Influence of size and etiology of glottal gap in glottic incompetence dysphonia

Preliminary Findings of Vocal Fold Vibratory Characteristics of Singers Analyzed by Laryngeal High-Speed Videoendoscopy

OBJECTIVES

This study investigates the vocal fold vibratory dynamics of singers, which are postulated to differ from those of normal speakers due to the singers' regular vocal training. The measurement of vocal fold vibration involved the utilization of laryngeal high-speed videoendoscopy (LHSV) and subsequent LHSV-based analysis. The focus of the present study is to characterize and compare the LHSV-based measures derived from the glottal area waveform (GAW), namely fundamental frequency (F0GAW), glottal perturbation (jitterGAW and shimmerGAW), open quotient (OQGAW), and Nyquist plots, between singers and normal speakers across genders.

METHODS

Participants comprised 13 singers from a local cultural and heritage academy and 56 normal speakers from a local university, all were evaluated to have normal voices. Each participant underwent LHSV procedures to capture images of vocal fold vibration, which were subsequently analyzed to generate the LHSV-based measures.

RESULTS

Male singers exhibited lower F0GAW, jitterGAW, shimmerGAW, and OQGAW than female singers. When compared to normal speakers, male singers demonstrated higher F0GAW, and lower jitterGAW and shimmerGAW. No difference in OQGAW was found between male singers and normal speakers. Female singers exhibited lower jitterGAW compared to normal speakers, but no differences were observed in shimmerGAW and OQGAW. The results of Nyquist plots indicated no gender-related associations between types of rim width and among singers. However, for rim pattern, male singers were associated with a higher percentage of clustered rim, suggesting more regular vocal fold vibration, compared to female singers and normal male speakers.

CONCLUSIONS

Singers, particularly male singers, demonstrate distinct and potentially superior vocal fold vibrations compared to normal speakers, likely attributed to their regular vocal training, resulting in refined vocal fold configurations even during speaking. Despite the limited sample of singers, the study offers valuable insights into the vocal fold vibratory behaviors in singers analyzed using LHSV.

A Chaotic Approach to Glottal Gap Voice

OBJECTIVE

Airway glottic insufficiency, or glottal gap, may lead to a breathy voice quality. It is hypothesized that a glottal gap may be a source of nonlinearity in speech production. This study aims to gain a chaotic and acoustic profile of glottal gap voice provided by phonation of excised larynges subjected to the insertion of a metal shim in the posterior glottis.

STUDY DESIGN

Nonrandomized quasi-experimental study.

METHODS

Posterior glottal gap varied from 0 to 3.5 mm in 0.5 mm intervals. Each treatment was investigated independently in a sample population of eight excised canine larynges. Phonation of the larynges for each treatment was recorded and analyzed for the cepstral peak prominence (CPP), harmonics-to-noise ratio (HNR), and correlation dimension.

RESULTS

Kruskal-Wallis rank-sum tests yielded significant differences across shim groups for all parameters. Dunn-Bonferroni post-hoc tests revealed that the control group differed significantly from the 1.5, 2, 2.5, 3, and 3.5 mm groups for all metrics. Moreover, Kendall correlation tests indicated a moderately positive correlation between glottal gap size and correlation dimension, a moderately negative correlation between glottal gap size and CPP and between glottal gap size and the HNR.

CONCLUSIONS

Glottic insufficiency provides a source of nonlinearity in phonation. Nonlinear dynamic analysis provides quantitative insight into glottal gap voice. This study encourages future studies to further evaluate the relationship between glottal gap and correlation dimension.

Sensitivity of Videolaryngostroboscopic Rating Tools to Differences in Dysphonia Severity

OBJECTIVES

This study evaluated the validity of two videolaryngostroboscopic (VLS) rating tools to detect differences in VLS ratings between normophonic speakers, mild, and moderate-severely dysphonic speakers.

METHODS

Sixteen rigid VLS exams were obtained from four normophonic controls and 12 speakers with dysphonia (8 =mild, 4 =moderate-severe) secondary to laryngeal pathology. Eight clinicians rated nine vibratory VLS parameters for each exam using both the Voice-vibratory Assessment of Laryngeal Imaging (VALI) tool and a 100 mm visual analog scales (VAS). Ratings obtained for both right and left vocal folds (eg, mucosal wave, amplitude of vibration, nonvibrating portion) were averaged. One rating of overall severity of laryngeal function using a 100 mm VAS also was obtained. ANOVAs were used to evaluate differences in VLS parameters between three speaker groups (normophonic, mildly dysphonic, moderate-severely dysphonic) using these two rating tools.

RESULTS

There were statistically significant differences between controls and moderate-severely dysphonic speakers and for all VLS parameters except phase symmetry (P < 0.05) for both VALI and VAS ratings. Differences between mildly dysphonic and moderate-severely dysphonic and speakers were observed for 4/6 VALI ratings (mucosal wave, nonvibratory portions, phase closure, and regularity) and 5/6 parameters (mucosal wave, amplitude of vibration, nonvibratory portions, phase closure, and regularity) for VAS ratings. Significant differences between controls and mildly dysphonic speakers were not observed for VLS parameter rated using the VALI. There were significant differences between controls and mildly dysphonic speakers for 3/6 parameters (mucosal wave, amplitude of vibration, nonvibratory portion) using a VAS. Ratings of overall severity of laryngeal function differed between all levels of dysphonia severity.

CONCLUSIONS

Significant differences in VLS ratings were observed for comparisons of normophonic and moderate-severely dysphonic speakers and mild to moderately dysphonic speakers using the VALI and the VAS. However, the VAS scale appeared to better differentiate differences in VLS measures between normophonic speakers and those with mild dysphonia. Future studies should consider rating scale sensitivity when VLS rating tools are selected for clinical and research purposes.

