Tipos de fibras de los músculos intrínsecos laríngeos de seres humanos: una revisión de la literatura / Fiber types in human intrinsic laryngeal muscles: a literature review

El estudio de las fibras musculares permite comprender con mejor detalle la composición de los músculos y sus características funcionales. Además, facilita la aplicación de programas de entrenamiento y rehabilitación basados en las vías energéticas que regulan la contracción muscular. Su estudio generalmente va unido al análisis de las cadenas pesadas de miosina (MyHC), las que informan sobre las características y propiedades funcionales del músculo. El objetivo de este trabajo fue sintetizar la evidencia científica disponible sobre la distribución de fibras musculares y de isoformas de cadenas pesadas de miosina de los músculos intrínsecos de la laringe de seres humanos. Se realizó una revisión sistemática de la literatura mediante el análisis de artículos encontrados en las bases de datos PubMed, EBSCOHost y SciELO. Los hallazgos informan sobre la existencia de fibras tónicas lentas y tipo I, II, IIA y IIX/IIB. Además, se reconoce la presencia de las isoformas MyHC-I, MyHC-IIA, MyHC-IIX, MyHC-Fetal, MyHC-L y MyHC-IIB. En conclusión, los músculos intrínsecos de la laringe presentan una mezcla de fibras y de isoformas de MyHC lentas y rápidas,la que obedece a adaptaciones y cambios evolutivos que han permitido, por ejemplo, las características fonatorias que presenta la voz del ser humano.

The study of muscle fibers allows the composition of muscles and their functional characteristics to be understood in greaterdetail. In addition, it makes it possible to applytraining and rehabilitation programs based on the energypathways that regulatemuscle contraction. Studying muscle fibers is generally associated withthe analysis of myosin heavy chains (MHC) which provide information on the functional characteristics and properties of muscles. The objective of this study was to synthesize the available scientific evidence onthe distribution of muscle fibers and myosin heavy chain isoforms present in the intrinsic laryngeal muscles of human beings. A systematic reviewof the literature was carried outand articles found on PubMed, EBSCOHost,and SciELOwere analyzed.The findings showthe presenceof slow-tonic, type I, type II, type IIA, and type IIX/IIB fibers. Additionally,isoforms MHC-I, MHC-IIA, MHC-IIX, MHC-Fetal, MHC-L, and MHC-IIB canbe found. In conclusion, intrinsic laryngeal muscles are composed ofa combination of slow and fast fibers and MHC isoforms, derived from evolutionary adaptations and changes which have given way, among other things, to the phonetic characteristics ofthe human voice.

Combined autologous fascia transplantation with autologous fascia and fat injection into the vocal fold for sulcus vocalis / 中华耳鼻咽喉头颈外科杂志

Objective: To assess voice outcomes after surgical technique for typeⅡ and type Ⅲ sulcus vocalis. Methods: The data of 39 cases of bilateral type Ⅱ-Ⅲ sulcus vocalis were collected and analyzed retrospectively. There were 29 patients with bilateral type Ⅲ sulcus vocalis, and 10 patients with type Ⅲ on one side and typeⅡon the contralateral vocal cord. All of vocal cords were applied autologous anterior rectus sheath fascia transplant, and 68 sides of vocal cords with type Ⅲ sulcus vocalis were also applied autologous fascia and fat injection. Two male patients, whose results from transplant and injection were not satisfied, were carried out cricothyroid myotomy one year after surgery. Subjective and objective voice evaluations were performed before and after operation. Results: One patient was found mild adhesion on the middle part of vocal cords, and all the other 38 patients recovered well and there were no complications. During 5-6 weeks after surgery, breathy voice was the feather. Then vocal quality and glottal closure were gradually improved and became steady in 12 months. It showed that all the subjective and objective parameters, except for fundamental frequency, were significantly improved (P<0.05), and obvious improvement was achieved in glottal closures and mucosal waves in 35 patients. Three patients obtained no significant vocal quality improvement after transplant and injection surgery, and two male patients of them achieved improvement in mucosal waves and MPT after bilateral cricothyroid muscle amputations. One patient, who was revealed with mild adhesion, achieved a satisfied result after adhesion separation and suture. All the patients who originally had feelings of fatigue and voice discontinuity during phonation gained significant improvement postoperatively. Steady function with no complications was observed during the 36 months (up to 5 years in 20 patients) follow-up period. Conclusions: Autologous fascia transplantation combined fascia and fat injcetion can lead to excellent long-term results, and it is a good treatment option for pathologic sulcus vocalis. Cricothyroid muscle amputations can reduce the tension, and may improve vibration property of the vocal fold in patients with pathological sulcus vocalis.

