Timing of Glottic Closure during Swallowing: A Combined Electromyographic and Endoscopic Analysis

2005 ◽  
Vol 114 (6) ◽  
pp. 478-487 ◽  
Author(s):  
Douglas J. Van Daele ◽  
Timothy M. McCulloch ◽  
Phyllis M. Palmer ◽  
Susan E. Langmore

Objectives: We performed a case series to enhance our understanding of the coupling between neuromuscular events and glottic closure. Methods: We performed combined flexible video laryngoscopy and electromyography in 4 healthy human subjects. Hooked-wire electrodes were placed in the superior pharyngeal constrictor, longitudinal pharyngeal, cricopharyngeus, thyroarytenoid, genioglossus, suprahyoid, and posterior cricoarytenoid muscles. A flexible endoscope tip was positioned in the oropharyngeal-hypopharyngeal region. The subjects performed multiple trials each of 10-mL normal and super-supraglottic liquid swallows. Results: Arytenoid movement consistently preceded full glottic closure and was associated with cessation of activity of the posterior cricoarytenoid muscle. In 89% of normal swallows, the glottis was partially open in the video frame before bolus passage. The maximum amount of thyroarytenoid electromyographic activity occurred during endoscopic white-out. When subjects executed a super-supraglottic swallow, early thyroarytenoid activity coincided with arytenoid contact. Conclusions: The initial medialization of the arytenoids is due to a decrease in motor tone of the posterior cricoarytenoid muscle. Full glottic closure typically occurs late in the process of swallowing, with activation of the thyroarytenoid muscle. Shifting of arytenoid medialization and glottic closure earlier in the super-supraglottic swallow indicates that glottic closure is under significant voluntary control.

1990 ◽  
Vol 99 (3) ◽  
pp. 167-174 ◽  
Author(s):  
Ian N. Jacobs ◽  
Bei-Lian Wu ◽  
Ira Sanders ◽  
Hugh F. Biller

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.


2005 ◽  
Vol 114 (4) ◽  
pp. 264-270 ◽  
Author(s):  
Pamela Reed Kearney ◽  
Eric A. Mann ◽  
Christopher J. Poletto ◽  
Christy L. Ludlow

Repeated stimulation of the laryngeal mucosa occurs during speech. Single stimuli, however, can elicit the laryngeal adductor response (LAR). Our hypothesis was that the LAR to repeated rapid air pressure stimuli is centrally suppressed in humans. Hookedwire electrodes were inserted into the thyroarytenoid and cricothyroid muscles on both sides and into the posterior cricoarytenoid muscle on one side. Pairs of air puff stimuli were presented to the mucosa over the arytenoids at pressure levels three times threshold with interstimulus intervals from 250 to 5,000 ms. Bilateral thyroarytenoid responses occurred at around 150 ms to more than 70% of the initial stimuli. With repeated presentation at intervals of 2 seconds or less, the percent occurrence decreased to less than 40% and response amplitudes were reduced by 50%. Central suppression of adductor responses to repeated air puff stimuli may allow speakers to produce voice without eliciting reflexive spasms that could disrupt speech.


2005 ◽  
Vol 114 (7) ◽  
pp. 563-572 ◽  
Author(s):  
David L. Zealear ◽  
Matthew R. Swelstad ◽  
Scott Fortune ◽  
Ricardo J. Rodriguez ◽  
Sung-Min Chung ◽  
...  

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.


1993 ◽  
Vol 75 (2) ◽  
pp. 902-911 ◽  
Author(s):  
M. Sammon ◽  
J. R. Romaniuk ◽  
E. N. Bruce

Rats breathing from reduced end-expiratory volumes (EEV) exhibit transient bursting of inspiratory airflow local to the expiratory-inspiratory transition (E-I) accompanied by increases in inspiration-to-expiration duration ratio. Continuous positive (CPAP) and negative (CNAP) airway pressures (+3 to -9 cmH2O) were applied to tracheal openings of 17 unilaterally vagotomized rats (urethan anesthetized) to evaluate the feedback mechanisms associated with these oscillatory "expiratory interrupts." Whole nerve recordings of afferent vagus (Vag) were primarily inspiratory with CPAP. As tracheal pressure was reduced in a stepwise manner, progressive decreases in inspiratory peaks and increases in activity during late expiration were seen on Vag. Single-fiber recordings correlate Vag expiratory activity with slowly adapting receptors sensitive to lung deflation. With CNAP, 1) progressively earlier onsets of activity in inspiratory muscles (e.g., diaphragm, genioglossus, posterior cricoarytenoid) were observed (increased inspiratory duration, decreased expiratory duration); oscillations at E-I developed only when expiratory peaks on Vag were significant. 2) Thyroarytenoid muscle exhibited onset of electromyographic activity that immediately succeeded onset of Vag during late expiration. When the trachea is intact, these two actions might combine to produce a respiratory pattern similar to the "grunting" often seen in newborns breathing from reduced EEVs. In contrast to larger mammals, rats rely strongly on deflation reflexes for control of E-I phase switching, presumably to aid in maintenance of an elevated EEV.


