Laryngeal Electromyography: Clinical Application

Predicting Dysphonia by Measuring Surface Electromyographic Activity of the Supralaryngeal Muscles

PURPOSE

This study set out to investigate whether individuals with dysphonia, as determined by either self-assessment or clinician-based auditory-perceptual judgment, exhibited differences in perilaryngeal muscle activities using surface electromyography (sEMG) during various phonatory tasks. Additionally, the study aimed to assess the effectiveness of sEMG in identifying dysphonic cases.

METHOD

A total of 77 adults (44 women, 33 men, Mage = 30.4 years) participated in this study, with dysphonic cases identified separately using either a 10-item Voice Handicap Index (VHI-10) or clinician-based auditory-perceptual voice quality (APVQ) evaluation. sEMG activities were measured from the areas of suprahyoid and sternocleidomastoid muscles during prolonged vowel /i/ phonations at different pitch and loudness levels. Normalized root-mean-square value against the maximal voluntary contraction (RMS %MVC) of the sEMG signals was obtained for each phonation and compared between subject groups and across phonatory tasks. Additionally, binary logistic regression analysis was performed to determine how the sEMG measures could predict the VHI-10-based or APVQ-based dysphonic cases.

RESULTS

Participants who scored above the criteria on either the VHI-10 (n = 29) or APVQ judgment (n = 17) exhibited significantly higher RMS %MVC in the right suprahyoid muscles compared to the corresponding control groups. Although the RMS %MVC value from the right suprahyoid muscles alone was not a significant predictor of self-evaluated dysphonic cases, a combination of the RMS %MVC values from both the right and left suprahyoid muscles significantly predicted APVQ-based dysphonic cases with a 69.66% fair level.

CONCLUSIONS

This study found that individuals with dysphonia, as determined by either self-assessment or APVQ judgment, displayed more imbalanced suprahyoid muscle activities in voice production compared to nondysphonic groups. The combination of the sEMG measures from both left and right suprahyoid muscles showed potential as a predictor of dysphonia with a fair level of confidence.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25112804.

Vocal Fold Paresis and Voice Outcomes following Vocal Fold Mass Excision

OBJECTIVE

To correlate the surgical results of vocal fold mass excision with pre-operative existence of vocal fold paresis.

METHODS

Data were collected on 66 patients who underwent excision of benign vocal fold masses from 2015 to 2020. The pre- and post-operative strobovideolaryngoscopy (SVL) examinations for all patients included were evaluated blindly by three otolaryngologists using THE Voice-Vibratory Assessment with Laryngeal Imaging (VALI) Form for scar severity, mucosal wave, free edge contour, glottal closure, and phase closure. The success of mass excision surgery was determined based on the presence of the following criteria post-operatively: 1) improved mucosal wave motion 2) improved phase closure or glottic closure 3) improved free edge contour and 4) lack of worsening of vocal fold scar severity. Surgery was considered successful if 3 or 4 criteria were met, partially successful if 1 or 2 criteria were met, and unsuccessful if no criteria were met. The percent recruitment of the thyroarytenoid, posterior cricoarytenoid (PCA), and cricothyroid muscles were used evaluated the severity of paresis as mild (70-99% recruitment), moderate (40-60% recruitment), or severe (0-39% recruitment). VHI-10 scores were used as subjective measures of pre- and post-operative voice.

RESULTS

Sixty-six patients (26 male, 40 female) were included in this study, with a mean age of 37.25 ± 16.6 (range 18-78). Twelve patients had no evidence of VF paresis noted during the initial clinical evaluation; and 52 patients had paresis and had undergone laryngeal EMG. 81% of these patients had mild paresis, 12.8% had moderate paresis, and 5.8% had severe paresis. Based on pre- and post-operative strobovideolaryngoscopy, there was improvement in mucosal wave in 44.9% of cases, improvement of phase or glottic closure in 85.4% of cases, improved free edge contour in 95.5% of cases, and worsening of scar in 38.5% of cases. 39.6% of surgeries were fully successful, 33.3% of surgeries were partially successful, and 27.1% were not successful. There was a significant correlation between female gender and vocal fold paresis (P = 0.048). Paresis severity did not correlate with complete or partial surgical success (P = 0.956), pre-operative VHI-10 scores (P = 0.519), post-operative VHI-10 scores (P = 0.563), or strobovideolaryngoscopy parameters. Unilateral and bilateral paresis did not correlate with any other parameter of surgical success (P >0.05).

CONCLUSION

This study suggests that there is no correlation between pre-operative vocal fold paresis and voice outcomes after mass excision surgery, that the majority of mass excision surgeries (72.9%) are successful based on improvement in stroboscopic parameters, and that the proportion of patients with moderate and severe paresis is consistent across all laryngeal nerves.

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 Relationship Between Vocal Fold Mobility Disorders and Ineffective Esophageal Motility

OBJECTIVE

Deglutition, speech production, and airway protection are extraordinarily complex, interrelated functions that are coordinated, in large part, by the motor and sensory innervation of CN X. Previous studies assessing the relationship between neurogenic voice disorders and dysphagia have focused on the risk of aspiration due to glottic insufficiency and the association of vocal fold hypomobility (VFH) with systemic neurologic disease. The purpose of this study was to investigate the relationship between VFH disorders and ineffective esophageal motility (IEM).

METHODS

Adult voice patients who underwent laryngeal electromyography (LEMG) and dual 24-hour pH impedance with high-resolution manometry (HRM) testing were included in the study. Subjects were assigned to one of two groups based on the presence or absence of moderate-to-severe RLN and/or SLN VFH (Mo-SLNH/RLNH) using results from six muscle LEMG tests. In subjects with Mo-SLNH/RLNH, there was 0-60% muscle recruitment on LEMG, whereas control subjects in the non-Mo-SLNH/RLNH group demonstrated 61-100% muscle recruitment. Analysis of mild-to-severe VFH (80% muscle recruitment or less) was also performed in a similar manner. The prevalence of IEM, defined using Chicago Classification Version 4.0 (CCv4.0), was compared between groups, as were HRM parameters.

RESULTS

One hundred sixty-two subjects were included (37.7% male/62.3% female, mean age of 43.88 ± 17.285). No differences in IEM prevalence were found when stratifying for cases of mild-to-severe VFH. However, there was significantly higher percentage of IEM in those with Mo-SLNH/RLNH. Mo-SLNH/RLNH subjects demonstrated higher rates of weak swallows and inefficient swallows, as well as lower IBP and UES residual pressures on HRM.

