Analysis of voice and quantitative measurement of glottal gap after thyroplasty type I in the treatment of unilateral vocal paralysis

Acoustics and aerodynamic effects following glottal and infraglottal medialization in an excised larynx model

OBJECTIVE

This study aimed to investigate the impact of the implant's vertical location during Type 1 Thyroplasty (T1T) on acoustics and glottal aerodynamics using excised canine larynx model, providing insights into the optimal technique for treating unilateral vocal fold paralysis (UVFP).

METHODS

Measurements were conducted in six excised canine larynges using Silastic implants. Two implant locations, glottal and infraglottal, were tested for each larynx at low and high subglottal pressure levels. Acoustic and intraglottal flow velocity field measurements were taken to assess vocal efficiency (VE), cepstral peak prominence (CPP), and the development of intraglottal vortices.

RESULTS

The results indicated that the implant's vertical location significantly influenced vocal efficiency (p = 0.045), with the infraglottal implant generally yielding higher VE values. The effect on CPP was not statistically significant (p = 0.234). Intraglottal velocity field measurements demonstrated larger glottal divergence angles and stronger vortices with the infraglottal implant.

CONCLUSION

The findings suggest that medializing the paralyzed fold at the infraglottal level rather than the glottal level can lead to improved vocal efficiency. The observed larger divergence angles and stronger intraglottal vortices with infraglottal medialization may enhance voice outcomes in UVFP patients. These findings have important implications for optimizing T1T procedures and improving voice quality in individuals with UVFP. Further research is warranted to validate these results in clinical settings.

Treatment Outcomes of Type 1 Thyroplasty Using Gore-Tex® Following Injection Laryngoplasty

OBJECTIVE

To compare voice-related outcomes of type 1 thyroplasty using Gore-Tex® between patients with and without augmentation injection laryngoplasty (IL) prior to surgery.

METHODS

Forty-five patients who underwent Gore-Tex® thyroplasty at a single institution by a single surgeon between November 2016 and February 2019 were identified as those who previously had IL (n = 20) and those without IL (n = 25). Pre- and post-operative voice-related primary outcomes were evaluated using the GRBAS, and CAPE-V auditory-perceptual rating scales and secondary outcome were evaluated using the VRQOL. Pre- and post-operative voice samples were blinded, randomized, and analyzed by 3 voice-specialized speech pathologists to obtain CAPE-V scores. The VRQOL and GRBAS scores were obtained from retrospective chart review. Student's t test with a paired one-tailed distribution was used for comparisons within groups and 2-sample equal variance for comparisons between groups. Intraclass correlation coefficient determined interrater agreement.

RESULTS

GRBAS, and VRQOL significantly improved post Gore-Tex® thyroplasty. There was no difference in improvement between patients who received pre-surgery IL and those who did not in either GRBAS or VRQOL scores, but CAPE-V showed significant improvement in the IL group. A strongly positive correlation was demonstrated between the severity of CAPE-V pre-op score and the overall improvement following surgery for both groups combined.

CONCLUSION

Patients with vocal fold paralysis have a significantly better voice after Gore-Tex® thyroplasty by self-report (VRQOL) and assessment by trained voice professionals (GRBAS). Having IL prior to surgery does not adversely affect later surgical outcomes. This paper represents one of the largest analyses of voice quality outcomes of Gore-Tex® thyroplasty using validated patient scales and randomized blinded analyses.

A retrospective analysis of revision framework surgeries for unilateral vocal fold paralysis

INTRODUCTION

Revision framework surgeries might be required for unilateral vocal fold paralyses. However, outcomes and indications of revision surgeries have not been adequately documented. For a better understanding of indications for the procedure and to help in achieving better vocal outcomes, we performed a retrospective chart review of patients who underwent revision framework surgeries for unilateral vocal fold paralysis.

OBJECTIVES

This study aimed to present clinical features of patients who underwent revision framework surgeries for the treatment of unilateral vocal fold paralysis.

