Clinical Utility and Validation of the Acoustic Voice Quality and Acoustic Breathiness Indexes for Voice Disorder Assessment in English Speakers

BACKGROUND

While several acoustic voice metrics are available for clinical voice assessment, there remains a significant need for reliable and ecologically valid tools. The Acoustic Voice Quality Index version 03.01 (AVQI-3) and Acoustic Breathiness Index (ABI) hold potential due to their comprehensive assessment approach, incorporating diverse voice aspects. However, these tools still need to be validated in English-speaking populations.

METHODS

This study assessed the discriminatory accuracy and validity of AVQI-3 and ABI in 197 participants, including 148 with voice disorders. Voice samples were collected, followed by AVQI-3 and ABI calculations. Additionally, auditory-perceptual assessments were conducted by a panel of speech-language pathologists.

RESULTS

AVQI-3 and ABI effectively identified disordered voice quality, evidenced by high accuracy (AUCs: 0.84, 0.89), sensitivity, and specificity (thresholds: AVQI-3 = 1.17, ABI = 2.35). Strong positive correlations were observed with subjective voice quality assessments (rs = 0.72, rs = 0.77, p < 0.001).

CONCLUSIONS

The study highlights AVQI-3 and ABI as promising instruments for clinically assessing voice disorders in U.S. English speakers, underscoring their utility in clinical practice and voice research.

Voice Biofeedback via Bone Conduction Headphones: Effects on Acoustic Voice Parameters and Self-Reported Vocal Effort in Individuals With Voice Disorders

PURPOSE

This study explores sidetone amplification (amplified playback of one's own voice) provided via bone conduction in participants with voice disorders. The effects of bone conduction feedback on acoustic voice parameters and vocal effort ratings are examined.

METHODS

Speech samples of 47 participants with voice disorders were recorded in three auditory feedback conditions: two with sidetone amplification delivered via bone conduction and one condition with no alteration of the feedback. After each task, the participants rated their vocal effort on a visual analog scale. The voice recordings were evaluated by a speech-language pathologist through the GRBAS scale and processed to calculate the within-participant centered sound pressure level (SPL) values, the mean pitch strength (PS), the time dose (Dt%), and cepstral peak prominence smoothed (CPPS). The effects of the feedback conditions on these acoustic parameters and vocal effort ratings were analyzed.

RESULTS

The high sidetone amplification condition resulted in a statistically significant decrease in the within-participant centered SPL values and mean pitch strength across all participants. The feedback conditions had no statistically significant effects on the vocal effort ratings, time dose (Dt%), or CPPS.

CONCLUSIONS

This study provides an evidence that bone conduction sidetone amplification contributes to a consistent adaptation in the within-participant centered SPL values (ΔSPL) in patients with vocal hyperfunction, glottal insufficiency, and organic/neurological laryngeal pathologies compared to conditions with no feedback.

Flexible Versus Rigid Laryngoscopy: A Prospective, Blinded Comparison of Image Quality

OBJECTIVE

To compare flexible distal-chip laryngoscopy (FDL) and rigid telescopic laryngoscopy (RTL) in image quality and diagnostic ability.

STUDY DESIGN

Prospective cohort study; blinded comparison.

METHODS

Eighteen normal adult subjects were recruited to undergo both FDL and RTL and normalized videos were recorded. Three blinded laryngologists compared the videos for color fidelity, illumination, resolution, and vascularity, and indicated superiority with FDL, RTL, or no difference. Raters also reported if an abnormality was seen and in which video it was better visualized. Videos for two subjects were repeated to assess intra-rater reliability, making 20 video comparisons across 3 raters for a total of 60 ratings. Differences in responses were analyzed via Mann-Whitney U and Pearson Χ². Inter-rater reliability was assessed via Fleiss' kappa, and intra-rater reliability was assessed via percent agreement.

