Superior laryngeal nerve evoked potentials: An experimental study in the rabbit

Abstract

An experimental model is described for recording laryngeal evoked potentials at the brainstem level through electrical stimulation of the superior laryngeal nerve. Rabbits were divided into two groups according to age: Group 1 consisted of 20 adults (over 6 months old), while group 2 was comprised of 1‐month‐old rabbits. Under general anesthesia, the superior laryngeal nerve was electrically stimulated and the corresponding evoked potentials were recorded by needle electrodes placed close to the dorsal and ventral aspects of the brain stem. Clear age‐related differences were observed for latency, amplitude, and morphology of the potentials. This fact suggests postnatal maturation of the nerve structures, both peripheral and central. Sectioning the superior laryngeal nerve abolished all responses. Adduction of both vocal cords was observed in conjunction with the use of stimulation.

Laryngeal Evoked Brainstem Responses in Humans: A Preliminary Study

“…Although a repeatable waveform was recorded with a combination of parameters, variation of waveforms in different subjects was noticed. A similar phenomenon was seen in animal studies 15‐21 . In addition, the possible effects of a vibrator at the neck on the other cranial nerve have not been ruled out in this preliminary study.…”

“…Studies have reported that the stimulation of the SLN in the neck is effective in animals 15‐22 as well as in humans 10,11 . Generation of LBR by a vibratory stimulation of the SLN may have an anatomic basis.…”

“…Wide clinical applications of auditory, visual, and somatosensory evoked potentials have prompted investigators to utilize evoked potentials to investigate central laryngeal motor control functions. The laryngeal evoked brainstem responses (LBRs) to electrical stimulation of the SLN have been recently recorded in animal models to observe the central motor control of laryngeal functions 15‐22 . The results of animal experiments have shown that the LBR, consisting of various peaks with consistent latencies, is a reproducible electrophysiological test.…”

“…The laryngeal evoked brainstem responses (LBRs) to electrical stimulation of the SLN have been recently recorded in animal models to observe the central motor control of laryngeal functions. [15][16][17][18][19][20][21][22] The results of animal experiments have shown that the LBR, consisting of various peaks with consistent latencies, is a reproducible electrophysiological test. In addition, the near-field recording closely matched the far-field recording in laryngeal evoked responses.…”

Superior Laryngeal Nerve Brain Stem Evoked Response in the Cat

“…Pancuronium bromide was used throughout the entire procedure to avoid possible muscular contraction artifact. Montait et al 16 stated that adequate sedation may eliminate bothersome muscular artifacts without the need of curarinic drugs or mechanical ventilation. However, curarinic drugs have been commonly used until now.…”