Quantitative Evaluation of Vocal Bowing Following Bilateral Thyroplasty in Age-Related Vocal Atrophy

OBJECTIVE

Age-related vocal atrophy (ARVA) is associated with vocal fold bowing, persistent glottal gap during phonation, and dysphonia. Bilateral medialization thyroplasty is sometimes performed in patients with ARVA to improve vocal fold closure and voice. We set out to quantify stroboscopic changes in vocal fold bowing, glottal closure, and abduction angle following bilateral thyroplasty and determine how these changes affect voice quality among patients with ARVA.

METHODS

Fifteen individuals with ARVA who underwent bilateral medialization thyroplasty were included in this study. Two independent investigators calculated bowing index (BI), normalized glottal gap area (NGGA), and maximum abduction angle from laryngostroboscopic exams using ImageJ™. Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) and patient-reported measures were collected before and after thyroplasty.

RESULTS

Thyroplasty resulted in a 10-point improvement in overall CAPE-V (Mean dif -10; 95% CI -17, -3.3, p < 0.01) and VHI-10 (mean dif -3.8; 95% CI -9.8, 2.3, p = 0.19, n = 8). NGGA and BI significantly decreased following surgery (mean dif -78; 95% CI -155, -1.5, p = 0.05; and mean dif -2.1; 95% CI -2.4, -0.84, p < 0.01, respectively). BI correlated with CAPE-V scores (r = 0.66, 95% CI 0.22, 0.87, p < 0.01). When considering the normalized combined contributions of both NGGA and BI, there was a stronger correlation in CAPE-V scores (r = 0.87, 95% CI 0.50, 0.97, p < 0.01) compared with either measure alone.

CONCLUSIONS

Thyroplasty resulted in a decrease in vocal fold bowing, glottal gap area, and CAPE-V scores in patients with ARVA. Correction of vocal bowing and glottal gap, following bilateral thyroplasty, improved voice measures following surgery. Quantitative evaluation of vocal fold morphology may be valuable when assessing the severity and treatment-response in patients with ARVA following bilateral thyroplasty. Laryngoscope, 134:835-841, 2024.

VoxMore: technological artifact to assist voice acoustic evaluation in the teaching-learning process and clinical practice

PURPOSE

to present a technological artifact, the VoxMore plugin, to assist the academic teaching of voice acoustic assessment, as well as to optimize the speech therapy intervention in the practice of vocal clinics.

METHODS

this is a multidisciplinary methodological study for the development of a technological artifact, a plugin, to be used in the Praat software. This tool performs vocal acoustic analysis and generates a report, with information and images referring to the domains of time, frequency, time-frequency, and que-frequency, as well as values of acoustic measures related to fundamental frequency (f0), period measures, disturbance measures of the period of f0, f0 amplitude perturbation measurements, spectral measurements, glottal noise measurements and cepstral measurements.

RESULTS

in the VoxMore acoustic report, four files are generated with the following information: oscillograms of the voice signal and traces of f0 and intensity; images related to the frequency domain, Fourier spectrum and LPC spectrum, and to the time-frequency domain, spectrogram; information on cepstral and cepstrogram analysis; the values of all acoustic measurements, in numerical results format and in vertical bar graphs.

CONCLUSION

VoxMore can contribute both to the teaching-learning process, acting as an auxiliary tool with a formative character in the undergraduate and graduate courses in Speech-Language Pathology, as well as to the clinical practice process, making the use of acoustic analysis in the vocal clinic feasible and supporting decision-making by speech-language pathologist.

Dynamic CT Study on the Morphology and the Motor Ability of Unilateral Vocal Fold Paralysis

OBJECTIVE

To investigate the morphological changes and motor functions of the larynx in unilateral vocal fold paralysis by using dynamic three-dimensional CT, and to explore the differences between vocal fold paralysis with different nerves involved.

METHODS

Twenty-five patients with unilateral vocal fold paralysis and 10 healthy subjects were selected as the paralytic group and the normal group, respectively. Ten dynamic sequence images of laryngeal movement from inhalation to phonation were reviewed, and the glottic morphology at the coronal position, the minimum glottic area at the horizontal position, and the overall activity of the two groups were compared. The 25 patients with unilateral vocal fold paralysis were divided into the thyroarytenoid (TA) muscle group, the TA and posterior cricoarytenoid (PCA) (TA + PCA) muscle group, and the PCA muscle group. The coronal and horizontal parameters of the three types were compared as noted above and the dynamic parameter changes were also compared between the groups.

RESULTS

The height and thickness of bilateral vocal cords, the minimum glottic area, and the whole glottic activity were different in the paralysis group and were significantly different from those of the normal group (P < 0.05). The value of the glottic gap ratio and its decrease rate in the TA + PCA group was smaller than those in the TA and PCA group, and the glottic gap ratio was the largest in the PCA group.

CONCLUSION

Dynamic CT can provide a qualitative evaluation of laryngeal morphology and quantitative evaluation of motor function in vocal fold paralysis.

LEVEL OF EVIDENCE: 4

Quantitative Analysis of Unilateral and Bilateral Vocal Fold Immobility

OBJECTIVE

To analyze the correlation between clinical and video laryngoscopy findings for 89 patients with bilateral vocal fold immobility (BVFI), unilateral vocal fold immobility (UVFI), and healthy controls by quantitative analysis of normalized laryngeal outlet (NLO), bowing index (BI), and supraglottic compression (SGC).

METHODS

Laryngoscope pictures were taken by two reviewers, and all pictures were standardized by scaling and calibrating to the same width and height in Image J. Three reviewers used quantitative measures to calculate BI, NLO, and SGC in Image J. We assessed reliability for each measurement by two-factor analysis of variance (ANOVA) without replication to calculate the interclass correlation coefficient. Analysis was broken down for each measurement in each group of interest by using a one-way test. The total glottic area was obtained by calculating the normalized glottal gap area from each image of maximum glottal closure during phonation.