CONCLUSIONS

Patients with Mo-SLNH/RLNH demonstrated a significantly higher prevalence of IEM. Those with mild-to-severe VFH did not. Higher rates of ineffective and weak swallows, and lower IBP and UES residual pressures among Mo-SLNH/RLNH subjects suggest a possible connection between Mo-SLNH/RLNH and IEM disorders. These manometric differences were more prominent with sub-stratification of the Mo-SLNH/RLNH group by IEM. Additional research is advised.

Assessing the Prevalence and Associated Risk Factors for Presbylarynx in the Elderly Laryngology Population

OBJECTIVE

The primary objective of this study was to assess the prevalence of presbylarynx and its associated features in an elderly population representative of patients seen in a tertiary care laryngology practice. The secondary objective of this study was to compare laryngeal electromyography (LEMG) findings, coexisting VF conditions, medical history, surgical history, medication use, and other parameters between patients with and without presbylarynx.

METHODS

Adult voice patients aged 60 years and older who underwent strobovideolaryngoscopy were included in the study. Patients were assigned to one of two groups based on the majority (≥2/3) agreement of three blinded authors' (GA, KL, and HP) graded examinations of strobovideolaryngoscopy (SVL) videos for findings consistent with presbylarynx (atrophic vocal folds [VFA], vocal fold bowing [VFB], vocal process prominence [VPP] and anterior glottic insufficiency [GI]). Patient demographics, medical history, surgical history, medication use, laboratory results, and SVL videos were compiled. Statistical analysis was performed using SPSS 28.0.0.0 (IBM, Armonk, NY). All tests were performed two-tailed, and a P-value of less than 0.05 was considered statistically significant.

RESULTS

One hundred sixty-four patients (84 female/80 male, mean age of 68.397 ± 4.947 years) were included in this study. The prevalence of presbylarynx was 52.4% (n = 86) in the study population. The mean age of patients in the presbylarynx group was significantly higher than the nonpresbylarynx group. Additionally, there were significantly more males than females in the presbylarynx group. The presbylarynx group also was found to have a higher proportion of ACE inhibitor (ACEi) use. Further, laboratory results revealed a significantly higher proportion of patients with elevated thyroid stimulating hormone (TSH) levels in the presbylarynx group. Conversely, patients in the nonpresbylarynx group were found to have a significantly higher rate of levothyroxine use. On SVL, patients in the nonpresbylarynx cohort were found to have a significantly higher proportion of benign vocal fold lesions and vocal fold paresis. However, LEMG testing revealed no statistically significant differences in muscle recruitment between groups. Men with presbylarynx were found to have a significantly higher proportion of VFB and VPP compared to women with presbylarynx.

CONCLUSION

This retrospective study investigated the prevalence and risk factors associated with presbylarynx in patients representative of those treated by laryngologists. Signs consistent with presbylarynx are observable even in the presence of coexisting VF conditions. Older age, elevated TSH, the use of ACEi, and male gender was associated with signs of presbylarynx on SVL. Of those diagnosed with presbylarynx, males were identified as having higher proportions of VFB and VPP compared to females. More education regarding presbylarynx and further studies to improve standardization of the criteria for its diagnosis, as well as its relationship with other VF conditions, are encouraged to improve management of the aging voice.

3D VOSNet: Segmentation of endoscopic images of the larynx with subsequent generation of indicators

Video laryngoscope is available for visualizing the motion of vocal cords and aid in the assessment of analyzing the larynx-related lesion preliminarily. Laryngeal Electromyography (EMG) needs to be performed to diagnose the factors of vocal cord paralysis, which may cause patient feeling unwell. Thus, the problem is the lack of credible larynx indicators to evaluate larynx-related diseases in the department of otolaryngology. Therefore, this paper aims to propose a 3D VOSNet model, which has the characteristics of sequence segmentation to extract the time-series features in the video laryngoscope. The 3D VOSNet model can keep the time-series features of three images before and after of the specific image to achieve translation and occlusion invariance, which explicitly signifies that our model can segment and classify each item in the video of laryngoscopy not affected by extrinsic causes such as shaking or occlusion during laryngoscope. Numerical results revealed that the testing accuracy rates of the glottal, right vocal cord, and the left vocal cord are 89.91%, 94.63%, and 93.48%, respectively. Our proposed model can segment glottal and vocal cords from the sequence of laryngoscopy. Finally, using the proposed algorithm computes six larynx indicators, which are the area of the glottal, area of vocal cords, length of vocal cords, deviation of length of vocal cords, and symmetry of the vocal cords. In order to assist otolaryngologists in staying credible and objective when making decisions without any doubt during diagnosis and also explaining the clinical symptoms of the larynx such as vocal cord paralysis to patients after diagnosis, our proposed algorithm provides otolaryngologists with explainable indicators (X-indicators).

Does the Severity of Vocal Fold Paresis on Laryngeal Electromyography Correlate With Radiographic Findings on Cross Sectional Imaging?

OBJECTIVES

Unilateral vocal fold paresis or paralysis (UVFP) is a condition for which radiographic evaluation and laryngeal electromyography (LEMG) are valuable to evaluate severity of injury and direct treatment plans. Despite extensive research involving findings suggestive of UVFP with radiographic imaging, no study has attempted to determine which findings suggestive of UVFP on imaging are clinically significant and suggest a need for intervention. The purpose of this study was to evaluate whether the severity of vocal fold paresis/paralysis affects the likelihood of encountering radiographic findings suggestive of UVFP. We also aimed to determine which findings suggestive of UVFP on imaging were clinically significant and were associated with surgical intervention.

MATERIALS AND METHODS

A retrospective chart review was conducted of patients who had been diagnosed with unilateral vocal fold paresis or paralysis and had been evaluated by CT scan and/or magnetic resonance imaging and laryngeal electromyography (EMG) between the dates of January 1, 2017 and January 9, 2018. Fisher's exact testing with Monte Carlo Simulation was utilized to determine statistical significance of identified relationships. Univariate analysis was conducted to assess for individual relationships between imaging results and the potential predictor variables. Chi square analysis was conducted with the various categorical variables to assess for any potential relationships to imaging results. Statistical significance was determined utilizing chi square analysis.

