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Tracicaru RV, Bräuer L, Döllinger M, Hînganu D, Paulsen F, Hînganu MV. Muscular and neuronal control of voice production - forgotten findings, current concepts, and new developments. Ann Anat 2024; 255:152283. [PMID: 38763330 DOI: 10.1016/j.aanat.2024.152283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 04/07/2024] [Accepted: 05/13/2024] [Indexed: 05/21/2024]
Abstract
Voice production has been an area of interest in science since ancient times, and although advancing research has improved our understanding of the anatomy and function of the larynx, there is still little general consensus on these two topics. This review aims to outline the main developments in this field and highlight the areas where further research is needed. The most important hypotheses are presented and discussed highlighting the four main lines of research in the anatomy of the human larynx and their most important findings: (1) the arrangement of the muscle fibers of the thyroarytenoid muscle is not parallel to the vocal folds in the internal part (vocalis muscle), leading to altered properties during contraction; (2) the histological structure of the human vocal cords differs from other striated muscles; (3) there is a specialized type of heavy myosin chains in the larynx; and (4) the neuromuscular system of the larynx has specific structures that form the basis of an intrinsic laryngeal nervous system. These approaches are discussed in the context of current physiological models of vocal fold vibration, and new avenues of investigation are proposed.
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Affiliation(s)
- Rareş-Vasile Tracicaru
- Institute of Functional and Clinical Anatomy, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany; Department of Morphofunctional Sciences, Chair of Anatomy and Embryology, Grigore T Popa University of Medicine and Pharmacy Iași, University street No 16, Iași 700115, Romania.
| | - Lars Bräuer
- Institute of Functional and Clinical Anatomy, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Michael Döllinger
- Division of Phoniatrics and Pediatric Audiology at the Department of Otorhinolaryngology Head & Neck Surgery, Laboratory for Computational Medicine, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Delia Hînganu
- Department of Morphofunctional Sciences, Chair of Anatomy and Embryology, Grigore T Popa University of Medicine and Pharmacy Iași, University street No 16, Iași 700115, Romania
| | - Friedrich Paulsen
- Institute of Functional and Clinical Anatomy, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Marius Valeriu Hînganu
- Department of Morphofunctional Sciences, Chair of Anatomy and Embryology, Grigore T Popa University of Medicine and Pharmacy Iași, University street No 16, Iași 700115, Romania
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Walluks K, Hoffmann B, Svensson CM, Förster G, Müller AH, Jarvis J, Perkins J, Figge MT, Arnold D. Long-term stimulation by implanted pacemaker enables non-atrophic treatment of bilateral vocal fold paresis in a human-like animal model. Sci Rep 2024; 14:10440. [PMID: 38714750 PMCID: PMC11076618 DOI: 10.1038/s41598-024-60875-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 04/29/2024] [Indexed: 05/10/2024] Open
Abstract
A wide variety of treatments have been developed to improve respiratory function and quality of life in patients with bilateral vocal fold paresis (BVFP). One experimental method is the electrical activation of the posterior cricoarytenoid (PCA) muscle with a laryngeal pacemaker (LP) to open the vocal folds. We used an ovine (sheep) model of unilateral VFP to study the long-term effects of functional electrical stimulation on the PCA muscles. The left recurrent laryngeal nerve was cryo-damaged in all animals and an LP was implanted except for the controls. After a reinnervation phase of six months, animals were pooled into groups that received either no treatment, implantation of an LP only, or implantation of an LP and six months of stimulation with different duty cycles. Automated image analysis of fluorescently stained PCA cross-sections was performed to assess relevant muscle characteristics. We observed a fast-to-slow fibre type shift in response to nerve damage and stimulation, but no complete conversion to a slow-twitch-muscle. Fibre size, proportion of hybrid fibres, and intramuscular collagen content were not substantially altered by the stimulation. These results demonstrate that 30 Hz burst stimulation with duty cycles of 40% and 70% did not induce PCA atrophy or fibrosis. Thus, long-term stimulation with an LP is a promising approach for treating BVFP in humans without compromising muscle conditions.
