Function of the Posterior Cricoarytenoid Muscle in Phonation: In vivo Laryngeal Model

1993 ◽  
Vol 109 (6) ◽  
pp. 1043-1051 ◽  
Author(s):  
Hong-Shik Choi ◽  
Gerald S. Berke ◽  
Ming Ye ◽  
Jody Kreiman
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Fundamental Frequency ◽  
Nerve Stimulation ◽  
Sound Intensity ◽  
Vocal Folds ◽  
Laryngeal Nerve ◽  
Posterior Cricoarytenoid Muscle ◽  
Posterior Cricoarytenoid ◽  
Stimulation Of

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.

Measurement of Young's Modulus in the in Vivo Human Vocal Folds

1993 ◽  
Vol 102 (8) ◽  
pp. 584-591 ◽  
Author(s):  
Quang T. Tran ◽  
Bruce R. Gerratt ◽  
Gerald S. Berke ◽  
Jody Kreiman
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Young’S Modulus ◽  
Nerve Stimulation ◽  
Vocal Fold ◽  
Young's Modulus ◽  
Vocal Folds ◽  
Laryngeal Nerve ◽  
New Device ◽  
Vocal Fold Vibration

Currently, surgeons have no objective means to evaluate and optimize results of phonosurgery intraoperatively. Instead, they usually judge the vocal folds subjectively by visual inspection or by listening to the voice. This paper describes a new device that measures Young's (elastic) modulus values for the human vocal fold intraoperatively. Physiologically, the modulus of the vocal fold may be important in determining the nature of vocal fold vibration in normal and pathologic states. This study also reports the effect of recurrent laryngeal nerve stimulation on Young's modulus of the human vocal folds, measured by means of transcutaneous nerve stimulation techniques. Young's modulus increased with increases in current stimulation to the recurrent laryngeal nerve. Ultimately, Young's modulus values may assist surgeons in optimizing the results of various phonosurgeries.

Sensitivity and Specificity of Intraoperative Recurrent Laryngeal Nerve Stimulation in Predicting Postoperative Nerve Paralysis

2002 ◽  
Vol 111 (11) ◽  
pp. 1005-1007 ◽  
Author(s):  
Randal A. Otto ◽  
C. Spencer Cochran
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Sensitivity And Specificity ◽  
Nerve Stimulation ◽  
Predictive Value ◽  
Injury Rate ◽  
Laryngeal Nerve ◽  
Nerve Paralysis ◽  
Posterior Cricoarytenoid Muscle ◽  
The Status ◽  
Posterior Cricoarytenoid

Bilateral recurrent laryngeal nerve (RLN) paralysis after thyroidectomy is infrequent, but serious when it occurs. Intraoperative knowledge of the status of the nerve after dissection could potentially provide the surgeon with important decision-making information. The current study examines the sensitivity and specificity of intraoperative stimulation of the RLN during thyroid surgery for predicting postoperative RLN deficits. Eighty-one RLNs in 55 patients were identified to be at risk of injury during thyroidectomy or parathyroidectomy performed between January 1998 and February 2000. Intraoperative determination of RLN function was evaluated with a disposable nerve stimulator (Xomed, Jacksonville, Florida) set at 0.5 mA. Injury was assessed by palpating for a contraction of the posterior cricoarytenoid muscle while the stimulus was applied. Postoperative assessment of RLN integrity was determined by using indirect or direct laryngoscopy to visualize vocal fold mobility. Nine RLNs failed to elicit a posterior cricoarytenoid contraction after nerve stimulation, and 4 RLNs were determined to be deficient in the postoperative evaluation. The calculated sensitivity and specificity were 75% and 92.2% with a positive predictive value of 33.3% and negative predictive value of 98.6%. The RLN injury rate was 4.94%. We conclude that intraoperative RLN stimulation is a relatively safe and useful method of determining what RLN function will be after thyroid or parathyroid surgery.

