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L. A. Engel - One of the best experts on this subject based on the ideXlab platform.
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Effects of Cricothyroid Muscle contraction on upper airway flow dynamics in dogs
2016Co-Authors: T. C. Amis, A. Brancatisano, A. Tully, L. A. EngelAbstract:Effects of Cricothyroid Muscle contraction on upper airway flo
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Pharyngeal dilation associated with Cricothyroid Muscle contraction in dogs.
Journal of applied physiology (Bethesda Md. : 1985), 1992Co-Authors: T. C. Amis, A. Brancatisano, A. Tully, L. A. EngelAbstract:The mechanical function of phasic respiratory-related activity of the Cricothyroid Muscle of the larynx is poorly understood. We studied five adult cross-bred dogs (weight 14–20 kg) deeply anesthetized with pentobarbitone sodium, mechanically ventilated via a tracheostomy, and placed prone with the mouth open. Bilateral Cricothyroid Muscle contraction was induced by supramaximal electrical stimulation of the external branches of the superior laryngeal nerve. Computerized axial tomography was used to assess effects of Cricothyroid Muscle contraction. During Cricothyroid Muscle contraction, oropharyngeal (tip of epiglottis) cross-sectional area increased by 18.0 +/- 3.0% (SE) (P = 0.008), whereas combined left and right piriform recess cross-sectional area increased by 85 +/- 25% (n = 4; P = 0.02) at the midepiglottic level and by 152 +/- 37% (P = 0.01) at the base of the epiglottis. Furthermore, at the base of the epiglottis the maximum horizontal distance between the alae of the thyroid cartilage increased by 21 +/- 8% (P = 0.05). In contrast, lateral glottic diameter decreased by 52 +/- 2% (n = 4; P = 0.01), whereas dorsoventral glottic diameter increased by 18 +/- 5% (n = 4; P less than 0.02). The Cricothyroid Muscle, therefore, has the capacity to act simultaneously as a pharyngeal dilator and a glottic constrictor and thus may play a role in the control of oropharyngeal as well as laryngeal patency.
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Effects of Cricothyroid Muscle contraction on upper airway flow dynamics in dogs.
Journal of applied physiology (Bethesda Md. : 1985), 1992Co-Authors: T. C. Amis, A. Brancatisano, A. Tully, L. A. EngelAbstract:We studied the effects of Cricothyroid Muscle (CT) contraction on upper airway flow dynamics in eight prone open-mouth anesthetized dogs. Animals were mechanically ventilated via a tracheostomy while a constant airflow (Vuaw) passed through the isolated upper airway. Nasal airflow (Vn) was monitored using a nasal mask and pneumotachograph. Bilateral CT contraction was induced by electrical stimulation of the external branches of the superior laryngeal nerves. During CT contraction with Vuaw of 100–443 ml/s in the inspiratory direction, total upper airway resistance (Ruaw) fell by 49.1 +/- 5.4% (SE) while supraglottic resistance fell by 63.6 +/- 3.6%; simultaneously Vn fell by 55.3 +/- 3.8% and Vuaw increased by 7.2 +/- 1.7%. Similar results were obtained when Vuaw was in the expiratory direction. In three dogs in which the attachments of the CT to either the thyroid or cricoid cartilage were severed, superior laryngeal nerve stimulation had no systematic effect on Ruaw. Because visual assessment during CT contraction consistently revealed dilation of the piriform recesses, we suggest that CT contraction is associated with pharyngeal dilation, which in open-mouth dogs (with overlapping soft palate and epiglottis) redistributes flow to the oral route with a net reduction in Ruaw. Thus the CT may have a respiratory role as a pharyngeal dilator.
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Respiratory-related activity of Cricothyroid Muscle in awake normal humans
Journal of applied physiology (Bethesda Md. : 1985), 1991Co-Authors: John R. Wheatley, A. Brancatisano, L. A. EngelAbstract:The role of the Cricothyroid Muscle (CT) in respiration is unclear. To examine the respiratory-related electrical activity of the CT, we measured its electromyogram (EMG) and compared it with that of the alae nasi (AN) in eight healthy subjects. During quiet breathing the CT EMG phasing was inspiratory in seven subjects. This pattern was similar to the AN with respect to phasing and shape of the integrated EMG. The onset of phasic CT and AN activity related to inspiration preceded flow by 173 +/- 39 and 570 +/- 76 (SE) ms, respectively (P less than 0.01). We measured the duration from onset of phasic activity to peak of the EMG (TA) and the total cycle duration (TT). TA/TT of the CT was 0.29 +/- 0.02, similar to that of the AN (0.28 +/- 0.03). Inspiratory resistive loading, panting, and voluntary hyperventilation increased CT activity above the peak level seen during tidal breathing. Voluntary glottic closure increased CT activity to a level above tonic but below peak tidal activity. The findings suggest that the phasic electrical activity of the CT simulates predominantly that of an upper airway dilator.