METHODS

Of the 149 framework surgeries performed between October 2004 and October 2019, 21 revision framework surgeries were performed in 19 patients. Self-assessments by patients using the voice handicap index-10 questionnaire, and objective aerodynamic and acoustic assessments performed pre- and post-operatively were analyzed using the Wilcoxon's signed-rank test for paired comparisons.

RESULTS

Undercorrection was indicated as reasons for revision surgeries in all cases. The revision techniques included type I thyroplasty, type IV thyroplasty, and arytenoid adduction, and revision surgeries were completed without any severe complication in all cases. Pre- and post-operative voice handicap index-10 scores were obtained in 12 cases, and other parameters were evaluated in 18 cases. Significant improvements were observed in voice handicap index-10 scores, maximum phonation time, mean flow rate, Current/Direct Current ratio, and pitch perturbation quotient.

CONCLUSION

Undercorrection was observed in all patients who underwent revision framework surgeries for unilateral vocal fold paralysis, and the initial assessment and planning are thought to be important in order to avoid revision surgeries. Revision surgeries were performed safely in all cases, and significantly improved vocal outcomes were observed, even after multiple procedures. Revision surgery should be considered for patients with unsatisfactory vocal functions after primary framework surgeries for unilateral vocal fold paralysis.

Breathiness and Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) in Patients Undergoing Medialization Laryngoplasty With or Without Arytenoid Adduction

OBJECTIVES

We hypothesized that, in patients with unilateral vocal fold paralysis (UVFP), the auditory-perception of breathiness measured with Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) would be higher preoperatively in patients who undergo medialization laryngoplasty (ML) with arytenoid adduction (AA) compared to ML alone. We further hypothesized that increased breathiness would correlate with increased glottal area at maximum glottal closure.

STUDY DESIGN

Retrospective chart review.

METHODS

CAPE-V recordings were rated by expert judges in 105 subjects with UVFP (47 ML+AA and 58 ML). Component scores of the CAPE-V prior to laryngeal framework surgery and those at 3 and/or 12 months postoperatively were compared. Assessment of glottal area width during maximum glottal closure was attempted.

RESULTS

Breathiness scores prior to laryngeal framework surgery were significantly greater in UVFP patients having ML+AA compared to ML only (P < 0.001). Roughness was greater for ML only (P = 0.003). At 3 months, adjusted for age and previous injection laryngoplasty, the ML+AA group showed greater improvement for breathiness (P <0.001), loudness (P < 0.001), strain (P = 0.037), and pitch (P = 0.039), while the ML only group showed greater improvement in roughness (P = 0.009). Results were similar at 12 months. Only 26% of glottal area widths were ratable using methods previously described; therefore, no further analysis was attempted.

CONCLUSIONS

In patients with UVFP baseline perception of breathiness is greater in those clinically selected for ML+AA compared to ML only. Glottal area measurements were not representative of the UVFP cohort and more stringent criteria are needed for valid and reliable glottal area assessment when using clinical flexible stroboscopic exams. Findings support the idea that surgeons may be making decisions about AA based, to at least some degree, on auditory perceptual evaluation of voice.

Voice outcome indicators for unilateral vocal fold paralysis surgery: a review of the literature

INTRODUCTION

There is no consensus on which voice outcome indicators (VOIs) should be used to compare the merits of the various surgical treatments for unilateral vocal fold paralysis (UVFP). Authors performed a literature review to identify which VOIs are most frequently used and most relevant, in terms of significant change in pre- and post-operative measurements, to assess UVFP surgical treatments.

METHOD

A Medline/Pubmed literature review was performed and the most frequently used VOIs were identified using a Pareto diagram. For these most frequently used VOI's, the number of studies that showed a statistically significant change in pre- and post-operative results were compared to the total number of studies found using that same VOI, this portion was expressed in percent. This percentage was defined as the "percentage of significance" and used to assess changes of each VOI.

RESULTS

Eleven VOIs were identified using the Pareto analysis. These were, in decreasing order of frequency of citation: maximum phonation time (MPT), jitter, Shimmer, video-stroboscopic examination, noise to harmonic ratio (NHR/HNR), mean air flow (MeAF), fundamental frequency (F0), "Infrequent Perceptional Scales", GRBAS scale, mean subglottic pressure (MSGP). MPT, MeAF, factor G of GRBAS-I, Jitter, shimmer and VHI-30 had respective "percentage of significance" of 90, 86, 85, 74, 68 and 64%, respectively.