RESULTS

RTL was rated superior in all categories of image quality (47 vs 5 vs 8, P < 0.01; 47 vs 7 vs 6, P < 0.01; 51 vs 5 vs 4, P<0.01; 44 vs 9 vs 7, P < 0.01, respectively). An abnormality was seen 33 times with both modalities and 6 times with RTL only. When seen with both modalities, visualization was superior in RTL compared with FDL (29 vs 4, P <0.01).

CONCLUSIONS

There was significant superiority of RTL in all categories of image quality, with slight inter-rater agreement for color fidelity, resolution, and vascularity. RTL was also significantly better for visualization of abnormalities. These findings suggest superior image quality in RTL compared with FDL, but further research is required to determine if this difference is clinically significant.

Hyoid Bone Syndrome and Dysphonia: Can Throat Pain Affect the Voice?

OBJECTIVES/HYPOTHESIS

To investigate the relationship of throat pain and dysphonia.

STUDY DESIGN

Prospective cohort study.

METHODS

Forty-five subjects presenting with hyoid bone syndrome (HBS) and dysphonia were asked to rate their pain on a numerical rating scale and complete the 10-item Voice-Related Quality of Life (V-RQOL) questionnaire prior to and at 1-week follow-up after treatment with triamcinolone injection into the attachments to the affected greater cornu(s). Wilcoxon signed-rank tests were applied to evaluate if the overall V-RQOL scores, the physical functioning (PF) and social-emotional (SE) domain scores, and pain scores changed significantly after treatment. To evaluate how change in perceived pain affected V-RQOL, the differences in the V-RQOL, PF, and SE domain scores, and in pain scores were calculated for each subject. Three linear models were fit to the response variables, ΔV-RQOL, ΔPF, and ΔSE, using ΔPain as a predicting variable.

RESULTS

V-RQOL, PF, and SE domain scores, and pain scores all improved significantly with treatment. A bigger decrease in the pain score led to a bigger increase in V-RQOL and domain scores, with slopes varying between -1.1 and -1.4. The PF domain scores showed the greatest improvement with decrease in pain scores.

CONCLUSIONS

Effective treatment of HBS led to improvement in patients' voice complaints, suggesting that throat pain may have a direct effect on voice. This may be related to compensatory perilaryngeal adjustments patients make when speaking with a "guarding" effect when they have throat pain.

LEVEL OF EVIDENCE

IV (Cohort study) Laryngoscope, 131:E2303-E2308, 2021.

Telemedicine and the Interdisciplinary Clinic Model: During the COVID-19 Pandemic and Beyond

The emergence of the novel coronavirus disease 2019 (COVID-19) and the subsequent need for physical distancing have necessitated a swift change in health care delivery. Prior to the COVID-19 outbreak, many institutions utilized an interdisciplinary clinic model including both a laryngologist and a speech-language pathologist for the evaluation of patients with voice, swallowing, and upper airway disorders. To improve access, many providers are pursuing the use of interdisciplinary telemedicine to provide individualized patient-centered care while allowing for physical distancing. The purpose of this commentary is to review the current literature regarding telemedicine in laryngology and speech-language pathology as well as the current and future states of practice for interdisciplinary tele-evaluations.

Reproducibility of Voice Parameters: The Effect of Room Acoustics and Microphones

INTRODUCTION

Computer analysis of voice recordings is an integral part of the evaluation and management of voice disorders. In many practices, voice samples are taken in rooms that are not sound attenuated and/or sound-proofed; further, the technology used is rarely consistent. This will likely affect the recordings, and therefore, their analyses.

OBJECTIVES

The objective of this study is to compare various acoustic outcome measures taken from samples recorded in a sound-proofed booth to those recorded in more common clinic environments. Further, the effects from six different commonly used microphones will be compared.

