Vocal fold atrophy: quantitative glottic measurement and vocal function

Endoscopic Distance and its Impact on Quantified Age-related Vocal Fold Atrophy Measures

INTRODUCTION

The bowing index (BI) and normalized glottal gap area (NGGA) are used to quantify vocal fold morphology in ARVA; however, the influence of the distance between the flexible laryngoscope lens and the target area is not known. The goal is to test whether the endoscopic distance impacts vocal fold morphology measurements in patients with ARVA during flexible video laryngostroboscopy (VLS).

METHOD

Patients with ARVA who underwent VLS were included. Images were classified into near (close to the petiole of the epiglottis) and far (below nasopharynx, with tongue base and entire epiglottis visible) conditions. BI was calculated using a mobile application, and NGGA was measured using ImageJ.

RESULTS

This study included 23 patients; the mean age was 77 ± 7 years. Mean BI measured at the near distance was higher than far distances with a mean difference of 1.94 (95% CI: 0.92-2.96, p = 0.001). NGGA showed difference with changed distance -0.24 (95% CI: -0.48 to 0.01, p < 0.05).When stratifying patients into two groups based on median BI measurement, there was a statistically significant difference between near and far conditions, with increased BI in the near condition for patients above the median (p < 0.05), but no difference between the near and far condition for patients with BI below the median.

CONCLUSION

The BI and NGGA were impacted by the endoscopic distance during flexible VLS. BI was significantly higher in the near condition compared with the far condition. The difference in BI between the near and far conditions was more pronounced when the vocal fold bowing was greater. These findings call for heightened awareness of measurement discrepancies secondary to the endoscopic distance during flexible laryngostroboscopy.

LEVEL OF EVIDENCE

Level 2 Laryngoscope, 2024.

Physiological Effects of Voice Therapy for Aged Vocal Fold Atrophy Revealed by EMG Study

OBJECTIVES

Age-related voice changes are characterized as breathy, weak and strained, and a deterioration in vocal function in the elderly has been putatively linked to a reduced intensity of speech. They contribute to undesirable voice changes known as presbyphonia. These changes are caused by histological alterations in the lamina propria of the vocal fold mucosa and atrophy of the thyroarytenoid muscle, as well as by decreased respiratory support. There are several clinical studies on presbylarynx dysphonia showing the effectiveness of voice therapy. However, physiological changes of the presbylarynx following voice therapy have not been verified. The purpose of this prospective study was to demonstrate the clinical effectiveness of voice therapy for rehabilitating presbylarynx dysphonia, using vocal function assessments and thyroarytenoid muscular activity detection on laryngeal electromyography (LEMG).

METHODS

10 patients who were diagnosed with aged vocal fold atrophy from ages 60 to 87 years (mean age: 72 years) underwent approximately 12 weeks of voice therapy, mainly using forward-focused voice and vocal resistance training. Stroboscopic examination, aerodynamic assessment, acoustic analysis, Voice Handicap Index (VHI)-10, and LEMG were performed pre- and post-voice therapy. Vocal fold vibratory amplitude (VFVA) was measured by image analysis from the stroboscopic examinations. Turns analysis during steady phonation on LEMG was also assessed.

RESULTS

Maximum phonation time, subglottic pressure, jitter, shimmer, VFVA, and VHI-10 significantly improved after voice therapy. The number of turns per second on LEMG also significantly increased.

CONCLUSION

Our data suggest that voice therapy may improve vocal function and thyroarytenoid muscle activity in patients with aged vocal fold atrophy.

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.

A Systematic Review of Speech-Language Pathology Interventions for Presbyphonia Using the Rehabilitation Treatment Specification System

BACKGROUND

The prevalence of voice disorders for people aged >65 years is four times higher than for the population at large. The most common cause of dysphonia in this group is presbyphonia, the preferred first-line treatment for which is voice therapy with a speech-language pathologist. This systematic review seeks to identify how voice therapy affects multidimensional voice outcomes in people with presbyphonia.

METHODS

A systematic search of CINAHL, Embase, Emcare, MEDLINE, and Google Scholar was conducted in March 2023. Comparative and noncomparative studies of voice therapy in participants aged >50 years with presbyphonia were considered for inclusion. No limitations were placed on date or language of publication. Study quality and risk of bias were assessed with the Cochrane Risk of Bias 2 tool and the Methodological Index for Non-Randomized Studies. Subgroup analysis was used to compare studies based on participant sex, intervention duration, study design, and intervention content. Interventions were specified using the Rehabilitation Treatment Specification System (RTSS) employing a consensus methodology among reviewers. The results were synthesized utilizing meta-analysis when outcomes were adequately specified and narrative analysis when they were not.

RESULTS

Twenty-three studies were included with 1050 subjects (mean age: 72.5 ± 8.6 years; 51% female). The most reported intervention was vocal function exercises. Per the RTSS, 14 interventions employed a predominantly Organ Functions approach, and the 14 remaining interventions employed a Skills & Habits approach. Meta-analysis confirmed posttherapy improvement in patient-related outcome measures of 0.93 standard mean difference (P < 0.00001, 95% confidence interval [CI]: 0.70-1.17); studies with predominantly males and with longer treatment periods were associated with larger improvements, while randomized controlled trials reported more modest improvements. Meta-analysis also identified a mean posttherapy increase in maximum phonation time (MPT) of 5.37 seconds (P < 0.00001, 95% CI: 3.52-7.22). Treatments with an Organ Functions focus resulted in greater gains in MPT than those with a Skills & Habits focus (7.52 seconds versus 2.90 seconds). Finally, meta-analysis identified reductions in acoustic perturbation measures (jitter: 0.62%, P < 0.001, 95% CI: 0.26%-0.97%; shimmer 1.05%, P < 0.00001, 95% CI: 0.67%-1.44%). Narrative synthesis further identified improvement in auditory-perceptual voice quality in all active treatment groups as well as improved glottal function in most studies that reported this.

