Injury to the Facial Nerve Associated with the Use of a Disposable Nerve Stimulator

Abstract

IN December 1976 a 3-cm acoustic neuroma was removed from a 37-year-old Woman. A combined suboccipital and retrolabyrinthine approach was used, anatomically sparing the facial nerve. During the last stages of tumor removal from the Internal auditory canal, the facial nerve was stimulated using a Week disposable stimulator. The face was observed to move well with stimulation, although the 2-mamp setting was required. Observation through the operating microscope at 16 power magnification showed that the stimulator actually blanched the neural sheath and bubbled the surface fluids. The stimulator was then applied to the dura, the edge of which curled as if cauterized. Six months postoperatively the patient has yet to regain facial function.Subsequent clinical applications were observed when the marginal mandibularis branch of the facial nerve was stimulated during a submaxillary gland removal. A paresis of this branch resulted, TX 77550 (Mrs Suzanne Crow). lasting four months with eventual full recovery. Another case prompted more study when, during a parotidectomy, the stimulator tip visualized through the operating microscope appeared to cauterize a small vessel.Although absolute conclusions from such observations cannot be made, several points were obvious: (1) Few observations of the tissues stimulated are made due to the usual short length of stimulation and the failure to visualize the field through the operating microscope. (2) Some careful studies should be instigated to determine any deleterious effect, if any, upon normal nerve tissue.Immediate steps were taken to employ careful use of the stimulator and to use the operating microscope whenever possible. Studies were then begun to evaluate the stimulator and its effect upon tissues.

Electrophysiologic facial nerve monitoring during parotidectomy

“…Because electrically evoked facial nerve responses during electrophysiologic facial nerve monitoring are obtained using a pulsed nerve stimulator, facial nerve injury arising from overstimulation that theoretically may occur from prolonged stimulation with a battery-powered direct current nerve stimulator is unlikely. 22 Complications of facial nerve monitoring are uncommon. A potential complication is surgeon reliance on a false-negative response with subsequent nerve division.…”

Preservation of the Marginal Mandibular Branch of the Facial Nerve Using a Plexus Block Nerve Stimulator

“…Despite early reports warning against possible neural injuries subsequent to the use of some disposable nerve stimulators, 9 a review of the literature does not yield strong argumentation against the use of such technology for nerve identification. In addition, more recently developed nerve stimulation devices appear reliable as to the consistency of their electrical output over time 10 .…”

Reliability of Disposable Intraoperative Facial Nerve Stimulators

“…The 3.0 mA produced by the Axostim may be more than is desired to apply directly to an exposed nerve. Those references describing injury to nerves and other structures involved 2.0 mA outputs, though these were constant DC stimulators, but documented safety of even prolonged contact with 2.0 mA pulsed stimulation ( 1‐3 ). Pulsed stimulators have been shown to have a wider margin of safety ( 7 ).…”

“…3. Clinical and laboratory reports document injury from stimulation to peripheral motor and facial nerves ( 1‐3 ). This study evaluated the output parameters over time of the four disposable facial nerve stimulators available commercially in the United States (Fig.…”