RESULTS

Overall reliability of all the measurements was 0.69 (IQ 0.58-0.83). Mean NLO from UVFI, BVFI, and control groups differed significantly. There was no significant difference between control and BVFI. The total glottic area did not consistently predict normalized laryngeal outlet values. Mean normalized laryngeal outlet values of UVFI and BVFI were significantly smaller in the BVFI groups compared with controls and UVFI. BI values consistently predicted total glottic area in the BVFI group. Static SGC measurement did not predict a difference between groups.

CONCLUSION

This is a reliable novel technique, which can be utilized in clinical settings. These measurements have clinical relevance for managing voice disorders. NLO is the most accurate measurement correlating with glottal incompetence. BI findings are sufficiently specific to identify between UVFI and BVFI.

Office-Based Laser Therapy in Vocal Fold Polyps: A Systematic Review and Meta-Analysis

OBJECTIVES

To analyze voice outcomes and lesion regression in patients with vocal fold polyps treated in-office using lasers.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

The search was performed in the Medline, Embase, and Cochrane databases using the preferred reporting items for systematic review and meta-analyses framework. There were no limitations to the year of publication and the search included studies looking at voice outcomes and lesion evolution of in-office laser treatment for vocal fold polyps measured through voice-handicap index, GRB, acoustic analysis or aerodynamics measures. Risk of bias was assessed using Cochrane's ROBINS-I tool for observational studies. Data analysis was performed SPSS software with a significance level of 5%.

RESULTS

We identified 167 articles, 10 of which met the inclusion criteria and were analyzed. The total number of participants was 242. Meta-analysis showed significant improvement in voice handicap index-10 scores (95% CI, [0.86; 1.45]) and decrease in GRB score (95% CI, [1.09; 4.13]) after in-office laser therapy. It also showed significant improvement in percent shimmer (95% CI, [0.26; 1.01]), and significant increase in maximum phonation time (95% CI, [-0.92; -0.18]).

CONCLUSIONS

Laser therapy an outpatient office setting is a reliable alternative to classical phono-microsurgery. Results show Office-based laser therapy of vocal fold polyps results in a significant improvement in subjective voice outcomes measures. This subjective improvement in voice quality is associated with partial or complete disease regression on laryngeal examination and an increase in maximum phonation time. Ovlaryngeal examination in patients with polyps treated with in-office laser.

Performance of Acoustic Measures for the Discrimination Among Healthy, Rough, Breathy, and Strained Voices Using the Feedforward Neural Network

OBJECTIVE

To identify and evaluate the best set of acoustic measures to discriminate among healthy, rough, breathy, and strained voices.

METHODS

This study used the vocal samples of the sustained /ε/ vowel from 251 patients with the vocal complaints, among which 51, 80, 63, and 57 patients exhibited healthy, rough, breathy, and strained voices, respectively. Twenty-two acoustic measures were extracted, and feature selection was applied to reduce the number of combinations of acoustic measures and obtain an optimal subset of measures according to the information gain attribute ranking algorithm. To classify signals as a function of predominant voice quality, a feedforward neural network was applied using a Levenberg-Marquardt supervised learning algorithm.

RESULTS

The best results were obtained from 11 combinations, with each combination presenting six acoustic measures. Kappa indices ranged from 0.7527 to 0.7743, the overall hit rates are 81.67%-83.27%, and the hit rates of healthy, rough, breathy, and strained voices are 74.51%-84.31%, 78.75%-90.00%, 85.71%-98.41%, and 68.42%-82.46%, respectively.

CONCLUSIONS

We obtained the best results from 11 combinations, with each combination exhibiting six acoustic measures for discriminating among healthy, rough, breathy, and strained voices. These sets exhibited good Kappa performance and a good overall hit rate. The hit rate varied between acceptable and good for healthy voices, acceptable and excellent for rough voices, good and excellent for breathy voices, and poor and good for strained voices.

Pathology-Related Influences on the VEM: Three Years' Experience since Implementation of a New Parameter in Phoniatric Voice Diagnostics

The vocal extent measure (VEM) represents a new diagnostic tool to express vocal capacity by quantifying the dynamic performance and frequency range of voice range profiles (VRPs). For VEM calculation, the VRP area is multiplied by the quotient of the theoretical perimeter of a circle with equal VRP area and the actual VRP perimeter. Since different diseases affect voice function to varying degrees, pathology-related influences on the VEM should be investigated more detailed in this retrospective study, three years after VEM implementation. Data was obtained in a standardized voice assessment comprising videolaryngostroboscopy, voice handicap index (VHI-9i), and acoustic-aerodynamic analysis with automatic calculation of VEM and dysphonia severity index (DSI). The complete dataset comprised 1030 subjects, from which 994 adults (376 male, 618 female; 18-86 years) were analyzed more detailed. The VEM differed significantly between pathology subgroups (p < 0.001) and correlated with the corresponding DSI values. Regarding VHI-9i, the VEM reflected the subjective impairment better than the DSI. We conclude that the VEM proved to be a comprehensible and easy-to-use interval-scaled parameter for objective VRP evaluation in all pathology subgroups. As expected, exclusive consideration of the measured pathology-related influences on the VEM does not allow conclusions regarding the specific underlying diagnosis.

Examination of laryngeal function of healthy dogs by using sedation protocols with dexmedetomidine

OBJECTIVE

To determine the ability to evaluate laryngeal function under sedation with dexmedetomidine alone or in combination with opioids.

STUDY DESIGN

Randomized, crossover, blinded study.

ANIMALS

Eight adult research hounds weighing 8 to 22.5 kg.

METHODS

Dogs were sedated with propofol, dexmedetomidine, dexmedetomidine and butorphanol, or dexmedetomidine and hydromorphone. Digital images were collected with video laryngoscopy before and after doxapram administration. Maximal inspiratory normalized glottal gap (GGA_n ) and laryngeal motion were compared between and within protocols before and after doxapram by using a difference of least squares mean.