CONCLUSIONS

Despite the uncertainty around internal validity introduced by the inclusion of a wide range of study designs, there is convincing evidence that voice therapy for presbyphonia results in significant improvement in patient-reported, aerodynamic, acoustic, and expert-rated voice outcomes. Treatments with an Organ Functions focus may better address the underlying physiological deficits of presbyphonia, although future comparative studies with multidimensional voice assessment are warranted.

Acute Effects of Systemic Glucocorticoids on the Vocal Folds in a Pre-Clinical Model

OBJECTIVES/HYPOTHESIS

Systemic glucocorticoids (GC)s are employed to treat various voice disorders. However, GCs have varying pharmacodynamic properties with adverse effects ranging from changes in epithelial integrity, skeletal muscle catabolism, and altered body weight. We sought to characterize the acute temporal effects of systemic dexamethasone and methylprednisolone on vocal fold (VF) epithelial glucocorticoid receptor (GR) nuclear translocation, epithelial tight junction (ZO-1) expression, thyroarytenoid (TA) muscle fiber morphology, and body weight using an established pre-clinical model. We hypothesized dexamethasone and methylprednisolone will elicit changes in VF epithelial GR nuclear translocation, epithelial ZO-1 expression, TA muscle morphology, and body weight compared to placebo-treated controls.

METHODS

Forty-five New Zealand white rabbits received intramuscular injections of methylprednisolone (4.5 mg; n = 15), dexamethasone (450 µg; n = 15), or volume matched saline (n = 15) into the iliocostalis/longissimus muscle for 6 consecutive days. Vocal folds from 5 rabbits from each treatment group were harvested at 1-, 3-, or 7 days following the final injection and subjected to immunohistochemistry for ZO-1 and GR as well as TA muscle fiber cross-sectional area (CSA) measures.

RESULTS

Dexamethasone increased epithelial GR nuclear translocation and ZO-1 expression 1-day following injections compared to methylprednisolone (P = .024; P = .012). Dexamethasone and methylprednisolone increased TA CSA 1-day following injections (P = .011). Methylprednisolone decreased body weight 7 days following injections compared to controls (P = .004).

CONCLUSIONS

Systemic dexamethasone may more efficiently activate GR in the VF epithelium with a lower risk of body weight loss, suggesting a role for more refined approaches to GC selection for laryngeal pathology.

Vocal Fold Thinning in Transgender Patients

PURPOSE

Transgender individuals strive to match their voice and gender identity. An increased glottal gap is often noted on stroboscopy without a clear etiology. We hypothesize this gap can be quantified and results from hormone replacement therapy impacting laryngeal tissues.

METHODS

Videostroboscopy exams were retrospectively collected for transgender patients from a tertiary care laryngology practice over two years. Data included hormone duration/type and voice therapy duration. Modal pitch videostroboscopy frame counts determined the open quotient in consecutive vocal fold cycles. Glottal opening was measured using the widest still frame gap during stroboscopy with fully adducted arytenoids.

RESULTS

Sixteen transgender patients, along with male and female controls, were included, with 15 patients on hormone therapy (mean = 18 months). Voice therapy, employed in 9/16 patients, ranged from 0 to 23 months (mean = 10.67). One-way ANOVA testing revealed a difference between the open quotient in transgender individuals, males, and females.Tukey's post hoc test identified transgender patients as different from both male (P <0.001) and female (P = 0.037) controls. Length of hormone therapy did not correlate to glottal area measurement or open quotient. Conversely, voice therapy length correlated to increased glottal area (Kendall's Tau = 0.03). Mean phonation time, VHI-10, and mean pitch did not correlate to measured glottal area on stroboscopy.

CONCLUSIONS

The increased glottal gap noted in many transgender patients, quantified via the open quotient, differs from male and female controls. Results suggest these findings may correlate to duration of voice therapy.

Treatments for Age-related Vocal Atrophy: A Systematic Review

OBJECTIVE

Age-related vocal atrophy (ARVA) can dramatically affect voice, communication, and quality of life. The objectives of this systematic review were to (1) determine whether treatments for ARVA were superior to controls (2) compare the relative efficacy of procedural and behavioral treatments (3) review the various types of outcome measures, and (4) evaluate the quality of studies.

REVIEW METHODS

The literature was searched using strategies designed by a medical librarian (2/18/21, updated 3/9/22). Studies investigating treatments for bilateral vocal atrophy were included. Studies involving unilateral atrophy, presbyphonia (without endoscopic findings), or an absent comparator group were excluded. The Preferred Reporting Items for Systematic Reviews and Meta-analyses checklist was used to guide this study.

RESULTS

After applying the inclusion/exclusion criteria, 8 articles remained, including 4 randomized trials and 4 cohort studies, and a narrative synthesis was performed. Surgical and behavioral treatments for ARVA appeared to be superior to control groups, based on specific outcome measures. However, the superiority of these treatments over controls was not uniformly observed across multiple outcome measures. When comparing different treatments, superiority could not be established based on the quality and completeness of the studies included in the systematic review. Outcome measures also varied between individual studies. Finally, the risk of bias was analyzed and scored. Consistent point deductions among reviewed studies were noted.

CONCLUSIONS

When comparing treatments for ARVA. Surgery and voice therapy were both superior to control groups based on specific outcome measures from different domains. Superiority of one treatment could not be established.

LEVEL OF EVIDENCE

N/A Laryngoscope, 133:2846-2855, 2023.