2007 ◽  
Vol 116 (8) ◽  
pp. 576-581 ◽  
Author(s):  
Wen Xu ◽  
Demin Han ◽  
Lizhen Hou ◽  
Li Zhang ◽  
Gongwei Zhao

Objectives: We sought to determine the value of laryngeal electromyography (LEMG) and evoked LEMG in the diagnosis of vocal fold immobility. Methods: We analyzed 110 cases of vocal fold immobility by their clinical manifestations and LEMG characteristics, including spontaneous potential activity, motor unit potential measurement, recruitment pattern analysis, and evoked LEMG signals. Results: With LEMG, we identified 87 patients with neuropathic laryngeal injuries. Neurogenic vocal fold immobility showed a wide variety of abnormal activity. Fibrillation potentials and positive sharp waves were found in patients with laryngeal nerve injuries. For laryngeal paralysis, there was no reaction with LEMG and evoked LEMG. For incomplete laryngeal paralysis, decreased evoked LEMG signals were also seen with delayed latency (thyroarytenoid muscle, 2.2 ± 1.0 ms, p < 01; posterior cricoarytenoid muscle, 2.4 ± 1.0 ms, p < .05) and lower amplitude (thyroarytenoid muscle, 0.9 ± 0.7 mV, p < .05; posterior cricoarytenoid muscle, 1.2 ± 1.0 mV, p < .01). Nineteen patients with vocal fold mechanical limitations generally had normal LEMG and evoked LEMG signals. Four patients with neoplastic infiltration of the laryngeal muscles demonstrated abnormal LEMG signals but nearly normal evoked LEMG signals. Conclusions: We conclude that LEMG and evoked LEMG behavior plays a crucial role in the diagnosis of vocal fold immobility. The decreased recruitment activities on LEMG and the decreased evoked LEMG signals with longer latency and lower amplitude reflect the severity of neuropathic laryngeal injury.


1989 ◽  
Vol 100 (2) ◽  
pp. 110-118 ◽  
Author(s):  
Jonathan E. Aviv ◽  
Ira Sanders ◽  
David Silva ◽  
Warren M. Kraus ◽  
Bei-Lian Wu ◽  
...  

The intent of this study was to demonstrate that the technique of transmucosal electrical stimulation of laryngeal muscles may be of clinical use in airway management. Specifically, its ability to overcome laryngospasm was evaluated. Laryngospasm was induced in eight tracheotomized dogs by hyperventilating each dog, and then applying 0.1 M ammonia to the laryngeal mucosa while administering continuous positive airway pressure (CPAP). Laryngospasm was defined by steady apposition of the vocal cords, massive electromyographic activity in the laryngeal adductor muscles, absence of such activity in the posterior cricoarytenoid muscle (PCA), and intraglottic pressure greater than 80 mm Hg. Upon transmucosal application of 10 mAmp current to the PCA bilaterally, the vocal cords abducted for the duration of the stimulus. We theorize that overcoming laryngospasm by electrostimulation involves a reflexive inhibition of the laryngeal adductors. This study provides an objective model for laryngospasm, and demonstrates that electrical manipulation of the vocal cords may have clinical relevance.


2018 ◽  
Vol 127 (11) ◽  
pp. 806-811
Author(s):  
Xinlin Xu ◽  
Pan Yang ◽  
Peiyun Zhuang ◽  
Jiao Yanchao ◽  
Ma Yanli ◽  
...  

