory McJunkin M.D
Complex regional pain syndrome (CRPS), formerly known as Reflex Sympathetic Dystrophy (RSD), is a chronic pain and sensory condition that typically affects the upper and lower extremities (arms and legs). Women are more likely to be affected than men and the disease is most common between the ages of 40-60.
The two main symptoms seen in patients with CRPS are allodynia and hyperalgesia. Other symptoms seen are swelling, skin color changes, change in hair growth, muscle atrophy, and limited range of motion. Allodynia is defined as pain produced by a stimulus that is not usually painful (an example of this would be wind touching your skin and causing pain). In hyperalgesia, a normally painful stimulus causes much more irritation and pain than would be typically produced.
The CRPS effects of allodynia and hyperalgesia are thought to be a development involving both the peripheral nervous system (PNS) and the central nervous system (CNS). Local tissue injury and inflammation activate the PNS, which sends signals through the spinal cord and to the brain. There is an increase in the excitability of neurons within the CNS so that normal inputs from the PNS begin to produce abnormal responses.
Low-threshold sensory fibers activated by light touch excites neurons in the spinal cord that normally only respond to noxious (painful), or more severe, stimuli. As a result, an input that would normally produce a harmless sensation now produces significant pain.
CRPS is most frequently seen after trauma to an arm or leg. Major traumas including car accidents, penetrating wounds, and crush injuries. Other traumas can include surgery, infection, and fractures, all of which can lead to complex regional pain syndrome.
Diagnosis of CRPS
Prospective studies confirmed an incidence of >10% of CRPS developing in patients after distal radial fractures (Schurmann 2007). Because this disease can be rare, if anyone is suspected of suffering from CRPS it is necessary to be evaluated immediately by a pain physician.
Your physician may perform a physical examination demonstrating tenderness over certain areas as well as assessing limitations in movement. The doctor will evaluate the extent of your restricted movements, the amount of pain produced, and your sensory function. Your physician may also order radiological imaging such as X-ray, CT scan, MRI, or bone scan depending on their clinical suspicion and the history obtained.
- Sympathetic Nerve Blocks: The procedure involves inserting a small, fine needle through the skin to the origins of the sympathetic nervous system. When the nerves are blocked, pain relief can be dramatic for some individuals. Procedures that focus on the face and upper extremities include the stellate ganglion block and brachial plexus nerve block. Lumbar sympathetic nerve blocks are commonly performed for CRPS in the lower extremities.
- Infusions Techniques: The procedure involves inserting a small catheter through a needle into the epidural space or directly next to affected nerves. Local anesthetic and other medicines are often given through the catheter for extended time periods. When the nerves are blocked continuously with an infusion, pain relief can be dramatic and long-lasting.
- Spinal Cord Stimulation: This method involves tiny electrodes being placed within the epidural space close to the spinal cord. The electrodes release a small electrical current to the spinal cord that inhibits pain transmission, thereby providing pain relief. A recent study noted that: ‘Ten consecutive active duty United States military personnel with newly diagnosed complex regional pain syndrome underwent early intervention with spinal cord stimulation with favorable results, including decreased pain scores and decreased opioid intake” (Verdolin 2007).
- Peripheral Nerve Stimulation: This method involves tiny electrodes being placed close to the affected nerves. The electrodes release a small electrical current that inhibits pain transmission and provides pain relief.
- Medical management: Important, pharmacological treatments for medical management of CRPS can be membrane stabilizing drugs, NSAIDs, or opiate-like medications.
- Physical therapy: In order to decrease or prevent functional limitations, physical therapy and occupational therapy are recommended as well as medical treatments (Perez 2007). Physical therapy focuses on exercising the affected limbs, improving range of motion and strength.
- Biofeedback: Patients learn to have a better awareness and familiarity with their body. As they learn to relax their body, pain relief is obtained. The psychological component of treatment can work with medical therapies to improve function and decrease the severity of the disease (Breuhl 2006).
- Others: Living with a chronic pain condition can be extremely difficult. People with CRPS have an exceptionally difficult time because others do not understand the amount of pain that they experience. Arizona Pain Specialists are aware of the emotional hardship that you face and can help you relax and de-stress by offering you coping techniques. Some of the methods they offer include therapeutic acupuncture, massage, and group therapy.
Dramatic improvements and even remission of complex regional pain syndrome are possible. The sooner treatment is initiated, the more likely dramatic improvements are obtained. Recently, the use of regional anesthetic and nerve stimulating techniques have also been found to be successful in treating CRPS (Perez 2007).
Clinical practice guideline ‘Complex regional pain syndrome type I Perez RS, Zollinger PE, Dijkstra PU, Thomassen-Hilgersom IL, Zuurmond WW, Rosenbrand CJ, Geertzen JH. Ned Tijdschr Geneeskd. 2007 Jul 28;151(30):1674-9 PMID: 17725255 Early diagnosis in post-traumatic complex regional pain syndrome Schürmann M, Gradl G, Rommel O. Orthopedics. 2007 Jun;30(6):450-6 PMID: 17598489 Clinical presentation of cutaneous manifestations in complex regional pain syndrome (type 1). Kandi B, Kaya A, Turgut D, Ozgocmen S, Cicek D. Skinmed. 2007 May-Jun;6(3):118-21 PMID: 17478989 Ten consecutive cases of complex regional pain syndrome of less than 12 months duration in active duty United States military personnel treated with spinal cord stimulation. Verdolin MH, Stedje-Larsen ET, Hickey AH. Anesth Analg. 2007 Jun; 104(6):1557-60, table of contents PMID: 17513657 Psychological and behavioral aspects of complex regional pain syndrome management. Bruehl S, Chung OY. Clin J Pain. 2006 Jun;22(5):430-7 PMID: 16772797