METHODS

Thirty-six speakers were recorded while reading a text and producing sustained vowels in a controlled acoustic environment. The collected samples were reproduced by a Head and Torso Simulator and recorded in three clinical rooms and in a sound booth using six different microphones. Newer measures (eg, Pitch Strength, cepstral peak prominence, Acoustic Voice Quality Index), as well as more traditional measures (eg Jitter, Shimmer, harmonics-to-noise ratio and Spectrum Tilt), were calculated from the samples collected with each microphone and within each room.

RESULTS

The measures which are more robust to room acoustic differences, background noise, and microphone quality include Jitter and smooth cepstral peak prominence, followed by Shimmer, Acoustic Voice Quality Index, harmonics-to-noise ratio, Pitch Strength, and Spectrum Tilt.

CONCLUSIONS

The effect of room acoustics and background noise on voice parameters appears to be stronger than the type of microphone used for the recording. Consequently, an appropriate acoustical clinical space may be more important than the quality of the microphone.

The Effect of Unilateral Hearing Protection on Vocal Intensity With Varying Degrees of Background Noise

INTRODUCTION

The Lombard effect (LE) is a phenomenon in which speakers adjust their vocal production by raising the volume in noisy environments. As a result, the LE can create problems of vocal strain, fatigue and potential injury.

OBJECTIVES

This study aims to examine the difference in vocal intensity output in subjects wearing unilateral hearing protection versus no hearing protection in the presence of background noise.

METHODS

Each subject was seated inside a sound booth wearing a head-mounted microphone. Subjects were asked to read an excerpt from "The Rainbow Passage" while various levels of background noise were played: 50, 60, 70, and 80 dBA (Multitalker Babble). Each noise level was played while the subject was with and without unilateral ear protection (Optime 98 Earmuff [3M]) in random order. The earmuff has a noise reduction rating of 25 dB. After each reading of the text, subjects were asked to rate communication disturbance, vocal clarity, and discomfort during talking using a 10 cm visual analogue scale.

RESULTS

The LE is reduced from 0.38 dB/dB to 0.29 dB/dB with unilateral ear occlusion. However, self-perception of disturbance, clarity and comfort were not affected by unilateral occlusion, only by noise level.

CONCLUSIONS

Unilateral hearing protection reduces the LE and may protect against phonotrauma when speaking in an environment with loud background noise.

Comparison of Pitch Strength With Perceptual and Other Acoustic Metric Outcome Measures Following Medialization Laryngoplasty

INTRODUCTION

The diagnoses of voice disorders, as well as treatment outcomes, are often tracked using visual (eg, stroboscopic images), auditory (eg, perceptual ratings), objective (eg, from acoustic or aerodynamic signals), and patient report (eg, Voice Handicap Index and Voice-Related Quality of Life) measures. However, many of these measures are known to have low to moderate sensitivity and specificity for detecting changes in vocal characteristics, including vocal quality.

OBJECTIVE

The objective of this study was to compare changes in estimated pitch strength (PS) with other conventionally used acoustic measures based on the cepstral peak prominence (smoothed cepstral peak prominence, cepstral spectral index of dysphonia, and acoustic voice quality index), and clinical judgments of voice quality (GRBAS [grade, roughness, breathiness, asthenia, strain] scale) following laryngeal framework surgery.

METHODS

This study involved post hoc analysis of recordings from 22 patients pretreatment and post treatment (thyroplasty and behavioral therapy). Sustained vowels and connected speech were analyzed using objective measures (PS, smoothed cepstral peak prominence, cepstral spectral index of dysphonia, and acoustic voice quality index), and these results were compared with mean auditory-perceptual ratings by expert clinicians using the GRBAS scale.

RESULTS

All four acoustic measures changed significantly in the direction that usually indicates improved voice quality following treatment (P < 0.005). Grade and breathiness correlated the strongest with the acoustic measures (|r| ~ 0.7) with strain being the least correlated.

CONCLUSIONS

Acoustic analysis on running speech highly correlates with judged ratings. PS is a robust, easily obtained acoustic measure of voice quality that could be useful in the clinical environment to follow treatment of voice disorders.