A 4-Week Straw Phonation in Water Exercise Program for Aging-Related Vocal Fold Atrophy

PURPOSE

This study evaluated the efficacy of a 4-week straw phonation in water (SPW) exercise program on aging-related vocal fold atrophy (VFA), with a secondary objective to examine the immediate effects of SPW exercises.

METHOD

Thirty-eight older adults aged 60 years and above formally diagnosed with aging-related VFA were randomly assigned into an experimental group undergoing SPW exercises with an 8-cm depth of straw submersion into water for 4 weeks plus vocal hygiene practice (n = 20), and a control group with only vocal hygiene practice (n = 18). Outcome measures included laryngeal endoscopic measures of glottal gap, auditory-perceptual ratings of voice quality, acoustic measures, aerodynamic measures, and standardized self-assessment questionnaire scores. An additional round of acoustic and aerodynamic assessment following 20 min of SPW exercises was conducted to examine the immediate effects.

RESULTS

Significant improvements in normalized glottal gap area, perceptual rating of breathiness, smoothed cepstral peak prominence, harmonics-to-noise ratio (HNR), mean oral airflow, subglottal pressure and laryngeal airway resistance at comfortable loudness, Voice-related Quality of Life scores, and Chinese Vocal Fatigue Index Factor 3 scores were observed in the experimental group relative to the control group. There were also significant immediate effects for HNR, mean oral airflow, subglottal pressure, and laryngeal airway resistance.

CONCLUSIONS

These findings suggested significant immediate improvements in vocal function following SPW exercises, with additional significant improvements in vocal function as well as significant improvements in quality of life following the 4-week SPW exercise program. Further studies with more long-term follow-up are recommended to better understand the efficacy of SPW exercises with deep levels of straw submersion into water as an effective clinical option for the management of hypofunctional dysphonia associated with aging-related VFA.

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.

The Additive Effectiveness of Inspiratory Muscle Training on Glottic Closure and Subjective Voice Outcomes of Patients With Benign Lesion After Hyaluronic Acid Laryngoplasty

OBJECTIVES

For patients with glottic insufficiency disease, injection laryngoplasty is a rapid and efficient management option that complements voice therapy. Some studies have indicated that respiratory muscle training may also show promise in patients with voice disorders. However, the effect of respiratory muscle training in patients with glottic insufficiency was reported to be limited, and whether it provides additional benefit after standard management requires further evaluation. We aimed to investigate the effectiveness of inspiratory muscle training on glottis closure and patient-reported voice quality in glottic insufficiency patients who had been treated with hyaluronic acid injection.

STUDY DESIGN

Retrospective observational study.

METHODS

We included 46 patients with glottic insufficiency who had undergone hyaluronic acid injection. Twenty of them had undergone inspiratory muscle training during three months. We measured patients' changes in glottic status according to the normalized glottal gap area and bowing index, as well as voice quality of life according to the voice handicap index 10 and the voice outcome survey, before and after training.

RESULTS

Patients who underwent inspiratory muscle training had higher odds of experiencing better improvement in all scores. The range of odds ratios ranged from 2.5 to 6.3 for changes in scores, and from 3.8 to 22.2 for changes in score percentages. Of note, the effect of training on percentage changes in the normalized glottal gap area score was significant (P= 0.0127) after adjustment for the duration of vocal disease, body mass index and BMI, and history of gastroesophageal reflux disease.

CONCLUSIONS

Inspiratory muscle training can improve the glottal gap after injection laryngoplasty, and may be applied in clinical practice.

Quantification of Vocal Fold Atrophy in Age‐Related and Parkinson's Disease‐Related Vocal Atrophy

OBJECTIVE

Vocal fold atrophy (VFA) is associated with aging and Parkinson's disease (PD). Clinical diagnosis of VFA depends on several visual-perceptual laryngostroboscopy findings that are inherently subjective. The purpose of this study was to use quantitative measurements to; (1) examine the relationships between VFA and dysphonia severity and (2) evaluate differences in VFA in patients with age-related VFA versus PD.

METHODS

Thirty-six patients >60 years of age with VFA were included in this retrospective cohort study. Demographic information, medical history, Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V), Voice Handicap Index-10 (VHI-10), and still images from the stroboscopic exam were obtained. Image J™ was used to measure VFA, including bowing index (BI), normalized glottal gap area, and normalized mucosal wave amplitude. Pearson's correlation was used to evaluate the relationship between VFA, CAPE-V, and VHI-10. t-Tests and multivariate linear regression were used to compare VFA measures by dysphonia severity (CAPE-V <30 vs. >30) and diagnosis (age-related vocal atrophy [ARVA] and PD).

RESULTS

BI was positively correlated with CAPE-V. Patients with CAPE-V >30 had a significantly larger BI compared to those with CAPE-V <30. Patients with PD had significantly larger BI than those with ARVA. Diagnosis of PD also predicted a larger BI after controlling for age and CAPE-V.

CONCLUSION

Quantitative measures supported an association between bowing severity and dysphonia severity in patients with PD and ARVA. A PD diagnosis significantly predicted more severe BI. These findings demonstrate the potential utility of BI. Quantitative VFA measures might also provide insight into the mechanisms of ARVA and dysphonia.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:1462-1469, 2023.