Objective: The aim of this study was to investigate the physiological activity of intrinsic laryngeal muscle under different functional states of larynx by measuring the normal laryngeal electromyography parameters. Methods: Laryngeal electromyography (EMG) was performed in 112 patients with unilateral vocal cord movement disorder. The duration and amplitude of the motor unit potential (MUP) of the thyroarytenoid muscle (TA), posterior cricoarytenoid muscle (PCA), and cricothyroid muscle (CT) were measured when patients were asked to make a deep inspiration and phonate /i/. The normal side of the patients’ vocal chords was used as the research object. Results: (1) The motor unit potential of TA, CT, and PCA were measured when inspiration and phonating /i/. Waveforms were normal. (2) There were significant differences in duration of TA between inspiration and phonating /i/ in comfortable tone. (3) When comparing the duration and amplitude of any 2 of TA, CT, and PCA during inspiration and phonating /i/, there were significant differences in duration between CT and PCA when phonating /i/ only. There were no significant differences in any other comparisons. Conclusions: Under either deep inspiration or pronunciation, the TA, CT, and PCA muscles were activated. The TA may play a major role in phonating. The PCA may play a major role in the action of deep inspiration.


1990 ◽  
Vol 69 (1) ◽  
pp. 268-273 ◽  
Author(s):  
G. Insalaco ◽  
S. T. Kuna ◽  
F. Cibella ◽  
R. D. Villeponteaux

Intramuscular electromyographic activity of the thyroarytenoid (TA) muscle, a vocal cord adductor, was recorded in nine normal adult humans during progressive isocapnic hypoxia and hyperoxic hypercapnia. Four of the nine subjects also performed voluntary isocapnic hyperventilation. During quiet breathing of room air, the TA exhibited phasic activity in expiration and often tonic activity throughout the respiratory cycle. Both phasic and tonic TA activity progressively decreased with either increasing hypoxia or hypercapnia. Tonic activity appeared to decrease more rapidly than phasic activity with increasing chemical stimulation. At comparable tidal volume increments, the relative decrease in phasic TA activity appeared to be greater under hypoxic than under hypercapnic conditions. During voluntary isocapnic hyperventilation, phasic TA activity decreased without significant change in tonic activity. At tidal volumes approximately double those of base line, the relative decrease in TA activity was similar during both hypercapnia and voluntary hyperventilation, although differences appeared at higher tidal volumes. The results, in combination with recent findings in humans regarding the posterior cricoarytenoid muscle, a vocal cord abductor, suggest that vocal cord position is dependent on the net balance of counteracting forces not only during quiet breathing but also during involuntary and voluntary hyperpnea.


1991 ◽  
Vol 71 (3) ◽  
pp. 977-982 ◽  
Author(s):  
A. Brancatisano ◽  
D. S. Dodd ◽  
L. A. Engel

We measured the electromyographic activity of the posterior cricoarytenoid (PCA) muscle simultaneously with glottic width (dg) in five normal human subjects during hyperpnea induced by hypoxia (7% CO2 in N2) or hypercapnia (9% CO2 in 50% O2). The glottic aperture was measured during inspiration at the time corresponding to peak inspiratory PCA activity and during expiration at the time corresponding to the minimum tonic activity. During hyperpnea, peak and tonic PCA activity increased simultaneously with widening of the vocal cords in both phases of the respiratory cycle. The PCA activity during both inspiration and expiration showed a single curvilinear relationship with dg of the form dg = A - Be-k.PCA (where A, B, and k are constants) in three of the five subjects. At 50% of maximum PCA activity, dg already reached 95% of its maximum value, which was less than that recorded during a voluntary forced expiratory maneuver. The single curvilinear relationship between PCA activity and dg could be due to the length-tension relationship of the PCA muscle and/or changes in its mechanical coupling, as well as simultaneous agonist and antagonist laryngeal muscle activity during progressive chemical stimulation. Also, further widening of the glottis during forced expiration suggests recruitment of additional muscles, e.g., the arytenoideus.


1971 ◽  
Vol 14 (4) ◽  
pp. 769-775 ◽  
Author(s):  
Robert E. McGlone ◽  
Thomas Shipp

Subglottal air pressure, airflow, and electromyographic activity of four intrinsic larygeal muscles were recorded during sustained phonation in the vocal-fry and low-frequency modal registers. Nine young adult males were subjects. In modal phonation there was greater airflow, greater cricothyroid and interarytenoid muscle activity, and decreased thyroarytenoid activity than in vocal fry. No differences were found between registers for subglottal air pressure or posterior cricoarytenoid muscle activity.


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