Consensus statement: Using laryngeal electromyography for the diagnosis and treatment of vocal cord paralysis.

INTRODUCTION: The purpose of this study was to develop an evidence-based consensus statement regarding use of laryngeal electromyography (LEMG) for diagnosis and treatment of vocal fold paralysis after recurrent laryngeal neuropathy (RLN). METHODS: Two questions regarding LEMG were analyzed: (1) Does LEMG predict recovery in patients with acute unilateral or bilateral vocal fold paralysis? (2) Do LEMG findings change clinical management in these individuals? A systematic review was performed using American Academy of Neurology criteria for rating of diagnostic accuracy. RESULTS: Active voluntary motor unit potential recruitment and presence of polyphasic motor unit potentials within the first 6 months after lesion onset predicted recovery. Positive sharp waves and/or fibrillation potentials did not predict outcome. The presence of electrical synkinesis may decrease the likelihood of recovery, based on 1 published study. LEMG altered clinical management by changing the initial diagnosis from RLN in 48% of cases. Cricoarytenoid fixation and superior laryngeal neuropathy were the most common other diagnoses observed. CONCLUSIONS: If prognostic information is required in a patient with vocal fold paralysis that is more than 4 weeks and less than 6 months in duration, then LEMG should be performed. LEMG may be performed to clarify treatment decisions for vocal fold immobility that is presumed to be caused by RLN. Muscle Nerve 53: 850-855, 2016.

Options for treatment of a small glottic gap.

Background: Glottic insufficiency, or glottic gap as it is commonly called, is a common cause of dysphonia, producing symptoms of soft voice, decreased projection, and vocal fatigue. The etiology of glottic gap can occur from issues related to muscle atrophy, neurologic impairment, structural abnormalities, and trauma related causes. Treatment of glottic gap can include surgical and behavioral therapies or a combination of the two. When surgery is chosen, closure of the glottic gap is the primary goal. Options for surgical management include injection medialization, thyroplasty, and other methods of medializing the vocal folds. Methods: This manuscript reviews the current literature regarding the options for treatment of glottic gap. Discussion: This manuscript discusses options for treatment of glottic gap, including the indications for temporary and permanent treatment modalities; the differences between the available materials for injection medialization laryngoplasty and how they affect the vibratory function of the vocal folds and vocal outcome; and the evidence that supports an algorithm for treatment of glottic gap. Level of Evidence: 3a-Systematic review of case-control studies.

The voice and laryngeal dysfunction in stroke: a report from the Neurolaryngology Subcommittee of the American Academy of Otolaryngology-Head and Neck Surgery.

OBJECTIVE: Stroke is the third leading cause of death in the United States, behind heart disease and cancer. It affects as many as 5% of the population over 65 years old, and this number is growing annually due to the aging population. A significant portion of stroke patients that initially survive are faced with the risk of aspiration, as well as quality-of-life issues relating to impaired communication. The goal of this paper is to define the scope of practice in otolaryngology for these patients, and to review pertinent background literature. STUDY DESIGN: Consensus report and retrospective literature review. RESULTS: Otolaryngology involvement in these patients is critical to their rehabilitation, which often requires an interdisciplinary team of specialists. This committee presentation explores epidemiological data regarding the impact of stroke and its complications on hospitalizations. A pertinent review of neuroanatomy as it relates to laryngeal function is also discussed. State-of-the-art diagnostic and therapeutic procedures are presented. CONCLUSION: There is a well-defined set of diagnostic and therapeutic options for laryngeal dysfunction in the stroke patient. SIGNIFICANCE: Otolaryngologists play a critical role in the interdisciplinary rehabilitation team.

Clinical anatomy and physiology of the voice.

The anatomy and physiology of voice include not only the larynx but also all body systems. The larynx consists of a skeleton, mucosa, intrinsic muscles, and extrinsic muscles. The vocal folds form the oscillator of the vocal tract, the subglottic vocal tract acts as a power source, and the supraglottic vocal tract functions as a resonator. Complex interactions are responsible for voice production.

Medical history in voice professionals.

A careful and thoughtful history is extremely important in helping to elucidate the cause of a patient's voice complaints. An understanding of the patient's performance and rehearsal environment and demands is also important in guiding the treatment process. A thorough history helps the clinician understand the vocal problem and how to interpret findings on physical examination that may be contributing to the pathophysiology of the vocal complaint.

Physical examination of voice professionals.

Comprehensive physical examination is essential when evaluating patients. Often it includes objective voice assessment and measures along with strobovideolaryngoscopy. In all cases physical examination involves a thorough examination of the ears, nose, throat, neck, posture, cranial nerve function (usually), and assessment of the patient's general (systemic) physical condition. Performance assessment usually should be included for professional voice.

