Effect of denervation on primate laryngeal muscles: a morphologic and morphometric study

1986 ◽  
Vol 100 (5) ◽  
pp. 553-560 ◽  
Author(s):  
V. Sahgal ◽  
M. H. Hast
Keyword(s):  
Size Variation ◽  
Morphometric Study ◽  
Type I ◽  
Type Ii ◽  
Laryngeal Muscles ◽  
Fibre Size ◽  
Show Evidence ◽  
Posterior Cricoarytenoid ◽  
Intrinsic Laryngeal Muscles ◽  
Thyroarytenoid Muscle

AbstractPrimate intrinsic laryngeal muscles studied consisted of Type I and Type II fibres. Type II fibres were larger than Type I fibres. The coefficient of variance of these muscles suggested that the fibre-size variation was similar in all of these muscles. Denervation resulted in shrinking of Type II fibres at two weeks in all the muscles, while at four weeks the thyroarytenoid showed an inflammatory reaction and far greater reduction in size than the other muscles. At eight weeks, however, all the muscles were fibrosed. We conclude that laryngeal muscles begin to show evidence of denervation at two weeks and are fibrosed in eight weeks. The thyroarytenoid muscle showed inflammatory degeneration, while the posterior cricoarytenoid and cricothyroid muscles showed classical changes of denervation. These findings should have clinical significance in the timing of reinnervation procedures.

Intrinsic Laryngeal Muscle Activity in a Spastic Dysphonia Patient

1985 ◽  
Vol 50 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Thomas Shipp ◽  
Krzysztof Izdebski ◽  
Charles Reed ◽  
Philip Morrissey
Keyword(s):  
Muscle Activity ◽  
Emg Activity ◽  
Muscle Paralysis ◽  
Normal Morphology ◽  
Laryngeal Muscles ◽  
Laryngeal Muscle ◽  
Intrinsic Laryngeal Muscle ◽  
Posterior Cricoarytenoid ◽  
Recurrent Laryngeal Nerves ◽  
Intrinsic Laryngeal Muscles

EMG activity from four intrinsic laryngeal muscles (thyroarytenoid, posterior cricoarytenoid, interarytenoid, and cricothyroid) was obtained from one female spastic dysphonia patient while she performed a variety of speech and nonspeech tasks. These tasks were performed before and during a period of temporary unilateral laryngeal muscle paralysis. In the nonparalyzed condition, adductory muscle activity showed intermittent sudden increases that coincided with momentary voice arrests. These muscle patterns and accompanying voice interruptions were not present either when speech was produced in falsetto register or at anytime during the paralysis condition. The data suggest that individuals with this type of spastic dysphonia have normal morphology of recurrent laryngeal nerves and intrinsic laryngeal muscles, which means that the triggering mechanism(s) for spastic dysphonia symptoms must be located at some point neurologically upstream from the larynx.

scholarly journals Observations on Normal Skeletal Muscle of Mature Dogs: A Cytochemical, Histochemical, and Morphometric Study

1982 ◽  
Vol 19 (6) ◽  
pp. 577-595 ◽  
Author(s):  
K. G. Braund ◽  
J. A. Mcguire ◽  
C. E. Lincoln
Keyword(s):  
Skeletal Muscle ◽  
Size Variation ◽  
Biceps Femoris ◽  
Morphometric Study ◽  
Type I ◽  
Triceps Brachii ◽  
Diameter Range ◽  
Age Related ◽  
Mean Diameter ◽  
Fiber Size

Cytochemical, histochemical, and morphometric features of skeletal muscle were evaluated in 140 specimens from five appendicular muscles of 28 dogs which were free of neuromuscular disease. Dogs ranged from six months to 15 years of age. Evidence of degeneration and regeneration, cell reactions and architectural change was found but with an incidence of less than 1% of the total myofiber population in any muscle. The number of fibers with internal nuclei never exceeded 1%. The only changes that appeared to be age-related were fiber size variation associated with the presence of small angular type IIA fibers in muscles of dogs seven years of age and older. Percentages of type I, type IIA, and type IIC fibers remained relatively constant in the various muscles in the age range examined. Type I fibers predominated in medial head of triceps brachii and superficial digital flexor muscles, whereas type IIA fibers were more numerous in biceps femoris and long head of triceps brachii muscles. An approximately equal ratio was found in gastrocranius muscles. In any given muscle, type IIC fibers represented less than 2% of the fibers. Statistically significant differences were found in values for fiber size between groups of dogs weighing more than (mean diameter range = 40 to 50 μm) and less than (mean diameter range = 30 to 40 μm) 15 kilograms.