Effects of Recurrent Laryngeal Nerve Transection and Vagotomy on Respiratory Contraction of the Cricothyroid Muscle

1989 ◽  
Vol 98 (5) ◽  
pp. 373-378 ◽  
Author(s):  
Gayle E. Woodson
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Superior Laryngeal Nerve ◽  
Upper Airway ◽  
Vocal Folds ◽  
Laryngeal Nerve ◽  
Electromyographic Activity ◽  
Airway Occlusion ◽  
Cricothyroid Muscle ◽  
Bilateral Vagotomy ◽  
Posterior Cricoarytenoid

The cricothyroid muscle (CT) appears to be an accessory muscle of respiration. Phasic inspiratory contraction is stimulated by increasing respiratory demand. Reflex activation of the CT may be responsible for the paramedian position of the vocal folds, and hence airway obstruction, in patients with bilateral recurrent laryngeal nerve (RLN) paralysis. Previous research has demonstrated the influence of superior laryngeal nerve (SLN) afferents on CT activity. The present study addresses the effects of vagal and RLN afferents. Electromyographic activity of the CT and right posterior cricoarytenoid muscle was monitored in anesthetized cats during tracheotomy breathing and in response to tracheal or upper airway occlusion in the intact animal. This was repeated following left RLN transection, bilateral vagotomy, and bilateral SLN transection. Vagotomy abolished CT response to tracheal occlusion and markedly reduced the response to upper airway occlusion. Vocal fold position following RLN transection appeared to correlate with CT activity; however, observed changes were minor.

Surgical Anatomy of the Recurrent Laryngeal Nerve: Implications for Laryngeal Reinnervation

2003 ◽  
Vol 112 (5) ◽  
pp. 434-438 ◽  
Author(s):  
Edward J. Damrose ◽  
Robert Y. Huang ◽  
Gerald S. Berke ◽  
Ming Ye ◽  
Joel A. Sercarz
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Adductor Muscle ◽  
Surgical Anatomy ◽  
Laryngeal Nerve ◽  
Main Trunk ◽  
Posterior Cricoarytenoid Muscle ◽  
Laryngeal Reinnervation ◽  
Human Cadavers ◽  
Muscle Groups ◽  
Posterior Cricoarytenoid

Functional laryngeal reinnervation depends upon the precise reinnervation of the laryngeal abductor and adductor muscle groups. While simple end-to-end anastomosis of the recurrent laryngeal nerve (RLN) main trunk results in synkinesis, functional reinnervation can be achieved by selective anastomosis of the abductor and adductor RLN divisions. Few previous studies have examined the intralaryngeal anatomy of the RLN to ascertain the characteristics that may lend themselves to laryngeal reinnervation. Ten human larynges without known laryngeal disorders were obtained from human cadavers for RLN microdissection. The bilateral intralaryngeal RLN branching patterns were determined, and the diameters and lengths of the abductor and adductor divisions were measured. The mean diameters of the abductor and adductor divisions were 0.8 and 0.7 mm, while their mean lengths were 5.7 and 6.1 mm, respectively. The abductor division usually consisted of one branch to the posterior cricoarytenoid muscle; however, in cases in which multiple branches were seen, at least one dominant branch could usually be identified. We conclude that the abductor and adductor divisions of the human RLN can be readily identified by an extralaryngeal approach. Several key landmarks aid in the identification of the branches to individual muscles. These data also indicate the feasibility of selective laryngeal reinnervation in patients who might be candidates for laryngeal transplantation after total laryngectomy.

Thyroid cartilage movements during breathing

1995 ◽  
Vol 78 (2) ◽  
pp. 441-448 ◽  
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.

Effects of Driving Pressure and Recurrent Laryngeal Nerve Stimulation on Glottic Vibration in a Constant Pressure Model

1996 ◽  
Vol 115 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Andrew Verneuil ◽  
Jody Kreiman ◽  
Kevin Kevorkian ◽  
Ming Ye ◽  
Bruce R. Gerratt ◽  
...  
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Fundamental Frequency ◽  
Nerve Stimulation ◽  
Constant Pressure ◽  
Muscular Contraction ◽  
Laryngeal Nerve ◽  
Driving Pressure ◽  
Laryngeal Function ◽  
Flow Models ◽  
Dependent Variables

