Laryngeal Synkinesis: Its Significance to the Laryngologist

1989 ◽  
Vol 98 (2) ◽  
pp. 87-92 ◽  
Author(s):  
Roger L. Crumley
Keyword(s):  
Vocal Cord ◽  
Vocal Cord Paralysis ◽  
Basic Research ◽  
Laryngeal Electromyography ◽  
Bilateral Vocal Cord Paralysis ◽  
Laryngeal Function ◽  
Adductor Muscles ◽  
Posterior Cricoarytenoid Muscle ◽  
Posterior Cricoarytenoid ◽  
Intrinsic Laryngeal Muscles

Basic research and surgical cases have shown that the injured recurrent laryngeal nerve (RLN) may regenerate axons to the larynx that inappropriately innervate both vocal cord adductors and abductors. Innervation of vocal cord adductor muscles by those axons that depolarize during inspiration is particularly devastating to laryngeal function, since it produces medial vocal cord movement during inspiration. Many patients thought to have clinical bilateral vocal cord paralysis can be found to have synkinesis on at least one side. This will make the glottic airway smaller, particularly during inspiration, than would true paralysis of all the intrinsic laryngeal muscles. Patients with bilateral vocal cord paralysis should undergo laryngeal electromyography. If inspiratory innervation of the adductor muscles is present, simple reinnervation of the posterior cricoarytenoid muscle will fail. The adductor muscles also must be denervated by transection of the adductor division of the regenerated RLN.

Reinnervation of the Canine Posterior Cricoarytenoid Muscle with Sympathetic Preganglionic Neurons

1990 ◽  
Vol 99 (3) ◽  
pp. 167-174 ◽  
Author(s):  
Ian N. Jacobs ◽  
Bei-Lian Wu ◽  
Ira Sanders ◽  
Hugh F. Biller
Keyword(s):  
Vocal Cord Paralysis ◽  
Fiber Type ◽  
Electromyographic Activity ◽  
Glycogen Depletion ◽  
Bilateral Vocal Cord Paralysis ◽  
Preganglionic Neurons ◽  
Posterior Cricoarytenoid Muscle ◽  
Posterior Cricoarytenoid ◽  
The Right ◽  
Stimulation Of

This experiment investigated the reinnervation of the canine posterior cricoarytenoid (PCA) muscle with preganglionic neurons of the sympathetic nervous system. Six dogs had their right recurrent laryngeal nerve (RLN) sectioned. Four of these dogs had the sympathetic cervical trunk (SCT) implanted into the right PCA muscle, and the two remaining dogs served as denervated controls. Four months later all dogs underwent videolaryngoscopy, electromyography, and electrical stimulation of the SCT. The PCA muscles were excised, sectioned, and stained for glycogen and ATPase. All four experimental PCA muscles demonstrated electrically evoked abduction and tonic electromyographic activity. In two of the specimens, staining (ATPase and PAS) revealed areas of reinnervation with fiber type grouping and glycogen depletion. These results are consistent with the successful reinnervation of the PCA muscle. Further refinement of this technique could be of benefit to patients with bilateral vocal cord paralysis.

Laryngeal response to passively induced hypocapnia during NREM sleep in normal adult humans

1993 ◽  
Vol 75 (3) ◽  
pp. 1088-1096 ◽  
Author(s):  
S. T. Kuna ◽  
M. P. McCarthy ◽  
J. S. Smickley
Keyword(s):  
Vocal Cord ◽  
Spontaneous Breathing ◽  
Nrem Sleep ◽  
Normal Adult ◽  
Positive Pressure ◽  
Adductor Muscles ◽  
Posterior Cricoarytenoid Muscle ◽  
Adult Humans ◽  
Inspiratory Activity ◽  
Posterior Cricoarytenoid

Passively induced hypocapnia in animals activates vocal cord adductor muscles and decreases the glottic aperture. The purpose of this study was to determine if passively induced hypocapnia has similar effects in normal adult humans in stage 3/4 non-rapid-eye-movement (NREM) sleep. Hypocapnia was induced by hyperventilating the subjects with a positive-pressure ventilator via a nose mask. At hypocapnic levels below the CO2 apneic threshold, abrupt cessation of mechanical ventilation was followed by an apnea. In protocol 1, intramuscular electromyographic recordings of intrinsic laryngeal muscles were obtained in nine subjects. Activity of the posterior cricoarytenoid muscle, a vocal cord abductor, disappeared during passive hyperventilation. The muscle remained electrically silent during an apnea, but phasic inspiratory activity reappeared with the first respiratory effort. The thyroarytenoid and arytenoideus muscles, both vocal cord adductors, were electrically silent during spontaneous breathing in NREM sleep. Hypocapnia was frequently associated with activation of both adductor muscles. Once activated, the adductor muscles remained tonically active during an ensuring apnea. In protocol 2, a fiber-optic scope was advanced transnasally into the hypopharynx to determine glottic aperture size during passively induced hypocapnic apnea. In the seven subjects who achieved stable NREM sleep, the glottic aperture during an apnea was smaller than at any time throughout the respiratory cycle during spontaneous breathing just before positive-pressure ventilation. The results suggest that the decrease in glottic aperture observed during an induced hypocapnic apnea is due to suppression of the posterior cricoarytenoid muscle and/or activation of vocal cord adductor muscles.

