Patient's question:
Main symptoms: No pain when sitting, pain when lying downOnset time: September 2007
Laboratory test results: No tests performed
Doctor's answer:
Analysis of the condition: What is Reflex Sympathetic Dystrophy (RSD)?Answer: RSD is a multisymptomatic syndrome that primarily affects a single limb but can also spread to other limbs or parts of the body. The pathophysiological changes involve nerves, skin, muscles, blood vessels, and bones. The main characteristic is pain, which is usually mild to moderate, though it may not occur in some cases. Other symptoms vary from person to person. The sympathetic dysfunction in the affected area is typically referred to as RSD. The afferent fibers and postganglionic sympathetic fibers form a reflex loop: abnormal nociceptive stimuli can cause sympathetic afferent fibers to discharge, leading to sympathetic nervous system impulses that disrupt local homeostasis, resulting in swelling, muscle spasms, vasodilatory dysfunction, bone destruction, motor nerve dysfunction, and sweating. Among the terms used to describe these issues, "Reflex Sympathetic Dystrophy" is the most commonly used. Currently, SMP (Sympathetically Mediated Pain) is often used to replace RSD to encompass various clinical syndromes that share some features of RSD. However, many of these features are atypical. As research on naming continues to evolve, SMP is becoming increasingly prevalent, while RSD is more often considered a distinct subtype.
Guidelines for Treatment:
8. What are the treatments for RSD?
Answer: Sympathetic block is the most reliable treatment for RSD. Combining somatic and sympathetic blocks, such as brachial plexus block and epidural block, can also achieve therapeutic goals but is not diagnostic. Sympathetic block can be administered as a single procedure or through the placement of a catheter for continuous blockage of signal transmission. Occasionally, phenol or alcohol is used for sympathetic block, or sympathectomy is performed surgically. However, it is important to note that these methods can cause prolonged, though not necessarily permanent, sympathetic neuritis.
Intravenous sympathetic block may also yield some success. Guaethidine 20mg dissolved in 30ml of 0.5% lidocaine is used for the upper limb, while 40mg dissolved in 50ml of 0.5% lidocaine is used for the lower limb, administered every 2–4 days, producing effects similar to repeated sympathetic ganglion blocks. Guaethidine works by depleting norepinephrine at sympathetic nerve endings. In the U.S., intravenous guanethidine is still in the trial phase, and intravenous phenylephrine has only been successful in a limited number of patients.
Oral medications can also be effective. Prazosin and phenoxybenzamine administered orally have successfully achieved sympathetic block at nerve endings. Both are α-adrenergic blockers. Oral nonsteroidal anti-inflammatory drugs or steroid medications also have varying degrees of efficacy.
Antidepressants work by reducing nociceptive perception rather than alleviating depression. Their blocking effect is achieved through presynaptic 5-hydroxytryptamine (5-HT) and norepinephrine in the synapse. The role of antidepressants in pain perception is unclear, although it appears to function by modulating neurotransmitters. Depression symptoms are not required for diagnosis, and their therapeutic doses are much lower than those used for depression alone. They are typically taken at night to take advantage of their sedative effects, and it may take 4 weeks to determine if they are effective. Painkillers are fundamentally ineffective for RSD pain, and their side effects, tolerance, and dependence also exclude them from being considered as options.
Some patients may find success with transcutaneous electrical nerve stimulation (TENS), while others may not. Dorsal column and peripheral nerve stimulation may also hold promise for treating RSD patients, but these methods require sufficient expertise to be used effectively.
Lifestyle Management:
Regardless of the pain relief method chosen, the treatment process must include physical therapy to restore function. When treating RSD with depression, psychotherapy plays a very important role.
Hope this helps. Please provide feedback. Thank you!!