Functional electrical stimulation of the left recurrent laryngeal nerve using a vagus nerve stimulator in a normal horse

The recurrent laryngeal nerve (RLN) of four anesthetized adult Macaca fascicularis monkeys was stimulated by applying current with blunt electrodes placed unilaterally and bilaterally on the intact neck skin along the tracheoesophageal groove. The stimulus consisted of 2.5- to 4.0-mA cathodal pulses, each of 1-ms duration, beginning at a frequency of 10 Hz and increasing by 10-Hz increments to 100 Hz. Unilateral stimulation from 10 to 30 Hz resulted in a graded vocal cord abduction, with the maximal glottic aperture occurring at 30 Hz. Stimulation above 30 Hz produced a graded cord adduction, with nearly complete glottic closure at 100 Hz; bilateral stimulation yielded similar results, with total glottic closure at 100 Hz. Confirmation of the RLN as mediator of this frequency-dependent cord motion was achieved by surgically isolating it and attaining identical results with direct stimulation. No cardiopulmonary alterations were observed in any trial. Transcutaneous electrical stimulation of the RLN seems to be a relatively safe, reliable, and noninvasive method of controlling vocal cord position and thereby the glottic airway in monkeys.

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Thyroid cartilage movements during breathing

Journal of Applied Physiology ◽

10.1152/jappl.1995.78.2.441 ◽

1995 ◽

Vol 78 (2) ◽

pp. 441-448 ◽

Cited By ~ 5

Author(s):

T. C. Amis ◽

A. Brancatisano ◽

A. Tully

Keyword(s):

Electrical Stimulation ◽

Recurrent Laryngeal Nerve ◽

Thyroid Cartilage ◽

Superior Laryngeal Nerve ◽

Laryngeal Nerve ◽

Electromyographic Activity ◽

Tidal Breathing ◽

Left And Right ◽

Posterior Cricoarytenoid ◽

Stimulation Of

We measured lateral (outward) thyroid cartilage displacement (TCD) of the larynx in six supine anesthetized (intravenous chloralose) dogs. Combined left and right TCDs were measured with linear transducers attached by a thread to the thyroid alae. During tidal breathing via a tracheostomy, phasic inspiratory TCD occurred in all dogs [0.66 +/- 0.2 mm (mean +/- SE)] together with phasic inspiratory electromyographic activity in the cricothyroid (CT) and posterior cricoarytenoid (PCA) muscles. During brief tracheal occlusions, TCD increased significantly to 1.27 +/- 0.2 mm (P = 0.001), accompanied by an increase of 95–115% in the peak CT and PCA electromyograms. Bilateral supramaximal electrical stimulation of the external branches of the superior laryngeal nerve (ExSLN) produced a TCD of 9.9 +/- 0.8 mm; however, similar stimulation of the recurrent laryngeal nerve (RLN) produced a TCD of only 1.33 +/- 0.1 mm (P = 0.0001). Furthermore, bilateral section of the ExSLN in five dogs significantly reduced tidal TCD by 48.7 +/- 24.4% (P < 0.05), and bilateral section of both the ExSLN and RLN resulted in slight phasic inward TCD (-0.06 +/- 0.05 mm). Thus, it appears that the activities of both the CT and RLN-innervated muscles (probably the PCA muscle) contribute to tidal breathing TCD. These findings suggest that inspiratory dilation of the hypopharynx is mediated by contractions of CT and PCA muscles.

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Synchronous Electrical Stimulation of Laryngeal Muscles: An Alternative for Enhancing Recovery of Unilateral Recurrent Laryngeal Nerve Paralysis

Journal of Voice ◽

10.1016/j.jvoice.2014.01.004 ◽

2014 ◽

Vol 28 (4) ◽

pp. 524.e1-524.e7 ◽

Cited By ~ 10

Author(s):

Alejandro Garcia Perez ◽

Xochiquetzal Hernández López ◽

Víctor Manuel Valadez Jiménez ◽

Arturo Minor Martínez ◽

Pablo Antonio Ysunza

Keyword(s):

Electrical Stimulation ◽

Recurrent Laryngeal Nerve ◽

Laryngeal Nerve ◽

Recurrent Laryngeal Nerve Paralysis ◽

Nerve Paralysis ◽

Laryngeal Muscles ◽

Laryngeal Nerve Paralysis ◽

Stimulation Of

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Electrical stimulation of the human recurrent laryngeal nerve during thyroid operation

Acta Oto-Laryngologica ◽

10.3109/00016487009131523 ◽

1970 ◽

Vol 69 (sup263) ◽

pp. 63-67 ◽

Cited By ~ 31

Author(s):

K. Flisberg ◽

T. Lindholm

Keyword(s):

Electrical Stimulation ◽

Recurrent Laryngeal Nerve ◽

Laryngeal Nerve ◽

Thyroid Operation ◽

Stimulation Of

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Functional Electrical Stimulation for the Treatment of Bilaterial Recurrent Laryngeal Nerve Paralysis

Otolaryngology ◽

10.1177/019459988609500111 ◽

1986 ◽

Vol 95 (1) ◽

pp. 47-51 ◽

Cited By ~ 8

Author(s):

Randal A. Otto ◽

William Davis

Keyword(s):

Electrical Stimulation ◽

Recurrent Laryngeal Nerve ◽

Vocal Cord ◽

Functional Electrical Stimulation ◽

Intrathoracic Pressure ◽

Laryngeal Nerve ◽

Recurrent Laryngeal Nerve Paralysis ◽

Nerve Paralysis ◽

Laryngeal Nerve Paralysis ◽

Trigger Stimulus

We have previously presented the concept of electrophysiologic pacing of bilaterally paralyzed vocal cord abductors as a solution to the difficult problem incurred in this clinical situation. Initially, we demonstrated that it was indeed feasible to electrophysiologically pace abduction of the vocal cords synchronously with respiration, employing the EMG activity of the diaphragm as a trigger stimulus. Further research has led us to evaluate other possible physiologic trigger stimuli to ascertain which of these will prove most suitable in long-term pacing studies. In this article, we will report our preliminary results, employing negative intrathoracic pressure occurring with respiration—as detected by an implanted pressure transducer as a trigger stimulus. This device was interfaced with a muscle stimulator attached to electrodes placed in the cricoarytenoid muscles in five canines whose recurrent laryngeal nerves had been sectioned bilaterally. In all animals, obvious physiologic synchrony of vocal cord abduction and a reduciton of negative inspiratory intratracheal pressure was achieved during electrical pacing. This reinforces our initial findings that it is indeed feasible to pace vocal cord abduction in bilaterial recurrent laryngeal nerve paralysis with resultant return of physiologic normality to the glottis. Thus, functional electrical stimulation offers an alternative approach to the difficult problems incurred in the patient with bilateral recurrent laryngeal nerve paralysis. It also demonstrates that physiologic negative intrathoracic pressure activity occurring with inspiration can be a trigger source.

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