Rate and extent of early axonal degeneration of the human facial nerve.

Electrophysiologic and histologic studies on a severed human facial nerve have shown that 1) response to stimulation by electroneuronography was lost on the sixth day following injury, 2) wallerian degeneration progressed in a nonuniform "front," leaving some of the distal stump axons still viable and responsive to intraoperative stimulation 2 days following injury, and 3) the extent of proximal retrograde degeneration was far greater than to the next node of Ranvier. These findings are discussed in light of the current knowledge regarding peripheral nerve degeneration, and explanations are suggested.