The Art of Caring for the Professional Singer

Training in care of the voice for the general otolaryngologist has improved with the presence of more fellowship-trained laryngologists within academic training programs. However, preparation for caring for the professional singer goes beyond the basic understanding of voice evaluation, laryngeal imaging, and microlaryngeal surgery. The otolaryngologist must have a deeper understanding of the demands, vocabulary, psyche, and economics of the professional singer to provide optimal care. The ramification of recommendations made or procedures undertaken by the otolaryngologist can have serious consequences in a singer's career. This article introduces the otolaryngologist to the specifics of caring for professional singers.

Laryngeal paraganglioma in a patient with multiple head and neck paragangliomas

Paragangliomas of the larynx are rare neuroendocrine tumors, with fewer than 70 cases reported in the literature. 1 Typically, laryngeal paragangliomas are not found in patients with multicentric or familial paragangliomas. Only 1 case of laryngeal paraganglioma has been reported in a patient with a synchronous lesion elsewhere (carotid body tumor). 2 We report an additional case of a patient with a laryngeal and multiple other paragangliomas.

Injection Laryngoplasty 2014: Indications, Techniques, and Pitfalls in Modern Vocal Fold Augmentation

Program Description:

Injection laryngoplasty has a long history in vocal fold augmentation, and its use continues to evolve in otolaryngology. This miniseminar will provide a contemporary update on the indications, injectable materials, operative techniques, and potential pitfalls of injection laryngoplasty in modern otolaryngology practice. Particular attention will be paid to the latest developments in injection materials and office-based injection techniques for the general otolaryngologist. In addition, the presentation will include case presentations of pitfalls in injection laryngoplasty with a candid discussion of the inherent risks and possible mistakes that can be made with this technique and how to avoid them.

Educational Objectives:

(1) Define the various indications for injection laryngoplasty in modern otolaryngology practice and recognize the benefits and controversies of currently available injection materials for laryngoplasty. (2) Compare the benefits and indications for clinic or office-based injection techniques, including thorough descriptions of clinic-based injection techniques. (3) Recognize potential patient care risks with injection laryngoplasty and methods to avoid or ameliorate these risks.

The role of laryngoscopy in the diagnosis of spasmodic dysphonia

IMPORTANCE

Spasmodic dysphonia (SD) can be difficult to diagnose, and patients often see multiple physicians for many years before diagnosis. Improving the speed of diagnosis for individuals with SD may decrease the time to treatment and improve patient quality of life more quickly.

OBJECTIVE

To assess whether the diagnosis of SD can be accurately predicted through auditory cues alone without the assistance of visual cues offered by laryngoscopic examination.

DESIGN, SETTING, AND PARTICIPANTS

Single-masked, case-control study at a specialized referral center that included patients who underwent laryngoscopic examination as part of a multidisciplinary workup for dysphonia. Twenty-two patients were selected in total: 10 with SD, 5 with vocal tremor, and 7 controls without SD or vocal tremor.

INTERVENTIONS

The laryngoscopic examination was recorded, deidentified, and edited to make 3 media clips for each patient: video alone, audio alone, and combined video and audio. These clips were randomized and presented to 3 fellowship-trained laryngologist raters (A.D.R., A.T.H., and A.M.K.), who established the most probable diagnosis for each clip. Intrarater and interrater reliability were evaluated using repeat clips incorporated in the presentations.

MAIN OUTCOMES AND MEASURES

We measured diagnostic accuracy for video-only, audio-only, and combined multimedia clips. These measures were established before data collection. Data analysis was accomplished with analysis of variance and Tukey honestly significant differences.