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Cricothyroid Muscle responses to increased chemical drive in awake normal humans.
Journal of applied physiology (Bethesda Md. : 1985), 1991Co-Authors: John R. Wheatley, A. Brancatisano, L. A. EngelAbstract:To examine the response of the Cricothyroid Muscle (CT) to increased chemical drive, we measured its electromyogram simultaneously with that of the alae nasi (AN) in seven normal awake subjects. During both progressive hyperoxic hypercapnia and hypoxia, peak integrated inspiratory activity (moving time average, MTA) of the CT and AN increased as a power function of mean inspiratory flow (ratio of tidal volume to inspiratory time, VT/TI), given by MTA = a(VT/TI)b + c (where a, b, and c are constants). The exponent b varied from 0.009 to 3.4 among subjects but was correlated between CT and AN both during hypercapnia (r = 0.86) and hypoxia (r = 0.81). The onset of inspiratory activity of the CT and AN preceded that of inspiratory flow. Expressed as a percentage of expiratory time, the CT lead time rose from 7% at rest to 20% during hyperpnea. The corresponding values for the AN were from 22 to 52% (both P less than 0.03). Thus the pattern of response of the CT and AN is similar and related to that of the inspiratory Muscles in a curvilinear manner. The findings suggest that during chemical stimulation the electrical activity of the CT is analogous to that of the AN, an upper airway dilator.
Gregory W Randolph - One of the best experts on this subject based on the ideXlab platform.
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normative intra operative electrophysiologic waveform analysis of superior laryngeal nerve external branch and recurrent laryngeal nerve in patients undergoing thyroid surgery
World Journal of Surgery, 2013Co-Authors: Andre S Potenza, Eimear Phelan, Claudio Roberto Cernea, Cristian M Slough, Dipti Kamani, Ashlie Darr, David Zurakowski, Gregory W RandolphAbstract:Background Injury to the external branch of the superior laryngeal nerve (EBSLN) can occur during superior pole dissection in thyroid surgery; the EBSLN injury rate is reported as high as 28 % (Cernea et al., Head Neck 14:380–383, 1992). Injury to the EBSLN leads to variable symptoms that may be overlooked, but that can be significant, especially to professional speakers and singers. Intraoperative nerve monitoring (IONM) is employed widely to aid in nerve identification. We report on normative electroneuromyography (EMG) data on EBSLN-IONM and Cricothyroid Muscle (CTM) twitch response during stimulation as an aid to EBSLN identification.
Thomas V. Mccaffrey - One of the best experts on this subject based on the ideXlab platform.
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Study of vibratory pattern of the vocal folds in the excised canine larynx.
Archives of otolaryngology--head & neck surgery, 1992Co-Authors: Eriko Yanagi, Thomas V. MccaffreyAbstract:• The effect of simulated thyroarytenoid and Cricothyroid Muscle contraction on the vibratory pattern of the vocal folds was studied in the excised canine larynx. To simulate the action of the thyroarytenoid Muscle, small balloons were inflated in the paraglottic space at the level of the vocal folds. To simulate the action of the Cricothyroid Muscle, longitudinal tension was applied to the anterior commissure of the vocal folds. The photoglottographic and electroglottographic signals, sound intensity, and airflow rate were measured. This study showed that balloon inflation simulating thyroarytenoid Muscle contraction produced an elevation of frequency of vibration with a decrease in open quotient, and that an increase in longitudinal tension simulating Cricothyroid Muscle contraction produced an elevation of frequency with an increase in open quotient. Vocal resistance decreased with increasing open quotient, amplitude of the photoglottographic waveform, and the frequency of vibration. Vocal efficiency increased with increasing photoglottographic amplitude and decreased with increasing frequency. The vocal efficiency peaked when the open quotient was approximately 0.5. This study suggests that glottographic parameters may be useful in assessing the effect of intrinsic laryngeal Muscle activity on vocal efficiency and glottic resistance. ( Arch Otolaryngol Head Neck Surg. 1992;118:30-36)
Dragan Gabelica - One of the best experts on this subject based on the ideXlab platform.