RESULTS

After data collection, 130 patients were included in the study population. Of the 112 patients with documented MRI results, 17% had a reported imaging abnormality suggestive of true vocal fold paresis or paralysis (VFP). Of the 71 patients with documented CT Neck results, 15.4% had an abnormality potentially concerning for true VFP. The average decrease in recruitment of the right and left SLN was 23.8% and 26.1%, respectively. The average decrease in recruitment of the right and left RLN was 37.3% and 57.78%, respectively. Seventy four percent of patients who exhibited abnormal MRI were found to have isolated SLN weakness, and 21% of patients were found to have a combined SLN and ipsilateral RLN weakness. In patients with abnormal CT scans 45% were found to have isolated SLN weakness, and 35% were found to have a combined SLN and RLN weakness. MRI imaging again failed to display any significant degree of paresis. However, abnormal CT results displayed severe CN X paresis in 36.84% vs 1.96% in normal scans. The chance of an abnormal MRI and CT result was 2.78 and 5.55 times greater, respectively, for each increase in the degree of severity of CN X paresis. When looking at the ability of imaging to predict the chance of a patient undergoing surgery, 34.8% of patients with an abnormal MRI underwent surgery compared to just 14.61% of those with normal scans. For CT scans, 35% of patients with an abnormal scan underwent surgery, compared with only 15.69% with normal imaging. When pooled, over 33% of patients with any abnormal imaging underwent a laryngeal procedure compared to 13% of patients with normal imaging.

CONCLUSIONS

There is a relationship between severity of vocal fold paresis found on laryngeal EMG and likelihood of detection on imaging. While CT was more likely to find characteristics of UVFP than MRI, patients who had an abnormal finding on either modality were more likely to undergo surgical intervention. These findings highlight the importance of early referral of patients with abnormal laryngeal imaging to an otolaryngologist for evaluation and possible intervention.

Safety of Laryngeal Electromyography and Repetitive Stimulation

OBJECTIVES

Laryngeal Electromyography (LEMG) is a procedure used to assess electrical signals from laryngeal muscles. It is considered to be the gold standard test for examining vocal fold paresis/paralysis. Repetitive stimulation studies, which usually are performed at the time of LEMG, can aid in assessment of neuromuscular function. Electromyography poses risks to the patient due to the use of electricity and needles. The purpose of this paper was to evaluate the safety of LEMG and discuss the possible complications.

METHODS

This was a retrospective review of patients from January 2015 through February 2022. Information from patient charts included age, sex, chief complaint, past medical history, family medical history, medications, social history, strobovideolaryngoscopy results, type of paresis, professional voice user status, presence of pacemaker, laryngeal electromyography and repetitive stimulation study results, and reported complications. Complications were considered to be anything that differed from the norm. Pain was included as a complication. Data were analyzed for relationships and significance.

RESULTS

Five hundred patients were included. Eighteen of the 500 (3.6%) experienced complications. Four (2.1%) males and 14 (4.5%) females experienced complications. Nine of the 18 (50%) reported pain after the procedure, 1 (5.56%) had excessive bleeding (controlled with pressure), 5 (27.78%) reported voice changes, and 3 (16.67%) experienced difficulty with completion of the procedure. No patients with pacemakers or patients taking anticoagulants had complications, but repetitive stimulation studies were not performed on patients with pacemakers.

CONCLUSIONS

LEMG and repetitive stimulation studies are safe and effective procedures to examine laryngeal muscles. Repetitive stimulation studies are not recommended for patients with pacemakers.

The Use of Laryngeal Electromyography to Determine Surgical Success Following Anastomosis and Implantation Reinnervation Surgeries for Vocal Fold Paralysis: A Systematic Review

BACKGROUND

The goal of this systematic review is to elucidate an evidence-based review of the benefit of laryngeal electromyography (LEMG) in determining surgical success following reanastamosis and implantation reinnervation surgery for treating vocal fold paralysis.

METHODS

We searched the following databases: PubMed, Embase and MEDLINE from inception to September 2022. Articles that included postoperative LEMG as a tool to evaluate patients after surgery for vocal fold paralysis were included.

RESULTS

A total of 203 studies were identified, 106 were read in full, and 11 that met the inclusion criteria were systematically reviewed.

CONCLUSION

The available evidence suggests that postoperative LEMG data is consistent with visual, perceptual, and acoustic analysis and therefore is a reliable tool in determining surgical success. LEMG provides both qualitative and quantitative evaluation, rather than the qualitative evaluation provided by standard methods, which yields additional parameters that more effectively and definitively characterize percent of muscle reinnervation at each stage and timeline the patient's recovery.

Clinical usefulness of transcutaneous laryngeal ultrasonography in otolaryngology practice during COVID-19 pandemic: a literature review

As a consequence of the outbreak of SARS-CoV-2, the clinical practice of otolaryngologists underwent profound transformations. Non-aerosol-generating procedures have been researched and implemented. Transcutaneous laryngeal ultrasonography (TLUSG) provides a rapid and noninvasive method to assess laryngeal function and can support the management of laryngeal disorders. With the aim of investigating the clinical usefulness of TLUSG in otolaryngology practice, a review of the literature published on PubMed, Cochrane Library and Ovid/ Medline databases was performed up to March 2022. 38 studies were eligible to be included in the review. The selected papers were divided into six topics of interest: evaluation of vocal cords function, diagnosis of laryngeal disorders in infants and children, evaluation of swallowing disorders, assessment of laryngeal cancer and other laryngeal lesions, ultrasound-guided cricothyroidotomy, ultrasound-guided laryngeal electromyography. The results of this review demonstrated that TLUSG, applied to ENT practice, can be a valid method for dynamic laryngeal assessment and airway management, since it is time-efficient, non invasive, well tolerated and easily performed.

Exploring the Clinical Characteristics of Superior Laryngeal Nerve Injury

OBJECTIVES

To observe the cases of superior laryngeal nerve injury along with summarizing and analyzing its clinical characteristics.

METHODS

A total of 14 patients with unilateral superior laryngeal nerve injury (SLN) diagnosed by laryngeal electromyography (LEMG) in our department from 2018 to 2020 were collected as SLN injury group. A total of 14 healthy subjects with normal laryngeal electromyography were recruited as normal group matched by age and sex. The etiology and LEMG of the SLN injury group were analyzed, and the video stroboscopic manifestations of SLN injury group and normal group were compared to see the characteristic video stroboscopic manifestations of SLN injury.

RESULTS

The most common causes of SLN injury were surgery and idiopathic etiology. Compared with normal group, the most frequent video stroboscopic manifestations of SLN injury group were vocal fold dyskinesia. Abnormal video stroboscopic manifestations occurred in normal group except larynx deviation, epiglottic petiole deviation, and dyskinesia. There was a significant difference between the two groups in various abnormal video stroboscopic manifestations (P < 0.05). Time limit widening was the most common manifestation of LEMG.