Voice surgery.

There have been many advances in microsurgery for voice professionals over the last three decades. Driven by a greater understanding of the anatomy and physiology of phonation, most of the advances provide greater surgical precision through improved exposure and more delicate instrumentation. Laryngologists who perform laryngoscopic surgery should be familiar with the current state-of-the-art and should use the latest techniques and technology for all voice patients and particularly for voice professionals. Video procedures for surgical management of voice disorders accompany this content online.

Laryngeal electromyography.

Laryngeal electromyography (LEMG) evaluates the integrity of the neuromuscular system in the larynx by recording action potentials generated in the laryngeal muscles during voluntary and involuntary contraction. LEMG is particularly useful for helping to differentiate between disorders involving upper motor neurons, lower motor neurons, peripheral nerves, the neuromuscular junction, muscle fibers, and the laryngeal cartilages and joints. LEMG should be considered to be an extension of the physical examination, not an isolated laboratory procedure. A careful history and laryngeal evaluation determine the indication for LEMG and which muscles or muscle groups, in particular, are to be studied. Abnormalities detected by LEMG are always interpreted within the context of the clinical picture.

Mild vocal fold paresis: understanding clinical presentation and electromyographic findings.

The implications of mild vocal fold hypomobility are incompletely understood. This study describes the clinical, electromyographic, and probable etiologic findings in patients who presented with complaints of dysphonia and whose physical examination revealed vocal fold paresis as a factor possibly contributing to their voice complaints. A retrospective chart review of all patients who presented to a tertiary laryngology referral center over a 13-month period, who had a clinical diagnosis of mild vocal fold hypomobility and who underwent laryngeal electromyography, were included in the study. A total of 22 patients completed the medical evaluation of their voice complaint. Of these patients, 19 (86.4%) were found to have evidence of neuropathy on laryngeal electromyography. The clinical picture indicated the following probable origins for the vocal fold paresis: goiter/thyroiditis (7/22 or 31.8%), idiopathic (4/22 or 18.2%), viral neuritis (4/22 or 18.2%), trauma (3/22 or 13.6%), and Lyme's disease (1/22 or 4.5%). This article describes the clinical entity of mild vocal fold hypomobility and associated flexible laryngoscopic, rigid strobovideolaryngoscopic, and laryngeal electromyographic findings.

The value of laryngeal electromyography in the evaluation of laryngeal motion abnormalities.

SUMMARY: Laryngeal electromyography (EMG) functions routinely as a prognostic tool in the evaluation of vocal fold paralysis, as a guide for therapeutic injections into the laryngeal muscles, and more recently as an assessment tool in the evaluation of vocal fold paresis. This study investigates the clinical utility of laryngeal EMG as a diagnostic aid in the evaluation of movement disorders of the larynx in patients complaining of dysphonia. A retrospective chart review of all laryngeal EMGs performed at a tertiary laryngology referral center over a 13-month period was performed. All laryngeal EMGs were performed to evaluate laryngeal motion abnormalities in dysphonic patients. Thirty-seven laryngeal EMGs were completed during this study period. Analysis of the data revealed that the medical treatment plan changed as a result of findings on laryngeal EMG in 10/37 patients (27.0%); laryngeal EMG guided and/or confirmed the course of treatment in 12/37 patients (32.4%) and did not change the treatment plan in 15/37 patients (40.5%). Laryngeal EMG is a useful diagnostic tool that, in this study, contributed significantly to and helped guide the evaluation and management of motion disorders in the larynx of dysphonic patients.

Common movement disorders affecting the larynx: a report from the neurolaryngology committee of the AAO-HNS.

Laryngeal physiology depends on dynamic neuromuscular forces acting on a basic framework of cartilage and specialized soft tissues, that is, the vocal folds. A working understanding of this organ in health and disease requires knowledge of specific neurological processes that may affect voice, swallowing, and airway regulation. Neuromuscular impairment continues to be a dominant topic in the study of laryngeal disorders. This subcommittee presentation reviews important aspects of the neurolaryngeal history and physical examination. After this foundation, 4 common movement disorders affecting the larynx are covered in separate subsections. These are stroke, Parkinson's disease, laryngeal tremor, and spasmodic dysphonia. State-of-the-art reviews reflecting our understanding of these clinical issues are presented in this summary.

Determinants of fatal apnea responses to acid stimulation of the larynx in piglets.