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Affiliation(s)
- Kassandra Walluks
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena, Germany
- Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany
- Institute of Zoology and Evolutionary Research, Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany
| | - Bianca Hoffmann
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena, Germany
| | - Carl-Magnus Svensson
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena, Germany
| | - Gerhard Förster
- Clinic for Otorhinolaryngology/Plastic Surgery, Wald-Klinikum Gera, Gera, Germany
| | - Andreas H Müller
- Clinic for Otorhinolaryngology/Plastic Surgery, Wald-Klinikum Gera, Gera, Germany
| | - Jonathan Jarvis
- Faculty of Science, Sport and Exercise Sciences, John Moores University, Liverpool, UK
| | | | - Marc Thilo Figge
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Jena, Germany.
- Institute of Microbiology, Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany.
| | - Dirk Arnold
- Clinic and Polyclinic for Otorhinolaryngology, University Hospital Jena, Jena, Germany.
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Mok A, Allen J, Haney MM, Deninger I, Ballenger B, Caywood V, Osman KL, Zitsch B, Hopewell BL, Thiessen A, Szewczyk M, Ohlhausen D, Newberry CI, Leary E, Lever TE. A Surgical Mouse Model for Advancing Laryngeal Nerve Regeneration Strategies. Dysphagia 2019; 35:419-437. [PMID: 31388736 DOI: 10.1007/s00455-019-10045-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 02/06/2019] [Accepted: 07/31/2019] [Indexed: 01/16/2023]
Abstract
Iatrogenic recurrent laryngeal nerve (RLN) injury is a morbid complication of anterior neck surgical procedures. Existing treatments are predominantly symptomatic, ranging from behavioral therapy to a variety of surgical approaches. Though laryngeal reinnervation strategies often provide muscle tone to the paralyzed vocal fold (VF), which may improve outcomes, there is no clinical intervention that reliably restores true physiologic VF movement. Moreover, existing interventions neglect the full cascade of molecular events that affect the entire neuromuscular pathway after RLN injury, including the intrinsic laryngeal muscles, synaptic connections within the central nervous system, and laryngeal nerve anastomoses. Systematic investigations of this pathway are essential to develop better RLN regenerative strategies. Our aim was to develop a translational mouse model for this purpose, which will permit longitudinal investigations of the pathophysiology of iatrogenic RLN injury and potential therapeutic interventions. C57BL/6J mice were divided into four surgical transection groups (unilateral RLN, n = 10; bilateral RLN, n = 2; unilateral SLN, n = 10; bilateral SLN, n = 10) and a sham surgical group (n = 10). Miniaturized transoral laryngoscopy was used to assess VF mobility over time, and swallowing was assessed using serial videofluoroscopy. Histological assays were conducted 3 months post-surgery for anatomical investigation of the larynx and laryngeal nerves. Eight additional mice underwent unilateral RLN crush injury, half of which received intraoperative vagal nerve stimulation (iVNS). These 8 mice underwent weekly transoral laryngoscopy to investigate VF recovery patterns. Unilateral RLN injury resulted in chronic VF immobility but only acute dysphagia. Bilateral RLN injury caused intraoperative asphyxiation and death. VF mobility was unaffected by SLN transection (unilateral or bilateral), and dysphagia (transient) was evident only after bilateral SLN transection. The sham surgery group retained normal VF mobility and swallow function. Mice that underwent RLN crush injury and iVNS treatment demonstrated accelerated and improved VF recovery. We successfully developed a mouse model of iatrogenic RLN injury with impaired VF mobility and swallowing function that can serve as a clinically relevant platform to develop translational neuroregenerative strategies for RLN injury.
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Affiliation(s)
- Alexis Mok
- Department of Communication Science and Disorders, University of Missouri School of Health Professions, Columbia, MO, USA
| | - Jakob Allen
- Department of Medicine, University of Missouri School of Medicine, Columbia, MO, USA
| | - Megan M Haney
- Department of Veterinary Pathobiology, University of Missouri College of Veterinary Medicine, Columbia, MO, USA
| | - Ian Deninger
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Brayton Ballenger
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Victoria Caywood
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Kate L Osman
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Bradford Zitsch
- Department of Medicine, University of Missouri School of Medicine, Columbia, MO, USA
| | - Bridget L Hopewell
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Aaron Thiessen
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Marlena Szewczyk
- Department of Medicine, University of Missouri School of Medicine, Columbia, MO, USA
| | - Daniel Ohlhausen
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | | | - Emily Leary
- Department of Orthopedic Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Teresa E Lever
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA. .,One Hospital Dr. MA314, Columbia, MO, 65212, USA.