CONCLUSIONS

Vocal fold dyskinesia was a prominent finding in SLN injury, laryngeal deviation and epiglottic petiole deviation were relative specific signs of SLN injury. Vocal fold bowing combined with shortening will contribute to the diagnosis of SLN injury. There were no specific diagnostic signs for SLN injury, clinicians need further LEMG for a firm diagnosis.

Vocal fold immobility with normal LEMG: A range of possibilities

OBJECTIVE

The objective of this paper is to study the etiology of vocal fold immobility with non-pathological LEMG.

METHODS

A retrospective study was performed on patients who presented with vocal fold immobility and underwent LEMG from 2009 to 2017. Those patients with normal LEMG findings were selected. The different causes of vocal fold impairment were studied.

RESULTS

Of the 120 patients included in this study, 15 had a normal LEMG recording. The different etiologies of vocal fold immobility were idiopathic, central nervous system damage, iatrogenic, and external compression.

CONCLUSIONS

Vocal fold immobility and vocal fold paralysis are not equal terms. Vocal fold immobility with normal LEMG has a heterogeneous group of causes. It is not correct to assume that the major cause of immobility in patients with normal LEMG is always cricoarytenoid joint fixation.

Vocal fold immobility with normal LEMG: A range of possibilities

OBJECTIVE

The objective of this paper is to study the etiology of vocal fold immobility with non-pathological LEMG.

METHODS

A retrospective study was performed on patients who presented with vocal fold immobility and underwent LEMG from 2009 to 2017. Those patients with normal LEMG findings were selected. The different causes of vocal fold impairment were studied.

RESULTS

Of the 120 patients included in this study, 15 had a normal LEMG recording. The different etiologies of vocal fold immobility were idiopathic, central nervous system damage, iatrogenic, and external compression.

CONCLUSIONS

Vocal fold immobility and vocal fold paralysis are not equal terms. Vocal fold immobility with normal LEMG has a heterogeneous group of causes. It is not correct to assume that the major cause of immobility in patients with normal LEMG is always cricoarytenoid joint fixation.

Abnormal Laryngeal Electromyography Findings in Asymptomatic Adults Across the Age Spectrum

OBJECTIVES/HYPOTHESIS

Laryngeal electromyography (LEMG) is a diagnostic tool for patients with suspected neurogenic abnormalities of the larynx. LEMG is often used with the assumption that any abnormality is symptom-/disease-related. We sought to determine the prevalence of abnormal LEMG findings in a group of healthy asymptomatic adults across a large age spectrum.

STUDY DESIGN

Open, prospective study, gender-match and age balanced by decade.

METHODS

Forty-six healthy participants (age 20-78) underwent LEMG, including 178 muscles. Participants had no history of voice problems, normal VHI-10, and normal flexible laryngoscopy. Qualitative and quantitative LEMG (bilateral) were performed involving the thyroarytenoid-lateral cricoarytenoid muscle complex (TA-LCA) and cricothyroid (CT) muscles. LEMG parameters included evaluation for fibrillation potentials, sharp waves, reduced recruitment, polyphasic potentials, electrical synkinesis, and measurement of turns per second.

RESULTS

Of participants, 4% had at least one abnormal qualitative finding (slightly reduced recruitment or two to three discrete polyphasic potentials). There were no findings of fibrillation potentials or sharp waves. There were no abnormal qualitative findings in the CT muscles tested. Of participants, 16% had at least one abnormal synkinesis finding. LEMG qualitative abnormalities and quantitative abnormalities do not appear to correlate with gender or age.

CONCLUSION

Abnormal qualitative and quantitative LEMG findings were uncommon and minor in severity in our group of asymptomatic healthy adults. The likelihood of abnormal LEMG results in asymptomatic adults was 2.2% for qualitative findings, 9.3% for synkinesis, and 5.4% for turns/s.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:2065-2069, 2021.

The Poor Validity of Asymmetric Laryngoscopic Findings in Predicting Laterality in Vocal Fold Paresis

OBJECTIVE

To determine the laryngoscopic findings most predictive of laterality in vocal fold paresis in patients with known RLN and/or SLN paresis by laryngeal electromyography (LEMG).

STUDY DESIGN

Blinded, prospective video perceptual analysis study.

METHODS

Patients with vocal fold paresis diagnosed by LEMG at a tertiary care hospital from 2017 to 2019 were identified. Two fellowship-trained laryngologists blinded to clinical history and LEMG results reviewed laryngostroboscopic examinations and assessed for evidence of paresis using defined criteria. Inclusion criteria were adults with laryngeal asymmetry and evidence of decreased recruitment on LEMG. Exclusion criteria were children, presence of laryngeal lesions, myasthenia gravis, vocal fold paralysis, and normal laryngeal symmetry.

RESULTS

We identified 95 patients who were diagnosed with vocal fold paresis with LEMG who met inclusion and exclusion criteria (mean age 43.8 ± 20.4 years (18-88), 38.9% male). When comparing the laterality of the observed laryngoscopic finding with LEMG, we found that in patients who had severe true vocal fold (TVF) range of motion disturbance, the laterality of the finding matched the LEMG distribution of paresis in 12 out of 13 (92.3%) patients (P = 0.002). No other laryngoscopic findings reliably predicted laterality including corniculate and cuneiform cartilage asymmetry, pyriform sinus dilation, abnormal TVF show, petiole deviation, abnormal ventricular show, increased supraglottic area, and FVF hyperfunction of the opposite side.

CONCLUSION

With the exception of severe TVF range of motion disturbance, there seems to be poor validity of laryngoscopic findings in predicting the affected side in vocal fold paresis. We recommend neurophysiologic testing to confirm the clinical diagnosis of vocal fold paresis.

Guidelines for the Management of Unilateral Vocal Fold Paralysis From the Korean Society of Laryngology, Phoniatrics and Logopedics

The Korean Society of Laryngology, Phoniatrics and Logopedics appointed a task force to establish clinical practice guidelines for the management of unilateral vocal fold paralysis (UVFP). These guidelines cover a comprehensive range of management-related factors, including the diagnosis and treatment of UVFP, and provide in-depth information based on current, up-to-date knowledge. Detailed evidence profiles are provided for each recommendation. The CORE databases, including OVID Medline, Embase, the Cochrane Library, and KoreaMed, were searched to identify all relevant papers, using a predefined search strategy. When insufficient evidence existed, expert opinions and Delphi questionnaires were used to fill the evidence gap. The committee developed 16 evidence-based recommendations in six categories: initial evaluation (R1–4), spontaneous recovery (R5), medical treatment (R6), surgical treatment (R7–14), voice therapy (R15), and aspiration prevention (R16). The goal of these guidelines is to assist general otolaryngologists and speech-language pathologists who are primarily responsible for treating patients with UVFP. These guidelines are also intended to facilitate understanding of the condition among other health-care providers, including primary care physicians, nurses, and policy-makers.