Impacto en la calidad de vida del tratamiento de disfonía espasmódica aductora con toxina botulínica A / Impact on the quality of life of the treatment of adductor spasmodic dysphonia with botulinum toxin A

Introducción. La distonía laríngea o disfonía espasmódica se caracteriza por con-tracciones involuntarias de los músculos laríngeos internos que se desencadenan al hablar, siendo la forma aductora la más frecuente. La inyección de toxina botulínica es el manejo de elección. Para evaluar la respuesta a la terapia existen varios instru-mentos validados, uno de ellos es el cuestionario Voice Handicap Index-10 (VHI-10). El objetivo de este estudio es caracterizar a los pacientes con disfonía espasmódica aductora y evaluar el impacto de la toxina en su calidad de vida.Método. Éste se centró en un estudio retrospectivo descriptivo en pacientes adultos con diagnóstico de disfonía espasmódica aductora tratados con toxina botulínica A, en el Hospital Clínico Universidad de Chile (HCUC), en el periodo comprendido en-tre 2013 y 2021. El mismo permitió la obtención de los datos epidemiológicos de los pacientes, a quienes se les solicitó responder la encuesta VHI-10 previo y posterior a un mes de cada inyección de la toxina.Resultados. Se incluyeron 55 pacientes (218 procedimientos). La dosis promedio utilizada fue de 9,18 UI con un intervalo promedio de 7,4 meses. El puntaje VHI-10 promedio en la evaluación inicial fue de 29,4 y posinfiltración de 14,96, siendo esta diferencia significativa (p < 0,000001). En nuestra serie casi un tercio tiene asociada alguna patología neurológica, y se reportó un 3,67% de complicaciones leves y transitorias.Conclusión. La disfonía espasmódica aductora tiene un gran impacto en la calidad de vida de los pacientes, que se reduce significativamente mediante la inyección de toxina botulínica A, procedimiento que ha demostrado ser seguro y eficaz

Introduction. Laryngeal dystonia or spasmodic dysphonia is characterized by in-voluntary contractions of internal laryngeal muscles that are triggered when speak-ing, being the adductor form the most frequent. Botulinum toxin injection is the management of choice. There are several validated instruments to assess response to therapy, one of them is the Voice Handicap Index-10 (VHI-10) questionnaire. The objective of this study is to characterize patients with adductor spasmodic dysphonia and evaluate the impact of the toxin in their quality of life.Method. A descriptive retrospective study was carried out in adult patients with a diagnosis of adductor spasmodic dysphonia treated with botulinum toxin A, between 2013-2021 at the Hospital Clínico Universidad de Chile. The epidemiological data of the patients and the VHI-10 survey were obtained before and after one month of each toxin injection was requested.Results. 55 patients (218 procedures) were included. The average dose used was 9.18 IU with an average interval of 7.4 months. The average VHI-10 score in the initial evaluation was 29.4 and post-infiltration was 14.96, being this difference sig-nificant (p <0.000001). In our series, almost a third had an associated neurological pathology, and 3.67% of mild and transitory complications were reported.Conclusion. Adductor spasmodic dysphonia has a great impact on the quality of life of patients, which is significantly reduced by injecting botulinum toxin A, a pro-cedure that has been shown to be safe and effective

Disfonía por tensión muscular: concepto y criterios diagnósticos / Muscle tension dysphonia: concept and diagnostic criteria

Introducción. La disfonía por tensión muscular fue definida, desde 1983, como un desorden que ocasiona un desbalance en las fuerzas de tensión muscular laríngea sin evidencia de patología estructural o neurológica. Denominado también disfonía por tensión muscular, tipo 1, este desorden aún no tiene estandarizadas las características que en la práctica han sido consideradas parte de su diagnóstico.Objetivo. Revisar la información actual, no mayor a cinco años, sobre disfonía por tensión muscular para unificar criterios y diagnósticos actuales.Metodología. Se realizó una búsqueda sistemática a través de las bases de datos PubMed, Google Scholar y Cochrane. Los términos MESH utilizados fueron: dis-fonía por tensión muscular, disfonía funcional, disfonía hipercinética y fatiga vocal. Criterios de inclusión: artículos publicados en revistas arbitradas, sin importancia del diseño y antigüedad no mayor a cinco años. Criterios de exclusión: artículos cuyo enfoque principal no fuera disfonía por tensión muscular y con idioma diferente al inglés o español.Resultados. Dos estudios refieren mayor patología en mujeres que hombres; cuatro investigaciones reportan presión subglótica aumentada (>90 mmHg); tres trabajos reportaron medidas fonatorias; un trabajo propone video de alta resolución como demostración de hiperfunción vocal; una investigación evaluó onda mucosa por elec-troglotografía; una investigación estudió el uso de resonancia magnética funcional; otro trabajo propuso un estudio piloto de evaluación de flujo sanguíneo de músculos infrahioideos. Otro trabajo hace una revisión del uso de métodos diagnósticos.Conclusiones. Los parámetros de mayor peso fueron pico cepstral y presión sub-glótica. Aún es necesario ampliar el conocimiento con nuevas investigaciones que permitan criterios universales