CONCLUSION

The results indicate that MPT, MeAF and GRBAS-I, represent the top-three most frequently used and the most relevant VOIs in terms of "percentage of significance". VHI-30 showed a relatively low rate of use and low "percentage of significance". The role of Jitter and Shimmer remains unclear. Finally, MSGP and the F0 appear to be less relevant VOIs for the evaluation of UFVP surgical treatments in terms of significant change in pre- and post-operative measurements.

Voice Range Change After Injection Laryngoplasty for Unilateral Vocal Fold Paralysis

OBJECTIVES

Patients with unilateral vocal fold paralysis (UVFP) caused by nerve injury manifest with voice changes. This study investigated vocal performance measured by voice range profile (VRP) in patients with UVFP and changes in VRP in response to intracordal hyaluronate injection.

METHODS

Eighty-five patients with UVFP were enrolled prospectively, among whom 68 received intracordal hyaluronate injections. The outcome measurements included VRP, acoustic and aerodynamic analyses, peak turn frequency of thyroarytenoid-lateral cricoarytenoid muscle complex (TA-LCA) measured by laryngeal electromyography, and normalized glottal gap area by videolaryngostroboscopy.

RESULTS

The peak turn frequency of the paralyzed TA-LCA showed a modest correlation with max fundamental frequency (F0) and F0 range. Closed-phase normalized glottal gap area showed modest negative correlations with max F0 and F0 semitone range. Regarding conventional acoustic and aerodynamic analyses, the paralyzed TA-LCA peak turn frequency was only correlated with maximal phonation time. Intracordal hyaluronate injection improved VRP performance by increasing max F0, decreasing min F0, increasing F0 range, and increasing semitone range (all P <0.01) with small or medium strength of effect size (Cohen d, 0.39-0.76).

CONCLUSIONS

Change in voice pitch in patients with UVFP can partly predict impairment of neuromuscular functions and glottal gap. VRP provides a more sensitive reflection of the severity of neuromuscular impairment, compared with conventional voice analysis. The validity of VRP is further supported by a robust response to voice improvements following injection laryngoplasty.

A Comparison of Indirect and Direct Methods for Estimating Transglottal Airflow Rate

OBJECTIVE

The purpose of this study was to compare indirect estimates of transglottal airflow rate using measures of phonation quotient with direct measures of mean airflow rate derived from a pneumotachograph.

STUDY DESIGN

This study used prospective, repeated measures design.

METHODS

Nineteen male and female participants, matched for age, completed tasks for maximum phonation time and vital capacity in addition to the comfortable sustained phonation protocol of the Phonatory Aerodynamic System (PAS), Model 6600. Phonation quotient was calculated from the vital capacity and phonation time measures, whereas actual transglottal airflow was obtained from the flow waveforms recorded on the PAS system. Statistical analyses compared transglottal airflow rate measures as a function of instrument and separately as a function of gender.

RESULTS

Statistically significant differences were present only as a function of gender on airflow measures but not as a function of the instrument. There were no interaction effects present between instrument and gender.

CONCLUSIONS

Phonation quotient can be used as an estimate of transglottal airflow in the absence of a pneumotachograph-based system.

Acoustic Analysis of Autologous Fat Injection versus Thyroplasty in the Same Patient

We objectively measured the acoustic effects of treatment of unilateral vocal fold paralysis by injection of autologous fat and by polytetrafluoroethylene thyroplasty, in the same patient. To our knowledge, this is the first report comparing the two techniques by using the patient's normal voice as the control. The voice of a male patient was recorded before and after onset of unilateral vocal fold paralysis, after treatment with autologous fat, and after polytetrafluoroethylene thyroplasty. Acoustic analysis was performed on a long-term average spectrum of text and on the MDVP (Kay Elemetrics) evaluation of the vowel /a/. Jitter and shimmer were not normalized, but they improved to a greater extent after fat injection. The cepstral peak prominence, spectral skewness, and long-term average spectrum returned to preparalytic values after both treatments, but improved to a greater extent after fat injection. This study showed that both techniques can return the voice to preparalytic values. Spectral measurements best reflected the voice improvement. Further prospective studies in a larger number of patients will be necessary to confirm these results and to determine the long-term objective voice outcome obtained with these techniques.

