CRPS affects around 3 million people in the United States. It is more common among people ages 40 to 60, but it may affect anyone. Studies show that women are affected by RSD more often than men.
The cause of complex regional pain syndrome is not clearly understood, but scientist believe it is related to an overactive nervous system. Researchers believe that after an injury, the brain has a memory of pain, causing the nerves to continue to perceive pain. Peripheral nerve abnormalities are often found in patients with CRPS, and this involves certain nerve fibers that carry pain messages and signals to the blood vessels. In addition, CRPS affects the immune system, which contributes to many of the symptoms associated with the condition.
The symptoms of CRPS include swelling, joint tenderness, changes in skin color/temperature, loss of decreased motor function, muscle spasms, bone softening, and increased sweating. A person with this condition may have only one symptom, whereas another patient has all symptoms.
The diagnosis of CRPS is often difficult to make. There is no one laboratory test used to diagnose this condition. The doctor will conduct a detailed physical examination and take a medical history. He/she will also ask you questions about your symptoms. In order to rule out life-threatening disorders, the doctor will have to order several diagnostic tests. A thermogram is often used to measure heat emission from the surface of the body.
The pain specialist may use a combination of treatment modalities to treat CRPS. Options include:
Medications – Agents prescribed include hypnotics, analgesics, muscle relaxants, antidepressants, corticosteroids, calcium channel blockers, anticonvulsants, alpha-2 blocking drugs, and local anesthetics.
Physical therapy – This treatment focuses on range of motion exercises and mobilization of the affected limb. CRPS patients are at risk for joint injury and osteoporosis, so only a physical therapist should perform these maneuvers. The main goal of therapy is to return the patient to normal functioning. Pain relief measures offered at therapy include heat/cold treatments, ultrasound, and massage.
Spinal cord stimulation (SCS) – When other treatments fail, the pain specialist can surgically implant a spinal cord stimulator. The device is implanted in the buttock or abdomen, and wires run from the unit to electrodes positioned near the spinal cord. In one case study, SCS provide excellent pain relief for over three years.
Sympathetic nerve block – This is a procedure done to both diagnose and treat pain. Since the sympathetic nerves control sweating, blood vessel dilation, and temperature, blocking these structures results in pain relief. The different techniques include the selective sympathetic ganglion block, lumbar sympathetic block, stellate ganglion block, intravenous regional sympathetic block, and epidural clonidine injection.
Radiofrequency neurolysis – Done similar to a nerve block, studies show this procedure to have an 80-97% efficacy rate. With this procedure, radiofrequency energy is used to destroy a portion of the nerve root.
Intrathecal drug delivery – With this measure, pain medicine is delivered through the catheter to the spinal cord. This allows for bypass of the gastrointestinal tract so that long-term symptoms are relieved.