Selective recurrent laryngeal nerve stimulation using a penetrating electrode array in the feline model

The function of the posterior cricoarytenoid (PCA) muscle in phonation has not been well documented. To date, several electromyographic studies have suggested that the PCA muscle is not simply an abductor of the vocal folds, but also functions in phonation. This study used an in vivo canine laryngeal model to study the function of the PCA muscle. Subglottic pressure and electroglottographic, photogiottographic, and acoustic waveforms were gathered from five adult mongrel dogs under varying conditions of nerve stimulation. Subglottic pressure, fundamental frequency, sound intensity, and vocal efficiency decreased with increasing stimulation of the posterior branch of the recurrent laryngeal nerve. These results suggest that the PCA muscle not only acts to brace the larynx against the anterior pull of the adductor and cricothyroid muscles, but also functions inhibitorily in phonation by controlling the phonatory glottal width.

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Effects of Driving Pressure and Recurrent Laryngeal Nerve Stimulation on Glottal Vibration in a Constant Pressure Mode

Otolaryngology ◽

10.1016/s0194-5998(05)80780-6 ◽

1995 ◽

Vol 113 (2) ◽

pp. P127-P127

Author(s):

Andrew Verneuil ◽

Jody Kreiman ◽

Gerald Berke

Keyword(s):

Recurrent Laryngeal Nerve ◽

Nerve Stimulation ◽

Constant Pressure ◽

Laryngeal Nerve ◽

Driving Pressure

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Does Recurrent Laryngeal Nerve Stimulation at 30 Hz Produce Vocal Cord Abduction?

Otolaryngology ◽

10.1177/019459988709600621 ◽

1987 ◽

Vol 96 (6) ◽

pp. 593-593 ◽

Cited By ~ 1

Author(s):

Gerald S. Berke

Keyword(s):

Recurrent Laryngeal Nerve ◽

Vocal Cord ◽

Nerve Stimulation ◽

Laryngeal Nerve

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A Device for the Intraoperative Identification of the Recurrent Laryngeal Nerve in Piglets

Otolaryngology ◽

10.1177/019459988910000210 ◽

1989 ◽

Vol 100 (2) ◽

pp. 137-145 ◽

Cited By ~ 1

Author(s):

Dale B. Smith ◽

Edward A. Woody ◽

Margaret Richardson ◽

Herbert L. Olsen ◽

Don B. Blakeslee

Keyword(s):

Recurrent Laryngeal Nerve ◽

Nerve Stimulation ◽

Vocal Fold ◽

Human Study ◽

Injury Rate ◽

Neck Surgery ◽

Laryngeal Nerve ◽

Surgical Morbidity ◽

Adequate Model ◽

Routine Identification

The recurrent laryngeal nerve (RLN) is one of the most frequently injured nerves in head and neck surgery. Routine identification of the RLN during thyroid surgery has reduced the injury rate from 10% to less than 4%. Difficulty in identification of the RLN contributes to this surgical morbidity. Devices previously used for intraoperative identification of the RLN have failed to achieve the simplicity and reliability necessary for clinical use. This animal study uses a simple double-ballooned endotracheal tube and pressure transducer system, which assists intraoperative RLN identification through nerve stimulation and graphic documentation of vocal fold (VF) motion. Iatrogenic injury is demonstrated by a dampened stimulation-pressure tracing. The RLNs of three piglets were injured and examined, and the degree of injury was correlated with perioperative nerve stimulation patterns. The piglet proved to be an adequate model for laryngeal research. An FDA-approved multi-institutional prospective human study using this system of Identification of the RLN is in progress.

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Partial Thyroarytenoid Myectomy: An Animal Study Investigating a Proposed New Treatment for Adductor Spasmodic Dysphonia

Otolaryngology ◽

10.1177/019459989310800309 ◽

1993 ◽

Vol 108 (3) ◽

pp. 256-264 ◽

Cited By ~ 26

Author(s):

Sheldon H. Genack ◽

Peak Woo ◽

Raymond H. Colton ◽

Donna Goyette

Keyword(s):

Recurrent Laryngeal Nerve ◽

Nerve Stimulation ◽

Vocal Fold ◽

Compound Muscle Action Potential ◽

Contralateral Side ◽

Laryngeal Nerve ◽

Spasmodic Dysphonia ◽

True Vocal Cord ◽

Laryngeal Function ◽

Adductor Spasmodic Dysphonia

A new surgical procedure with potential application for the treatment of adductor spasmodic dysphonia was performed on ten rabbits to assess surgical effects on laryngeal function. Using an external approach, partial unilateral thyroarytenoid (TA) muscle excision was performed through a thyroplasty cartilage window. The contralateral side was left undisturbed as a control. The animals were studied acutely and at 3 months using videolaryngoscopy. Electrophysiologic measurements were recorded at 3 months. The procedure was well tolerated by all animals, with no postoperative infection or aspiration. At 3 months, spontaneous and evoked (recurrent laryngeal nerve stimulation) TA muscle electromyographic potentials were measurable bilaterally. TA compound muscle action potential amplitudes were reduced on the side of myectomy. The threshold of recurrent laryngeal nerve stimulation needed to produce observable vocal fold adduction was increased on the side operated on. Perioperative and long-term (3 months) videolaryngoscopy demonstrated preservation of laryngeal competence with good true vocal cord adduction. Histologic analysis with whole organ sections showed replacement of excised muscle with loose fibroareolar tissue. No evidence of muscle regeneration was observed. The vocal ligament and vocal fold mucosa were intact and undistorted in all specimens. This procedure is technically simple and appears to effectively result in a functional yet weakened TA muscle. Because myectomy includes motor unit end-plate excision, problems associated with reinnervation may be circumvented. TA myectomy may be applicable in patients with focal laryngeal dystonia to decrease muscle spasm.

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