Laryngology Education in Otolaryngology Residency Programs - A Pilot Study

Laryngology is a relatively new subspecialty, and experience and training vary among residency programs. Graduated residents are expected to have training adequate to manage common laryngeal disorders, but the current adequacy of laryngology training is not known.

OBJECTIVES

To evaluate resident exposure to laryngology during otolaryngology residency.

METHODS

An anonymous, web-based, multiple choice, electronic questionnaire was sent to all 125 accredited otolaryngology training programs in the United States to distribute to otolaryngology senior residents (postgraduate year [PGY]-4, PGY-5).

RESULTS

Sixty-four residents (33 PGY-4 and 31 PGY-5) responded to the survey. 85.9% had had training in strobovideolaryngoscopy. Only 7.8% of residents had had training in performing or interpreting objective voice measurements, and 26.6% had had training in performing or interpreting laryngeal electromyography. 42.2% of residents had participated in a laryngeal surgical laboratory. Only 19.4% of residents had attended a national laryngology meeting during the preceding 12 months. 92.2% of residents reported that their program had a laryngologist attending, 95.3% had a speech-language pathologist in their department, and 21.9% had a laryngology fellow. 87.5% of residents reported that they do not have to transfer any laryngeal cases to another facility. Exposure to microdirect laryngoscopy, vocal fold mass excision with microflap technique, type I thyroplasty, and subglottic stenosis repair was (100%, 92.2%, 84.4%, and 96.9%, respectively). 54.7% of residents were exposed to arytenoidectomy, and 14.1% of residents were exposed to reduction of arytenoid dislocation/subluxation. 45.3% of residents reported that they had an interest in music, 25% had an interest in singing, 14.1% had an interest in acting.

CONCLUSIONS

More comprehensive laryngeal education could be achieved during otolaryngology residency by increasing exposure to objective voice measurements, laryngeal electromyography, and laryngeal surgery, especially arytenoid procedures including dislocation/subluxation reduction and arytenoidectomy.

Laryngeal Electromyography-Guided Hyaluronic Acid Vocal Fold Injections for Glottic Insufficiency

OBJECTIVES

To assess voice outcomes using the novel technique of in-office laryngeal electromyography-guided vocal fold injections (LEVFI) with hyaluronic acid to treat glottal insufficiency. Secondary objectives included determining the complication/completion rates and if any factors were associated with improved voice outcomes.

METHODS

Retrospective review of patients who received their first LEVFI from August 2017 to December 2018. Three- and six-month voice outcomes were assessed. Outcomes included voice handicap index-10 (VHI-10), maximum phonation time (MPT), perceptual analysis of voice (GRBAS), fundamental frequency, and stroboscopy.

RESULTS

Of the 121 eligible patients (55.4% male, age 63.7 years), 94 (77.7%) had complete 3-month data and 59 (48.8%) had complete 6-month data. VHI-10 was significantly improved from 25.7 ± 7.5 to 20.9 ± 10.9 at 3 months (P < .001) and to 19.1 ± 11.5 at 6 months (P < .001). MPT improved from 6.2 ± 5.4 seconds to 9.4 ± 7.1 seconds at 3 months (P < .001) and to 11.3 ± 8.2 seconds at 6 months (P < .001). GRBAS was improved in 74.8% of patients ([65.2, 82.8] 95% CI) at 3 months and 80.8% ([69.9, 89.1]) 95% CI) at 6 months. Stroboscopy showed a glottic gap improvement in 74.8% of patients ([65.8, 82.4] 95% CI) at 3 months and in 80.3% ([65.9, 88.5] 95% CI) at 6 months. Fundamental frequency was unchanged, as expected. Multivariate analysis reported that no factors were associated with better voice outcomes. Overall, 177/181 (97.8%) injections were completed. There were no complications.

CONCLUSION

In-office LEVFI is an effective, novel technique to treat glottic insufficiency with improved voice outcomes, high completion rate, and no significant complications.

Current management of arytenoid sub-luxation and dislocation

PURPOSE

To review the current management of arytenoid subluxation/dislocation (AS/AD) focusing on diagnostic, therapeutic, and prognostic controversies.

METHODS

The international literature of the last 20 years has been considered. After the application of inclusion criteria, 20 studies were selected (471 AS/AD cases in total).

RESULTS

All the included investigations were retrospective case series. AS/AD was often iatrogenic occurring at least in 0.01% of patients undergone endo-tracheal intubation. The most common symptom was persistent hoarseness. The diagnosis was made by video-laryngoscopy and neck computed tomography in most reports, while some used also laryngeal electromyography. Laryngeal electromyography was fundamental to rule out unilateral vocal fold paralysis, the main differential diagnosis. The surgical relocation of AS/AD under general or local anesthesia was achieved in about 80% of patients.

CONCLUSION

AS/AD is a mechanical disorder of the larynx that can be successfully treated if promptly diagnosed. Clinical trials and multi-centric studies are necessary to set management guidelines.

Diagnostic Value of Acoustic and Aerodynamic Measurements in Vocal Fold Movement Disorders and their Correlation with Laryngeal Electromyography and Voice Handicap Index

OBJECTIVES

Investigate the relationships between the Voice Handicap Index, laryngeal electromyography, and objective acoustic voice testing in order to determine the utility of these measures in the management of vocal fold movement disorders.

METHODS

A retrospective review of patients who had completed a Voice Handicap Index-10 (VHI-10) questionnaire, laryngeal electromyography (LEMG), and objective acoustic measurements (including jitter, relative average perturbation, shimmer, noise-to-harmonic ratio, and standard deviation of fundamental frequency). All three tests had been completed within 30 days of the initial evaluation. All patients' results for acoustic measures were recorded as standard deviations from the norm. LEMG results were converted to grade of paresis (mild, moderate, severe) based on the muscle with the lowest recruitment. Spearman correlation coefficients were calculated to determine the relationship between these three parameters.