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Mascarello F, Toniolo L, Cancellara P, Reggiani C, Maccatrozzo L. Expression and identification of 10 sarcomeric MyHC isoforms in human skeletal muscles of different embryological origin. Diversity and similarity in mammalian species. Ann Anat 2016; 207:9-20. [PMID: 26970499 DOI: 10.1016/j.aanat.2016.02.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 02/15/2016] [Indexed: 10/22/2022]
Abstract
In the mammalian genome, among myosin heavy chain (MyHC) isoforms a family can be identified as sarcomeric based on their molecular structure which allows thick filament formation. In this study we aimed to assess the expression of the 10 sarcomeric isoforms in human skeletal muscles, adopting this species as a reference for comparison with all other mammalian species. To this aim, we set up the condition for quantitative Real Time PCR assay to detect and quantify MyHC mRNA expression in a wide variety of human muscles from somitic, presomitic and preotic origin. Specific patterns of expression of the following genes MYH1, MYH2, MYH3, MYH4, MYH6, MYH7, MYH8, MYH13, MYH14/7b and MYH15 were demonstrated in various muscle samples. On the same muscle samples which were analysed for mRNA expression, the corresponding MyHC proteins were studied with SDS PAGE and Western blot. The mRNA-protein comparison allowed the identification of 10 distinct proteins based on the electrophoretic migration rate. Three groups were formed based on the migration rate: fast migrating comprising beta/slow/1, alpha cardiac and fast 2B, slow migrating comprising fast 2X, fast 2A and two developmental isoforms (NEO and EMB), intermediate migrating comprising EO MyHC, slow B (product of MYH15), slow tonic (product of MYH14/7b). Of special interest was the demonstration of a protein band corresponding to 2B-MyHC in laryngeal muscles and the finding that all 10 isoforms are expressed in extraocular muscles. These latter muscles are the unique localization for extraocular, slow B (product of MYH15) and slow tonic (product of MYH14/7b).
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Affiliation(s)
- Francesco Mascarello
- Department of Comparative Biomedicine and Food Science, University of Padova, viale dell'Università 16, Legnaro, 35020 Padova, Italy.
| | - Luana Toniolo
- Department of Biomedical Sciences, University of Padova Via Marzolo 3, 35131 Padova, Italy
| | - Pasqua Cancellara
- Department of Biomedical Sciences, University of Padova Via Marzolo 3, 35131 Padova, Italy
| | - Carlo Reggiani
- Department of Biomedical Sciences, University of Padova Via Marzolo 3, 35131 Padova, Italy
| | - Lisa Maccatrozzo
- Department of Comparative Biomedicine and Food Science, University of Padova, viale dell'Università 16, Legnaro, 35020 Padova, Italy
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Kletzien H, Russell JA, Connor NP. The effects of treadmill running on aging laryngeal muscle structure. Laryngoscope 2015; 126:672-7. [PMID: 26256100 DOI: 10.1002/lary.25520] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 05/06/2015] [Accepted: 06/25/2015] [Indexed: 11/10/2022]
Abstract
OBJECTIVES/HYPOTHESIS Age-related changes in laryngeal muscle structure and function may contribute to deficits in voice and swallowing observed in elderly people. We hypothesized that treadmill running, an exercise that increases respiratory drive to upper airway muscles, would induce changes in thyroarytenoid muscle myosin heavy chain (MHC) isoforms that are consistent with a fast-to-slow transformation in muscle fiber type. STUDY DESIGN Randomized parallel group controlled trial. METHODS Fifteen young adult and 14 old Fischer 344/Brown Norway rats received either treadmill running or no exercise (5 days/week/8 weeks). Myosin heavy chain isoform composition in the thyroarytenoid muscle was examined at the end of 8 weeks. RESULTS Significant age and treatment effects were found. The young adult group had the greatest proportion of superfast-contracting MHCIIL isoform. The treadmill running group had the lowest proportion of MHCIIL and the greatest proportion of MHCIIx isoforms. CONCLUSION Thyroarytenoid muscle structure was affected both by age and treadmill running in a fast-to-slow transition that is characteristic of exercise manipulations in other skeletal muscles. LEVEL OF EVIDENCE NA. Laryngoscope, 126:672-677, 2016.