OBJECTIVES: This study explores the physiological determinants of laryngeal chemoreflex (LCR) response severity under hypoxic conditions. METHODS: Thirty-four piglets underwent hypoxic laryngeal stimulation. Physiologic data were collected, and responses were graded as mild, moderate, or profound. RESULTS: Prestimulation hypoxia caused respiratory depression and carbon dioxide retention in profound responders and respiratory stimulation in mild and moderate responders (p < .05). Resumption of respiration occurred in all animals when the PaCO2 rose by a mean +/- SD of 15.1 +/- 6.5 mm Hg (p > .05). There was a significant difference between mild, moderate, and severe responders in change in arterial PaO2 and hydrogenated hemoglobin saturation during the LCR-induced response (p < .001 for both). CONCLUSIONS: Resumption of respiration is associated with accumulation of arterial PaCO2. The respiratory response to hypoxia predicts the severity of the LCR response. The severity of the LCR-induced response is associated with changes in arterial PaO2 and hydrogenated hemoglobin saturation during the LCR-induced apnea.

Use of silicone hearing aid mold material in laryngotracheal reconstruction.

OBJECTIVES: Endolaryngeal stenting in patients with irregularly shaped larynges can be challenging. In such cases, the use of a moldable yet reasonably rigid endolaryngeal stent is desirable. The purpose of this report is to describe our experience with silicone hearing aid material as a moldable endolaryngeal stent in a patient with an atypically shaped larynx. METHODS: A patient with relapsing polychondritis that resulted in complete stenosis of the subglottic airway underwent laryngotracheal reconstruction. Moldable silicone, commonly used to prepare ear canal molds for hearing aids, was molded into the neo-endolarynx to serve as a custom-made endolaryngeal stent. RESULTS: The patient tolerated the moldable silicone stent well and had a patent airway with epithelialization 8 months after removal. CONCLUSIONS: Silicone mold material is a suitable substance for endolaryngeal stenting. It conforms to the configuration of the individual's airway, is tolerated well, can be removed relatively easily, and is a useful alternative to prefabricated stents in laryngotracheal reconstruction.

How I do it: miniplate reconstruction of the lateral thyroid lamina: one-stage restoration of voice after teflon granuloma resection.

This case report describes a one-stage technique for long-term voice restoration and laryngeal reconstruction in the treatment of Teflon (Dupont, Wilmington, Delaware) granuloma. A patient who presented with severe dysphonia underwent resection of a Teflon granuloma via a lateral laryngotomy. A pedicled strap muscle flap was used to reconstruct the paraglottic space. The muscle flap was positioned through the lateral laryngotomy with direct endoscopic visualization of the endolarynx to ensure correct vertical positioning and medialization of the vocal fold. The muscle flap was secured in this position with suture fixation. The trapdoor piece of cartilage that was elevated to create the window in the lateral thyroid lamina was repositioned over the pedicled muscle flap and reinforced with a titanium miniplate, which was secured to the remaining thyroid cartilage. The patient had excellent voice results and has not required revision or augmentation. Reinforcement of the lateral thyroid lamina using titanium miniplate fixation helps to stabilize the muscle pedicle flap and the position of the vocal fold, in this case resulting in good long-term voice results after a single-stage reconstruction.

Diagnostic tools in laryngology.

PURPOSE OF REVIEW: Laryngology has become recognized as a subspecialty within the field of otolaryngology-head and neck surgery over the course of the past 30 years. The evolution of laryngology stems primarily from our better understanding of the physiology of vocal production, society's increased reliance on oral communication in industry, and the resultant demand for improvements in diagnostic and therapeutic protocols to enhance vocal performance. The purpose of this review is to describe current advances in diagnostic tools in laryngology that contribute to our understanding of vocal physiology and our ability to improve quality of life as it relates to vocal performance. RECENT FINDINGS: Diagnostic tools in laryngology allow the clinician the ability to assess the vibratory function of the vocal folds, evaluate laryngeal structure and airway patency, assess glottal and pulmonary airflow, assess the neurologic integrity of the vocal folds, analyze the quality of the voice signal, and assess the degree of functional disability as it relates to laryngeal pathology. SUMMARY: Primary advances in diagnostic laryngology include improvements in laryngoscopy techniques, imaging, electromyography, aerodynamic testing, acoustic analysis, and functional assessment, each of which is improving our ability to understand, diagnose, and treat a wider spectrum of voice, airway, and swallowing disorders.

Cepstral peak prominence: a more reliable measure of dysphonia.

Quantification of perceptual voice characteristics allows the assessment of voice changes. Acoustic measures of jitter, shimmer, and noise-to-harmonic ratio (NHR) are often unreliable. Measures of cepstral peak prominence (CPP) may be more reliable predictors of dysphonia. Trained listeners analyzed voice samples from 281 patients. The NHR, amplitude perturbation quotient, smoothed pitch perturbation quotient, percent jitter, and CPP were obtained from sustained vowel phonation, and the CPP was obtained from running speech. For the first time, normal and abnormal values of CPP were defined, and they were compared with other acoustic measures used to predict dysphonia. The CPP for running speech is a good predictor and a more reliable measure of dysphonia than are acoustic measures of jitter, shimmer, and NHR.