Peroxisome Proliferator-Activated Receptor-γ Agonist Attenuates Vocal Fold Fibrosis in Rats via Regulation of Macrophage Activation

Macrophages aid in wound healing by changing their phenotype and can be a key driver of fibrosis. However, the contribution of macrophage phenotype to fibrosis following vocal fold injury remains unclear. Peroxisome proliferator-activated receptor-γ (PPARγ) is expressed mainly by macrophages during early wound healing and regulates the macrophage phenotype. This study aimed to evaluate the effects of pioglitazone (PIO), a PPARγ agonist, on the macrophage phenotype and fibrosis following vocal fold injury in rats. PIO was injected into the rat vocal folds on days 1, 3, 5, and 7 after injury, and the vocal fold lamina propria was evaluated on days 4 and 56 after injury. Moreover, THP-1-derived macrophages were treated with PIO, and the expression of proinflammatory cytokines under lipopolysaccharide/interferon-γ stimulation was analyzed. PIO reduced the expression of Ccl2 both in vivo and in vitro. Furthermore, PIO decreased the density of inducible nitric oxide synthase⁺ CD68⁺ macrophages and inhibited the expression of fibrosis-related factors on day 4 after injury. On day 56 after injury, PIO inhibited fibrosis, tissue contracture, and hyaluronic acid loss in a PPARγ-dependent manner. These results indicate that PPARγ activation could inhibit accumulation of inflammatory macrophages and improve tissue repair. Taken together, these findings imply that inflammatory macrophages play a key role in vocal fold fibrosis.

Effects of Age and Parkinson's Disease on the Relationship between Vocal Fold Abductory Kinematics and Relative Fundamental Frequency

PURPOSE

This study reports on two experiments to examine vocal fold abduction and its relationship with relative fundamental frequency (RFF), considering two attributes that have been shown to elicit group differences in RFF: age (Experiment 1) and Parkinson's disease (PD; Experiment 2).

METHODS

For both experiments, simultaneous acoustic and nasendoscopic recordings were collected as participants produced the utterance, /ifi/. RFF values were computed from the acoustic signal, whereas abduction duration and glottic angle at voicing offset were identified from the laryngoscopic images. In Experiment 1, 50 speakers with typical voices (18-83 years) were analyzed to examine (1A) the effects of speaker age on individual outcome measures (RFF, abduction duration, glottic angle) via Pearson's correlation coefficients, and (1B) the effects of abductory measures and age on RFF via an analysis of covariance. In Experiment 2, 20 speakers with PD and 20 matched controls were analyzed to examine (2A) the effects of group (with/without PD) on outcome measures via an analysis of variance, and (2B) the relationship of RFF with abduction duration, glottic angle, and age when considering group via an analysis of covariance.

RESULTS

Age demonstrated a significant, negative relationship with glottic angle (1A) but was not a significant factor when examining the relationship of vocal fold abduction and RFF (1B). Speaker group (with/without PD) demonstrated a significant effect on measures of RFF and abduction duration (2A) but was not a significant factor when examining the relationship of vocal fold abduction and RFF (2B).

CONCLUSIONS

RFF is sensitive to changes in vocal fold abductory patterns during devoicing, irrespective of speaker age or PD status.

Objective Laryngoscopic Measures From Older Patients With Voice Complaints and Signs of Aging

PURPOSE

The purpose of this study was to use objective measures of glottal gap, bowing, and supraglottic compression from selected images of laryngoscopic examinations from adults over 60 years of age with voice complaints and signs of aging to test current hypotheses on whether degree of severity impacts treatment recommendations and potential follow-through with treatment.

METHOD

Records from 108 individuals 60 years or older with voice complaints and signs of aging were reviewed. Three objective measures (normalized glottal gap area [NGGA], total bowing index, and normalized true vocal fold width) were derived. Each measure was subsequently divided into three categories by severity: absence, small degree, or large degree. Nonparametric statistics tested associations between severity and treatment recommendations as well as potential follow-through.

RESULTS

Noninvasive treatments (observation/voice therapy) were marginally associated with no glottal gap (p = .09). More invasive treatments (injection/bilateral thyroplasty) were associated with glottal gaps being present (p = .026), but bilateral thyroplasty recommendations were not significantly associated with the largest gaps. Treatment modalities were not characterized by specific severity categories for any of the objective measures. No significant differences were found for any of the three objective measures between those who followed through with recommended treatment and those who did not.

DISCUSSION

Results demonstrated some support for current hypotheses on how degrees of severity of objective measures relate to treatment recommendations. Of the three measures, NGGA appears to be more informative regarding treatment recommendations and follow-through, but due to low power, larger sample sizes are needed to confirm clinical relevance.

Voice and Respiratory Characteristics of Men and Women Seeking Treatment for Presbyphonia

BACKGROUND AND OBJECTIVES

Impaired respiratory function could potentially explain why some older speakers experience voice-related handicap whereas others do not, despite presenting with similar age-related laryngeal characteristics. The objectives of this study were therefore to (1) describe voice and respiratory function across men and women in a sample of treatment-seeking patients with presbyphonia; (2) assess how respiratory function differed from the general elderly population, based on normative data; and 3) discuss how respiratory function may play a role in the development of voice symptoms across men and women.

METHODS

Twenty one participants with presbyphonia underwent respiratory assessments (spirometry and respiratory muscle strength testing) in addition to standard of care voice assessments. Respiratory variables included forced vital capacity (FVC), forced expiratory volume in one second (FEV₁), FEV₁/FVC, maximum inspiratory pressure (MIP), and maximum expiratory pressure (MEP).

RESULTS

Voice features were consistent with the diagnosis of presbyphonia and values did not different significantly between males and females, although some trends were noted. Regarding respiratory variables, one-third of the participants (n = 7) presented with FVC and FEV₁ less than 80% of predicted, and 57% (n = 12) were <90% of predicted. Nine percent of the males (n = 1) and none of the females had a MIP below the lower limit of normal (LLN) expected for their age, sex, and weight. Eighteen percent of the males (n = 2) and 20% of the females (n = 2) fell below the LLN for MEP.