RESULTS

A total of 313 subjects were included in the analysis. VHI-10, LEMG (grade of paresis), and objective acoustic measures were, at best, weakly correlated. VHI-10 was better correlated than LEMG to each acoustic parameter including the average acoustic scores; however, the highest correlation observed only reached ρ = 0.349 (P < 0.001). The acoustic variables that correlated best with VHI-10 and LEMG were the standard deviation of the fundamental frequency (ρ = 0.349, P < 0.001) and shimmer (ρ = 0.207, P < 0.001), respectively.

CONCLUSION

This study demonstrates that these measures are, at best, weakly associated. VHI-10 correlated better than LEMG (grade of paresis) to each acoustic voice analysis parameter. However, the maximum correlation coefficient observed was 0.349. Therefore, VHI-10 scores and objective voice acoustic measurements are not useful for predicting the severity of vocal fold movement disorders. Moreover, a given severity of paresis can have different effects on voice handicap and acoustic output in different individuals.

Difficulty producing high-pitched sounds in singing: correlations with laryngostroboscopy and electromyographic findings

INTRODUCTION

Difficulties or limitations in producing high-pitched sounds while singing may be due to the vocal technique used or organic factor. The observation of such difficulty or limitation by singing teachers is one of the main reasons affected individuals are referred to otolaryngologists.

OBJECTIVE

To evaluate the laryngostroboscopic and electromyographic changes in the cricothyroid muscles of singers with difficulties or limitations producing high-pitched sounds.

METHODS

This is a cross-sectional study. Ten singers with difficulty producing high-pitched sounds underwent voice, laryngostroboscopic, and electromyographic evaluations.

RESULTS

None of the evaluated singers presented signs of impairment of the superior laryngeal nerve on laryngostroboscopy. The electromyographic findings for the cricothyroid muscle were normal for all singers. Six singers presented vocal fold lesions, seven had signs suggestive of laryngopharyngeal reflux, and two presented vascular changes.

CONCLUSION

No signs suggestive of superior laryngeal nerve paresis or paralysis were observed on laryngostroboscopy and electromyography of the cricothyroid muscle in singers with difficulties or limitations producing high-pitched sounds. The presence of vocal fold lesions should be investigated in this population.

High-density surface electromyography: A visualization method of laryngeal muscle activity

OBJECTIVES/HYPOTHESIS

Laryngeal muscle activation is a complex and dynamic process. Current evaluation methods include needle and surface electromyography (sEMG). Limitations of needle electromyography include patient discomfort, interpretive complexity, and limited duration of recording. sEMG demonstrates interpretive challenges given loss of spatial selectivity. Application of high-density sEMG (HD sEMG) arrays were evaluated for potential to compensate for spatial selectivity loss while retaining benefits of noninvasive monitoring.

STUDY DESIGN

Basic science.

METHODS

Ten adults performed phonatory tasks while a 20-channel array recorded spatiotemporal data of the anterior neck. Data were processed to provide average spectral power of each electrode. Comparison was made between rest, low-, and high-pitch phonation. Two-dimensional (2D) spectral energy maps were created to evaluate use in gross identification of muscle location.

RESULTS

Three phonatory tasks yielded spectral power measures across the HD sEMG array. Each electrode within the array demonstrated unique power values across all subjects (P < .001). Comparison of each electrode to itself across phonatory tasks yielded differences in all subjects during rest versus low versus high, rest versus low, and rest versus high and in 9/10 subjects (P < .001) for low versus high phonation. Symmetry of HD sEMG signal was noted. Review of 2D coronal energy maps allowed for gross identification of cricothyroid muscle amidst anterior strap musculature.

CONCLUSIONS

HD sEMG can be used to identify differences in anterior neck muscle activity between rest, low-, and high-pitch phonation. HD sEMG of the anterior neck holds potential to enhance diagnostic and therapeutic monitoring for pathologies of laryngeal function.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:2347-2353, 2019.

Vocal fold paresis: Medical specialists' opinions on standard diagnostics and laryngeal findings

PURPOSE

There is still no clear consensus on the diagnostic value of specific laryngeal findings in patients with suspected vocal fold paresis (VFP). The aim of the study was to establish expert opinion on criteria for the diagnosis of VFP in Europe.

METHODS

A cross-sectional survey using the questionnaire introduced by Wu and Sulica for US American experts was addressed to laryngeal experts in Germany, Austria, and Switzerland and in a second survey wave to members of the European Laryngological Society.

RESULTS

100 respondents returned survey 1 (response rate 47.2%). 26% worked at a university department. 28% regularly used laryngeal electromyography (LEMG). A pathologic test results in LEMG was considered to have the strongest positive predictive value for VFP (79 ± 23%), followed by a decreased vocal fold abduction (70 ± 29%), decreased vocal fold adduction (61 ± 34%), and atrophy of the hemilarynx (61 ± 31%). The multivariate analysis showed the predictive value of LEMG was estimated lower by respondents from non-university hospital (β = - 16.33; confidence interval (CI) = - 25.63 to - 7.02; p = 0.001) and higher in hospitals with higher frequency of VFP patients per months (β = 1.57; CI = - 0.98 to 2.16; p < 0.0001). 30 ELS members returned survey 2 (response rate, 8.4%). Their answers were not significantly different to survey 1.

CONCLUSIONS

The laryngology experts in Europe rely on LEMG for diagnosis of VFP like the US American experts, but paradoxically only a minority uses LEMG frequently. Next to LEMG, motion abnormities were considered to have the best predictive value for the diagnosis of VFP.

Vocal fold paresis – a debilitating and underdiagnosed condition

Objectives:

To review the clinical signs of vocal fold paresis on laryngeal videostroboscopy, to quantify its impact on patients’ quality of life and to confirm the benefit of laryngeal electromyography in its diagnosis.

Methods:

Twenty-nine vocal fold paresis patients were referred for laryngeal electromyography. Voice Handicap Index 10 results were compared to 43 patients diagnosed with vocal fold paralysis. Laryngeal videostroboscopy analysis was conducted to determine side of paresis.

Results:

Blinded laryngeal electromyography confirmed vocal fold paresis in 92.6 per cent of cases, with vocal fold lag being the most common diagnostic sign. The laryngology team accurately predicted side of paresis in 76 per cent of cases. Total Voice Handicap Index 10 responses were not significantly different between vocal fold paralysis and vocal fold paresis groups (26.08 ± 0.21 and 22.93 ± 0.17, respectively).

Conclusion:

Vocal fold paresis has a significant impact on quality of life. This study shows that laryngeal electromyography is an important diagnostic tool. Patients with persisting dysphonia and apparently normal vocal fold movement, who fail to respond to appropriate speech therapy, should be investigated for a diagnosis of vocal fold paresis.