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Affiliation(s)
- Heidi Kletzien
- Department of Surgery, Otolaryngology-Head and Neck Surgery, University of Wisconsin, Madison, Wisconsin, U.S.A.,Department of Biomedical Engineering, University of Wisconsin, Madison, Wisconsin, U.S.A
| | - John A Russell
- Department of Surgery, Otolaryngology-Head and Neck Surgery, University of Wisconsin, Madison, Wisconsin, U.S.A.,Department of Communication Sciences and Disorders, University of Wisconsin, Madison, Wisconsin, U.S.A
| | - Nadine P Connor
- Department of Surgery, Otolaryngology-Head and Neck Surgery, University of Wisconsin, Madison, Wisconsin, U.S.A.,Department of Biomedical Engineering, University of Wisconsin, Madison, Wisconsin, U.S.A.,Department of Communication Sciences and Disorders, University of Wisconsin, Madison, Wisconsin, U.S.A
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Li J, Liu S, Cheng Q, Nie M, Zhang S, Sheng X, Chen S, Ge P. Changes in electrical response function and myosin heavy chain isoforms following denervation and reinnervation of bilateral posterior cricoarytenoid muscles in dogs. Acta Otolaryngol 2014; 134:318-25. [PMID: 24460155 DOI: 10.3109/00016489.2013.860657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONCLUSIONS Both electrical response function and mRNA expression of myosin heavy chain (MyHC) types 2X, 1, and Neonatal of bilateral posterior cricoarytenoid (PCA) muscle changed after denervation or reinnervation in canines. OBJECTIVES There is a need to investigate the electrical response function MyHC alteration of denervation or reinnervation in the bilateral PCA muscle of large animals. METHODS MyHC isoforms expression profile and PCA muscle function outcome were detected by real-time reverse transcribed-polymerase chain reaction and muscle response to functional electrical stimulation, 9 weeks after denervation and reinnervation with ansa-recurrent laryngeal nerve anastomosis in dogs. RESULTS Denervation produced up-regulation of MyHC-1 and MyHC-Neonatal messenger ribonucleic acid (mRNA) expression. Reinnervation caused a decrease of MyHC-2X mRNA expression. The electrical voltage threshold of vocal fold movement and maximum abduction of denervation were greater than that of the reinnervated or control group. The denervated vocal abduction maximum of response to electrical stimulation was less than that in reinnervation or control groups.
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Affiliation(s)
- Jingyuan Li
- Department of Otolaryngology, Guangdong General Hospital & Guangdong Academy of Medical Sciences , Guangzhou city and
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Kletzien H, Russell JA, Leverson GE, Connor NP. Differential effects of targeted tongue exercise and treadmill running on aging tongue muscle structure and contractile properties. J Appl Physiol (1985) 2012; 114:472-81. [PMID: 23264540 DOI: 10.1152/japplphysiol.01370.2012] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Age-associated changes in tongue muscle structure and strength may contribute to dysphagia in elderly people. Tongue exercise is a current treatment option. We hypothesized that targeted tongue exercise and nontargeted exercise that activates tongue muscles as a consequence of increased respiratory drive, such as treadmill running, are associated with different patterns of tongue muscle contraction and genioglossus (GG) muscle biochemistry. Thirty-one young adult, 34 middle-aged, and 37 old Fischer 344/Brown Norway rats received either targeted tongue exercise, treadmill running, or no exercise (5 days/wk for 8 wk). Protrusive tongue muscle contractile properties and myosin heavy chain (MHC) composition in the GG were examined at the end of 8 wk across groups. Significant age effects were found for maximal twitch and tetanic tension (greatest in young adult rats), MHCIIb (highest proportion in young adult rats), MHCIIx (highest proportion in middle-aged and old rats), and MHCI (highest proportion in old rats). The targeted tongue exercise group had the greatest maximal twitch tension and the highest proportion of MHCI. The treadmill running group had the shortest half-decay time, the lowest proportion of MHCIIa, and the highest proportion of MHCIIb. Fatigue was significantly less in the young adult treadmill running group and the old targeted tongue exercise group than in other groups. Thus, tongue muscle structure and contractile properties were affected by both targeted tongue exercise and treadmill running, but in different ways. Studies geared toward optimizing dose and manner of providing targeted and generalized tongue exercise may lead to alternative tongue exercise delivery strategies.