CONCLUSION

Our sample of participants with presbyphonia included a non-negligible proportion of patients with decreased percent predicted values of FVC and FEV₁, and with respiratory muscle strength (MEP) below the LLN. Standardized values of pulmonary function were not different across sexes, indicative of a similar respiratory health. However, a lower raw pulmonary function and respiratory muscle strength in women may compound laryngeal changes and have an impact on perceived voice-related handicap. Together, findings warrant further studies to explore the impact of decreased respiratory function on voice and, ultimately, on the response to voice therapy in patients with presbyphonia.

The Role of Vocal Fold Bowing on Cough and Swallowing Dysfunction in Progressive Supranuclear Palsy

OBJECTIVES

Progressive supranuclear palsy (PSP) is a neurodegenerative disease which results in cough and swallowing dysfunction and aspiration pneumonia. Relationships among vocal fold atrophy, cough, and swallowing have been identified in related diseases, but remain unknown in PSP. This study examined: 1) the prevalence of vocal fold bowing in PSP, and 2) the influence of vocal fold bowing on cough and swallowing in PSP.

STUDY DESIGN

Prospective Cohort Study.

METHODS

Twenty-three participants with PSP completed instrumental assessments of cough and swallowing. Vocal fold bowing (BI) and swallowing safety (PAS) was assessed using flexible laryngoscopy. Measures of cough effectiveness were obtained using spirometry. Statistical analyses were used to determine the frequency of mild-moderate (BI > 0) and severe (BI > 12.2) bowing, and to assess the influence of BI on PAS and cough effectiveness in PSP.

RESULTS

Fifty-two percent (n = 12) of participants exhibited severe bowing while 48% (n = 11) exhibited mild-to-moderate bowing. Voluntary cough peak expiratory flow rate (P = .01), as well as reflex (P = .02) and voluntary (P = .005) cough volume acceleration were lower for participants with severe BI when compared to mild-to-moderate BI. However, BI did not influence PAS (P > .05).

CONCLUSIONS

Findings from this study suggest that vocal fold bowing is highly prevalent in PSP and associated with reduced reflex and voluntary cough effectiveness. These findings provide insight into the pathophysiology of compromised airway protection in this patient population. Future studies should examine vocal fold atrophy as a treatment target for behavioral and medical intervention in PSP.

LEVEL OF EVIDENCE

3 (Prospective Observational Study) Laryngoscope, 131:1217-1222, 2021.

Respiratory Muscle Strength Training to Improve Vocal Function in Patients with Presbyphonia

BACKGROUND AND OBJECTIVE

The effects of presbyphonia are compounded by the decline in respiratory function that occurs with age. Commonly recommended exercises to optimize the use of respiratory muscles during speech, such as diaphragmatic breathing, are unlikely to be intensive enough to induce respiratory changes and impact vocal function. The objective of this study was to assess the effect of adding a targeted intervention, respiratory muscle strength training, to voice exercises in a sample of patients with presbyphonia.

METHODS/DESIGN

In this prospective, randomized-controlled trial, 12 participants received either (1) vocal function exercises (VFE), (2) VFE combined with inspiratory muscle strength training (IMST), or (3) VFE combined with expiratory muscle strength training (EMST). Data collected prior to and following 4 weekly intervention sessions included respiratory measures (pulmonary function and respiratory muscle strength) and voice measures (videostroboscopy, acoustic, auditory-perceptual, aerodynamic, and self-assessment measures).

RESULTS

Participants who received IMST improved their voice quality during connected speech (smoothed cepstral peak prominence and ratings of overall voice quality) and their scores on the three self-assessment questionnaires with large to very large within-group effect sizes (|d| = 0.82-1.61). In addition, participants in the IMST group reduced their subglottal pressure with a large effect size (d = -0.92). Participants who received EMST improved their maximum expiratory strength and smoothed cepstral peak prominence with large effect sizes (d = 0.80 and 0.99, respectively) but had limited improvements in other outcomes. Participants who received only VFE decreased their amount of vocal fold bowing, improved their voice quality on a sustained vowel (amplitude perturbation quotient), and improved their Glottal Function Index score with large effect sizes (|d| = 0.74-1.00).

CONCLUSION

Preliminary data indicate that adding IMST to voice exercises may lead to the greatest benefits in patients with presbyphonia by promoting improved subglottal pressure control as well as increasing air available for phonation, resulting in improved self-assessment outcomes.

The Impact of Respiratory Function on Voice in Patients with Presbyphonia

BACKGROUND AND OBJECTIVE

Presbyphonia is an age-related voice disorder characterized by vocal fold atrophy and incomplete glottal closure during phonation. The extent to which the effects of presbyphonia may be compounded by age-related declines in the respiratory system and further impact communication and quality of life remains unknown. Therefore, the objective of this study was to determine how variations in respiratory function impacts voice measures in a sample of participants with presbyphonia.

METHODS

In this pilot study, 21 participants with presbyphonia underwent respiratory assessments (spirometry and respiratory muscle strength testing) and voice assessments (videostroboscopy, acoustic analysis, auditory-perceptual ratings, aerodynamic assessment, and self-assessments). Factor and cluster analyses were conducted to extract voice and respiratory constructs and to identify groups of participants with similar profiles. Correlations and regression analyses were conducted to better describe the relationships between voice and respiratory function.

RESULTS

Respiratory function was found to impact voice via two main pathways: through its physiological effect on voice and through its impact on general health and impairment. A lower respiratory function was associated with a lower vocal fold pliability and regularity of vibration and with an elevated aerodynamic resistance accompanied by laryngeal hyperfunction. Standardized measures of respiratory function were associated with perceived voice-related handicap. Respiratory function did not associate with voice quality, which was mostly influenced by the severity of vocal fold atrophy.

CONCLUSION

Poor respiratory health exacerbates the burden of vocal fold atrophy and, therefore, implementation of respiratory screening prior to starting voice therapy may significantly affect the treatment plan and consequently the outcomes of voice therapy in this patient population.