Repeatedly Successful Closure of the Larynx for the Treatment of Chronic Aspiration with the Use of Botulinum Toxin A

1996 ◽  
Vol 105 (7) ◽  
pp. 521-524 ◽  
Author(s):  
Claus A. Pototschnig ◽  
Hans E. Eckel ◽  
Imma Schneider ◽  
Walter F. Thumfart
Keyword(s):  
Botulinum Toxin ◽  
Botulinum Toxin A ◽  
Toxin A ◽  
Lower Cranial Nerve ◽  
Laryngeal Muscles ◽  
Cricopharyngeal Muscle ◽  
Speech Rehabilitation ◽  
Posterior Cricoarytenoid ◽  
False Vocal ◽  
Intrinsic Laryngeal Muscles

Botulinum toxin A was used preoperatively to temporarily paralyze the intrinsic laryngeal muscles to hinder movements during the healing period after operation. In addition, toxin was injected into the cricopharyngeal muscle to allow a better passive drainage of the saliva into the esophagus. We treated six patients. Three suffered from chronic aspiration problems after multiple lower cranial nerve lesions, and three patients were apallic (after stroke and major brain injury). Two weeks before scheduled operation, we injected the toxin into the posterior cricoarytenoid muscles, the aryepiglottic muscles, and the vocalis muscle on both sides, as well as the cricopharyngeal muscle. The amount of injected toxin varied between 1.0 and 1.4 mL, equal to 200 to 280 units of botulinum toxin A (Dysport). After a complete palsy of these muscles (controlled by direct electromyography), a closure of the larynx was performed. After laminotomy and exposure of the intralaryngeal structures, the false vocal cords were mobilized and adapted with sutures. Because involuntary movements of the intralaryngeal musculature were absent, primary healing without complications occurred in all cases. Aspiration and related complications disappeared in all patients. In addition, the intensity of patient care could be considerably reduced. Preoperative use of botulinum toxin A allows sufficient laryngeal closure. This procedure is especially useful in the treatment of children and young adults, preserving the ability of later speech rehabilitation because of the return of voluntary movements of the intrinsic laryngeal muscles 6 months after the injection. Furthermore, this technique, as minimal surgical intervention, can be performed in high-risk patients.

scholarly journals Probing the AGN unification model at redshift z ∼ 3 with MUSE observations of giant Ly α nebulae

2020 ◽  
Vol 495 (2) ◽  
pp. 1874-1887
Author(s):  
J S den Brok ◽  
S Cantalupo ◽  
R Mackenzie ◽  
R A Marino ◽  
G Pezzulli ◽  
...  
Keyword(s):  
Early Universe ◽  
Active Galactic Nucleus ◽  
High Redshift ◽  
Type I ◽  
Type Ii ◽  
Host Galaxies ◽  
Future Studies ◽  
Show Evidence ◽  
Spatial Morphology ◽  
Inner Parts

ABSTRACT A prediction of the classic active galactic nucleus (AGN) unification model is the presence of ionization cones with different orientations depending on the AGN type. Confirmations of this model exist for present times, but it is less clear in the early Universe. Here, we use the morphology of giant Ly α nebulae around AGNs at redshift z ∼ 3 to probe AGN emission and therefore the validity of the AGN unification model at this redshift. We compare the spatial morphology of 19 nebulae previously found around type I AGNs with a new sample of four Ly α nebulae detected around type II AGNs. Using two independent techniques, we find that nebulae around type II AGNs are more asymmetric than around type I, at least at radial distances r > 30 physical kpc (pkpc) from the ionizing source. We conclude that the type I and type II AGNs in our sample show evidence of different surrounding ionizing geometries. This suggests that the classical AGN unification model is also valid for high-redshift sources. Finally, we discuss how the lack of asymmetry in the inner parts (r ≲ 30 pkpc) and the associated high values of the He ii to Ly α ratios in these regions could indicate additional sources of (hard) ionizing radiation originating within or in proximity of the AGN host galaxies. This work demonstrates that the morphologies of giant Ly α nebulae can be used to understand and study the geometry of high-redshift AGNs on circumnuclear scales and it lays the foundation for future studies using much larger statistical samples.