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Affiliation(s)
- Heidi Kletzien
- Department of Surgery, Otolaryngology-Head and Neck Surgery, University of Wisconsin, Madison, Wisconsin, USA
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Björck G, Margolin G, Måbäck GM, Persson JKE, Mattsson P, Hydman J. New animal model for assessment of functional laryngeal motor innervation. Ann Otol Rhinol Laryngol 2012; 121:695-9. [PMID: 23130547 DOI: 10.1177/000348941212101013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVES The functional motor innervation of the larynx is not fully understood because of the complexity of the peripheral neuroanatomy. Since the late 19th century, there has been controversy regarding the role of the superior laryngeal nerve, which may have wider motor projections than are currently acknowledged. The aim of this study was to develop a large animal model to characterize and quantify the functional motor input to the intrinsic laryngeal muscles. METHODS We performed invasive electrophysiology (evoked electromyography) in normal pigs. RESULTS The thyroarytenoid, lateral cricoarytenoid, and posterior cricoarytenoid muscles receive dual innervation from both the superior and recurrent laryngeal nerves, whereas the cricothyroid muscle is innervated only by the superior laryngeal nerve. CONCLUSIONS The dual innervation pattern from both laryngeal nerves supports the concept of a laryngeal nerve plexus. The motor input through the external branch of the superior laryngeal nerve was surprisingly high. The animal model presented here may be used in future investigations of laryngeal reinnervation following nerve injury.
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Affiliation(s)
- Gunnar Björck
- Department of Otorhinolaryngology, Karolinska University Hospital, Stockholm, Sweden
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Connor NP, Russell JA, Jackson MA, Kletzien H, Wang H, Schaser AJ, Leverson GE, Zealear DL. Tongue muscle plasticity following hypoglossal nerve stimulation in aged rats. Muscle Nerve 2012; 47:230-40. [PMID: 23169566 DOI: 10.1002/mus.23499] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2012] [Indexed: 11/10/2022]
Abstract
INTRODUCTION Age-related decreases in tongue muscle mass and strength have been reported. It may be possible to prevent age-related tongue muscle changes using neuromuscular electrical stimulation (NMES). Our hypothesis was that alterations in muscle contractile properties and myosin heavy chain composition would be found after NMES. METHODS Fifty-four young, middle-aged, and old 344/Brown Norway rats were included in this study. Twenty-four rats underwent bilateral electrical stimulation of the hypoglossal nerves for 8 weeks and were compared with control or sham rats. Muscle contractile properties and myosin heavy chain (MHC) in the genioglossus (GG), styloglossus (SG), and hyoglossus (HG) muscles were examined. RESULTS Compared with unstimulated control rats, we found reduced muscle fatigue, increased contraction and half-decay times, and increased twitch and tetanic tension. Increased type I MHC was found, except for in GG in old and middle-aged rats. CONCLUSION Transitions in tongue muscle contractile properties and phenotype were found after NMES.
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Affiliation(s)
- Nadine P Connor
- Department of Surgery, Otolaryngology-Head and Neck Surgery, 600 Highland Avenue, Room K4/711, University of Wisconsin, Madison, Wisconsin 53792, USA.
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Abstract
PURPOSE OF REVIEW Laryngeal reinnervation for bilateral vocal fold paralysis (BVFP) patients is a promising technique to achieve good airway, although preserving a good quality of voice. On the other hand, the procedure is not simple. This review explores the recent literature on surgical technique and factors that may contribute to the success. RECENT FINDINGS Research and literature in this area are limited due to variability and complexity of the nerve supply. The posterior cricoarytenoid (PCA) muscle also receives nerve supply from the interarytenoid branch. Transection of this nerve at the point between interarytenoid and PCA branch may prevent aberrant reinnervation of adductor nerve axons to the PCA muscle. A varying degree of regeneration of injured recurrent laryngeal nerves (RLN) in humans of more than 6 months confirms subclinical reinnervation, which may prevent denervation-induced atrophy. SUMMARY Several promising surgical techniques have been developed for bilateral selective reinnervation for BVFP patients. This involves reinnervation of the abductor and adductor laryngeal muscles. The surgical technique aims at reinnervating the PCA muscle to trigger abduction during the respiratory cycle and preservation of good voice by strengthening the adductor muscles as well as prevention of laryngeal synkinesis.