Delayed Reinnervation of Unilateral Vocal Cord Paralysis in Dogs

1981 ◽  
Vol 89 (4) ◽  
pp. 608-612 ◽  
Author(s):  
G. David Neal ◽  
Charles W. Cummings ◽  
Dwight Sutton
Keyword(s):  
Vocal Cord ◽  
Vocal Cord Paralysis ◽  
Histologic Examination ◽  
Implantation Technique ◽  
Posterior Cricoarytenoid Muscle ◽  
Chronic Denervation ◽  
Posterior Cricoarytenoid ◽  
Unilateral Vocal Cord Paralysis

The neuromuscular implantation technique for rehabilitation of unilateral vocal cord paralysis was performed in four dogs at the time of denervation and in six dogs after varying intervals of chronic denervation. As would be expected, the chronically denervated animals did not achieve the vocal cord excursion of the acute denervations, but some return of motion was noted even after six months. Histologic examination of the posterior cricoarytenoid muscle was correlated with the return of movement.

Laryngeal Electromyography Findings in Idiopathic Congenital Bilateral Vocal Cord Paralysis

1996 ◽  
Vol 105 (3) ◽  
pp. 207-212 ◽  
Author(s):  
Robert G. Berkowitz
Keyword(s):  
Vocal Cord ◽  
Vocal Cord Paralysis ◽  
Prognostic Significance ◽  
Early Recovery ◽  
Bilateral Vocal Cord Paralysis ◽  
Abductor Paralysis ◽  
Significant Clinical Improvement ◽  
Posterior Cricoarytenoid ◽  
Laryngeal Emg

Children with idiopathic congenital bilateral vocal cord paralysis (BVCP) were investigated by electromyography (EMG) of the posterior cricoarytenoid and thyroarytenoid muscles to determine whether laryngeal EMG findings had diagnostic or prognostic significance. Four children between 3 weeks and 33 months of age were studied. Three had abductor paralysis and were tracheostomy-dependent, while the fourth had adductor paralysis requiring a feeding gastrostomy. Two of these patients also had other anomalies. Motor unit potentials showing phasic bursts with respiration were found in all four cases, while three children developed a full interference pattern on lightening of the anesthetic. Follow-up for between 37 and 52 months showed no significant clinical improvement in any of the patients. While the diagnosis of idiopathic congenital BVCP can represent a heterogeneous group of conditions, the findings suggest that normal laryngeal EMG findings may be a feature of idiopathic congenital BVCP but do not imply a favorable prognosis for early recovery. They may, however, have implications to explain the likely site of lesion in idiopathic congenital BVCP.

Nerve-Muscle Pedicle Reinnervation of the Larynx: Avoiding Pitfalls and Complications

1982 ◽  
Vol 91 (4) ◽  
pp. 440-444 ◽  
Author(s):  
Harvey M. Tucker
Keyword(s):  
Vocal Cord Paralysis ◽  
Preoperative Evaluation ◽  
Neck Surgery ◽  
Patient Evaluation ◽  
Postoperative Evaluation ◽  
Bilateral Vocal Cord Paralysis ◽  
Posterior Cricoarytenoid Muscle ◽  
Posterior Cricoarytenoid ◽  
Nerve Muscle

The procedure for reinnervation of bilateral vocal cord paralysis using nerve-muscle pedicle technique has now been well established in the literature. Moreover, several other centers have reported success using this technique. Nevertheless, the author is aware that a significant number of well trained otolaryngology-head and neck surgery practitioners have found difficulty in making the procedure successful in their hands. It therefore seems appropriate to address those aspects of patient evaluation, technique and postoperative follow-up that have brought a satisfactory level of success in the author's hands. Preoperative evaluation of patients is the cornerstone of success in nerve-muscle pedicle reinnervation. It is imperative that the larynx be properly evaluated to be certain that there does not exist fixation or ankylosis of one or both arytenoids in addition to paralysis. Clearly if such fixation exists, nerve-muscle pedicle reinnervation cannot be successful. Several pertinent aspects of technique with special reference to the identification of the proper nerve-muscle pedicle, the design of the pedicle and proper identification of the posterior cricoarytenoid muscle will be discussed. Postoperative evaluation of patients may be difficult for inexperienced operators. The author has seen at least three patients who were operated on by other surgeons who were referred because of “failure” of the procedure only to find that all three of them were successfully reinnervated with satisfactory motion of the reinnervated cord for reasonable day-to-day activity. All aspects of postoperative evaluation and management will be discussed as well.

A Study of Vocal Cord Laterofixation during Ejnell's Technique for Bilateral Vocal Cord Paralysis.

2002 ◽  
Vol 53 (1) ◽  
pp. 1-5
Author(s):  
Etsuyo Tamura ◽  
Satoshi Kitahara ◽  
Naoyuki Kohno ◽  
Masami Ogura
Keyword(s):  
Vocal Cord ◽  
Vocal Cord Paralysis ◽  
Bilateral Vocal Cord Paralysis
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