Transcutaneous Electrical Stimulation of the Recurrent Laryngeal Nerve in Monkeys

Abstract

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.

Keywords

larynx recurrent laryngeal nerve stimulation

Get full access to this article

View all access options for this article.

References

Sanders

Aviv

Biller

. Transcutaneous stimulation of the recurrent laryngeal nerve: A method of controlling vocal cord position. Otolaryngol Head Neck Surg 1986; 95: 152–9

Nakamura

. Movement of the larynx induced by electrical stimulation of the laryngeal nerves. In: Brewer

, ed. Research potentials in voice physiology. New York: NY State University Press, 1964: 129–35

Martensson

Skoglund

. Contraction properties of intrinsic laryngeal muscles. Acta Physiol Scand 1964; 60: 318–36

Hast

. The primate larynx: A comparative physiological study of intrinsic muscles. Acta Otolaryngol (Stockh) 1969; 67: 84–92

Sato

Yanohara

Takenouchi

Suzuki

Hisa

Hyuga

. Mechanical properties of the laryngeal muscles and biomechanics of the glottis in the dog. Jpn J Otolaryngol 1982; 85: 951–6

Kempster

Kistler

Larson

. Contraction properties of human cricothyroid and thyroarytenoid motor units. Presented at the Eighth Midwinter Research Meeting of the Association for Research in Otolaryngology, Clearwater Beach, Florida, Feb 3–7, 1985.

Suzuki

Kirchner

. Laryngeal reflex pathways related to rate and rhythm of the heart. Ann Otol Rhinol Laryngol 1967; 76: 774–80

Loeb

White

Jenkins

. Biophysical considerations in electrical stimulation of the auditory nervous system. In: Parkins

Anderson

, ed. Cochlear prosthesis: An international symposium Ann NY Acad Sci 1983; 405: 123–36

Howell

Huber

. Physiology of the communicating branch between the recurrent laryngeal nerve and superior laryngeal nerve. J Physiol (Lond) 1891; 12: 5–11

10.

Strauss

Fukuda

Kirchner

. Arterial baroreceptor fibers in the recurrent laryngeal nerve. Ann Otol Rhinol Laryngol 1973; 82: 228–34

11.

Andrew

. A laryngeal pathway for aortic baroreceptor impulses. J Physiol (Lond) 1954; 125: 325–60

12.

Van Vliet

West

. Cardiovascular responses to electrical stimulation of the recurrent laryngeal nerve in conscious toads. J Comp Physiol 1986; 156: 363–75

13.

Lemere

. Innervation of the larynx. II. Ramus anastomoticus and ganglion cells of the superior laryngeal nerve. Anat Rec 1932; 54: 389–407

14.

Bosma

. Anatomic and physiologic development of the speech apparatus. In: Tower

, ed. The nervous system. Vol 3. Human communication and its disorders. New York: Raven Press, 1975: 469–81