Myelin and axon degeneration following direct current peripheral nerve stimulation: a prospective controlled experimental study.

A previous study by the authors compared pathologic changes in the mouse sciatic nerve following prolonged continuous stimulation with either pulsed or direct current. The pulsed current stimulator was found as equally effective yet far safer than the direct current (DC) stimulator. In an attempt to reproduce more accurately the clinical setting, the Ear, Nose, and Throat Device Classification Panel of the Food and Drug Administration requested a prospective, controlled study of repeated DC stimulation at one or more sites along a peripheral motor nerve. Again, repetitive DC stimulation both at one site and at multiple sites of the same nerve produced significant myelin and axon degeneration. The authors conclude that even routine use of the DC stimulator carries with it the potential for permanent nerve damage and muscle paralysis.