RESULTS

Of patients with SD, diagnostic accuracy was 10%, 73%, and 73% for video-only, audio-only, and combined, respectively (P < .001, df = 2). Of patients with vocal tremor, diagnostic accuracy was 93%, 73%, and 100% for video-only, audio-only, and combined, respectively (P = .05, df = 2). Of the controls, diagnostic accuracy was 81%, 19%, and 62% for video-only, audio-only, and combined, respectively (P < .001, df = 2).

CONCLUSIONS AND RELEVANCE

The diagnosis of SD during examination is based primarily on auditory cues. Viewing combined audio and video clips afforded no change in diagnostic accuracy compared with audio alone. Laryngoscopy serves an important role in the diagnosis of SD by excluding other pathologic causes and identifying vocal tremor.

Dysphagia due to inclusion body myositis: case presentation and review of the literature

OBJECTIVE

This report aimed to present a case of inclusion body myositis presenting with dysphagia and to review the literature.

METHODS

Case report and literature review.

RESULTS

Inclusion body myositis is a chronic progressive acquired myopathy, uniquely distinguished by its selective muscle involvement, normal or moderately elevated muscle enzyme concentrations, and a progressive corticosteroid-resistant course. Compared to other inflammatory myopathies, the esophagus is the most commonly involved organ. Specifically, upper esophageal sphincter dysfunction often occurs. Dysphagia may be the only symptom at the time of presentation.

CONCLUSION

Unlike other inflammatory myopathies, dysphagia in inclusion body myositis is steroid resistant. Management can be difficult. The otolaryngologist must consider underlying neuromuscular processes when evaluating the patient presenting with oropharyngeal dysphagia.

Spindle cell carcinoma of the larynx presenting as a vocal fold cyst

Spindle cell carcinoma (SPCC) is a rare, malignant variant of squamous cell carcinoma (SCC), which shows biphasic proliferation of the conventional SCC component and malignant spindle shape cells with sarcomatous appearance. We present two cases of SPCC of the true vocal fold that presented as a benign appearing subepithelial mass. We discuss the patient presentation, voice assessment, surgical treatment, and a review of the literature.

Globus Pharyngeus: Effectiveness of Treatment with Proton Pump Inhibitors and Gabapentin

Objectives:

This study was performed to investigate the effectiveness of treatment of globus pharyngeus with proton pump inhibitors, gabapentin, or both.

Methods:

The subjects all presented with globus pharyngeus during the years 2006 to 2011. The inclusion criteria included a chief (primary) complaint of globus pharyngeus; a trial of proton pump inhibitor therapy for at least 2 months and/or a trial of gabapentin for at least 2 weeks; and at least 1 follow-up visit. We reviewed 331 charts; 87 patients met the criteria. The response to treatment was graded as none, partial, or complete.

Results:

Seventy-seven percent of all patients had improvement. Sixty-seven percent of patients had a partial or complete response from aggressive reflux management. Sixty-six percent of patients who had a trial of gabapentin reported improvement. Eight of 14 patients who did not improve with aggressive reflux management improved with gabapentin.

Conclusions:

A majority of patients with globus pharyngeus can be helped by treating reflux or neuralgia. A trial of gabapentin should be considered for patients who do not respond or only partially respond to reflux management.

Hyoid Bone Syndrome: A Retrospective Review of 84 Patients Treated with Triamcinolone Acetonide Injections

Objectives:

We present a cohort of patients with hyoid bone syndrome who were treated with injections of triamcinolone acetonide (40 mg/mL), in order to raise awareness of this condition, validate its existence, and demonstrate the efficacy of this treatment.

Methods:

We performed a retrospective chart review of patients who were given a diagnosis of and treated for hyoid bone syndrome by the senior author (A.D.R.) between 2006 and 2009.

Results:

Eighty-four patients met the inclusion criteria. All patients presented with throat pain and had tenderness of 1 (63%) or both (38%) greater cornua of the hyoid bone. Seventy-four percent of the patients had complete resolution of symptoms with injection of the affected side(s), 15% had a partial response, and 10% had no response. One patient had a recurrence at 3 months and chose not to receive another treatment. Forty-five of the 62 patients with a complete response required only 1 injection. Forty-three patients (51%) also complained of dysphonia, only 5 of whom had additional laryngeal disorders that accounted for the dysphonia.

