Delayed bilateral median nerve injury due to low-tension electric current.

A 6-year-old boy inserted an opened metal clip into a domestic electric outlet using the thumb and index fingers of both hands. He suffered low tension electrical shock with mild cutaneous signs. After a few weeks, he developed bilateral numbness and weakness of both hands. Electrophysiologic studies revealed bilateral median nerve sensorimotor axonal loss. Low tension electric shock could have produced delayed bilateral median nerve damage indirectly via spasm and thermal coagulation of the vasa nervorum. The pinching position of the fingers, the "circuit" of the metal clip, and the low resistance due to the thinness and moistness of child's skin may account for: 1) the absence of an electrical cutaneous burn and 2) easy volume conduction of current along the neurovascular bundle containing the median nerve.