RESULTS

Normal laryngeal function was confirmed in all dogs with all protocols except propofol, which resulted in two false positive results. No difference between protocols was detected for predoxapram GGA_n . Postdoxapram GGA_n was greater than predoxapram GGA_n for all four sedation protocols (P ≤ .0030). Compared with propofol, postdoxapram GGA_n was greater for all three dexmedetomidine protocols (P ≤ .0420).

CONCLUSION

Dexmedetomidine alone or in combination with opioids was an effective sedation protocol for laryngeal examination, producing sufficient immobilization to prevent jaw motion and without affecting arytenoid abduction.

CLINICAL SIGNIFICANCE

Dexmedetomidine sedation does not inhibit normal laryngeal motion. Laryngeal examination with propofol alone can produce false positive results.

Effects of Voice Therapy Using the Lip Trill Technique in Patients With Glottal Gap

OBJECTIVES

Lip trills are widely used as a voice warm-up technique among singers. However, little is known about the effects of lip trills in cases of voice disorders. We examined the therapeutic effects of lip trills in patients with glottal gap.

METHODS

Patients with glottal gap were classified into three groups according to the type of gap: gap-only, gap with muscle tension dysphonia (MTD), and a sulcus vocalis group. Patients underwent perceptual, acoustic/aerodynamic analyses, stroboscopic evaluations, and subjective analyses using a questionnaire before and after lip trills. The results were analyzed before and after trills and according to and between the groups.

RESULTS

The results in 42 patients were analyzed. Most of the parameters were improved and glottal gap was significantly reduced after trills in all patients. In the gap-only group (n = 19), most of the parameters showed improvement and were within the respective normal ranges, and glottal gap was improved after trills. In the MTD group (n = 13), although many parameters were improved, the improvement was not as prominent as in the gap-only group. In the sulcus vocalis group (n = 10), only some of the parameters were improved and the improvement in glottal gap was limited.

CONCLUSIONS

Lip trills were an effective treatment for glottal gap. The therapeutic effect was prominent in the gap-only group, followed by the MTD and sulcus vocalis groups. Trills can be used as an adjuvant treatment option in voice therapy in cases of various voice disorders.

Characterization of Vocal Fold Vibration in Sulcus Vocalis Using High-Speed Digital Imaging

PURPOSE

The aim of the present study was to qualitatively and quantitatively characterize vocal fold vibrations in sulcus vocalis by high-speed digital imaging (HSDI) and to clarify the correlations between HSDI-derived parameters and traditional vocal parameters.

METHOD

HSDI was performed in 20 vocally healthy subjects (8 men and 12 women) and 41 patients with sulcus vocalis (33 men and 8 women). Then HSDI data were evaluated by assessing the visual-perceptual rating, digital kymography, and glottal area waveform.

RESULTS

Patients with sulcus vocalis frequently had spindle-shaped glottal gaps and a decreased mucosal wave. Compared with the control group, the sulcus vocalis group showed higher open quotient as well as a shorter duration of the visible mucosal wave, a smaller speed index, and a smaller glottal area difference index ([maximal glottal area - minimal glottal area]/maximal glottal area). These parameters deteriorated in order of the control group and Type I, II, and III sulcus vocalis. There were no gender-related differences. Strong correlations were noted between the open quotient and the type of sulcus vocalis.

CONCLUSIONS

HSDI was an effective method for documenting the characteristics of vocal fold vibrations in patients with sulcus vocalis and estimating the severity of dysphonia.

Non-stationary Bayesian estimation of parameters from a body cover model of the vocal folds

The evolution of reduced-order vocal fold models into clinically useful tools for subject-specific diagnosis and treatment hinges upon successfully and accurately representing an individual patient in the modeling framework. This, in turn, requires inference of model parameters from clinical measurements in order to tune a model to the given individual. Bayesian analysis is a powerful tool for estimating model parameter probabilities based upon a set of observed data. In this work, a Bayesian particle filter sampling technique capable of estimating time-varying model parameters, as occur in complex vocal gestures, is introduced. The technique is compared with time-invariant Bayesian estimation and least squares methods for determining both stationary and non-stationary parameters. The current technique accurately estimates the time-varying unknown model parameter and maintains tight credibility bounds. The credibility bounds are particularly relevant from a clinical perspective, as they provide insight into the confidence a clinician should have in the model predictions.

Sulcus Vocalis (Type III): Prevalence and Strobovideolaryngoscopy Characteristics

OBJECTIVES

The reported prevalence of sulcus vocalis (SV)/type III, a pathologic groove in the vibratory margin of the vocal fold, varies greatly in the literature. Difficulties in visualizing the defect and a variety of descriptions have complicated the evaluation of SV. The objective of this study was to determine the prevalence of SV by reviewing strobovideolaryngoscopy (SVL) examinations in subjects with and without dysphonia.

STUDY DESIGN

Retrospective chart review.

METHODS

Charts and SVL images were reviewed for subjects with and without dysphonia and analyzed using standard statistical techniques.

RESULTS

SVL images were reviewed for 94 nondysphonia subjects and 100 dysphonia subjects. For all subjects, 19.6% had type I, 2.1% had type II, and 5.7% had type III/SV. Per vocal fold, 14.7% had type I, 1.3% had type II, 3.1% had type III/SV and 13.1% had scar. The prevalence of SV per subject was not significantly different between the two groups (8% of dysphonia subjects, 3.2% of nondysphonia subjects). Male gender, decreased amplitude, decreased waveform, and hypodyamic motion were significantly higher in the dysphonia SV subjects compared with the non-SV subjects. All other SVL characteristics were not significantly different in subjects with SV compared with non-SV subjects.