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.

A Preliminary Quantitative Comparison of Vibratory Amplitude Using Rigid and Flexible Stroboscopic Assessment

STUDY OBJECTIVE

The purpose of this study was to establish preliminary, quantitative data on amplitude of vibration during stroboscopic assessment in healthy speakers with normal voice characteristics. Amplitude of vocal fold vibration is a core physiological parameter used in diagnosing voice disorders, yet quantitative data are lacking to guide the determination of what constitutes normal vibratory amplitude.

METHODS/STUDY DESIGN

Eleven participants were assessed during sustained vowel production using rigid and flexible endoscopy with stroboscopy. Still images were extracted from digital recordings of a sustained /i/ produced at a comfortable pitch and loudness, with F0 controlled so that levels were within ±15% of each participant's comfortable mean level as determined from connected speech. Glottal width (GW), true vocal fold (TVF) length, and TVF width were measured from still frames representing the maximum open phase of the vibratory cycle. To control for anatomic and magnification differences across participants, GW was normalized to TVF length. GW as a ratio of TVF width was also computed for comparison with prior studies.

RESULTS

Mean values and standard deviations were computed for the normalized measures. Paired t tests showed no significant differences between rigid and flexible endoscopy methods. Interrater and intrarater reliability values for raw measurements were found to be high (0.89-0.99).

CONCLUSIONS

These preliminary quantitative data may be helpful in determining normality or abnormality of vocal fold vibration. Results indicate that quantified amplitude of vibration is similar between endoscopic methods, a clinically relevant finding for individuals performing and interpreting stroboscopic assessments.

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.

[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.

Quantitative PCR analysis of laryngeal muscle fiber types

Voice and swallowing dysfunction as a result of recurrent laryngeal nerve paralysis can be improved with vocal fold injections or laryngeal framework surgery. However, denervation atrophy can cause late-term clinical failure. A major determinant of skeletal muscle physiology is myosin heavy chain (MyHC) expression, and previous protein analyses have shown changes in laryngeal muscle fiber MyHC isoform with denervation. RNA analyses in this setting have not been performed, and understanding RNA levels will allow interventions better designed to reverse processes such as denervation in the future. Total RNA was extracted from bilateral rat thyroarytenoid (TA), posterior cricoarytenoid (PCA), and cricothyroid (CT) muscles in rats. Primers were designed using published MyHC isoform sequences. SYBR Green real-time reverse transcription-polymerase chain reaction (SYBR-RT-PCR) was used for quantification. The electropherogram showed a clear separation of total RNA to 28S and 18S subunits. Melting curves illustrated single peaks for all type MyHC primers. All MyHC isoforms were identified in all muscles with various degrees of expression. Quantitative PCR is a sensitive method to detect MyHC isoforms in laryngeal muscle. Isoform expression using mRNA analysis was similar to previous analyses but showed some important differences. This technique can be used to quantitatively assess response to interventions targeted to maintain muscle bulk after denervation.

LEARNING OUTCOMES

(1) Readers will be able to describe the relationship between myosin heavy chain expression and muscle contractile properties. (2) Readers will be able to separate myosin heavy chain isoforms into slow and fast twitch phenotypes. (3) Readers will be able to describe differential muscle isoform expression between different laryngeal muscles. (4) Readers will be able to compare this study to other modalities of determining muscle fiber type.

Accuracy of measurements on digital videostroboscopic images of the vocal folds

OBJECTIVES

The reliability of objective measurements on digital laryngeal images was investigated.

METHODS

The magnitude of the error of measurement of surface areas by visually tracing the outline was determined for three different areas: the area of the lesion and, during vibration, the glottal area on maximal opening of the vocal folds and the glottal area on maximal closing of the vocal folds.

RESULTS

The errors in these areas were 10% to 30%. The results suggest that the error is mainly due to the uncertainty of the real outline of areas with a vague boundary. Correction for differences in magnification between two images (posttherapy and pretherapy) is of importance in about 25% to 65% of cases, depending on the area measured.

CONCLUSIONS

Only when the magnification ratio is small (less than about +/- 10% from 1.0) may a correction not be necessary.

Cross-linked hyaluronan versus collagen for injection treatment of glottal insufficiency: 2-year follow-up

OBJECTIVES

To evaluate the long-term (24 months) clinical performance (vocal fold function) and safety of hylan B gel as compared with bovine cross-linked collagen in the treatment of patients with glottal insufficiency.

MATERIAL AND METHODS

In a prospective trial, 70 patients with glottal insufficiency due to unilateral vocal fold paresis (n =35) or atrophy (n =35) were randomized to received either hylan B gel (n =47) or collagen (n =23) injections into 1 vocal fold. Forty-two of the patients were examined 24 months after treatment. Evaluations were made based on patients' subjective ratings, digitized videostroboscopic measurements, maximum phonation time and phonation quotient.

RESULTS

The patients' self-ratings were significantly improved in both the hylan B gel and collagen groups. Videostroboscopic measurements of glottal closure were significantly improved for both groups. The hylan B gel group showed a trend towards less resorption at the injected vocal fold edge in comparison with the collagen group (p =0.05). No serious adverse events were observed. Twenty-eight patients dropped out of the study after 12 months: 18 had been re-injected or operated on with medialization laryngoplasty due to insufficient voice and 10 had either died of causes unrelated to the study or refused to attend follow-up.

CONCLUSIONS

No long-term side-effects were found for either the hylan B gel or collagen groups after injection treatment. Both treatments resulted in significantly improved voice as rated by the patients and significantly improved glottal closure. Some resorption was noted for both substances, and approximately 25%, of the patients chose re-treatment 2 years after the initial treatment.