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Neurophysiologic markers of primary motor cortex for laryngeal Muscles and premotor cortex in caudal opercular part of inferior frontal gyrus investigated in motor speech disorder: a navigated transcranial magnetic stimulation (TMS) study
Cognitive Processing, 2016Co-Authors: Maja Rogić Vidaković, Ana Jerković, Tomislav Jurić, Igor Vujović, Joško Šoda, Nikola Erceg, Andreja Bubić, Marina Zmajević Schönwald, Pantelis Lioumis, Dragan GabelicaAbstract:Transcranial magnetic stimulation studies have so far reported the results of mapping the primary motor cortex (M1) for hand and tongue Muscles in stuttering disorder. This study was designed to evaluate the feasibility of repetitive navigated transcranial magnetic stimulation (rTMS) for locating the M1 for laryngeal Muscle and premotor cortical area in the caudal opercular part of inferior frontal gyrus, corresponding to Broca’s area in stuttering subjects by applying new methodology for mapping these motor speech areas. Sixteen stuttering and eleven control subjects underwent rTMS motor speech mapping using modified patterned rTMS. The subjects performed visual object naming task during rTMS applied to the (a) left M1 for laryngeal Muscles for recording corticobulbar motor-evoked potentials (CoMEP) from Cricothyroid Muscle and (b) left premotor cortical area in the caudal opercular part of inferior frontal gyrus while recording long latency responses (LLR) from Cricothyroid Muscle. The latency of CoMEP in control subjects was 11.75 ± 2.07 ms and CoMEP amplitude was 294.47 ± 208.87 µV, and in stuttering subjects CoMEP latency was 12.13 ± 0.75 ms and 504.64 ± 487.93 µV CoMEP amplitude. The latency of LLR in control subjects was 52.8 ± 8.6 ms and 54.95 ± 4.86 in stuttering subjects. No significant differences were found in CoMEP latency, CoMEP amplitude, and LLR latency between stuttering and control-fluent speakers. These results indicate there are probably no differences in stuttering compared to controls in functional anatomy of the pathway used for transmission of information from premotor cortex to the M1 cortices for laryngeal Muscle representation and from there via corticobulbar tract to laryngeal Muscles.
Gayle E. Woodson - One of the best experts on this subject based on the ideXlab platform.
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Botulinum toxin in the treatment of recalcitrant mutational dysphonia.
Journal of voice : official journal of the Voice Foundation, 1994Co-Authors: Gayle E. Woodson, Thomas MurryAbstract:Mutational falsetto is the failure of the normal drop in vocal pitch at puberty. Voice therapy almost always achieves an appropriate pitch; however, in cases of failure, surgical treatment has also been recommended. We report a case of a 47-year-old man with an above-average fundamental frequency and a thin voice quality in the absence of any signs of androgen insufficiency. Laryngeal examination revealed atrophy of the vocalis Muscle. Voice therapy was unsuccessful in achieving a stable voice. Injection of 15 units of botulinum toxin into each Cricothyroid Muscle initially resulted in aphonia, but the voice returned by 1 week. Average fundamental frequency was 84 Hz at 1 week, 104 Hz at 1 month, and 100 Hz at 1 year. We hypothesize that mutational dysphonia is an habitual dysfunction of the voice with inappropriate activation of the Cricothyroid Muscle and disuse of laryngeal adductor Muscles. Temporary deactivation of the Cricothyroid Muscle enforces adoption of a more appropriate vocal mechanism. Botulinum toxin as an adjunct to voice therapy should be considered before surgical alteration of the glottis in patients with recalcitrant mutational falsetto.
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configuration of the glottis in laryngeal paralysis ii animal experiments
Laryngoscope, 1993Co-Authors: Gayle E. WoodsonAbstract:It is widely believed that in isolated recurrent laryngeal nerve paralysis, the paralyzed vocal fold assumes a median or paramedian position, due to the action of the Cricothyroid Muscle. A review of the literature reveals that support for this theory is not conclusive and, in particular, experiments indicate that the Cricothyroid Muscle does not appreciably affect vocal fold position in acute paralysis. The research in this study compares the configuration of the glottis in chronic unilateral recurrent laryngeal nerve paralysis in cats, with and without concomitant denervation of the Cricothyroid Muscle. Results indicate that vocal fold position is not determined by the Cricothyroid Muscle. Incomplete denervation of intrinsic laryngeal Muscles as well as synkinetic reinnervation appear to be significant factors in determining vocal fold position in chronic laryngeal paralysis.
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Effects of hypoxia and hypercapnia on Cricothyroid Muscle response to airway pressure.
Respiration physiology, 1992Co-Authors: Gayle E. Woodson, Frank L. PowellAbstract:Abstract We studied the effects of hypercapnia (Fl CO 2 = 0.07) and hypoxia (Fl O 2 = 0.13) on the Cricothyroid Muscle response (peak integrated CT EMG) to graded inspiratory resistance (R i ). Five anesthetized dogs spontaneously breathed through the upper airway (UAB) or a side arm of a tracheotomy cannula bypassing the larynx (TB). With room air UAB, graded increases in R i increased CT EMG, upper airway pressure change (Paw) and esophageal pressure change (Pes, indicating increased inspiratory drive), but decreased V t . For room air TB, the effects of R i were much less but still significant. Hypercapnia increased V t , f r , Pes, Paw and CT EMG for any given R i during UAB more than during TB. Hypoxia increased f r but did not increase V t , Pes, Paw, or CT EMG. The results are consistent with a model predicting CT activity as additive functions of inspiratory drive and laryngeal receptor stimulation by Paw and no direct effects of chemoreceptor stimulation on the CT, independent of those resulting from changes in inspiratory drive and upper airway pressure.