CONCLUSIONS

We report a prevalence of SV/type III at 3.1% (per vocal fold) and 5.7% (per subject). Higher frequencies of male gender and waveform abnormalities were seen in the dysphonia SV subjects only. There were no significant differences in nondysphonia subjects with or without SV.

Quantitative analysis of digital videokymography: a preliminary study on age- and gender-related difference of vocal fold vibration in normal speakers

INTRODUCTION

Kymography is an effective method for assessing temporal patterns of vocal fold vibrations. Because kymographic data for a number of normal speakers based on high-speed digital imaging (HSDI) were limited in the literature, this prospective study was conducted to provide normative kymographic HSDI data and clarify gender- and age-related normal variations.

METHODS

Vocally healthy adults were divided into young (≤35 years) and elderly groups (≥65 years). Kymograms were recomposed from HSDI data at the midglottal level, and kymographic parameters were analyzed quantitatively. Then gender- and age-related differences were evaluated.

RESULTS

A total of 26 young subjects (9 men and 17 women, mean age: 27 years) and 20 elderly subjects (8 men and 12 women, mean age: 73 years) were investigated. Obtained data generally matched the values in the literature. Slight asymmetry was seen in all groups, with the elderly subjects having more evident asymmetry than the young subjects. Most of the kymographic parameters showed a negative correlation with fundamental frequency (F0), whereas the open quotient displayed a positive correlation with F0. There were significant intergroup differences in F0, amplitude and lateral peak at a speaking F0.

CONCLUSIONS

The present quantitative findings generally matched the qualitative kymographic data reported in the literature. When judging whether a vibratory pattern is normal or pathological, both gender and age should be taken into account, because gender- and age-related variations of symmetry, F0, and phase were frequently observed in the present study.

Age- and gender-related difference of vocal fold vibration and glottal configuration in normal speakers: analysis with glottal area waveform

INTRODUCTION

Glottal area waveform (GAW) analysis is widely used in the assessment of vocal fold vibration by high-speed digital imaging (HSDI). Because normative GAW data obtained from a large number of subjects have not been reported, we conducted a prospective study to obtain normative results for GAW analysis of HSDI findings and clarify normal variations associated with gender and age.

METHODS

Vocally healthy adults were divided into a young group (aged ≤ 35 years) and an elderly group (aged ≥ 65 years). The configuration and size of the glottal area were assessed at different phases of the glottal cycle, and gender- and age-related differences were evaluated.

RESULTS

A total of 26 young subjects (nine men and 17 women; mean age: 27 years) and 20 elderly subjects (eight men and 12 women; mean age: 73 years) were investigated. The glottal area at different points of the glottal cycle showed a negative correlation with frequency. Although the GAW parameters of young women appeared to be different from those of the other subgroups, the differences were not statistically significant. Young women predominantly had a triangular- or vase-shaped glottal configuration at all frequencies, whereas the other subgroups showed various glottal shapes.

CONCLUSION

The present study clarified gender- and age-related differences of GAW parameters obtained with HSDI. Young women were likely to show different glottal configurations and different responses to frequency changes from those of young men, elderly men, and elderly women. Phonosurgeons should pay attention to the normal variations detected in the present study.

Perceived vocal fatigue and effort in relation to laryngeal functional measures in paresis patients

OBJECTIVES/HYPOTHESIS

To determine if differences in objective measures of laryngeal function can meaningfully explain different levels of self-perceptions of effort or fatigue in patients with vocal fold paresis.

STUDY DESIGN

A retrospective chart review of 72 patients with vocal fold paresis diagnosed using laryngeal electromyography, who had either been observed (n=21), treated only by injection (n=24), or treated only by surgery (n=27).

METHODS

Before and after treatment/observation, patients' subjective ratings of severity of vocal effort and fatigue were assessed using the Glottal Function Index. Laryngeal function was assessed using maximum phonation time and translaryngeal flow.

RESULTS

None of the variables demonstrated a significant linear change across time. Post hoc Tukey analyses following analysis of variance (ANOVA) found significant differences in flow among three groups, those rating symptoms of effort as no problem, moderate problem, or severe problem. Post hoc Tukey analyses following ANOVA found significant differences in the amount that flow changed among three groups, those demonstrating no difference, minor differences, or major differences in ratings of effort before and after treatment.

CONCLUSIONS

Changes in reported symptom severity of effort were related to changes in translaryngeal midvowel flow that were not explained by passage of time.

LEVEL OF EVIDENCE

4.

Efficacy of intensive phonatory-respiratory treatment (LSVT) for presbyphonia: two case reports

OBJECTIVES

Research evidence has shown that neither traditional voice therapy nor surgery was efficacious in managing age-related dysphonia, specifically for more severe cases with pronounced fold atrophy or larger glottal gaps. The purpose of this study was to examine the efficacy of intensive respiratory-phonatory treatment (Lee Silverman voice treatment [LSVT]) for glottal incompetence associated with presbyphonia.

STUDY DESIGN

Nonrandomized prospective study.

METHODS

Two subjects with age-related vocal fold bowing received 4 weeks of the LSVT. Strobolaryngoscopic examination, phonatory function measurement, acoustical analyses, and perceptual judgments of voice were obtained at baseline and 2 weeks posttreatment. Additional acoustic measures of phonatory function, including vocal intensity, maximum phonation time, and pitch range, were also obtained during 16 treatment sessions.

RESULTS

Both subjects exhibited significant improvements in glottal closure, phonatory function, acoustic features, and perceptual ratings of voice after treatment. Significant changes of phonatory function measures were noticed relatively early and remained steady throughout the course of treatment.

CONCLUSIONS

These findings provide solid evidence that speakers with age-related vocal fold bowing and dysphonia may improve glottal competence and related vocal function with neither laryngeal trauma nor maladaptive laryngeal hyperfunction after the LSVT.