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Tacrolimus enhances the recovery of normal laryngeal muscle fibre distribution after reinnervation. The Journal of Laryngology & Otology 2012; 126:1155-8. [PMID: 22947322 DOI: 10.1017/s0022215112001788] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVES To assess the recovery of various muscle fibre types in the posterior cricoarytenoid muscle after laryngeal reinnervation in the rat, and to determine the influence of tacrolimus on this process. METHODS Four groups of rats underwent resection and anastomosis of the left vagus nerve, and were administered either tacrolimus at a low dose or an immunosuppressive dose, or cyclosporin A at a low dose or an immunosuppressive dose. A fifth group received surgery alone, and a sixth group received neither surgery nor drug treatment (healthy group). Muscles were removed for immunohistochemical analysis 45 days after surgery. RESULTS There was no difference in the proportion of types 1, 2a and 2b muscle fibres, comparing the immunosuppressive tacrolimus group and the healthy group, whereas there were fewer type 1 fibres in the group receiving surgery alone, compared with the healthy group (7 vs 12.1 per cent, respectively; p = 0.0303). CONCLUSION Tacrolimus enhanced the recovery of normal laryngeal muscle fibres after reinnervation in the rat, indicating a possible role in laryngeal transplantation.
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Bartlett RS, Jetté ME, King SN, Schaser A, Thibeault SL. Fundamental approaches in molecular biology for communication sciences and disorders. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2012; 55:1220-1231. [PMID: 22232415 PMCID: PMC3418393 DOI: 10.1044/1092-4388(2011/11-0152)] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
PURPOSE This contemporary tutorial will introduce general principles of molecular biology, common deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and protein assays and their relevance in the field of communication sciences and disorders. METHOD Over the past 2 decades, knowledge of the molecular pathophysiology of human disease has increased at a remarkable pace. Most of this progress can be attributed to concomitant advances in basic molecular biology and, specifically, the development of an ever-expanding armamentarium of technologies for analysis of DNA, RNA, and protein structure and function. Details of these methodologies, their limitations, and examples from the communication sciences and disorders literature are presented. Results/Conclusions The use of molecular biology techniques in the fields of speech, language, and hearing sciences is increasing, facilitating the need for an understanding of molecular biology fundamentals and common experimental assays.
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Birchall MA, Ayling SM, Harley R, Murison PJ, Burt R, Mitchard L, Jones A, Macchiarini P, Stokes CR, Bailey M. Laryngeal transplantation in minipigs: early immunological outcomes. Clin Exp Immunol 2012; 167:556-64. [PMID: 22288599 DOI: 10.1111/j.1365-2249.2011.04531.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Despite recent tissue-engineering advances, there is no effective way of replacing all the functions of the larynx in those requiring laryngectomy. A recent clinical transplant was a success. Using quantitative immunofluorescence targeted at immunologically relevant molecules, we have studied the early (48 h and 1 week) immunological responses within larynxes transplantated between seven pairs of National Institutes of Health (NIH) minipigs fully homozygous at the major histocompatibility complex (MHC) locus. There were only small changes in expression of some molecules (relative to interindividual variation) and these were clearest in samples from the subglottic region, where the areas of co-expression of CD25(+) CD45RC(-) CD8(-) and of CD163(+) CD172(+) MHC-II(-) increased at 1 week after transplant. In one case, infiltration by recipient T cells was analysed by T cell receptor (TCR) Vβ spectratype analysis; this suggested that changes in the T cell repertoire occur in the donor subglottis mucosal tissues from day 0 to day 7, but that the donor and recipient mucosal Vβ repertoires remain distinct. The observed lack of strong immunological responses to the trauma of surgery and ischaemia provides encouraging evidence to support clinical trials of laryngeal transplantation, and a basis on which to interpret future studies involving mismatches.
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Affiliation(s)
- M A Birchall
- Department of Clinical Sciences at South Bristol, University of Bristol, Bristol, UK.
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Birchall MA, Kingham PJ, Murison PJ, Ayling SM, Burt R, Mitchard L, Jones A, Lear P, Stokes CR, Terenghi G, Bailey M, Macchiarini P. Laryngeal transplantation in minipigs: vascular, myologic and functional outcomes. Eur Arch Otorhinolaryngol 2011; 268:405-14. [PMID: 20842506 PMCID: PMC3192951 DOI: 10.1007/s00405-010-1355-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Accepted: 07/25/2010] [Indexed: 12/01/2022]
Abstract
There is no effective way of replacing all the functions of the larynx in those requiring laryngectomy. Regenerative medicine offers promise, but cannot presently deliver implants with functioning neuromuscular units. A single well-documented laryngeal transplant in man was a qualified success, but more information is required before clinical trials may be proposed. We studied the early response of the larynx to laryngeal transplantation between 17 pairs of NIH minipigs full matched at the MHC2 locus. Following iterative technical improvements, pigs had good swallowing and a patent airway at 1 week. No significant changes in mucosal blood flux were observed compared with pre-operative measurements. Changes in muscle morphology and fibre phenotype were observed in transplant muscles retrieved after 7 days: the levels of fast and slow myosin heavy chain (MyHC) protein were reduced and embryonic MyHC was up regulated consistent with denervation induced atrophy. At 1 week laryngeal transplantation can result in good swallowing, and is not associated with clinical evidence of ischemia-reperfusion injury in MHC-matched pigs.
