Reflex Vocal Fold Adduction in the Porcine Model: The Effects of Stimuli Delivered to Various Sensory Nerves

2008 ◽  
Vol 117 (10) ◽  
pp. 749-752 ◽  
Author(s):  
Jeong-Soo Woo ◽  
Jagdeep S. Hundal ◽  
Clarence T. Sasaki ◽  
Mikhail W. Abdelmessih ◽  
Stephen P. Kelleher
Keyword(s):  
Vocal Fold ◽  
Porcine Model ◽  
Superior Laryngeal Nerve ◽  
Sensory Nerves ◽  
Internal Branch ◽  
Pharyngeal Plexus ◽  
Closing Force ◽  
Intercostal Nerves ◽  
Glottic Closure Reflex ◽  
Stimulation Of

Objectives: The aim of this study was to identify a panel of sensory nerves capable of eliciting an evoked glottic closure reflex (GCR) and to quantify the glottic closing force (GCF) of these responses in a porcine model. Methods: In 5 pigs, the internal branch of the superior laryngeal nerve (iSLN) and the trigeminal, pharyngeal plexus, glossopharyngeal, radial, and intercostal nerves were surgically isolated and electrically stimulated. During stimulation of each nerve, the GCR was detected by laryngeal electromyography and the GCF was measured with a pressure transducer. Results: The only nerve that elicited the GCR in the 5 pigs was the iSLN. The average GCF was 288.9 mm Hg. Conclusions: This study demonstrates that the only afferent nerve that elicits the GCR in pigs is the iSLN, and that it should remain the focus of research for the rehabilitation of patients with absent or defective reflex vocal fold adduction.

Cross-Innervation of the Thyroarytenoid Muscle by a Branch from the External Division of the Superior Laryngeal Nerve

1997 ◽  
Vol 106 (7) ◽  
pp. 594-598 ◽  
Author(s):  
Sina Nasri ◽  
Joel A. Sercarz ◽  
Pouneh Beizai ◽  
Young-Mo Kim ◽  
Ming Ye ◽  
...  
Keyword(s):  
Vocal Fold ◽  
Superior Laryngeal Nerve ◽  
Laryngeal Nerve ◽  
Spasmodic Dysphonia ◽  
Clinical Implications ◽  
Motor Innervation ◽  
Vocal Fold Vibration ◽  
Adductor Spasmodic Dysphonia ◽  
Thyroarytenoid Muscle ◽  
Stimulation Of

The neuroanatomy of the larynx was explored in seven dogs to assess whether there is motor innervation to the thyroarytenoid (TA) muscle from the external division of the superior laryngeal nerve (ExSLN). In 3 animals, such innervation was identified. Electrical stimulation of microelectrodes applied to the ExSLN resulted in contraction of the TA muscle, indicating that this nerve is motor in function. This was confirmed by electromyographic recordings from the TA muscle. Videolaryngostroboscopy revealed improvement in vocal fold vibration following stimulation of the ExSLN compared to without it. Previously, the TA muscle was thought to be innervated solely by the recurrent laryngeal nerve. This additional pathway from the ExSLN to the TA muscle may have important clinical implications in the treatment of neurologic laryngeal disorders such as adductor spasmodic dysphonia.

Modulation of Laryngeal Responses to Superior Laryngeal Nerve Stimulation by Volitional Swallowing in Awake Humans

2000 ◽  
Vol 83 (3) ◽  
pp. 1264-1272 ◽  
Author(s):  
Julie M. Barkmeier ◽  
Steve Bielamowicz ◽  
Naoya Takeda ◽  
Christy L. Ludlow
Keyword(s):  
Electrical Stimulation ◽  
Superior Laryngeal Nerve ◽  
Laryngeal Nerve ◽  
Internal Branch ◽  
Increased Risk ◽  
Main Effect ◽  
Laryngeal Vestibule ◽  
Electrical Stimuli ◽  
Muscle Responses ◽  
Stimulation Of