Electromyography-guided hyaluronic acid injection laryngoplasty in early stage of unilateral vocal fold paralysis

INTRODUCTION AND OBJECTIVE

To assess the effectiveness of electromyography-guided hyaluronic acid injection laryngoplasty in the early stage of unilateral vocal fold paralysis in terms of patient recovery from dysphonia and quality of life.

METHODS

Between January and December 2014, 28 patients with unilateral vocal fold paralysis underwent electromyography and injection of hyaluronic acid in the thyroarytenoid muscle. We compared the voice handicap index, grade, roughness, breathiness, asthenia, strain scale (GRBAS), videostroboscopic parameters and maximum phonation time assessed before, 15 days and 6 months after the intervention, using the non-parametric Wilcoxon rank test.

RESULTS

Out of the 28 patients, 1 had a haematoma in the injected vocal fold (3.57%) and 6 required second injections. The maximum phonation time of the vowel /e/ increased from 6.07 to 12.14 sec. (15 days post-intervention) and subsequently 12.75 (6 months post-intervention). There was also a significant improvement in the grade, roughness, breathiness, asthenia, strain scale in parameters G, B and A both 15 days and 6 months after the intervention. The voice handicap index score decreased from 58.29 to 37.63 (15 days post-intervention) and 29.64 (6 months post-intervention).

CONCLUSIONS

Electromyography-guided hyaluronic injection laryngoplasty in unilateral vocal fold paralysis enables, in the same intervention, neuromuscular assessment and temporary treatment of glottic insufficiency with a low risk of complications and improvement in patient's quality of life. This may reduce the need for subsequent treatments, but further research is required to confirm these findings.

Laryngeal electromyographic changes in postthyroidectomy patients with normal vocal cord mobility

Thyroidectomy has been used for the treatment of thyroid disease for more than 100 years. In spite of the advancement of surgical techniques, there is still a risk of laryngeal nerve injury. The risk of partial or complete injury still depends on some surgical and disease-related factors. The aim of this study is to show the partial injury and to establish these risk factors via laryngeal electromyographic analysis (LEMG) in postthyroidectomy patients with normal vocal cord motion and mucosal anatomy. Patients who had undergone thyroid surgery were enrolled in this prospective study. LEMG analysis was performed to all patients with normal vocal cord mobility preoperatively and was repeated after the first and the third months of surgery. Thyroarytenoid (TA) and cricothyroid (CT) muscles were used to evaluate recurrent and external branch of superior laryngeal nerves, respectively. Four of the 32 patients had mild-to-moderate degrees of partial LEMG changes during preoperative LEMG analysis of TA and CT muscles on each side. After 3 months of surgery, there was a statistically significant worsening of LEMG findings in the right and left external branches of superior and left recurrent laryngeal nerves. Disease and surgery-related risk factors were analyzed. However, there was no significant relationship on the progression of LEMG findings according to these parameters. This is the first prospective study which supports the risk of progression of LEMG changes in patients with normal laryngoscopic examination after thyroid surgery. No reliable significant risk factor was found influencing the LEMG progression.

Intraoperative Neurophysiological Monitoring of the Laryngeal Nerves During Anterior Neck Surgery: A Review

Contributions to the literature on intraoperative neuro monitoring (IONM) during endocrine and head and neck surgery have increased over recent years. Organizational support for neural monitoring during surgery is becoming evident and is increasingly recognized as an adjunct to visual nerve identification. A comprehensive understanding of the role of IONM for prevention of nerve injuries is critical to maximize safety during surgery of the anterior compartment of the neck. This review will explore the potential advantages of IONM to improve the outcomes among patients undergoing anterior neck surgery.

Diagnostic and prognostic contribution of laryngeal electromyography in unilateral vocal-fold immobility in adults

OBJECTIVES

To study the diagnostic and prognostic contribution of laryngeal electromyography in unilateral vocal-fold immobility in adults.

MATERIAL AND METHODS

A retrospective study included patients with unilateral vocal-fold immobility undergoing laryngeal electromyography between 2007 and 2015. Neurogenic, normal or myogenic findings were compared to the clinical aspect. Prognosis for recovery was assessed from motor unit potentials on laryngeal electromyography, and compared to subsequent progress on laryngoscopy.

RESULTS

Sixty-three patients (mean age, 59 years) were initially included; 2 were subsequently excluded from analysis. Mean time from onset of immobility to laryngeal electromyography was 7 months. 85% of the 61 patients showed neurogenic findings, indicating neural lesion; 13% showed normal electromyography, indicating cricoarytenoid joint ankylosis; and 1 patient showed a myogenic pattern. Neurogenic cases were usually secondary to cervical surgery. Thirty-eight patients were followed up. In total, 75% of patients showing reinnervation potentials recovered. The positive predictive value of laryngeal electromyography was 69.2%.

CONCLUSION

Laryngeal electromyography is effective in specifying the origin of unilateral vocal-fold immobility in adults. It also has a prognostic role, lack of reinnervation potentials being a possible indication for early medialization surgery.

Clinical Usefulness of Ultrasonography-Guided Laryngeal Electromyography

OBJECTIVES/HYPOTHESIS

To investigate the proper approach and technical method of ultrasonography-guided laryngeal electromyography (US-guided LEMG).

STUDY DESIGN

This is a prospective study.

METHODS

Twenty patients who underwent US-guided LEMG were enrolled. US-guided LEMG was cooperatively performed by one otolaryngologist, one neurologist, and one radiologist. The location of the needle electrode was confirmed with US after electrode insertion into the laryngeal intrinsic muscle. The US transducer was applied on the neck by a transverse/midline and transverse/oblique approach to identify the cricothyroid (CT), thyroarytenoid (TA) muscles, and the location of the needle electrode.

RESULTS

CT muscles were easily identified on US in all 20 patients. TA muscles were identified in 17 patients (85%). The transverse/oblique approach was helpful to detect TA muscle in case of calcified thyroid cartilage or anatomic variation.

CONCLUSIONS

US-guided LEMG, which enables the exact insertion of the needle electrode, improves the reliability of examination and is helpful in early detection and to prevent complications.

Types and timing of therapy for vocal fold paresis/paralysis after thyroidectomy: a systematic review and meta-analysis

OBJECTIVES

To perform a systematic literature review to evaluate the type and timing of therapy for vocal fold paresis/paralysis after thyroidectomy and develop a primary decision-making pathway.

