Reflex sympathetic dystrophy syndrome (RSD) is a rare disorder involving the sympathetic nervous system. Also, called complex regional pain syndrome (CRPS), RSD is characterized by severe, chronic, and burning pain.
What is the sympathetic nervous system?
The sympathetic nervous system is a portion of the autonomic nervous system that regulates involuntary functions of the body, including constricting blood vessels, increasing heart rate, and elevated blood pressure. Abnormal and excessive responses of the sympathetic nervous system are responsible for the symptoms associated with RSD, such as swollen skin, redness, temperature changes, and vasomotor instability (perspiration).
What tests are used to diagnose complex regional pain syndrome?
Diagnosing CRPS is based on your medical history and physical examination. No single diagnostic test is used, but some include:
Sympathetic nervous system tests – Used for disturbances in the nervous system.
Bone scan – Used to detect bone changes, and involves a radioactive substance injected into the veins.
Magnetic resonance imaging (MRI) scan – Used to capture tissue changes in the body.
X-rays – Loss of minerals from the bones, which show up on x-rays in later disease stages.
What are the treatment options for RSD?
Treatment options include:
Physical therapy – Daily PT begins with whirlpool and paraffin wax baths, which are sometimes beneficial to maintain mobility. Ice/heat applications are not used because they overstimulation nerve endings and increase discomfort. In addition, they splint the affected area so the patient can rest and prevent muscle contractures.
Transcutaneous nerve stimulation (TENS) – Used to treat many people during the early stages of RSD, TENS alters nerve transmissions and blocks nerve impulses. The device is worn outside the body, and it alters nerve function.
Local and/or systemic glucocorticosteroid drugs – These are useful with RSD. They decrease inflammation around the nerve.
Intravenous infusion – Certain drugs block nerve function when given IV, such as beta blockers (propranolol), anticonvulsants (phenytoin), and vasodilators (nifedipine).
Nerve group injections – Buflomedil, lidocaine, and bupivacaine can be injected onto the nerves that supply the extremity. The stellate ganglion block is used for upper arms. The lumbar sympathetic block is used for the lower extremities, and this provides rapid relief of pain for many.
Sympathectomy – A chemical procedure used to destroy certain blood vessels, which contribute to symptoms. This allows vessels to dilate, improving blood flow and reducing pain.
Ketamine infusion – This is an anesthetic drug used for blocking certain receptors that regulate pain. Ketamine prevents the passage of ions through the body, which interrupts pain signal transduction and gives the body a chance to reboot.
Spinal cord stimulation (SCS) – The stimulator implant is inserted into the body, and wires run from the device to electrodes placed along the spinal cord.
Antidepressants – These medicines are used to help with depression, but they also work for pain. Tricyclic antidepressants include amitriptyline and nortriptyline.
Intrathecal medication pump – The pump is placed inside the body, and a tube runs from the device to the dural space near the spinal cord. These medicines include morphine, Demerol, and other opioids that alleviate pain.
Psychological counseling – Because RSD can cause serious psychological distress, counseling helps for emotional support and to learn ways to cope with problems. Frustration, anger, and denial are common co-occurring problems with chronic illness. Through counseling, the patient learns better coping skills, such as meditation and relaxation.
Topical analgesics – These include medications that reduce hypersensitivity, such as capsaicin cream (Zostrix and Capsin), as well as lidocaine patches (Lidoderm).
Biofeedback – These techniques help relax the body and relieve pain, teaching patients to learn how to cope.