Laryngeal sensori-motor closure reflexes are important for the protection of the airway and prevent the entry of foreign substances into the trachea and lungs. The purpose of this study was to determine how such reflexes might be modulated during volitional swallowing in awake humans, when persons are at risk of entry of food or liquids into the airway. The frequency and the amplitude of laryngeal adductor responses evoked by electrical stimulation of the internal branch of the superior laryngeal nerve (ISLN) were studied during different phases of volitional swallowing. Subjects swallowed water on command while electrical stimuli were presented to the ISLN at various intervals from 500 ms to 5 s following the command. Laryngeal adductor responses to unilateral ISLN stimulation were recorded bilaterally in the thyroarytenoid muscles using hooked wire electrodes. Early ipsilateral R1 responses occurred at 17 ms, and later bilateral R2 began around 65 ms. The muscle responses to stimuli occurring during expiration without swallowing were quantified as control trials. Responses to stimulation presented before swallowing, during the swallow, within 3 s after swallowing, and between 3 and 5 s after a swallow were measured. The frequency and amplitude of three responses (ipsilateral R1 and bilateral R2) relative to the control responses were compared across the different phases relative to the occurrence of swallowing. Results demonstrated that a reduction occurred in both the frequency and amplitude of the later bilateral R2 laryngeal responses to electrical stimulation for up to 3 s after swallowing ( P= 0.005). The amplitude and frequency of ipsilateral R1 laryngeal responses, however, did not show a significant main effect following the swallow ( P = 0.28), although there was a significant time by measure interaction ( P = 0.006) related to reduced R1 response amplitude up to 3 s after swallowing ( P = 0.021). Therefore, the more rapid and shorter unilateral R1 responses continued to provide some, albeit reduced, laryngeal protective functions after swallowing, whereas the later bilateral R2 responses were suppressed both in occurrence and amplitude for up to 3 s after swallowing. The results suggest that R2 laryngeal adductor responses are suppressed following swallowing when residues may remain in the laryngeal vestibule putting persons at increased risk for the entry of foreign substances into the airway.

I. Internal Superior Laryngeal Nerve Afferent Activity during Respiration and Evoked Vocalization in Cats

2001 ◽  
Vol 110 (7_suppl) ◽  
pp. 3-17 ◽  
Author(s):  
Keith F. Clark ◽  
Jay P. Farber
Keyword(s):  
Vocal Fold ◽  
Cell Activity ◽  
Superior Laryngeal Nerve ◽  
Nerve Fibers ◽  
Laryngeal Nerve ◽  
Afferent Activity ◽  
Internal Branch ◽  
Bipolar Electrodes ◽  
Group 5 ◽  
Vibratory Pattern

The purpose of this project was to identify and categorize patterns of activity of the internal branch of the superior laryngeal nerve during vocalization evoked by midbrain stimulation in cats anesthetized with α-chloralose. Unit activity was isolated from the cut distal end of the internal branch of the superior laryngeal nerve by means of floating bipolar electrodes that retained their contact with nerve fibers despite movement due to vocalization. The phases of respiration and vocalization were determined with a diaphragm electromyogram, a photoglottogram, and a microphone recording. Five groups of discrete afferent activities were defined according to relationships between the spike activity and the phases of vocalization. Group 1 cell activity peaked just before phonation, during expiratory airflow (n = 26). Group 2 cells (n = 19) followed a vocal fold vibratory pattern during phonation. Group 3 cell activity (n = 6) peaked during phonation, but did not follow vocal fold vibration. Group 4 cells (n = 3) were active during inspiration between phonations. Group 5 cells (n = 4) showed both inspiratory and expiratory modulation. These results indicate that laryngeal afferent activity responds to phonation-specific events during vocalization. This stereotyped afferent information might be used by the central nervous system to modulate vocalization.

Laryngeal Spasm: A Neurophysiologic Redefinition

1977 ◽  
Vol 86 (2) ◽  
pp. 150-157 ◽  
Author(s):  
Masafumi Suzuki ◽  
Clarence T. Sasaki
Keyword(s):  
Sensory Input ◽  
Superior Laryngeal Nerve ◽  
Spatial Summation ◽  
Laryngeal Nerve ◽  
Glottic Closure ◽  
Laryngeal Spasm ◽  
Afferent Nerves ◽  
Temporal And Spatial ◽  
Glottic Closure Reflex ◽  
Stimulation Of

Within the limits of standard neurophysiologic techniques, we have attempted to redefine laryngeal spasm as distinct from the glottic closure reflex. This distinction is based upon the observation that laryngeal spasm is solely mediated by the superior laryngeal nerve. Stimulation of other afferent nerves, capable of eliciting the glottic closure reflex, produces little adductor after-discharge activity that is characteristic of laryngeal spasm. In this regard, modification of output function from the adductor motoneuron aggregate by means of temporal and spatial summation of sensory input data has been described, and its characteristics further defined in response to varying ventilatory states and barbiturate levels.