Posterior cricoarytenoid activity in normal adults during involuntary and voluntary hyperventilation

1991 ◽  
Vol 70 (3) ◽  
pp. 1377-1385 ◽  
Author(s):  
S. T. Kuna ◽  
R. A. Day ◽  
G. Insalaco ◽  
R. D. Villeponteaux
Keyword(s):  
Vocal Cord ◽  
Respiratory Cycle ◽  
Quiet Breathing ◽  
Laryngeal Muscles ◽  
Voluntary Hyperventilation ◽  
Adult Humans ◽  
Progressive Hypoxia ◽  
Posterior Cricoarytenoid ◽  
Intrinsic Laryngeal Muscles ◽  
Normal Adults

The effect of isocapnic hypoxia and hyperoxic hypercapnia on the electrical activity of the posterior cricoarytenoid (PCA) muscle was determined in eight normal adult humans by use of standard rebreathing techniques and was compared with PCA activity during voluntary hyperventilation performed under isocapnic and hypocapnic conditions. PCA activity was recorded with intramuscular hooked-wire electrodes implanted through a fiberoptic nasopharyngoscope. During quiet breathing in all subjects, the PCA was phasically active on inspiration and tonically active throughout the respiratory cycle. At comparable increments in respiratory output, hypercapnia, hypoxia, and voluntary hyperventilation appeared to be associated with similar increases in phasic or tonic PCA activity. During quiet breathing, the onset of phasic PCA activity usually occurred before inspiratory airflow and extended beyond the start of expiratory airflow. The duration of phasic PCA preactivation and postinspiratory phasic PCA activity remained unchanged during progressive hypercapnia and progressive hypoxia. The results, in combination with recent findings for vocal cord adductors, suggest that vocal cord position throughout the respiratory cycle during hyperpnea is actively controlled by simultaneously acting and antagonistic intrinsic laryngeal muscles.

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.

A morphometric study of the carotid body in chronically hypoxic rats

1984 ◽  
Vol 57 (5) ◽  
pp. 1430-1438 ◽  
Author(s):  
K. H. McGregor ◽  
J. Gil ◽  
S. Lahiri
Keyword(s):  
Blood Vessels ◽  
Carotid Body ◽  
Structural Changes ◽  
Volume Density ◽  
Morphometric Study ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Type I Cells ◽  
I Cells

We performed morphometric studies of carotid body in acutely and chronically hypoxic rats (inspired PO2 = 70 Torr, at sea level). Acute exposure was for the duration of about 10 min, and chronic exposure lasted for 28 days. We confirmed that the total volume of the organ increased by severalfold. At the light-microscopy level we found an enlargement of the volume density of the blood sinuses from 14 to 31% due to chronic hypoxia. The morphometric hematocrit increased from 39 to 70% paralleling changes in the conventionally measured venous hematocrit. These data do not show any specific plasma skimming in the carotid body blood vessels. With the electron microscope we found that the mean average volume of type I cells increased from 320 micron3 in controls to 1,120 micron3 in the chronically hypoxic rats without hyperplasia, whereas type II cells had increased in number without alteration in size. Qualitative observations revealed that the normal appearance of clusters of ovoid type I cells interspersed by capillaries had been transformed into a pattern of individual cells forming plates between expanded blood vessels with a large increase of contact area between the cells and vessels. Type II cells appeared to have proliferated without changes in individual size to cover the enlarged periphery of type I cells. The observed structural changes in the carotid body parenchyma and vasculature appear to be physiologically adaptive and provide further support for the idea that various elements in the organ are particularly sensitive to hypoxia.

