Intraoperative electrophysiologic monitoring of the recurrent nerve and the facial nerve were performed with a commercially available device (Synax®), Synax® was used for auditory brainstem response (ABR) testing. Two recurrent nerves and two facial nerves were successfully monitored with this system in four patients undergoing thyroidectomy or parotidectomy.
The stimulus thresholds for the evoked responses was 0.1 mA for the four nerves. Mechanically evoked potentials with acoustic signals were also detected during the surgical procedures. Synax® monitoring was compared with a disposable neuro stimulator (Varistim®). It was concluded that Synax® monitoring of the recurrent nerves and facial nerves provides a simplified, noninvasive technique.