Glottic phonatory parameters have been studied in constant flow models; however, the lung-thorax system is better viewed as a constant pressure source. Adjusting the driving pressure and recurrent laryngeal nerve stimulation as independent variables, rather than as dependent variables, may provide a more physiologic understanding of laryngeal function and glottic parameters, including subglottic pressure, airflow, fundamental frequency, and glottic area. In three dogs subglottic pressure and airflow were measured in two separate conditions: with constant recurrent laryngeal nerve stimulation and varying driving pressure, and with constant driving pressure and varying recurrent laryngeal nerve stimulation. Videostroboscopic measures on four dogs assessed glottic areas with constant recurrent laryngeal nerve stimulation at different driving pressures. With constant recurrent laryngeal nerve stimulation, increasing driving pressure had no effect on glottic areas, whereas subglottic pressure, fundamental frequency, and airflow increased significantly. However, changes in subglottic pressure were minimal in comparison with changes in driving pressure. At constant driving pressure, increasing recurrent laryngeal nerve stimulation increased subglottic pressure and fundamental frequency and decreased airflow. These findings suggest that during phonation subglottic pressure is primarily dependent on recurrent laryngeal nerve stimulation and laryngeal muscular contraction, but not on lung driving pressure.

Function of the Interarytenoid Muscle in a Canine Laryngeal Model

1994 ◽  
Vol 103 (12) ◽  
pp. 975-982 ◽  
Author(s):  
Sina Nasri ◽  
Jody Kreiman ◽  
Pouneh Beizai ◽  
Michael C. Graves ◽  
Joel A. Sercarz ◽  
...  
Keyword(s):  
Fundamental Frequency ◽  
Nerve Stimulation ◽  
Vocal Fold ◽  
Superior Laryngeal Nerve ◽  
Canine Model ◽  
Laryngeal Nerve ◽  
Activity Measurement ◽  
Nerve Branch

The interarytcnoid (IA) muscle has rarely been studied in the living larynx. In this work, the role of the IA muscle in phonation was studied in three dogs by means of an in vivo phonation model. The isolated action of the IA muscle was studied by sectioning and stimulating its nerve branch. As IA activity increased, subglottic pressure increased significantly until a plateau was reached. In the absence of superior laryngeal nerve stimulation, the fundamental frequency rose with increasing IA activity. In the presence of superior laryngeal nerve stimulation, however, no significant change in fundamental frequency was observed with increasing IA activity. Measurement of adductory force demonstrated that the IA muscle adducts primarily the posterior vocal fold. In this canine model, phonation was not possible without IA stimulation, owing to a large posterior glottic chink.

Evoked Electromyographic Technique for Quantitative Assessment of the Innervation Status of Laryngeal Muscles

2005 ◽  
Vol 114 (7) ◽  
pp. 563-572 ◽  
Author(s):  
David L. Zealear ◽  
Matthew R. Swelstad ◽  
Scott Fortune ◽  
Ricardo J. Rodriguez ◽  
Sung-Min Chung ◽  
...  
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Quantitative Information ◽  
Laryngeal Nerve ◽  
Noninvasive Technique ◽  
Laryngeal Muscles ◽  
Phase Study ◽  
Posterior Cricoarytenoid Muscle ◽  
Muscle Innervation ◽  
Posterior Cricoarytenoid ◽  
Thyroarytenoid Muscle

Objectives: The purpose of this study was to develop a minimally invasive, noninjurious evoked electromyographic technique that could accurately quantitate the level of innervation of laryngeal muscles with recurrent laryngeal nerve stimulation. Methods: A four-phase study was conducted in 24 canines, including 1) identification of the best stimulation-recording configuration, 2) statistical analysis of sensitivity and accuracy, 3) evaluation of safety, and 4) identification of the laryngeal muscle(s) that contribute to the evoked response. Results: The results demonstrated that an entirely noninvasive technique is not feasible. The stimulating cathode must be invasive to ensure discrete activation of the recurrent laryngeal nerve, whereas both recording electrodes should remain on the surface with one overlying the thyroid ala. This configuration proved to be highly accurate, with an error rate of only 6% to 7%, and with sensitivity sufficient to detect a signal in a nerve with fewer than 1% of the axons intact. There was no evidence of nerve injury in any animal over the course of 350 stimulus needle penetrations. By use of neuromuscular blockade to identify those muscles generating the surface response, the thyroarytenoid muscle was found to be the primary contributor, whereas the posterior cricoarytenoid muscle was uninvolved. Conclusions: This evoked electromyographic technique could provide quantitative information regarding the extent of muscle innervation during denervation and regeneration in case of laryngeal paralysis.

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