Pre and post operative voice analysis after medialization thyroplasty in cases of unilateral vocal fold paralysis

The present study was undertaken to assess the efficacy of medialization thyroplasty on outcome of voice quality in vocal cord paralysis by analyzing the voice. A total 19 patients with vocal cord paralysis of different etiologies were included in the study. Preoperative voice analysis was done by voice recordings, GRBAS score, maximum phonation time (MPT) and acoustic analysis using Dr Speech software (University version 4.0) using habitual fundamental frequency (F0), jitter %, shimmer % and normalized noise energy (NNE) as parameters. 18 patients underwent type 1 or medialization thyroplasty alone and 1 patient had undergone medialization thyroplasty along with arytenoids adduction. Post operative voice analysis was done using same parameters. There was post operative improvement of voice in 16 patients whereas 3 patients showed no significant improvement. Mean preoperative MPT was 4.8947 s and post operative was 13 s. Mean preoperative GRBAS score was 76.1579 and post operative was 30. On acoustic analysis, mean preoperative habitual fundamental frequency (F0), jitter %, shimmer % and NNE was 278.16 Hz, 1.7, 6.81 and 1.81 dB respectively whereas post operative mean was 132.37 Hz, 0.41, 1.65 and 123.38 dB respectively. Thyroplasty offers good voice outcome in patients of uncompensated vocal cord paralysis. Improvement can be documented in terms of perceptual evaluation of voice and acoustic analysis as well as maximum phonation time in addition to voice recording.

[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.

A Meta-analysis of Voice Outcome Comparing Calcium Hydroxylapatite Injection Laryngoplasty to Silicone Thyroplasty

Objectives

To compare the voice outcome of calcium hydroxylapatite (CaHA) injection laryngoplasty (IL) vs silicone medialization thyroplasty (MT) in the treatment of unilateral vocal fold paralysis (UVFP).

Data Sources

Systematic review of English literature from MEDLINE, Google Scholar, Web of Science, Scopus, and the Cochrane library from January 1, 1980, to December 31, 2010.

Review Methods

Included studies reporting voice-related quality of life (Voice Handicap Inventory [VHI]) following IL with CaHA or MT with silicone. The primary outcome measure was the improvement in VHI. The secondary outcome was improvement in maximum phonatory time (MPT).

Results

Of the 742 abstracts screened for relevancy, 24 studies qualified for analysis. The mean (SD) VHI scores were 72.22 (11.06) before MT and 34.02 (6.48) after MT. The mean (SD) VHI scores were 68.36 (6.88) before IL and 32.24 (7.33) after IL. The paired difference mean of VHI improvement was 38.20 (95% confidence interval [CI], 17.05-59.32; P = .007) for MT and 36.11 (95% CI, 29.65-42.57; P = .001) for IL. The mean (SD) MPT scores were 7.40 (3.14) before IL and 13.00 (1.75) after IL. The mean (SD) MPT scores were 6.16 (1.90) before MT and 12.40 (2.72) after MT. The paired difference mean of MPT improvement was 6.23 (95% CI, 4.74-7.73; P < .001) for MT and 5.60 (95% CI, 2.95-8.25; P = .006) for IL.

Conclusion

Injection laryngoplasty with CaHA and MT with silicone appear to achieve comparable voice improvement within 1 year, but a definitive conclusion is limited by a lack of standardized outcome measures.

Aerodynamic evaluation of the postthyroidectomy voice

OBJECTIVES/HYPOTHESES

Changes in vocal function before and after thyroidectomy were examined using aerodynamic and related assessments. Laryngeal airway resistance (R(law)) and phonation threshold pressure (PTP) were hypothesized to be sensitive to changes in laryngeal function that may occur after thyroidectomy separate from changes that may occur from endotracheal intubation alone.