Introduction. Muscle tension dysphonia has been defined since 1983 as a disorder in which there is an imbalance in laryngeal muscle tension forces, without evidence of structural or neurological pathology; it has also been called type I muscle tension dysphonia. The characteristics that in practice have been considered part of the di-agnosis are not standardized.Objective. To review current information, not older than 5 years, on muscle tension dysphonia, unifying current diagnostic criteria.Methodology. A systematic search was carried out through the Pub Med, Google scholar and Cochrane databases. The MESH terms used were: muscle tension dys-phonia, functional dysphonia, hyperkinetic dysphonia, and vocal fatigue. Inclusion criteria: articles published in peer-reviewed journals, regardless of design and pub-lished no more than 5 years before. Exclusion criteria: articles whose main focus was not muscle tension dysphonia and with a language other than English or Spanish.Results. Two studies report more pathology in women than men; four investiga-tions report increased subglottic pressure (> 90 mmHg); three studies reported pho-natory measures; a work proposes high resolution video as a demonstration of vo-cal hyperfunction; an investigation evaluated mucosal wave by electroglottography; an investigation studied the use of functional magnetic resonance imaging; another work proposed a pilot study of infrahyoid muscle blood flow assessment: another work reviews the use of diagnostic methods.Conclusions. The parameters of greater weight were cepstral peak and subglottic pressure. It is still necessary to expand the knowledge with new research that allows universal criteria

Alternativas para o estabelecimento de via aérea cirúrgica durante a pandemia de COVID-19 / Alternatives for establishing a surgical airway during the COVID-19 pandemic

RESUMO Atualmente médicos e profissionais da saúde encontram-se frente a uma pandemia desafiadora causada por uma nova cepa denominada 2019 Novel Coronavírus (COVID-19). A infecção humana pelo COVID-19 ainda não tem o espectro clínico completamente descrito, bem como não se sabe com precisão o padrão de letalidade, mortalidade, infectividade e transmissibilidade. Não há vacina ou medicamento específico disponível. O tratamento é de suporte e inespecífico. No Brasil, assim como no restante do mundo o número de casos de COVID-19 tem crescido de maneira alarmante levando a um aumento do número de internações assim como da mortalidade pela doença. Atualmente os estados com maior número de casos são, respectivamente, São Paulo, Rio de Janeiro, Distrito Federal e Ceará. O objetivo deste trabalho é oferecer alternativas a fim de orientar cirurgiões quanto ao manejo cirúrgico das vias aéreas em pacientes com suspeita e/ou confirmação para infecção pelo COVID-19.

ABSTRACT Currently doctors and health professionals are facing a challenging pandemic caused by a new strain called 2019 Novel Coronavirus (COVID-19). Human infection with COVID-19 does not yet have the clinical spectrum fully described, and the pattern of lethality, mortality, infectivity and transmissibility is not known with precision. There is no specific vaccine or medication available. Treatment is supportive and nonspecific. In Brazil, as in the rest of the world, the number of COVID-19 cases has grown alarmingly, leading to an increase in the number of hospitalizations as well as in mortality from the disease. Currently, the states with the highest number of cases are, respectively, São Paulo, Rio de Janeiro, Distrito Federal and Ceará. The objective of this work is to offer alternatives in order to guide surgeons regarding the surgical management of the airways in patients with suspicion and / or confirmation for COVID-19 infection.

Lesión traqueal con reparación de colgajo muscular / Tracheal Injury with Muscle Flap Repair

RESUMEN Los traumatismos en cuello se pueden clasificar las lesiones en contusas y penetrantes, en el caso de las heridas penetrantes las ocasionadas por arma punzocortante son las más frecuentes. Las manifestaciones clínicas dependen del mecanismo del trauma, tamaño y nivel de la lesión. Paciente masculino de 26 años de edad con heridas por arma punzocortante en cuello y muñecas se ingresó a quirófano de urgencia, se realizó una exploración vascular de cuello encontrando una avulsión completa del ligamento cricotiroideo, se realizó la reparación del defecto con un colgajo de los músculos cricotiroideos, cursando una buena evolución es egresado al duodécimo día. El diagnóstico de las lesiones traqueales es desafiante y debe realizase rápidamente. Se debe instalar una vía aérea definitiva de manera eficaz y planear la reconstrucción quirúrgica. El seguimiento postoperatorio realizado de manera interdisciplinaria es esencial para el pronóstico(AU)

ABSTRACT Neck injuries can be classified as blunt or penetrating injuries. Penetrating injuries caused by a puncturing gun are the most frequent. The clinical manifestations depend on trauma mechanism, and on lesion size and degree. We present the case of a 26-year-old male patient with puncture injuries to the neck and wrists. After he was admitted to the emergency room, a vascular exploration of the neck was performed, finding a complete avulsion of the cricothyroid ligament. The defect was repaired with a flap of the cricothyroid muscles. The patient had a good evolution and was discharged on the twelfth day. The diagnosis of tracheal lesions is challenging and must be carried out quickly. A definitive airway should be installed efficiently, as well as the planning of the surgical reconstruction. The postoperative follow-up performed in an interdisciplinary way is essential for the prognosis(AU)