STUDY DESIGN

Meta-analysis.

METHODS

Four databases and one journal were searched using the key words of "thyroidectomy," "vocal cord paresis/paralysis," and "therapy." Study quality was evaluated using the Cochrane Collaboration's risk of bias tools. Data regarding type and timing of therapy were extracted from 39 articles. Odds ratios (ORs), relative risk (RR), 95% confidence interval, and heterogeneity were recorded. Logistic regression analysis was performed to determine the relationships between timing and OR/RR.

RESULTS

Among the 13 studies investigating unilateral paresis/paralysis, five focused on early therapy (0-6 months). In these studies, the OR for clinical heterogeneity was significantly higher after neurolysis than after injection laryngoplasty and voice training (Q = 17.002, I(2) = 78%, P = 0.000), and the RR for heterogeneity was significantly higher after injection laryngoplasty at ≥12 months than <12 months (Q = 9.984, I(2) = 89.9%, P = 0.002). In the 26 studies that investigated bilateral paresis/paralysis, the OR for heterogeneity was significantly higher for bilateral posterior cordectomy than for endolaryngeal laterofixation (Q = 3.510, I(2) = 71.5%, P = 0.061) and laser arytenoidectomy with posterior cordectomy (Q = 2.90, I(2) = 65.6%, P = 0.088).

CONCLUSIONS

For unilateral vocal fold paresis/paralysis after thyroidectomy, we recommend absorbable mass injection laryngoplasty, voice training, and neurolysis during the first 12 months but laryngeal reinnervation after 12 months. For bilateral vocal fold paresis/paralysis, we recommend early laterofixation and combined laser arytenoidectomy with posterior cordectomy after 12 months.

Reliability of clinical office-based laryngeal electromyography in vocally healthy adults

OBJECTIVE

This study aimed to conduct a 3-session reliability assessment of the laryngeal electromyography (LEMG) signal in healthy participants during intensity controlled vocalization tasks. We hypothesized that vocal intensity level and testing session would affect LEMG measures.

METHODS

This prospective study used a 2-factor repeated measures design. Seven participants underwent bipolar needle LEMG of the right thyroarytenoid muscle. Data were collected over 3 testing sessions using vocalization tasks performed with visually guided intensity feedback targets (65 and 75 dB SPL). Root mean square amplitudes in microvolts were analyzed for within-session and between-session reliability.

RESULTS

The main effect for intensity was found to approach significance (F = 5.71, P = .054). However, intraclass correlation coefficients (ICCs) using a 2-factor mixed random effect model indicated poor to fair signal reliability between testing sessions (ICC = 0.56 at 65 dB, 0.40 at 70 dB). Intraclass correlation coefficients for within-session data indicated excellent reliability for all testing conditions (0.84-0.98).

CONCLUSION

Using a quantitative analysis protocol to inform an essentially qualitative technique, our results indicated that there was generally poor to fair reliability in the LEMG signal over testing sessions. Vocal intensity was an important variable that affected LEMG signal reliability. Standardization of LEMG protocols using vocal control parameters and quantitative analyses may help improve LEMG reliability in clinical settings.

Clinical Practice Guideline

Objective

Thyroidectomy may be performed for clinical indications that include malignancy, benign nodules or cysts, suspicious findings on fine needle aspiration biopsy, dysphagia from cervical esophageal compression, or dyspnea from airway compression. About 1 in 10 patients experience temporary laryngeal nerve injury after surgery, with longer lasting voice problems in up to 1 in 25. Reduced quality of life after thyroid surgery is multifactorial and may include the need for lifelong medication, thyroid suppression, radioactive scanning/treatment, temporary and permanent hypoparathyroidism, temporary or permanent dysphonia postoperatively, and dysphagia. This clinical practice guideline provides evidence-based recommendations for management of the patient’s voice when undergoing thyroid surgery during the preoperative, intraoperative, and postoperative period.

Purpose

The purpose of this guideline is to optimize voice outcomes for adult patients aged 18 years or older after thyroid surgery. The target audience is any clinician involved in managing such patients, which includes but may not be limited to otolaryngologists, general surgeons, endocrinologists, internists, speech-language pathologists, family physicians and other primary care providers, anesthesiologists, nurses, and others who manage patients with thyroid/voice issues. The guideline applies to any setting in which clinicians may interact with patients before, during, or after thyroid surgery. Children under age 18 years are specifically excluded from the target population; however, the panel understands that many of the findings may be applicable to this population. Also excluded are patients undergoing concurrent laryngectomy. Although this guideline is limited to thyroidectomy, some of the recommendations may extrapolate to parathyroidectomy as well.

Results

The guideline development group made a strong recommendation that the surgeon should identify the recurrent laryngeal nerve(s) during thyroid surgery. The group made recommendations that the clinician or surgeon should (1) document assessment of the patient’s voice once a decision has been made to proceed with thyroid surgery; (2) examine vocal fold mobility, or refer the patient to a clinician who can examine vocal fold mobility, if the patient’s voice is impaired and a decision has been made to proceed with thyroid surgery; (3) examine vocal fold mobility, or refer the patient to a clinician who can examine vocal fold mobility, once a decision has been made to proceed with thyroid surgery if the patient’s voice is normal and the patient has (a) thyroid cancer with suspected extrathyroidal extension, or (b) prior neck surgery that increases the risk of laryngeal nerve injury (carotid endarterectomy, anterior approach to the cervical spine, cervical esophagectomy, and prior thyroid or parathyroid surgery), or (c) both; (4) educate the patient about the potential impact of thyroid surgery on voice once a decision has been made to proceed with thyroid surgery; (5) inform the anesthesiologist of the results of abnormal preoperative laryngeal assessment in patients who have had laryngoscopy prior to thyroid surgery; (6) take steps to preserve the external branch of the surperior laryngeal nerve(s) when performing thyroid surgery; (7) document whether there has been a change in voice between 2 weeks and 2 months following thyroid surgery; (8) examine vocal fold mobility or refer the patient for examination of vocal fold mobility in patients with a change in voice following thyroid surgery; (9) refer a patient to an otolaryngologist when abnormal vocal fold mobility is identified after thyroid surgery; (10) counsel patients with voice change or abnormal vocal fold mobility after thyroid surgery on options for voice rehabilitation. The group made an option that the surgeon or his or her designee may monitor laryngeal electromyography during thyroid surgery. The group made no recommendation regarding the impact of a single intraoperative dose of intravenous corticosteroid on voice outcomes in patients undergoing thyroid surgery.