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.

A three-dimensional model of vocal fold abduction/adduction

A three-dimensional biomechanical model of tissue deformation was developed to simulate dynamic vocal fold abduction and adduction. The model was made of 1721 nearly incompressible finite elements. The cricoarytenoid joint was modeled as a rocking-sliding motion, similar to two concentric cylinders. The vocal ligament and the thyroarytenoid muscle's fiber characteristics were implemented as a fiber-gel composite made of an isotropic ground substance imbedded with fibers. These fibers had contractile and/or passive nonlinear stress-strain characteristics. The verification of the model was made by comparing the range and speed of motion to published vocal fold kinematic data. The model simulated abduction to a maximum glottal angle of about 31 degrees. Using the posterior-cricoarytenoid muscle, the model produced an angular abduction speed of 405 degrees per second. The system mechanics seemed to favor abduction over adduction in both peak speed and response time, even when all intrinsic muscle properties were kept identical. The model also verified the notion that the vocalis and muscularis portions of the thyroarytenoid muscle play significantly different roles in posturing, with the muscularis portion having the larger effect on arytenoid movement. Other insights into the mechanisms of abduction/adduction were given.

Relationship among glottal area, static supraglottic compression, and laryngeal function studies in unilateral vocal fold paresis and paralysis

In this study, we evaluated the relationship between laryngeal function measures and glottal gap ratio and normalized measures of supraglottic behaviors in patients with unilateral vocal fold paresis (UVFP). Thirty-one patients were found to have unilateral vocal fold paresis by videoendoscopy and laryngeal electromyography, and 13 controls participated in this study. Patients with UVFP demonstrated significantly larger glottal gap ratios (p = 0.016) than control subjects. The nonparalyzed or contralateral vocal fold was associated with significantly more static false vocal fold compression (p = 0.03) compared with the paralyzed vocal fold or with the controls. Patients with unilateral vocal fold paresis were divided into subgroups: those with normal or abnormal maximum phonation time, flow, or pressure measures. Smaller glottal gap ratios were identified in patients with normal maximum phonation times and flow measures. Greater false vocal fold activity was identified in unilateral vocal fold paresis patients with normal laryngeal function measures than in unilateral vocal fold paresis patients with abnormal measures. These findings suggest that some patients with documented unilateral paresis and glottal incompetence can compensate for vocal fold weakness such that their acoustic and aerodynamic measures are normal.

Cross-linked hyaluronan used as augmentation substance for treatment of glottal insufficiency: safety aspects and vocal fold function

OBJECTIVE

To examine safety aspects and vocal fold function after vocal fold augmentation with a cross-linked hyaluronan derivative (hylan B gel) as compared with bovine collagen. STUDY DESIGN; A prospective, randomized trial.

METHODS

Eighty-three patients with glottal insufficiency were treated with injection augmentation with hylan B gel and bovine collagen and were examined at 1, 6, and 12 months after treatment. Seventy patients with unilateral vocal fold paresis (n = 35) or atrophy (n = 35) were randomly assigned to receive either hylan B gel (n = 47) or collagen (n = 23) injections into one vocal fold. Thirteen patients with glottal insufficiency caused by scar defects or paresis resulting from malignant disease were included in a nonrandomized group and were treated only with hylan B gel. Evaluations were made from patients' subjective ratings (visual analogue scales), digitized videostroboscopic measurements, phonetograms, maximum phonation time, and phonation quotients.

RESULTS

Twelve months after injections, the patients' self-ratings were significantly improved for both the hylan B gel and the collagen groups. In addition, the videostroboscopic measurements showed significantly improved glottal closure for both groups. However, for the hylan B gel group, vibration amplitude and glottal area variations were preserved, and this group showed significantly less resorption at the injected vocal fold edge. Furthermore, maximum phonation time had increased significantly for the hylan B gel patients (collagen, nonsignificant). No serious adverse events were observed; three patients injected with hylan B gel had temporary inflammation at the injection site, which resolved without sequelae.

CONCLUSIONS

The results showed that both hylan B gel and collagen can be safely used for injection treatment of glottal insufficiency. Both treatments resulted in significantly improved voice as rated by the patients. However, the patients treated with hylan B gel showed better vocal fold status and longer maximum phonation time at 12 months after treatment as compared with patients treated with collagen.

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.

Effects of voice therapy as objectively evaluated by digitized laryngeal stroboscopic imaging

Objective measurements derived from digitized laryngeal stroboscopic images were used to demonstrate changes in vocal fold vibration and in the size of benign lesions after 3 months of voice therapy. Forty chronically dysphonic patients were studied. By means of a rigid stroboscope, pretreatment and posttreatment recordings were made of the vocal folds at rest and under stroboscopic light during phonation. From each recording, images of the positions at rest and during vibration at maximal opening and at maximal closure were digitized. The surface areas of any lesions and of the glottal gap were independently measured in the digitized images by 2 experienced laryngologists. Referential distances were determined in order to compensate for discrepancies in magnification in the various recordings. After 3 months of voice therapy, significant improvement in lesion size and degree of maximal closure during vibration could be demonstrated in about 50% of the patients. The degree of maximal opening did not prove to be a significant parameter.