Conclusions:

Hyoid bone syndrome should be considered in patients who present with throat pain. Injection of triamcinolone into the affected greater cornu can confirm the diagnosis and resolve symptoms. A positive response to triamcinolone injection may obviate the need for additional testing and procedures.

Influence of emotional expression, loudness, and gender on the acoustic parameters of vibrato in classical singers

OBJECTIVES

Vibrato is considered one of the most essential characteristics of the classical singing voice. Vibrato can be acoustically described by the rate, extent, onset, and regularity. The aim of this study was to determine the influence of emotional expression on acoustic parameters of vibrato in classically trained singers.

STUDY DESIGN

A prospective cohort study was performed.

METHODS

Thirty healthy classical singers were recruited for this study, 29 singers met inclusion criteria. Inclusion criteria for this study were as follow: 1) no history of vocal pathology in the past year, 2) to have at least 5 years of classical singing training. Each subject was asked to sing the phrase "I Love You," while expressing four different emotions (tenderness, anger, happiness, and sadness) and without emotion (neutral state). The musical tonality of the phrase was adapted to each singer's vocal classification. Subjects were also recorded at three levels of loudness (pianissimo, mezzo forte, and fortissimo), while expressing each emotion. Acoustical analysis was performed during the vowel /o/ of the word "Love" to determine rate of vibrato, the extent of vibrato, and vibrato jitter.

RESULTS

Vibrato parameters did not vary significantly when different emotions were expressed. However, vibrato jitter and extent did vary significantly between different levels of loudness. Significant differences were also noted in both rate and extent of vibrato when compared between sexes.

CONCLUSIONS

Expression of emotions does not affect the acoustic parameters of vibrato, although some parameters are affected by loudness and gender.

A new member of the multidisciplinary ALS team: the otolaryngologist

The multidisciplinary approach to treatment of amyotrophic lateral sclerosis (ALS) has improved the overall care of patients suffering from this disease ( 1 , 2 ). This approach typically has included neurologists, physiatrists, occupational therapists, respiratory therapists and speech therapists. Dysphonia, dysarthria, and dysphagia are three of the most common bulbar manifestations of ALS, and are often the presenting symptoms in bulbar-onset patients. Despite this, otolaryngologists are often not included in ALS management until a tracheostomy is considered. The otolaryngologist can play an important role in early diagnosis and subsequent management of bulbar manifestations of ALS, and would be a valuable member of the multidisciplinary team.

Potential for promoting recurrent laryngeal nerve regeneration by remote delivery of viral gene therapy

OBJECTIVES/HYPOTHESIS

The aims of this study were to demonstrate the ability to enhance nerve regeneration by remote delivery of a viral vector to the crushed recurrent laryngeal nerve (RLN), to demonstrate the usefulness of a crushed RLN model to test the efficacy of viral gene therapy, and to discuss future potential applications of this approach.

STUDY DESIGN

Animal study.

METHODS

Adult Sprague-Dawley rats were assigned to two groups. In the experimental group, an adeno-associated viral (AAV) vector carrying a zinc-finger transcription factor, which stimulates endogenous insulinlike growth factor I production (AAV2-TO-6876vp16), was injected into the crushed RLN. In the control group, an AAV vector carrying the gene for green fluorescent protein was injected into the crushed RLN. Unilateral RLN paralysis was confirmed endoscopically. At 1 week, laryngeal endoscopies were repeated and recorded. Larynges were cryosectioned in 15-μm sections and processed for acetylcholine histochemistry (motor endplates) followed by neurofilament immunoperoxidase (nerve fibers). Percentage nerve-endplate contact (PEC) was determined and compared. Vocal fold motion was evaluated by blinded reviewers using a visual analogue scale (VAS).

