Effect of cricothyroid and thyroarytenoid muscle botulinum toxin injection on patients with dyspnea caused by bilateral recurrent laryngeal nerve paresis / 中华耳鼻咽喉头颈外科杂志

Objective@#To discuss the clinical effect of small dose of botulinum toxin injection in cricothyroid muscle and thyroarytenoid muscle on patients with incomplete bilateral recurrent laryngeal nerve paresis.@*Methods@#Six patients were selected with Ⅰor Ⅱ or Ⅲ degree of dyspnea diagnosed as bilateral recurrent laryngeal nerve injury by laryngeal electromyography, and small dose of botulinum toxin injection was performed in cricothyroid muscle and thyroarytenoid muscle as a treatment. Degree of dyspnea was assessed one month before and after the treatment, and the stroboscopic laryngoscope results, acoustic parameters and CT image of the patients were collected in the 6 patients. The relevant parameters were also collected one month before and after treatment, including the degree of dyspnea, stroboscopic laryngoscope results, acoustic parameters and CT image of the patients. The angle between bilateral vocal cords in stroboscopy at full inspiratory was calculated, acoustic parameters (F0, jitter, shimmer) were analysed, and vocal length, width and the vocal region were measured. Then, the paired t test was performed for statistical analysis between before and after one month injection, the one way analysis of variance was performed among vocal parameters in CT image.@*Result@#Botulinum toxin injection was successfully completed in the 6 patients, followed without any serious complications. The degree of dyspnea was alleviated to some extent after treatment in all 6 patients; the angle between bilateral vocal cords at the end of a deep inspiration was significantly increased (t=2.44, P<0.05) after the treatment. The changes of F0 and jitter between before and after treatment were not statistically significant (t=0.72, t=1.42, P>0.05). Shimmer was significantly decreased after treatment (t=2.61, P<0.05). Vocal fold length, width and vocal region increased with F0, there was a statistically significant difference between different F0 before injection, and there was no statistically significant difference between different F0 after injection. The follow-up time was respectively seven months, 1 year, 1 year, 18 months, 22 months and 2 years respectively.@*Conclusion@#Small dose of botulinum toxin injection in bilateral cricothyroid muscles and thyroarytenoid muscles can relieve the dyspnea caused by bilateral vocal cords paresis to some extent, accompanied without serious complications, despite the sound quality was slightly worse.

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.

The Effects of Botulinium Toxin in Vocal Nodules / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Vocal nodules are the most common voice disorder due to vocal misuses. Vocal nodules are primarily treated with voice therapy and are rarely removed through laryngomicrosurgery. Although the rate of recovery for individual patients may vary, 60-70% of them are fully treated. Because vocal nodules have many possible causes, 30-40% of patients remain untreated. Also, vocal nodules recurrence after the surgical treatment is sometimes observed. The author claims that incomplete contact between vocal cords during phonation is a major cause of the vocal nodules. Most vocal nodules do occur from incomplete contact between vocal cords during phonation, and various voice therapies are designed to improve habitual misuses of the vocal cords. However, vocal nodules tend to remain unhealed unless patients change their habitual misuses of the vocal cords. The cricothyroid muscle tension is known to hinder the contact between vocal cords. The author injected a restricted amount of botulinium toxin to the cricothyroid muscle to reduce the muscle tension and observed changes in vocal cords' movement. SUBJECTS AND METHOD: In this study, the author injected botulinium toxin to the cricothyroid muscle of 21 patients. For 2-4 weeks, we observed patients' responses to the treatment, by measuring changes in subglottal pressure, mean air flow rate, maximum phonation time, jitter, shimmer, noise-to-harmonic ration of patients and subjective evaluation of voice changes. In addition, the author conducted stroboscopy to evaluate the usefulness of the treatment. RESULTS: The improvement was in the subjective evaluation of voice changes and stroboscopic findings. CONCLUSION: The observation demonstrated a great improvement in vocal nodules after the injection of botulinium toxin into the cricothyroid muscle.

Anatomia cirúrgica do ramo externo do nervo laríngeo superior / Surgical anatomy of the external branch of the superior laryngeal nerve

Introdução: o ramo externo do nervo laríngeo superior (RELS) é um ramo motor que tem origem no nível do osso hióide e desce medialmente à artéria carótida interna para inervar o músculo cricotireóideo da laringe. Nesse trajeto, aproxima-se do pólo superior da glândula tireóide. Muitos estudos têm sido feitos com o objetivo de avaliar a necessidade e viabilidade técnica de sua identificação durante operações sobre a glândula, mas alguns com resultados adversos. Objetivo: estudar a relação anatômica entre o RELS, a tireóide e a artéria tireoidiana superior e a viabilidade técnica e o tempo despendido em sua identificação durante procedimentos cirúrgicos sobre a glândula tireóide. Pacientes e método: foram estudados 40 RELS em pacientes que se submeteram a tireoidectomia por bócios nodulares, bócio difuso tóxico e câncer de tireóide. Foi analisado o tipo de disposição do nervo em relação à glândula tireóide e artéria tireoideana superior; a viabilidade de sua identificação durante a operação; e o tempo despendido para isso. Resultados: em mais da metade dos pacientes o RELS está a menos de 1,0cm da glândula e, em 62,5% dos casos, o nervo foi devidamente identificado em menos de quatro minutos. Conclusão: o RELS está muito próximo do pólo superior do lobo tireoideano; sua identificação cuidadosa é viável; e não acrescenta tempo significativo à cirurgia, devendo ser realizada sempre, para diminuir a morbidade da operação.

Introduction: the external branch of the superior laryngeal nerve (EBSL) is a motor branch that begins near the hyoid bone, than it goes down between the internal carotid artery and the larynx, and finds the cricothyroid muscle. In the way to the muscle, the nerve crosses the superior pole of the thyroid lobe. Many studies have been performed in order to observe the technical viability of finding the nerve during the thyroid surgery, and if we have to do it. There is some disagreement about this point. Objective: to study the anatomical relationship among the EBSL, the thyroid gland and the superior thyroid artery and the technical availability and the time spent in that identification during the surgical approach on the gland. Materials and methods: 40 EBLS were studied in patients who had the thyroid operated. These people had nodular goiter, toxic diffuse goiter, follicular adenoma or thyroid cancer. The anatomical relationship among the nerve, thyroid gland and superior thyroid artery were studied; as well as the viability of the nerve identification and the time spent to do it. Results: the nerve was near the superior pole of the lobe of the thyroid gland in 52.5% of cases; it was spent less than 4 minutes to find the EBSL in 62.5% of patients. Conclusion: the nerve is frequently very close to the gland, and its identification, which is possible in a few minuts, is recommended during thyroid surgery to avoid nerve damage.