Human pneumatic tourniquet paralysis.

A 47-year-old woman experienced loss of strength, sensation, and sweating distal to a pneumatic tourniquet applied to her upper arm during operation for a Dupuytren contracture. Electrophysiologic tests showed a severe conduction block of sensory and motor fibers, well localized to the presumed lower margin of the tourniquet, with little evidence of axonal degeneration. Reversal of block began at 5 weeks and was complete in 6 months, coincident with almost full clinical recovery. Sweating was absent before 5 weeks and then returned, accompanied by a causalgic syndrome that did not disappear until recovery from the electrophysiologic block. The findings in this case correspond closely to pneumatic tourniquet paralysis in baboons, the pathophysiology having been recently defined. The relationship of autonomic changes to the electrophysiologic block suggest a mechanism for this patient's causalgia.