Development of a glottal area index that integrates glottal gap size and open quotient

Because voice signals result from vocal fold vibration, perceptually meaningful vibratory measures should quantify those aspects of vibration that correspond to differences in voice quality. In this study, glottal area waveforms were extracted from high-speed videoendoscopy of the vocal folds. Principal component analysis was applied to these waveforms to investigate the factors that vary with voice quality. Results showed that the first principal component derived from tokens without glottal gaps was significantly (p < 0.01) associated with the open quotient (OQ). The alternating-current (AC) measure had a significant effect (p < 0.01) on the first principal component among tokens exhibiting glottal gaps. A measure AC/OQ, defined as the ratio of AC to OQ, was proposed to combine both amplitude and temporal characteristics of the glottal area waveform for both complete and incomplete glottal closures. Analyses of "glide" phonations in which quality varied continuously from breathy to pressed showed that the AC/OQ measure was able to characterize the corresponding continuum of glottal area waveform variation, regardless of the presence or absence of glottal gaps.

[Treatment of glottal gap]

Glottal gaps can be either physiological or pathological. The latter are multifactorial, predominantly organic in origin and occasionally functional. Organic causes include vocal fold paralysis or scarring, as well as a deficiency or excess of tissue. In addition to loss of the mucosal wave, the degree of hoarseness is primarily determined by the circumferential area of the glottal gap. It is thus important to quantify the extent of glottal insufficiency. Although a patient's symptoms form the basis for treatment decisions, these may be subjective and inadequately reflected by the results of auditory-perceptual evaluation, voice analysis and voice performance tests. The therapeutic approach should always combine phonosurgery with conventional voice therapy methods. Voice therapy utilises all the resources made available by the sphincter model of the aerodigestive tract and knowledge on the mechanism of voice production. The aim of phonosurgery is medialization, reconstruction or reinnervation by injection laryngoplasty or larynx framework surgery. These different methods can be combined and often applied directly after vocal fold surgery (primary reconstruction). In conclusion, the techniques described here can be effectively employed to compensate for glottal gaps.

Sulcus vocalis: a review

Sulcus vocalis is described as a groove at the free edge of the vocal fold. Different types have been described: sulcus type I is superficial and may be considered as moreless physiologic. Sulcus type IIa corresponds to a kind of vergeture along the margin of the vocal fold. Its deepness is variable but sulcus vergeture may involve deeper layers of the lamina propria. Sulcus type IIb or pounch may be considered as an open cyst. Sulcus lead to a complex glottic dysfunction with, in the same time, a glottal leakage responsible for the breathy component of the dysphonia and a stiffness of the free edge responsible for the roughness. Diagnosis may be difficult even with the help of stroboscopy and finally is sometimes done only under general anesthesia. Etiology remains controversial and the authors present arguments for each theory, acquired or congenital. Treatment options include phonosurgery and speech therapy but phonosurgery gives results often disappointing and surgical treatment must be indicated prudently and patient must be intensively informed on what he or she can expect from the treatment that is mainly an increase of the loudness of the voice.

Effects of doxapram HCl on laryngeal function of normal dogs and dogs with naturally occurring laryngeal paralysis

OBJECTIVES

To compare the effects of IV doxapram on glottic size and arytenoid motion in normal dogs and in dogs with laryngeal paralysis.

STUDY DESIGN

Prospective experimental and clinical trials.

ANIMALS

Six healthy dogs weighing 24.5 +/- 3.9 kg and six dogs weighing 27.4 +/- 11.5 kg suspected of having laryngeal paralysis.

METHODS

Dogs were pre-medicated with acepromazine and butorphanol, and a light plane of anesthesia was induced with isoflurane by mask. Videoendoscopic examination of laryngeal function was recorded before (baseline) and after IV doxapram administration. Normalized glottal gap area (NGGA) at maximal inspiration and expiration, and percentage change in height, width, area, and NGGA were calculated with measurements from digitized images of the glottal gap.

RESULTS

Active arytenoid motion was present in all normal dogs at baseline. After doxapram administration, depth of respiration appeared greater, but arytenoid motion, as measured by percentage change in NGGA, and in area and width, did not significantly increase in normal dogs. No arytenoid motion was detected in dogs with laryngeal paralysis at baseline; however, rima glottidis NGGA of dogs with laryngeal paralysis was greater at inspiration and expiration than normal dogs. After doxapram administration, dogs with laryngeal paralysis developed paradoxical arytenoid motion and significant, negative percentage change in area (-61%) and NGGA (-145%) because of inward collapse of the arytenoids during inspiration.

CONCLUSIONS AND CLINICAL RELEVANCE

Administration of doxapram during laryngeal examination is useful for differentiating normal dogs from dogs with laryngeal paralysis. Dogs with laryngeal paralysis may suffer extreme glottic constriction with vigorous respirations, and may require intubation during examination.

Laryngeal function and vocal fatigue after prolonged reading in individuals with unilateral vocal fold paralysis

The purpose of the present study was to examine the effect of prolonged loud reading, intended to induce fatigue, on vocal function in adults with unilateral vocal fold paralysis (UVFP). Subjects were 20 adults, 37-60 years old, with UVFP secondary to recurrent laryngeal nerve paralysis. Subjective ratings and instrumental measures of vocal function were obtained before and after reading. Statistical analysis revealed subjects rated their vocal quality and physical effort for voicing more severely following prolonged loud reading, whereas expert raters did not detect a significant perceptual difference in vocal quality. Reading fundamental frequency (F0) was significantly increased following prolonged loud reading, as were mean airflow rates at all pitch conditions. Maximum phonation times for comfort and low pitches significantly decreased during posttests. Multiple regression analyses revealed significant associations between ratings of posttest physical effort and select posttest measures. Interpretation of results indicates the prolonged loud reading task was successful in vocally fatiguing most of the UVFP subjects. Key physiologic correlates of vocal fatigue, in individuals with UVFP, include further reduction of glottic efficiency, resulting in decreased regulation of glottic airflow and a temporary destabilization of speaking fundamental frequency.

