Reflex sympathetic dystrophy associated with low lumbar disc herniation.

Reflex sympathetic dystrophy can be associated with lumbar disc herniations. Both central and peripheral neuroanatomic pathways can be implicated in the development of this syndrome. Clinical findings of vasomotor instability in the leg supported by plain roentgenograms showing osteopenia, bone scan showing increased uptake, and a favorable response with sympathetic blocks suggest the diagnosis. Symptoms should be relieved with appropriate nerve root decompression but may require, in addition, a therapeutic lumbar sympathetic blockade.