Quantification of static and dynamic supraglottic activity

For estimating supraglottic compression in disordered voice production, categorical rating scales of true vocal fold coverage by supraglottic structures are the current standard. Quantification of change in the position of supraglottic structures compared to no supraglottic activity would be a better method for distinguishing between and within voice-disordered groups. This study developed a method for quantifying static supraglottic activity and extent of false vocal fold (FVF) motion during dynamic supraglottic activity. Twelve control participants and 12 individuals with voice disorders (6 with complaints of vocal fatigue and 6 with vocal fold nodules) were enrolled in the study. These individuals participated in a transnasal fiberoptic laryngeal examination in which various speech tasks were recorded. Single-frame images were selected to represent the positions of minimum and maximum supraglottic compression for each speech task. Two individuals rated these single-frame images using a categorical rating scale. Two other individuals measured the anterior-to-posterior (A-P) distance, vocal fold length, and vocal fold area. A-P and FVF compression were derived from these three measures. Reliability was demonstrated between judges for the ratings and between and within judges for the measures. Significant differences in normalized static supraglottic compression measures corresponded to the rating scale categories. Significant differences in normalized dynamic supraglottic compression measures corresponded to the differences in category ratings between minimum and maximum compression. Using the normalized measures, the voice-disordered groups demonstrated significantly greater static A-P compression (t test, p < .03) than did the control participants. These results suggest that static supraglottic activity may be diagnostic of voice disorder. Normalized dynamic FVF compression ratios were not significantly different between groups. This supports a previous hypothesis that dynamic supraglottic activity serves as an articulatory function at the level of the larynx and is part of the linguistic/phonemic system, rather than evidence of disordered laryngeal function.

Electroglottographic and acoustic changes following type I thyroplasty or autologous fat injection

This study identified the electroglottographic (EGG) and acoustic measures that were most predictive of change in the glottic gap size of patients undergoing type I thyroplasty or autologous fat injection. Simultaneous EGG and acoustic recordings were made before and after autologous fat injection in 23 patients and type I thyroplasty in 45 patients. Relative measures of glottic gap size were obtained before and after operation from videostroboscopic images. Regression and correlation analysis was used to determine the strength of associations between the EGG or acoustic measures and glottic gap changes. A significant regression equation for both patient groups was constructed. The strongest predictors of glottic gap size change were changes in the EGG open quotient, signal-to-noise ratio, and mean fundamental frequency. Glottography provided a clinically useful means of evaluating glottic gap changes in patients undergoing vocal fold medialization procedures. Preoperative-postoperative differences in signal-to-noise ratio and mean fundamental frequency also were correlated to glottic gap size changes, but to a lesser degree.

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.

Intensive voice treatment (LSVT) for patients with Parkinson's disease: a 2 year follow up

OBJECTIVES

To assess long term (24 months) effects of the Lee Silverman voice treatment (LSVT), a method designed to improve vocal function in patients with Parkinson's disease.

METHODS

Thirty three patients with idiopathic Parkinson's disease were stratified and randomly assigned to two treatment groups. One group received the LSVT, which emphasises high phonatory-respiratory effort. The other group received respiratory therapy (RET), which emphasises high respiratory effort alone. Patients in both treatment groups sustained vowel phonation, read a passage, and produced a monologue under identical conditions before, immediately after, and 24 months after speech treatment. Change in vocal function was measured by means of acoustic analyses of voice loudness (measured as sound pressure level, or SPL) and inflection in voice fundamental frequency (measured in terms of semitone standard deviation, or STSD).

RESULTS

The LSVT was significantly more effective than the RET in improving (increasing) SPL and STSD immediately post-treatment and maintaining those improvements at 2 year follow up.

CONCLUSIONS

The findings provide evidence for the efficacy of the LSVT as well as the long term maintenance of these effects in the treatment of voice and speech disorders in patients with idiopathic Parkinson's disease.

DiHA (dextranomers in hyaluronan) injections for treatment of insufficient closure of the vocal folds: early clinical experiences

OBJECTIVE

To determine the clinical effects of injecting DiHA (a mixture of dextranomer molecules and 1% hyaluronan solution in equal proportions) as a "space filler" into the vocal folds of patients experiencing insufficient closure of the vocal folds resulting from either unilateral vocal fold paralysis or bowed vocal folds.

STUDY DESIGN

A consecutive series of patients with insufficient closure of the vocal folds treated with DiHA injections and prospectively followed up with videostroboscopy and voice recordings that were evaluated by expert panels.

METHODS

During a 21/2-year period, 14 patients with insufficient closure of the vocal folds were included. Six had a unilateral vocal fold palsy and 8 patients had "bowed" vocal folds. DiHA was injected into one vocal fold. Laryngoscopic examination and voice recordings were performed pre- and postoperatively. Expert panels did the evaluation of the stroboscopy examination and the perceptual voice analysis.

RESULTS

Three patients were operated on with local and 11 under general anesthesia. All patients with unilateral palsy improved their stroboscopic status regarding both the wave and the closure after injection. Also, their voice parameters were significantly improved. Among the patients with bowed vocal folds, all except 2 showed an improvement in the glottic wave, 5 of 8 improved in glottic closure, and 3 improved their voice parameters significantly.

CONCLUSION

This early clinical experience indicates that DiHA fulfills most of the requirements of an ideal "space-filling" substance for voice restoration in patients experiencing insufficient vocal fold closure.

Voice Quality Changes Following Phonatory-Respiratory Effort Treatment (LSVT®) Versus Respiratory Effort Treatment for Individuals with Parkinson Disease

Perceptual ratings of hoarseness and breathiness were used to assess the efficacy of two intensive methods for treating dysarthrophonia in individuals with idiopathic Parkinson disease. One method emphasized phonatory-respiratory effort (the Lee Silverman Voice Treatment, LSVT) and the other emphasized respiratory effort alone (RET). Perceptual ratings were performed by two expert listeners based on random order presentation of the patients' pretreatment and posttreatment recordings of the "Rainbow Passage." The listeners were blinded to the patients and their treatment group. Statistically significant pretreatment to posttreatment improvement in hoarseness and breathiness was observed in the LSVT group but not in the RET group. The present findings are consistent with acoustic and physiologic findings reported previously, providing further evidence for the efficacy of the LSVT.