Stereological estimates indicate that aging does not alter the capillary length density in the human posterior cricoarytenoid muscle

2007 ◽  
Vol 103 (5) ◽  
pp. 1815-1823 ◽  
Author(s):  
Michael J. Lyon ◽  
Linda M. Steer ◽  
Leslie T. Malmgren
Keyword(s):  
Muscle Fiber ◽  
Fiber Type ◽  
Interstitial Tissue ◽  
Type I ◽  
Type Ii ◽  
Capillary Length ◽  
Age Related ◽  
Posterior Cricoarytenoid Muscle ◽  
Posterior Cricoarytenoid ◽  
Age Related Changes

Studies of some human skeletal muscles demonstrate an age-related capillarity decrease. An age-related decrease in blood flow to the posterior cricoarytenoid muscle (PCA) in rats has been reported, as well as a decreased ability to abduct the vocal folds. We, therefore, hypothesized that decreased muscle capillarity may contribute to PCA dysfunction in the elderly. Using immunological and stereological techniques, human PCAs (ages 18–98 yr; 28 men, 23 women) were examined for age-related changes in muscle fiber-type-specific and/or total capillary length density. While analysis shows no age-related changes in total muscle or fiber-type-specific capillary length densities ( LV cap), there are significant age-related increases in LV cap within the interstitial tissue ( P = 0.001) and in the ratio of the type I LV cap to type I surface ( P = 0.002), with a strong trend for type II LV cap ( P = 0.055). There is also an age-related decrease in the muscle fiber surface density for both type I and II fibers ( P < 0.001 and 0.04, respectively). Data also show that women have a significantly higher type II LV cap ( P = 0.039), regardless of age. In addition, with the exception of female type I LV cap, all measured variables are significantly higher for type I fibers ( P < 0.001), independent of age or sex. While data indicate there are age-related changes of capillary-muscle fiber relationships within the PCA, they do not support the hypothesis of an age-related loss of capillarity.

Refinements in modeling the passive properties of laryngeal soft tissue

2007 ◽  
Vol 103 (1) ◽  
pp. 206-219 ◽  
Author(s):  
Eric J. Hunter ◽  
Ingo R. Titze
Keyword(s):  
Potential Significance ◽  
Load Bearing Capacity ◽  
Kelvin Model ◽  
Laryngeal Muscles ◽  
Nonlinear Viscoelastic ◽  
Technical Report ◽  
Data Files ◽  
Viscoelastic Characteristics ◽  
Posterior Cricoarytenoid ◽  
Intrinsic Laryngeal Muscles

The nonlinear viscoelastic passive properties of three canine intrinsic laryngeal muscles, the lateral cricoarytenoid (LCA), the posterior cricoarytenoid (PCA), and the interarytenoid (IA), were fit to the parameters of a modified Kelvin model. These properties were compared with those of the thyroarytenoid (TA) and cricothyroid (CT) muscles, as well as previously unpublished viscoelastic characteristics of the human vocal ligament. Passive parameters of the modified Kelvin model were summarized for the vocal ligament, mucosa, and all five laryngeal muscles. Results suggest that the LCA, PCA, and IA muscles are functionally different from the TA and CT muscles in their load-bearing capacity. Furthermore, the LCA, PCA, and IA have a much larger stress-strain hysteresis effect than has been previously reported for the TA and CT or the vocal ligament. The variation in this effect suggests that the connective tissue within the TA and CT muscles is somehow similar to the vocal ligament but different from the LCA, PCA, or IA muscles. Further demonstrating the potential significance of grouping tissues in the laryngeal system by functional groups in the laryngeal system was the unique finding that, over their working elongation range, the LCA and PCA were nearly as exponentially stiff as the vocal ligament. This paper was written in conjunction with an online technical report ( http://www.ncvs.org/ncvs/library/tech ) in which comprehensive muscle data and sensitivity analysis, as well as downloadable data files and computer scripts, are made available.

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