Terapia breve intensiva com fonação em tubo de vidro imerso em água: estudo de casos masculinos / Intensive short-term therapy with phonation into a glass tube immersed in water: male case studies

RESUMO Trata-se de um estudo de casos de três homens com 25, 39 e 40 anos de idade, avaliados antes e após dez sessões consecutivas de fonação em tubo de vidro imerso em água. O objetivo foi descrever os resultados vocais da terapia breve intensiva com fonação em tubo de vidro imerso em água, em três homens sem afecções laríngeas e com queixas vocais. Em dois sujeitos, a maioria das medidas de fonte glótica melhorou, mas sem entrar na normalidade. Nos três sujeitos, a maioria das medidas de pressão sonora aumentou acima da normalidade; a maioria dos tempos máximos de fonação aumentou, mas sem entrar na normalidade; a diferença entre a média das vogais e a contagem de números permaneceu fora da normalidade; os resultados das relações s/z e ė/e permaneceram ou entraram na normalidade. Os resultados dos questionários de autoavaliação (Perfil de Participação em Atividades Vocais, Escala de Desconforto do Trato Vocal e Autoavaliação do Grau de Quantidade de Fala e Volume de Voz) mostraram que os escores se mantiveram ou pouco mudaram após a terapia. Todos os sujeitos mostraram Pré-contemplação, primeiro estágio, na Escala URICA-Voz. Nos três homens, após terapia breve intensiva com fonação em tubo de vidro imerso em água, houve discreta melhora na maioria das medidas vocais, mas ainda permaneceram alteradas e, na escala URICA-Voz, o grupo se classificou em Pré-Contemplação.

ABSTRACT This is a case study of three men aged 25, 39, and 40 years old, evaluated before and after ten consecutive phonation sessions into a glass tube immersed in water. The objective of this study was to describe the vocal results of intensive short-term therapy with phonation into a glass tube immerse in water in three men without laryngeal disorders and vocal complaints. In two subjects, most glottic source measurements improved, but without becoming normal. In all three subjects, most sound pressure measurements increased above normal; most of the maximum phonation times have increased, but without becoming normal; the difference between vowel average and number count remained outside the normal range; the results of s/z and ė/e ratios remained or entered the normal range. The results of the self-assessment questionnaires (Voice Activity and Participation Profile, Vocal Tract Discomfort Scale, and Talkativeness and Vocal Loudness Self-Assessment Scale) showed that the scores remained or little changed after therapy. All subjects showed pre-contemplation, first stage, on the URICA-Voice Scale. In the three men, after intensive short-term therapy with phonation into a glass tube immerse in water, there was a slight improvement in most vocal measures, but they still remained altered and, on the URICA-Voice scale, the group was classified as Pre-Contemplation.

Development of a Novel Intraoperative Neuromonitoring System Using an Accelerometer Sensor in Thyroid Surgery: A Porcine Model Study

OBJECTIVES: The sensitivity and positive predictive value of widely used intraoperative neuromonitoring (IONM) using electromyography (EMG) of the vocalis muscle in thyroid surgery are controversial. Thus, we developed a novel IONM system with an accelerometer sensor that uses the piezoelectric effect instead of EMG to detect laryngeal twitching. The objective of this study was to evaluate the feasibility and safety of this novel IONM system during thyroid surgery in a porcine model. METHODS: We developed an accelerometer sensor that uses the piezoelectric effect to measure laryngeal twitching in three dimensions. This novel accelerometer sensor was placed in the anterior neck skin (transcutaneous) or postcricoid area. Stimulus thresholds, amplitude, and latency of laryngeal twitching measured using the accelerometer sensor were compared to those measured through EMG of the vocalis muscle. RESULTS: The amplitudes of the accelerometer sensor at the anterior neck and postcricoid area were significantly lower than those of EMG because of differences in the measurement method used to evaluate laryngeal movement. However, no significant differences in stimulus thresholds between the EMG endotracheal tube and transcutaneous or postcricoid accelerometer sensors were observed. CONCLUSION: Accelerometer sensors located at the anterior neck or postcricoid area were able to identify laryngeal twitching. The stimulus intensity measured with these sensors was equivalent to that from conventional vocalis EMG. Our novel IONM system with an accelerometer sensor that checks changes in surface acceleration can be an alternative to EMG of the vocalis muscle for IONM in the future.