Aerodynamics, voice quality, and laryngeal image analysis of normal and pathologic voices

PURPOSE OF REVIEW

The purpose of this review is to describe examinations of phonatory function and their relation to image analysis of the unilaterally immobile larynx. Special emphasis was placed on image analysis using three-dimensional endoscopic images produced from CT scans.

RECENT FINDINGS

Developments in modern image processing technique have led to the quantification of various aspects of vocal fold vibration. Stroboscopic images of the vocal fold were digitized and, subsequently, the glottal gap area, amplitude, and degree of bowing were analyzed quantitatively in relation to phonatory function. Vocal fold vibration was observed with the aid of videokymography, during which images from a single transverse line can be recorded. Successive line images were shown in real time on a monitor, with the time dimension displayed in the vertical direction. This system enabled the assessment of left-right asymmetries, open quotient, propagation of mucosal waves, and forth. Three-dimensional endoscopic images derived from multislice CT scans provided a novel method for evaluating morphologic characteristics of the laryngeal lumen in relation to phonatory function. The combination of three-dimensional endoscopy and coronal reconstructed images supplemented stroboscopic findings exemplified by differences in vertical position and thickness between the vocal folds.

SUMMARY

Depth information about the vocal fold as well as the presence of paradoxic movement of the affected vocal fold and overadduction of the healthy vocal fold during phonation should be taken into account when surgical intervention to improve hoarseness resulting from unilateral vocal fold immobility is performed. Phonatory function tests, videostroboscopy, and laryngeal image analysis are prerequisites to achieving this goal.

Effects of Various Anesthetic Agents on Laryngeal Motion During Laryngoscopy in Normal Dogs

OBJECTIVE

To evaluate the effects of various drugs and drug combinations conventionally used for anesthesia on arytenoid cartilage motion during laryngoscopy in normal dogs.

STUDY DESIGN

Experimental study.

ANIMALS

Six large breed healthy dogs with no previous history of respiratory dysfunction.

METHODS

Each dog was randomly assigned to a different injectable anesthetic protocol once weekly for 6 weeks, then in the 7th week all dogs were anesthetized with isoflurane. Videolaryngoscopy was performed and recorded starting immediately after induction until dogs could no longer be safely restrained for endoscopy. Video was digitized and 3 still images of maximal inspiration and expiration from the first 15 seconds (induction) and the last 15 seconds (recovery) were captured and imported into an image analysis software program. The height and area of the laryngeal ostium were measured in pixels. Normalization of the glottal gap area was performed using the formula (normalized glottal gap area (NGGA)=area in pixels/height(2)). ANOVA was performed on the NGGA of images collected at inspiration and expiration during induction and recovery. Fischer's exact test was performed when significance (P<.05) was found.

RESULTS

Within each protocol, laryngeal motion (defined as change in NGGA) at induction was not significantly different from laryngeal motion measured at recovery. Additionally, no significant differences were found in arytenoid motion immediately after induction when anesthetic protocols were compared. Arytenoid motion before recovery was significantly greater with thiopental when compared with propofol (P=.046), ketamine+diazepam (P=.0098), acepromazine+thiopental (P=.0021), and acepromazine+propofol (P=.0065). No significant difference in arytenoid motion was seen immediately after induction or before recovery when acepromazine+butorphanol+ isoflurane and thiopental were compared.

CONCLUSION

We concluded that intravenous thiopental given to effect is the best choice for assessing laryngeal function in dogs. Dogs premedicated with acepromazine with or without opioids that require further anesthetic restraint for laryngoscopy should be anesthetized with isoflurane administered by mask.

CLINICAL RELEVANCE

Misdiagnosis of laryngeal paralysis during laryngoscopy can be avoided by selecting the anesthetic regimens with the least effect on arytenoid motion.

Source characteristics of aged voice assessed from long-term average spectra

This study is the first to investigate age-related changes in the source characteristics of dynamic speech using long-term average spectral analysis (LTAS). A total of 80 speakers divided equally by age and gender participated. All participants were healthy, active community members. From the first paragraph of the Rainbow Passage, spectral energy measurements were completed for all speakers at 50 frequency levels across the LTAS. In comparison with young women, elderly women demonstrated: (1) significantly higher spectral amplitude levels at the frequencies of 320, 6080, 6240, 6400, 6560, and 6720 Hz; (2) significantly lower levels at the frequencies of 3040 and 3200 Hz; and (3) a tendency toward higher levels at 160 Hz. These findings suggest that both young and elderly women demonstrate spectral features associated with breathy voice quality, while differing in the specific spectral regions in which breathiness is indicated. Elderly men demonstrated significantly higher spectral amplitude levels than young men at 160 Hz, as well as significantly lower levels at 1600 Hz. Findings for men provide acoustic support for previous laryngoscopic findings of an age-related increase in the incidence of glottal gaps.

Results of fascial augmentation in unilateral vocal fold paralysis

The objective of this study was to evaluate the effects on voice quality of augmentation by injection of minced fascia in patients with unilateral vocal fold paralysis. Preoperative and postoperative voice samples from 14 patients (6 men and 8 women; mean age, 59 years) were analyzed by computerized acoustic analysis and blinded perceptual evaluation. Statistically significant improvements were seen in perturbation measurements (jitter and shimmer), noise-to-harmonics ratio, and maximum phonation time. A panel of evaluators rated 10 of the 14 postoperative voices as normal or near-normal. Injection laryngoplasty with minced fascia offers a new, effective, well-tolerated, and inexpensive method to medialize a paralyzed vocal fold. The graft seems to survive well, as indicated by good vocal results with a follow-up ranging from 5 to 32 months.

