Reflex Sympathetic Dystrophy
(Sudeck's Atrophy; Minor Causalgia and Posttraumatic Neuralgia)
This prototype of sympathetically mediated pain occurs following injury to bone and soft tissue. The diagnosis depends on pain associated with autonomic nervous system changes (eg, sweating or vasomotor abnormalities) and/or dystrophic changes (eg, skin or bone atrophy, hair loss, joint contractures).
Radionuclide bone scan (increased uptake), x-rays of the extremity (bone loss), and thermography (decreased skin temperature) may be useful confirmatory tests, but none need be positive for the pain syndrome to exist.
Causalgia may be viewed as a subtype of reflex sympathetic dystrophy. In this syndrome, usually partial injury to a nerve trunk (typically the median nerve above the elbow or sciatic nerve above the knee) produces severe, burning pain in the extremity. The pain usually occurs immediately or soon after the injury and in time becomes associated with the autonomic and trophic changes as described.
The exact nature of the this condition is not well understood as it does not occur in everyone following minor injuries. The possible use of hyperbaric therapy is investigative at this time.
Your friend,
Arnold Wolf MD