Quantitative Measurement of Laryngeal Electromyography Using Motor Unit Action Potential in Unilateral Vocal Cord Paralysis

BACKGROUND AND OBJECTIVES: Laryngeal electromyography (LEMG) is valuable to evaluate the innervation status of the laryngeal muscles and the prognosis of vocal fold paralysis (VFP). However, there is a lack of agreement on quantitative interpretation of LEMG. The aim of this study is to measure the motor unit action potentials (MUAP) quantitatively in order to find cut-off values of amplitude, duration, phase for unilateral vocal fold paralysis patients. MATERIALS AND METHOD: Retrospective chart review was performed for the unilateral VFP patients who underwent LEMG from March 2016 to May 2018. Patient's demography, cause of VFP, vocal cord mobility, and LEMG finding were analyzed. The difference between normal and paralyzed vocal folds and cut-off values of duration, amplitude, and phase in MUAP were evaluated. RESULTS: Thirty-six patients were enrolled in this study. Paralyzed vocal fold had significantly longer duration (p=0.021), lower amplitude (p=0.000), and smaller phase (p=0.012) than the normal. The cut-off values of duration, amplitude, and phase in MUAP for unilateral VFP were 5.15 ms, 68.35 µV, and 1.85 respectively. CONCLUSION: An analysis of MUAP successfully provided quantitative differences between normal and paralyzed vocal folds. But, additional research is needed to get more available cut-off value which is helpful to evaluate the status of laryngeal innervations.

Descripción anatómica de la musculatura intrínseca y cavidad de la laringe en cuatro especies de primates / Anatomical description of the intrinsic musculature and cavity of the larynx in four primate species

Los primates actualmente se clasifican en "Estrepsirrinos" y "Haplorrinos". Los estrepsirrinos habitan principalmente Madagascar y el sudeste de Asia, en cambio, los Haplorrinos se subdividen en "monos del viejo mundo" y "monos del nuevo mundo", distribuyéndose los primeros en África y Asia principalmente, mientras que los últimos tienen en Centro y Sudamérica sus principales áreas de distribución. Son animales frecuentes en zoológicos y centros de rehabilitación, que presentan abundantes estudios en cuanto a su distribución, hábitat, comportamiento y medidas de conservación, pero escasos son los estudios en relación a su anatomía. Por esta razón, el objetivo de nuestro estudio fue realizar una descripción anatómica de la musculatura intrínseca y cavidad de la laringe en cuatro ejemplares de primates, los cuales fueron donados por el Zoológico del Parque Metropolitano de Santiago de Chile, correspondientes a las especies: mono araña (Ateles fusciceps), mono capuchino (Cebus albifrons), gibón de manos blancas (Hylobates lar) y lémur cola anillada (Lémur catta). La disección se realizó desde superficial a profundo en cada laringe aislada, describiendo y comparando los hallazgos anatómicos observados, utilizando como guía comparativa la literatura anatómica humana. El estudio demostró diferencias anatómicas entre los primates en estudio, así como también diferencias con lo descrito en la literatura para la anatomía de la laringe humana.

Primates are currently classified as "Strepsirrhini" and "Haplorrhini". The strepsirrhines inhabit mainly Madagascar and Southeast Asia. However, the Haplorrhini are subdivided into "old world monkeys" and "new world monkeys", the first being distributed in Africa and Asia mainly, while the main distribution areas for the latter are in Central and South America. They are frequent animals in zoos and rehabilitation centers, allowing abundant studies regarding their distribution, habitat, behavior and conservation measures, but few studies are related to their anatomy. For this reason, the aim of our study was to perform an anatomical description of the intrinsic muscles and cavity of the larynx in four specimens of primates, which were donated by the Metropolitan Park of Santiago, Chile, corresponding to species: spider monkey (Ateles fusciceps), capuchin monkey (Cebus albifrons), white-handed gibbon (Hylobates lar) and ring-tailed lemur (Lemur catta). The dissection was performed from superficial to deep in each isolated larynx, describing and comparing the observed anatomical findings, using as a comparative guide the human anatomical literature. The study showed anatomical differences between the primates under study, as well as differences for what is described in the literature for the anatomy of the human larynx.

Comparison of botulinum toxin and propranolol for essential and dystonic vocal tremors

OBJECTIVES: Vocal tremors, which cause social difficulties for patients, may be classified as resting or action tremors. Of the vocal action tremors, essential and dystonic tremors are the most common. Botulinum toxin and oral medications have been used to treat vocal tremors, but no comparative clinical trials have been performed. The aim of this study was to compare the effects of botulinum toxin injection and the oral administration of propranolol in the treatment of essential and dystonic vocal tremors. METHODS: This clinical trial recruited 15 patients, divided into essential and dystonic vocal tremor groups. Patients in both groups received successive treatment with botulinum toxin and propranolol. The treatments were administered at different times; the order of treatment was randomly selected. Patients were assessed with flexible nasofibrolaryngoscopy and with perceptual and acoustic voice evaluations. A statistical significance level of 0.05 (5%) was used. RESULTS: Botulinum toxin produced statistically significant improvements in perceptual measures of vocal instability in patients with dystonic vocal tremors compared with baseline values and treatment with propranolol. The acoustic measure of variability in the fundamental frequency was significantly lower in patients with dystonic vocal tremors after treatment with botulinum toxin. CONCLUSION: Essential and dystonic vocal tremors responded differently to treatment. Dystonic vocal tremors responded significantly to treatment with botulinum toxin but not oral propranolol. Essential vocal tremors did not respond significantly to either treatment, perhaps due to the small number of patients, which is a limitation of this research.