STUDY DESIGN

Prospective longitudinal clinical trial with comparison group.

METHODS

Eighty patients were evaluated preoperatively, and 2 weeks and 3 months postoperatively to assess voice outcomes after thyroidectomy. In addition, 16 patients who underwent a nonneck operation were tested as a control group. Maximum phonation time (MPT), mean airflow, R(law), and PTP were determined at two vocal fundamental frequency (F0) levels (30% and 80% of the F0 range).

RESULTS

No systematic differences were detected for MPT, mean airflow, or R(law) as a short-term or intermediate-term outcome of either surgical group. PTP decreased significantly over time for both groups of participants and at both F0 levels. F0 range decreased significantly at the short-term postsurgical assessment and covaried with the PTP results, thereby explaining some of the variability in the PTP data.

CONCLUSIONS

Aerodynamic assessment did not reveal systematic changes in vocal function associated with thyroidectomy, although PTP decreased postoperatively for both surgical groups. This may be attributable in part to a learning effect or to postoperative reductions in F0 range.

Correlating voice handicap index and quantitative videostroboscopy following injection laryngoplasty for unilateral vocal paralysis

OBJECTIVE

1) Determine the correlation between voice handicap index and quantitative videostroboscopy for patients undergoing injection laryngoplasty for unilateral vocal paralysis; 2) assess which videostroboscopy measurements correlate best with voice handicap index in patients demonstrating progressive improvement beyond six months following injection laryngoplasty.

STUDY DESIGN

Case series with chart review.

SETTING

Patients undergoing outpatient injection laryngoplasty with hyaluronic acid between 2005 and 2007.

SUBJECTS AND METHODS

Twenty-eight patients were assessed preoperatively and postoperatively using voice handicap index and videostroboscopy. Various videostroboscopy measurements were quantified: glottic open area (ratio of open to total glottic area during closed phase of phonation), glottic closed phase (frame ratio of closed phase to total glottic cycle), supraglottic compression (percent encroachment of supraglottis onto best-fit ellipse around glottis), wave amplitude (difference in glottic open area between open and closed phases), and wave duration (number of frames per glottic cycle). Correlation coefficients were calculated using Spearman's r.

RESULTS

One hundred seventeen separate recordings were analyzed. Correlation coefficients between voice handicap index (normalized to preoperative values) and glottic closed phase showed moderate-strong correlation (r = -0.733, P < 0.001), while glottic open area and wave duration showed weak-moderate correlation (r = 0.465, P < 0.001 and r = -0.404, P < 0.001 respectively). Other parameters showed poor correlation. A subset of 25 recordings from eight patients with progressive voice handicap index improvement beyond six months showed highest correlation with supraglottic compression (r = 0.504, P < 0.05).

CONCLUSION

Voice handicap index correlates best with glottic closed phase, suggesting duration of vocal fold closure during the glottic cycle best represents patients' subjective outcome post-procedure. Progressive improvement in voice handicap index beyond six months may relate to gradual reduction in compensatory supraglottic compression, with moderate correlation.

Article Commentary: Shortfalls of the American Academy of Otolaryngology—Head and Neck Surgery's Clinical practice guideline: Hoarseness (Dysphonia)

The Clinical Practice Guideline (CPG) on hoarseness (dysphonia) has several shortcomings that undermine its initial intent to improve the care of patients with dysphonia. The purpose of this document is to identify and comment on those shortcomings. The guideline authors made curious and unsupported policy recommendations in some areas, such as the recommendation for performance of laryngoscopy for hoarseness. For example, the guideline provides a three-month allowance for patients with voice change prior to examination of the larynx, which is a marked change from prior American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) documents suggesting laryngoscopy after two to four weeks of dysphonia and poses a health risk to patients with dysphonia without an established diagnosis. We believe the use of laryngoscopy for the evaluation is dysphonia is primal, plays a vital role in the care of our patients, and should be strongly advocated by the CPG. A significant challenge of the CPG is rooted in its basis on a symptom as opposed to a diagnosis. The decision to confuse the difference between a symptom (hoarseness) and a diagnosis leads to several misleading statements and recommendations. Finally, problems with insufficient peer review and ineffective processes in the guideline's development are discussed.