Reliability of calculating the cepstral peak without linear regression analysis.

Measures of cepstral peak prominence, using the smoothing algorithm and linear regression analysis software developed by Hillenbrand, have been shown to be reliable predictors of dysphonia in voice samples.(1-4) Recently, the Computerized Speech Laboratory [(CSL) Kay Elemetrics, Pinebrook, New Jersey] has introduced cepstral analysis as a component of that software package. The cepstral peak, in this instance, is calculated by the voice clinician analyzing the phonatory sample by subtracting the value of the peak from the apparent baseline signal. This study compares the ability of cepstral peak values calculated from the CSL software to predict dysphonia reliably with that of the values produced by the smoothing algorithm and linear regression analysis of Hillenbrand. The results of this study show that linear regression analysis is an important step in calculating the cepstral peak prominence, thus limiting the usefulness of software programs that do not employ this step.

Determining the etiology of mild vocal fold hypomobility.

The prevalence of mild vocal fold hypomobility is unknown. In a study by Heman-Ackah et al, vocal fold hypomobility in a population of singing teachers was found to be associated more frequently with vocal complaints than was the presence of vocal fold masses. The etiology of mild vocal fold hypomobility has not been previously explored. In the present study, a retrospective chart review was performed of 134 patients who presented to a tertiary laryngology referral center over a 6-month period for evaluation of vocal complaints. Of the 134 patients, 61 (46%) were found to have mild vocal referring otolaryngologist. Imaging studies and laboratory tests to evaluate for structural, metabolic, and infectious causes of the decreased mobility had been ordered. Forty-nine patients completed the work-up. Of these, 41 out of 49 (84%) were found to have imaging or laboratory findings that could explain the hypomobility. Thyroid abnormalities were found to be associated with vocal fold hypomobility in 21 out of 49 (43%) of those with a complete evaluation. Other causes of vocal fold hypomobility included idiopathic (8 of 49, 16%), viral neuritis (5 of 49, 10%), central nervous system abnormality (4 of 49, 8%), neural tumor (3 of 49, 6%), joint dysfunction (3 of 49, 6%), iatrogenic nerve injury (2 of 49, 4%), myopathy (2 of 49, 4%), and noniatrogenic traumatic nerve injury (1 of 49, 2%), This study shows that unilateral vocal fold hypomobility often is associated with a physiologic process, and a complete investigation to determine the etiology is warranted in all cases.

Strobovideolaryngoscopic findings in singing teachers.

Professional voice users often present to otolaryngologists and laryngologists with specific voice complaints. The contributions of pathologic lesions to the patients' vocal complaints are not always clear on examination, and often, premorbid examinations of the larynx are not available for review. This study examines the incidence of laryngeal pathology among singing teachers. At a national convention of singing teachers, volunteers were recruited for a "free strobovideolaryngoscopic examination." All volunteers completed a detailed questionnaire of their vocal and medical history and underwent strobovideolaryngoscopic examination. Strobovideolaryngoscopic examinations were completed in 20 volunteers, 7 of whom had voice complaints and 13 of whom perceived their voices to be normal. Vocal fold masses were common among the asymptomatic singing teachers. Evidence of reflux laryngitis was a common finding among both symptomatic and asymptomatic singing teachers. Asymmetries in vocal fold hypomobility were more common among those with voice complaints than was the presence of vocal fold masses in the population studied.

The relationship between cepstral peak prominence and selected parameters of dysphonia.

Traditional measures of dysphonia vary in their reliability and in their correlations with perceptions of grade. Measurements of cepstral peak prominence (CPP) have been shown to correlate well with perceptions of breathiness. Because it is a measure of periodicity, CPP should also predict roughness. The ability of CPP and other acoustic measures to predict overall dysphonia and the subcategories of breathiness and roughness in pathological voice samples is explored. Preoperative and postoperative speech samples from 19 patients with unilateral recurrent laryngeal nerve paralysis who underwent operative intervention were analyzed by trained listeners and by measures of smoothed CPP (CPPS), noise-to-harmonic ratio (NHR), amplitude perturbation quotient (APQ), relative average perturbation (RAP), and smoothed pitch perturbation quotient (sPPQ). The data were analyzed with bivariate Pearson correlation statistics. Grade of dysphonia and breathiness ratings correlated better with measurements of CPPS than with the other measures. CPPS from samples of connected speech (CPPS-s) best predicted overall dysphonia. None of the measures were useful in predicting roughness.