The diagnostic value of laryngeal electromyography in vocal fold paralysis and arytenoid dislocation / 临床耳鼻咽喉头颈外科杂志

OBJECTIVES@#To identify diagnostic value of laryngeal electromyography (LEMG) in differentiating vocal fold paralysis (VFP) from arytenoid dislocation.@*METHODS@#The history, laryngeal morphologic characteristics and LEMG of 36 patients with VFP and 10 patients with arytenoid dislocation were compared and analyzed.@*RESULTS@#The most common cause of 36 VFP patients was surgical damage (24 cases), and the most common cause of 10 arytenoid dislocation patients was history of endotracheal intubation (9 cases). There was no statistical difference between the vocal fold and the fixed position of the vocal fold between the group of VFP patients and arytenoid dislocation patients. In the patients with VFP, 33 VFP patients (91.67%) had decreased recruitment; 9 cases (9/13) of denervation potential and 8 cases (8/9) of regeneration potential occurred within 1-6 months of the course of disease; 3 cases (3/4) of synkinesis occurred in the course of disease more than 6 months. In the patients with VFP, the amplitude (<0.01) and turns (<0.05) of thyroarytenoid muscles significantly decreased in the lesioned side comparing to the normal one, but the turns/amplitude ratio showed no statistical difference. In the patients with superior laryngeal nerve injury, the turns and amplitude analysis of cricothyroid muscles showed no statistical difference. All of 10 patients with arytenoid dislocation showed normal LEMG patterns.@*CONCLUSIONS@#LEMG can be used to differentiate the patients with vocal cord paralysis from arthrodesis dislocation, and can also carry out quantitative analysis to provide valuable help for the diagnosis.

Efeitos da terapia manual laríngea e da estimulação elétrica nervosa transcutânea (TENS) na diadococinesia laríngea em mulheres disfônicas: estudo clínico randomizado / Effects of laryngeal manual therapy (LMT) and transcutaneous electrical nerve stimulation (TENS) in vocal folds diadochokinesis of dysphonic women: a randomized clinical trial

RESUMO Objetivo Verificar e comparar os efeitos da terapia manual laríngea (TML) e da estimulação elétrica nervosa transcutânea (TENS) na diadococinesia laríngea de mulheres disfônicas. Método Participaram 20 mulheres com nódulos vocais, divididas igualmente por sorteio em: Grupo TML–aplicação de TML; Grupo TENS–aplicação de TENS; ambos receberam 12 sessões de tratamento, duas vezes por semana, 20 minutos cada, pelo mesmo terapeuta. As mulheres foram avaliadas quanto à diadococinesia (DDC) laríngea em três momentos, diagnóstico, pré-tratamento e pós-tratamento, o que produziu três grupos de medidas. A gravação da DDC foi realizada por meio da repetição entrecortada das vogais: /a/ e /i/. A análise da DDC foi realizada pelo programa Motor Speech Profile Advanced (MSP)-KayPentax. Os parâmetros da DDC das três avaliações foram comparados entre si pelo teste t pareado (p≤0,05). Resultados Parâmetros DDC se apresentaram semelhantes na fase sem tratamento, indicando que não houve variabilidade individual ao longo do tempo. Não houve modificação em relação à velocidade da DDC após intervenções, mas após TML, a DDC da vogal /i/ se apresentou mais estável em relação à duração do período e à intensidade das emissões. Estes resultados indicam que TML melhorou a coordenação de movimentos das pregas vocais à fonação. Não houve modificações dos parâmetros da DDC em relação à estabilidade das emissões após TENS. Conclusão TML promove maior regularidade de movimentos diadococinéticos das pregas vocais em mulheres disfônicas, o que amplia o conhecimento sobre o efeito do reequilíbrio da musculatura laríngea na função fonatória, já TENS não proporciona efeitos na diadococinesia laríngea.

