Reflex Sympathetic Dystrophy ============================ See Also: Myofascial Pain Syndromes Brachial and Cervicl Plexus Injury þ Definitions Complex Regional Pain Syndrome (CRPS) is a chronic progressive disease characterized by severe pain, swelling and changes in the skin. The International Association for the Study of Pain has divided CRPS into two types based on the presence of nerve lesion following the injury. * Type I, also known as Reflex Sympathetic Dystrophy (RSD), Sudeck's atrophy, Reflex Neurovascular Dystrophy (RND) or Algoneurodystrophy, does not have demonstrable nerve lesions. * Type II, also known as Causalgia, has evidence of obvious nerve damage. The cause of this syndrome is currently unknown. Precipitating factors include illness, injury and surgery, although there are documented cases that have no documentable injury to the original site. þ background - used to be called "causalgia" - No genetic or psychological predisposition; no evidence at all for this despite popular conception. - 50% of RSD is in people who have been casted. - C fibers and A delta fibers fire, causes genetic response from dorsal root ganglia, C-phos increases, produces more substance P and glutamate that is carried distally, and sensitize pain fibers, and also change the spinal cord function. Substance P interacts with lymphocytes and causes immune changes. - Usually associated with a local nerve traction or other injury; can often see reflex changes in the peripheral nerve distribution as well as in the sympathetic distribution that follows the vascular pattern. - according to Scientific American Medicine (1:XII:7) the root cause is likely disordered regulation of vosoactive mediators; reference: [Schott CD. An unsympathetic view of pain. Lancet 345:634, 1995.] þ early phase: - sympathetic dependent pain - edema, sometimes with ligature sign (looks like from a venous tourniquet) (is from neurogenic edema) þ second and third stage - sympathetic independent pain (sympathetic blocks don't help) - involuntary dystonic posturing + 4+5 fingers tend to flex + plantar flexed - increased collagen - autoimmune + Gardner-Diamond syndrome: autoimmune reaction against blood + tissue necrosis factor + chronic infections + depressed complement levels - Sudeck's atrophy: demineralization and osteoporosis secondary to reflex sympathetic dystrophy. It is a classic, though late RSD finding. - depression is common (though those who have their pain relieved have no more depresion than the normal population) þ Treatment if caught in phase one (still with edema), symathetic blocks and physical therapy may cut pain and interrupt the progress of RSD; best within the first three months, but even within this, the earlier the better. þ Diagnose RSD clinically with the following: 1. allodynia - mechanical allodynia (hurts to touch) - temperature allodynia (cold metal, e.g., reflex hammer, tuning fork) 2. pain not in dermatomal distribution 3. frequently, swelling - neurogenic edema - in pattern following the vascular symathetic pattern: often get a "ligature sign" looking like patient had a constricing band on the extremity. However, not completely straight; slightly angled to follow the vascular pattern. - may also see piloerection in early phases. 4. can't move: motor changes and posturing (sometimes suspected to be malingering because the patient can overcome the posturing voluntarily). 5. increased reflexes