Characteristics of Late Responses to Superior Laryngeal Nerve Stimulation in Humans

1992 ◽  
Vol 101 (2) ◽  
pp. 127-134 ◽  
Author(s):  
Christy L. Ludlow ◽  
Frederick Van Pelt ◽  
Junji Koda
Keyword(s):  
Muscle Activation ◽  
Superior Laryngeal Nerve ◽  
Laryngeal Nerve ◽  
Onset Latency ◽  
Internal Branch ◽  
Cricothyroid Muscle ◽  
External Branch ◽  
Muscle Responses ◽  
Thyroarytenoid Muscle ◽  
Stimulation Of

To characterize human thyroarytenoid and cricothyroid muscle responses to stimulation of the internal (sensory) and external (motor) branches of the superior laryngeal nerve (SLN), three awake subjects were studied at rest and during muscle activation with stimulation at different current levels. When only the external branch was stimulated, direct cricothyroid muscle responses were obtained without responses in either thyroarytenoid muscle. When only the internal branch was stimulated, no cricothyroid responses were obtained, but two late thyroarytenoid responses occurred (R1 and R2). The R1 response was usually ipsilateral and had a mean onset latency of 18 milliseconds, while the R2 response was bilateral and occurred between 66 and 70 milliseconds. Both responses tended to decrease in latency and increase in amplitude with increased stimulation level. The similarity of Rl to the adductor response and R2 to other late responses is discussed.

External Branch of the Superior Laryngeal Nerve Mediated Glottic Closing Force in the Porcine Model

2015 ◽  
Vol 125 (5) ◽  
pp. 421-424 ◽  
Author(s):  
David Folk ◽  
Boris Paskhover ◽  
Mikhail Wadie ◽  
Basim Wahba ◽  
Clarence T. Sasaki
Keyword(s):  
Porcine Model ◽  
Superior Laryngeal Nerve ◽  
Laryngeal Nerve ◽  
External Branch ◽  
Closing Force

Correlation between the Laryngeal Brain Stem Evoked Response and the Laryngeal Chemoreflex in the Porcine Model

1993 ◽  
Vol 102 (2) ◽  
pp. 92-99 ◽  
Author(s):  
Scott Cohen ◽  
Paul Kileny ◽  
Ramon M. Esclamado ◽  
Steven Telian
Keyword(s):  
Brain Stem ◽  
Porcine Model ◽  
Superior Laryngeal Nerve ◽  
Evoked Response ◽  
Reflex Pathways ◽  
Significant Difference ◽  
Brain Stem Evoked Response ◽  
The Brain ◽  
Supraglottic Larynx ◽  
Stimulation Of

The laryngeal brain stem evoked response (LBR) represents the neural activity involved in laryngeal reflex pathways. The laryngeal chemoreflex (LCR) is a centrally mediated response consisting of apnea and hemodynamic changes that result from laryngeal stimulation. The purpose of this study is to determine the characteristics of the LBR that are predictive of LCR severity in the porcine model. The duration of apnea resulting from stimulation of the supraglottic larynx defined LCR severity. The LBR tracings were recorded from electrodes flanking the brain stem following direct electrical stimulation of the superior laryngeal nerve. The LBR peak latencies from piglets demonstrating prolonged LCR apnea were compared to those without an exaggerated LCR response. Two LBR peak latencies demonstrated a statistically significant difference between the two piglet groups. These peak latencies appear to be indicators of susceptibility to exaggerated laryngeal reflex sensitivity. Thus, the LBR may prove useful in identifying and evaluating subjects predisposed to conditions associated with dysfunctional laryngeal reflex activity.

Central Facilitation of the Glottic Closure Reflex in Humans

2003 ◽  
Vol 112 (4) ◽  
pp. 293-297 ◽  
Author(s):  
Clarence T. Sasaki ◽  
Jagdeep Hundal ◽  
Basem Jassin ◽  
William Rosenblatt ◽  
Young-Ho Kim ◽  
...  
Keyword(s):  
Human Subjects ◽  
Superior Laryngeal Nerve ◽  
Lower Airway ◽  
Airway Protection ◽  
Minimal Alveolar Concentration ◽  
Internal Branch ◽  
Glottic Closure ◽  
Precise Understanding ◽  
Prolonged Sedation ◽  
Glottic Closure Reflex

The sphincteric function of the larynx, essential to lower airway protection, is most efficiently achieved through strong reflex adduction by both vocal cords. We hypothesize that central facilitation is an essential component of a bilateral adductor reflex and that its disturbance could result in weakened sphincteric closure. Five patients during supraglottic laryngectomy underwent evoked response laryngeal electromyography under 0.5 and 1.0 minimal alveolar concentration (MAC) isoflurane anesthesia. The internal branch of the superior laryngeal nerve was stimulated through bipolar platinum-iridium electrodes, and recording electrodes were positioned in the ipsilateral and contralateral thyroarytenoid muscles. Consistent threshold responses were obtained ipsilaterally from 0.5 to 1.0 MAC anesthesia. However, the contralateral reflex responses approached 0% in successive trials as anesthetic levels approached 1.0 MAC. In human subjects, alteration of central facilitation by deepening anesthesia abolishes the crossed adductor reflex, predisposing to a weakened glottic closure response. A precise understanding of this effect may improve the prevention of aspiration in patients emerging from prolonged sedation or under heavy psychotropic control.

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