ABSTRACT Purpose To verify and compare the effect of transcutaneous electrical nerve stimulation (TENS) and laryngeal manual therapy (LMT) on laryngeal diadochokinesis (DDK) of dysphonic women. Methods Twenty women with bilateral vocal nodules participated and were equally divided into: LMT Group – LMT application; TENS Group – TENS application; both groups received 12 sessions of treatment, twice a week, with a duration of 20 minutes each, applied by the same therapist. The women were evaluated as to laryngeal DDK at three moments: diagnostic, pre-treatment, and post-treatment, which produced three groups of measurements. The DDK recording was performed with intersected repetition of vowels /a/ and / i/. The analysis of vowels was performed by the program Motor Speech Profile Advanced (MSP)-KayPentax. The DDK parameters of the three evaluations were compared by means of the paired t-test (p≤0.05). Results The measurements of laryngeal DDK parameters were similar in the phase without treatment, indicating no individual variability over time. There was no change with respect to the speed of DDK after intervention, but after LMT, DDK of the vowel /i/ was more stable in terms of the duration of the emissions and intensity of emissions repeated. These results show improved coordination of vocal folds movement during phonation. There were no changes in the DDK parameters following TENS. Conclusion LMT provides greater regularity of movement during laryngeal diadochokinesis in dysphonic women, which extends knowledge on the effect of rebalancing the larynx muscles during phonation, although TENS does not impact laryngeal diadochokinesis.

Comparison of Clinical Characteristics Between Patients With Different Causes of Vocal Cord Immobility

OBJECTIVE: To analyze the clinical characteristics between neurogenic and non-neurogenic cause of vocal cord immobility (VCI). METHODS: The researchers retrospectively reviewed clinical data of patients who underwent laryngeal electromyography (LEMG). LEMG was performed in the bilateral cricothyroid and thyroarytenoid muscles. A total of 137 patients were enrolled from 2011 to 2016, and they were assigned to either the neurogenic or non-neurogenic VCI group, according to the LEMG results. The clinical characteristics were compared between the two groups and a subgroup analysis was done in the neurogenic group. RESULTS: Among the 137 subjects, 94 patients had nerve injury. There were no differences between the neurogenic and non-neurogenic group in terms of demographic data, underlying disease except cancer, and premorbid events. In general characteristics, cancer was significantly higher in the neurogenic group than non-neurogenic group (p=0.001). In the clinical findings, the impaired high pitched ‘e’ sound and aspiration symptoms were significantly higher in neurogenic group (p=0.039 for impaired high pitched ‘e’ sound; p=0.021 for aspiration symptoms), and sore throat was more common in the non-neurogenic group (p=0.014). In the subgroup analysis of neurogenic group, hoarseness was more common in recurrent laryngeal neuropathy group than superior laryngeal neuropathy group (p=0.018). CONCLUSION: In patients with suspected vocal cord palsy, impaired high pitched ‘e’ sound and aspiration symptoms were more common in group with neurogenic cause of VCI. Hoarseness was more frequent in subjects with recurrent laryngeal neuropathy. Thorough clinical evaluation and LEMG are important to differentiate underlying cause of VCI.

Electromyography-Guided Botulinum Toxin Injection Into the Cricothyroid Muscles in Bilateral Vocal Fold Abductor Paralysis

OBJECTIVES: Bilateral vocal fold abductor paralysis (BVFAP) both deteriorates quality of life and may cause life-threatening respiratory problems. The aim of this study was to reduce respiratory symptoms in BVFAP patients using cricothyroid (CT) botulinum toxin (BTX) injection. METHODS: Before and 2 weeks and 4 months after bilateral BTX injection into the CT muscles under electromyography; alterations in respiratory, acoustic, aerodynamic and quality of life parameters were evaluated in BVFAP patients with respiratory distress. For the respiratory evaluation modified Borg scale and spirometry, for the voice and aerodynamic evaluations Voice Handicap Index-30 (VHI-30), GRBAS, acoustic analysis (sound pressure level, F0, jitter%, shimmer%, noise-to-harmonic ratio) and maximum phonation time and for the quality of life assessment Short Form-36 (SF-36) form were used. RESULTS: All patients were female with a mean age of 47±8.1 years. There was a mean time of 11.8±5.5 (minimum 2, maximum 23) months between BVFAP development and BTX injection. In all cases, other than one case with unknown aetiology, the cause of vocal fold paralysis was prior thyroid surgery. In total 18.6±3.1 units of BTX were applied to the CTs. In the preinjection period, and the 2nd week and 4th month after injection, the Borg dyspnea scale was 7.3/5.3/5.0, FIV1 (forced inspiratory volume in one second) was 1.7/1.7/1.8 L, peak expiratory flow (PEF) was 1.4/1.7/2.1 L/sec, maximum phonation time was 7.0/6.4/6.2 seconds and VHI-30 was 63.2/52.2/61.7 respectively. There was no significant alteration in acoustic analysis parameters. Many of the patients reported transient dysphagia within the first week. There were insignificant increases in SF-36 sub-scale values. CONCLUSION: After BTX injection, improvements in the mean Borg score, PEF and FIV1 values and SF-36 sub-scale scores showed the restricted success of this approach. This modality may be kept in mind as a transient treatment option for patients refused persistent tracheotomy or ablative airway surgeries.