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Affiliation(s)
- M A Birchall
- Department of Clinical Sciences at South Bristol, Bristol, UK.
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Hydman J, Mattsson P. Collateral reinnervation by the superior laryngeal nerve after recurrent laryngeal nerve injury. Muscle Nerve 2008; 38:1280-9. [PMID: 18816603 DOI: 10.1002/mus.21124] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This study investigates the role of the intact superior laryngeal nerve (SLN) in the reinnervation process of one of the laryngeal muscles, the posterior cricoarytenoid muscle (PCA), following recurrent laryngeal nerve (RLN) injury. Using a chronic RLN injury model in the adult rat, PCA reinnervation was assessed by retrograde double-tracing techniques in combination with electrophysiology and immunohistochemistry of muscle sections. The results demonstrate that the PCA receives dual innervation from both laryngeal nerves even in the uninjured system. Functionally significant collateral reinnervation originates from intact SLN fibers following RLN injury, mainly due to intramuscular sprouting rather than by recruitment of more motor neurons. This may be important when choosing surgical and/or medical treatment for patients with RLN injury.
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Affiliation(s)
- Jonas Hydman
- Department of Clinical Neuroscience, Section of Neurosurgery R2:02, Karolinska Institute, S-171 76 Stockholm, Sweden.
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16
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Abstract
The peripheral nervous system has the intrinsic capacity to regenerate but the reinnervation of muscles is often suboptimal and results in limited recovery of function. Injuries to nerves that innervate complex organs such as the larynx are particularly difficult to treat. The many functions of the larynx have evolved through the intricate neural regulation of highly specialized laryngeal muscles. In this review, we examine the responses of nerves and muscles to injury, focusing on changes in the expression of neurotrophic factors, and highlight differences between the skeletal limb and laryngeal muscle systems. We also describe how artificial nerve conduits have become a useful tool for delivery of neurotrophic factors as therapeutic agents to promote peripheral nerve repair and might eventually be useful in the treatment of laryngeal nerve injury.
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Affiliation(s)
- Paul J Kingham
- Blond McIndoe Research Laboratories, University of Manchester, Manchester, UK.
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Kingham PJ, Hughes A, Mitchard L, Burt R, Murison P, Jones A, Terenghi G, Birchall MA. Effect of neurotrophin-3 on reinnervation of the larynx using the phrenic nerve transfer technique. Eur J Neurosci 2007; 25:331-40. [PMID: 17284173 DOI: 10.1111/j.1460-9568.2007.05310.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Current techniques for reinnervation of the larynx following recurrent laryngeal nerve (RLN) injury are limited by synkinesis, which prevents functional recovery. Treatment with neurotrophins (NT) may enhance nerve regeneration and encourage more accurate reinnervation. This study presents the results of using the phrenic nerve transfer method, combined with NT-3 treatment, to selectively reinnervate the posterior cricoarytenoid (PCA) abductor muscle in a pig nerve injury model. RLN transection altered the phenotype and morphology of laryngeal muscles. In both the PCA and thyroarytenoid (TA) adductor muscle, fast type myosin heavy chain (MyHC) protein was decreased while slow type MyHC was increased. These changes were accompanied with a significant reduction in muscle fibre diameter. Following nerve repair there was a progressive normalization of MyHC phenotype and increased muscle fibre diameter in the PCA but not the TA muscle. This correlated with enhanced abductor function indicating the phrenic nerve accurately reinnervated the PCA muscle. Treatment with NT-3 significantly enhanced phrenic nerve regeneration but led to only a small increase in the number of reinnervated PCA muscle fibres and minimal effect on abductor muscle phenotype and morphology. Therefore, work exploring other growth factors, either alone or in combination with NT-3, is required.
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Affiliation(s)
- Paul J Kingham
- Blond McIndoe Research Laboratories, Plastic and Reconstructive Surgery Research, Stopford Building, University of Manchester, Oxford Road, Manchester, M13 9PT, UK.
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