RESULTS

The difference between PEC on the crushed and uncrushed sides was statistically less in the experimental group (0.54 ± 0.18 vs. 0.30 ± 0.26, P = .0006). The VAS score at 1 week was significantly better in the experimental group (P = .002).

CONCLUSIONS

AAV2-TO-6876vp16 demonstrated a neurotrophic effect when injected into the crushed RLN. The RLN offers a conduit for viral gene therapy to the brainstem that could be useful for the treatment of RLN injury or bulbar motor neuron disease.

Methicillin-resistant Staphylococcus aureus laryngitis

Infections due to methicillin-resistant Staphylococcus aureus (MRSA) have become more prevalent, in part because of the emergence and spread of community-acquired MRSA. This trend is particularly concerning because of the significant rates of morbidity and mortality associated with MRSA infections, and because MRSA strains are often resistant to many classes of antibiotics. Reports of infections of the head and neck, including wound infections, cellulitis, sinusitis, otitis media, and otitis externa, are well documented. However, to our knowledge, there have been no reports of bacterial laryngitis due to MRSA. We report the first published case of bacterial laryngitis caused by MRSA.

Vocal fold paresis and paralysis: what the thyroid surgeon should know

The thyroid surgeon must have a thorough understanding of laryngeal neuroanatomy and be able to recognize symptoms of vocal fold paresis and paralysis. Neuropraxia may occur even with excellent surgical technique. Patients should be counseled appropriately, particularly if they are professional voice users. Preoperative or early postoperative changes in voice, swallowing, and airway function should prompt immediate referral to an otolaryngologist. Early recognition and treatment may avoid the development of complications and improve patient quality of life.

Neurolaryngologic evaluation of the performer

Numerous neurologic diseases affect voice production either through direct effects on the larynx or by affecting muscles involved with support or resonation of the voice. Voice changes can be the initial presenting symptoms of neurodegenerative disorders, especially in patients who have increased awareness of their vocal quality. Some patients present to the otolaryngologist before the neurologist. The otolaryngologist must have an understanding and familiarity with laryngeal manifestations of neurodegenerative diseases to make the appropriate diagnosis in a timely fashion. Moreover, the otolaryngologist can play a significant role in the care of patients who have neurodegenerative disease. Video procedures for neurolaryngologic evaluation accompany this content online.

Vocal fold paresis and paralysis

Diagnosis and treatment of the immobile or hypomobile vocal fold are challenging for the otolaryngologist. True paralysis and paresis result from vocal fold denervation secondary to injury to the laryngeal or vagus nerve. Vocal fold paresis or paralysis may be unilateral or bilateral, central or peripheral, and it may involve the recurrent laryngeal nerve, superior laryngeal nerve, or both. The physician's first responsibility in any case of vocal fold paresis or paralysis is to confirm the diagnosis and be certain that the laryngeal motion impairment is not caused by arytenoid cartilage dislocation or subluxation, cricoarytenoid arthritis or ankylosis, neoplasm, or other mechanical causes. Strobovideolaryngoscopy, endoscopy, radiologic and laboratory studies, and electromyography are all useful diagnostic tools.

Dysfunction of the recurrent laryngeal nerve and the potential of gene therapy

Injury to the recurrent laryngeal nerve causes vocal fold paresis or paralysis resulting in poor voice quality, and possibly swallowing dysfunction and/or airway compromise. Injury can occur as part of a neurodegenerative disease process or can be due to direct nerve trauma or tumor invasion. Management depends upon symptoms, the cause and severity of injury, and the prognosis for recovery of nerve function. Surgical treatment techniques can improve symptoms, but do not restore physiologic motion. Gene therapy may be a useful adjunct to enhance nerve regeneration in the setting of neurodegenerative disease or trauma. Remote injection of viral vectors into the recurrent laryngeal nerve is the least invasive way to deliver neurotrophic factors to the nerve's cell bodies within the nucleus ambiguus, and in turn to promote nerve regeneration and enhance both nuclear and nerve survival. The purpose of this review is to discuss the potential role for gene therapy in treatment of the unsolved problem of vocal fold paralysis.