Quantitative analysis of videostroboscopic images in presbylarynges

OBJECTIVE/HYPOTHESIS

Age-related dysphonia, or presbylarynges, is often identified as the cause of voice disorders in older individuals. It is a diagnosis of exclusion that typically includes the subjective videostroboscopic findings of vocal fold bowing or atrophy and incomplete glottal closure. We hypothesize that vocal fold bowing correlates directly with glottal gap in patients with presbylarynges and that these characteristics may be quantified objectively using measures obtained from videostroboscopic images.

STUDY DESIGN

Retrospective analysis of patient data and prospective analysis of control subjects.

METHODS

The quantitative measures of bowing index and normalized glottal gap, as well as a novel measure, normalized laryngeal outlet, were calculated from the videostroboscopic examinations of 46 patients with presbylarynges and 20 normal control subjects.

RESULTS

The mean bowing index values from the presbylarynges and control groups differed significantly, although there was overlap of individual values between groups. Bowing index values did not consistently predict normalized glottal gap values. Mean normalized laryngeal outlet values of the patients with presbylarynges were significantly smaller than those of the control group.

CONCLUSIONS

Bowing does not consistently predict the extent of glottal gap. Therefore, other presbylaryngeal changes are probably contributing to incomplete glottal closure, which are not well-visualized stroboscopically, so the finding of bowing is not sufficiently specific to identify presbylarynges. The significantly smaller normalized laryngeal outlet values suggest that this identifies a compensatory strategy for glottal gap to optimize vocal function. This is a novel finding that contrasts with medial ventricular fold squeezing, which is more routinely sought and is typically considered a maladaptive compensatory strategy. Despite the advantages of quantitative stroboscopic measures, limitations in reliability limit their clinical utility.

Effects of ageing on the insertion zones of the human vocal fold

The vocal ligaments insert at the anterior and posterior commissures of the larynx. These structures fulfil biomechanical functions, balancing the different elastic moduli of tendon, cartilage or bone and undergo age-related changes that may be responsible for voice changes with increasing age. The aim of this study was to analyse the insertion structures of the vocal ligaments by means of macroscopic, histological, immunohistochemical and electron-microscopic methods and to draw conclusions from age-related structural changes on a functional basis. Investigations were carried out on the larynges of 22 males and 15 females (aged 1-95 y). In adolescence, the insertion zone of the vocal ligament tendon, a dense network of connective tissue rich in sulphated glycosaminoglycans at the thyroid cartilage, is characterised by a layer between tendon and cartilage comparable to fibrocartilage. The insertion zone lacks a perichondrium. Collagen fibrils of the vocal ligament tendon penetrate directly into the thyroid cartilage. In the insertion area, the chondrocytes are surrounded by collagen fibrils, which show positive reactivity to antibodies against type I and type III collagen. Sulphated glycosaminoglycans are integrated between the collagen fibrils. In the area of the posterior glottis, elastic cartilage rests like a cap on the hyaline base of the arytenoid cartilage. There is no distinctive border between the structures. With increasing age, ossification of the laryngeal skeleton occurs, involving hyaline cartilage at the posterior glottis and hyaline and fibrocartilage at the anterior commissure. At the same time, a loss or sulphated glycosaminoglycans is observed inside the vocal ligament tendon. Advanced ossification of the laryngeal skeleton, particularly in the area of the commissures, an increasing loss of glycosaminoglycans in the vocal ligament tendon and changes in the elastic tissue reduce the elastic modulus between tendon, cartilage and bone, thus 'stiffening' the insertion zones, which could be one factor among others favouring voice changes with advancing age.

Etiology, pathophysiology, treatment choices, and voice results for unilateral adductor vocal fold paralysis: a 3-year retrospective

Unilateral vocal fold paralysis is now considered a common disorder seen in the practice of otolaryngology and voice pathology. Concern first is for the accurate diagnosis of the associated etiology in an efficient and thorough fashion. When etiology has been determined the focus of treatment becomes the management of the presenting symptoms, which typically include dysphonia and dysphagia. A retrospective study was conducted reviewing the records of 117 patients with unilateral adductor vocal fold paralysis who presented to a large otolaryngology practice and clinical voice lab from 1995 to 1998. Demographic data reveal most patients to range in age from 16 to 91 with a dominant clustering for ages 50 to 70. Gender distribution reveals males slightly exceed females in this sample. Data regarding etiology type are collected in great detail, revealing that disease and surgery involving the chest contribute the greatest to the overall number in this study and that anterior approach to cervical spine surgery contributes as much as thyroid surgery. General outcomes of the patients are reviewed. A small group (n = 25) of patients who had pretreatment and posttreatment data available revealed statistically significant differences between voice outcomes for patients who were treated with medialization and for those treated with therapy. Patients receiving therapy had less severe symptoms pretreatment, while greater gains pretreatment to posttreatment were shown for those who had surgical medialization.

Voice acoustics after autologous fascia injection for vocal fold paralysis

OBJECTIVES

The present study was carried out to assess the impact of fascial injection on voice acoustics Preliminary results had suggested that voice, as rated by a panel of listeners, was significantly improved after autologous fascia augmentation of a paralyzed vocal fold.

STUDY DESIGN

A prospective study among patients with unilateral vocal fold paralysis was carried out. Eighteen subjects were analyzed 9 months (mean) after the procedure.

METHODS

The preoperative and postoperative samples of vowel /a/ were analyzed by Key Elemetrics (Lincoln Park, NJ). Computerized Speech Lab.

RESULTS

There was a significant improvement (P<.05) in all parameters measured, including jitter, shimmer, noise-to-harmonic ratio, and maximum phonation time. No laryngeal complications were seen.

CONCLUSIONS

According to these preliminary results, vocal fold augmentation by an injection of autologous fascia seems a simple, inexpensive, reliable and safe method to restore voice quality after unilateral vocal fold paralysis.