Differential Diagnosis between Neurogenic and Functional Dysphonia

Voice disorder is classified into three categories, structural, neurogenic and functional dysphonia. Neurogenic dysphonia refers to a disruption in the nerves controlling the larynx. Common examples of this include complete or partial vocal cord paralysis, spasmodic dysphonia. Also it occurs as part of an underlying neurologic condition such as Parkinson's disease, myasthenia gravis, Lou Gehrig's disease or disorder of the central nervous system that causes involuntary movement of the vocal folds during voice production. Functional dysphonia is a voice disorder in the absence of structual or neurogenic laryngeal characteristics. A near consensus exist that Muscle tension dysphonia (MTD) is functional voice disorder wherein hyperfunctional laryngeal muscle activity whereas Spasmodic dysphonia (SD) is neurogenic, action-induced focal laryngeal dystonia including several subtype. Both Adductor type spasmodic dysphonia (AdSD) and MTD may be associated with excessive supraglottic contraction and compensation, resulting in a strained voice quality with spastic voice breaks. It makes these two disorders extremely difficult to differentiate based on clinical interpretation alone. Because treatment for AdSD and MTD are quite different, correct diagnosis is important. Clinician should be aware of the specific vocal characteristics of each disease to improve therapeutic outcome.

Surgical approach to the thyroarytenoid branch of the inferior laryngeal nerve through the thyroid cartilage

ABSTRACT PURPOSE: To describe the anatomical course of the intralaryngeal portion of the inferior laryngeal nerve (ILN) and to standardize the surgical access to its thyroarytenoid branch (TAb) through the thyroid cartilage. METHODS: Under surgical microscopy, 33 adult human excised larynges were dissected, to expose the intralaryngeal portion of ILN. The point of entry of TAb, ILN's terminal branch, in the thyroarytenoid (TA) muscle was determined and correlated with thyroid cartilage dimensions. RESULTS: After entering the larynx, the ILN consistently traveled between the thyroid cartilage and the lateral cricoarytenoid muscle in an anterior and slightly cranial course. The distance from the point of entry of the TAb in the TA muscle to the midline (TAb-H) and to the inferior border (TAb-V) of the thyroid cartilage differed according to gender. In females, mean distances of TAb-H and TAb-V were 20.5mm and 5.2mm and in males, 22.3mm and 5.9mm, respectively. CONCLUSION: The intralaryngeal course of the inferior laryngeal nerve presents low variability and measures from landmarks in the thyroid cartilage help to estimate the point of entry of thyroarytenoid branch in thyroarytenoid muscle.

Cause and treatment of unilateral vocal cord paralysis / 临床耳鼻咽喉头颈外科杂志

Unilateral vocal cord paralysis(UVCP) is defined as affected side vocal cord emerges immobility or motion weakening and abnormal tension due to unilateral intrinsic laryngeal muscles suffering from disorder about motor nerve. The patients usually present with hoarse voice, disability of high pitch, cough, aspiration, or a combination of these symptoms. There are increasing therapeutics researches and case analyses regarding UVCP in recent years. Thus this review summarized the progression about its causes and treatment methods.

Extraskeletal Myxoid Chondrosarcoma of Larynx / 대한이비인후과학회지

Primary cartilaginous tumors of the laryngeal lesion are rare and it accounts for only 1% of laryngeal tumor pathology. They are most commonly located on the endolaryngeal surface of cricoid cartilage, and it is extremely rare to find them in vocal muscle lesion. In most cases, treatment of choice is based on surgical excision, and postoperative radiotherapy is typically recommended. We experienced a case of a 22-year-old young woman without underlying disease, presenting extraskeletal myxoid chondrosarcoma of vocal cord, especially in the vocal muscle. The patient underwent mass excision through suspension laryngoscope and radiation therapy.

Management of Post-Throidectomy Voice Problems: Surgeon's Perspectives / 대한이비인후과학회지

Recurrent laryngeal nerve (RLN) injury is not the only cause of voice alteration after thyroidectomy; many patients noticed slight voice changes after thyroidectomy, without evidence of RLN injury. Typical symptoms are easy fatigue during phonation and difficulty with high-pitched and singing voices; other symptoms are paresthesia, vague voice changes, throat discomfort, swallowing difficulties, and the feeling of choking. This collection of symptoms appears to be a real syndrome, which we have named post-thyroidectomy syndrome. In the management of these patients with unilateral vocal cord paralysis, injection laryngoplasty techniques have regained popularity in recent years. Because it is easier and less invasive than conventional medialization thyroplasty and may provide equally durable and effective results. As a novel voice rehabilitation procedure, RLN reinnervation has advantages which prevent the progressive loss of thyroarytenoid muscle tone, tension and potential of restoring a normal voice with preserving of laryngeal anatomy. In this manuscript, we could get a lots of useful information how to manage thyroidectomy related vocal fold paralysis with adequate different techniques at different situations.