Repetitive phonatory tasks for identifying vocal fold paresis

Vocal fold paresis may be present in patients with voice complaints. Identification of paresis is important so that appropriate neurolaryngologic evaluation can be ordered and the appropriate treatment can be offered. Repetitive phonatory tasks (RPTs) fatigue patients vocally and may elicit signs of subtle paresis. In this study, four laryngologists independently reviewed the RPT portions of routine fiberoptic voice examinations of 100 patients in a blinded fashion. All patients had presented with voice complaints, were suspected of having a movement disorder of the larynx, and had been referred for laryngeal electromyography (LEMG). Predictions were compared with LEMG results and with predictions made at the time of each initial evaluation. Although RPTs are useful to laryngologists, predictions based on the entire examination are more accurate. LEMG can confirm clinical suspicions or identify paresis missed on fiberoptic laryngeal examination.

Arytenoid cartilage dislocation: a 20-year experience

SUMMARY

Arytenoid cartilage dislocation is an infrequently diagnosed cause of vocal fold immobility. Seventy-four cases have been reported in the literature to date. Intubation is the most common origin, followed by external laryngeal trauma. Decreased volume and breathiness are the most common presenting symptoms. We report on 63 patients with arytenoid cartilage dislocation treated by the senior author (RTS) since 1983. Significantly more posterior than anterior dislocations were represented. Although reestablishing joint mobility is difficult, endoscopic reduction should be considered to align the heights of the vocal processes. This process may result in significant voice improvement even long after the dislocation. Strobovideolaryngoscopy, laryngeal electromyography, and laryngeal computed tomography (CT) imaging are helpful in the evaluation of patients with vocal fold immobility to help distinguish arytenoid cartilage dislocation from vocal fold paralysis. Familiarity with signs and symptoms of arytenoid cartilage dislocation and current treatment techniques improves the chances for optimal therapeutic results.

Laryngeal hyperfunction during whispering: reality or myth?

For years, otolaryngologists and voice therapists have warned voice patients that whispering causes more trauma to the larynx than normal speech. However, no large series of patients has ever been examined fiberoptically during whispering to test this hypothesis. As part of our routine examination, patients are asked to count from 1 to 10 in a normal voice and in a whispered voice. We reviewed recorded fiberoptic examinations of 100 patients who had voice complaints. We compared supraglottic hyperfunction and vocal fold closure during the normal and whispered phonation of each patient. Sixty-nine percent of the patients demonstrated increased supraglottic hyperfunction with whispered voice. Eighteen percent had no change, and 13% had less severe hyperfunction. The most common glottal configuration during whisper was an inverted Y, which resulted from compression of the anterior and middle thirds of the true vocal folds. However, 12 patients had no true vocal fold contact during whispered voice, despite having adequate glottic closure with normal voice. Although whispering involves more severe hyperfunction in most patients, it does not seem to do so in all patients. In some patients, it may be less traumatic than normal voice.

Vocal process avulsion

Vocal process avulsion is a rare complication of intubation or external laryngeal trauma that can cause significant dysphonia. The vocal process develops independently from the body of the arytenoid cartilage, which results in a fusion plane that is vulnerable to trauma. The findings of vocal process avulsion may be subtle, and the relationship of the vocal process to the body of the arytenoid cartilage must be examined closely. Stroboscopy is critical in the evaluation. We describe three cases of vocal process avulsion encountered by the senior author (R.T.S.) over the last 5 years and discuss our approaches to evaluation and treatment. All cases were repaired endoscopically. However, we used three different techniques. These include chemical tenotomy with botulinum toxin, closed reduction with fat injection, and open reduction via cordotomy.