© 2010 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved.

Objective dysphonia quantification in vocal fold paralysis: comparing nonlinear with classical measures

Clinical acoustic voice-recording analysis is usually performed using classical perturbation measures, including jitter, shimmer, and noise-to-harmonic ratios (NHRs). However, restrictive mathematical limitations of these measures prevent analysis for severely dysphonic voices. Previous studies of alternative nonlinear random measures addressed wide varieties of vocal pathologies. Here, we analyze a single vocal pathology cohort, testing the performance of these alternative measures alongside classical measures. We present voice analysis pre- and postoperatively in 17 patients with unilateral vocal fold paralysis (UVFP). The patients underwent standard medialization thyroplasty surgery, and the voices were analyzed using jitter, shimmer, NHR, nonlinear recurrence period density entropy (RPDE), detrended fluctuation analysis (DFA), and correlation dimension. In addition, we similarly analyzed 11 healthy controls. Systematizing the preanalysis editing of the recordings, we found that the novel measures were more stable and, hence, reliable than the classical measures on healthy controls. RPDE and jitter are sensitive to improvements pre- to postoperation. Shimmer, NHR, and DFA showed no significant change (P>0.05). All measures detect statistically significant and clinically important differences between controls and patients, both treated and untreated (P<0.001, area under curve [AUC]>0.7). Pre- to postoperation grade, roughness, breathiness, asthenia, and strain (GRBAS) ratings show statistically significant and clinically important improvement in overall dysphonia grade (G) (AUC=0.946, P<0.001). Recalculating AUCs from other study data, we compare these results in terms of clinical importance. We conclude that, when preanalysis editing is systematized, nonlinear random measures may be useful for monitoring UVFP-treatment effectiveness, and there may be applications to other forms of dysphonia.

Increasing the Closed Quotient Improves Voice Quality After Type I Thyroplasty in Patients with Unilateral Vocal Cord Paralysis: Analysis Using SPEAD Program

The aim of this study was to determine the importance of the closed quotient in the improvement of voice quality after medialization thyroplasty by measuring acoustic parameters at the sentence level. The clinical records of patients who received type I thyroplasty were reviewed retrospectively. All of the patients underwent the perceptual, acoustic, and aerodynamic evaluation before the surgery and on the 60th postoperative day. The perceptual and acoustic measurements were obtained from a recording of a passage read aloud by the patients. Acoustic and aerodynamic parameters were investigated. A paired t test was used to compare presurgery and postoperative results. A correlation analysis was also used to discern which parameters were most correlated with improvement of postoperative voice quality. Statistically significant improvements were observed in subglottic pressure (Psub), maximum phonation time, and mean flow rate. Average fundamental frequency and average closed quotients were found to be the parameters that were most associated with an improvement of postoperative breathiness. The /G/ grade of GRBAS scale quality was found to be most associated with Psub and shimmer (P<0.05). An increase of the contact area of both vocal folds induced improvement in aerodynamic parameters and led to the stabilization of vocal fold vibration. This effect resulted in improvement of the acoustic parameters (shimmer, jitter, signal-to-noise ratio, voice range profile) and voice quality.

Relevance of subglottic pressure in normal and dysphonic subjects

The purpose of this study was to determine the clinical value of subglottic pressure (SGP) in normal and dysphonic subjects. "The airway interrupted method" was used to measure the intra-oral pressure. Voice samples from 60 healthy subjects and 79 dysphonic patients were recorded under normal conditions of pitch and intensity. In normal subjects, age and gender have no significant impact on mean and peak SGP. The peak SGP measurements are significantly higher in dysphonic patients and could be included in the basic clinical set of objective voice parameters. No differences could be shown between pre- and postoperative assessments or between groups of dysphonic patients.

Perceptual and Acoustic Assessment of Voice Pathology and the Efficacy of Endolaryngeal Phonomicrosurgery

Values for acoustic voice measurements were obtained from 88 normal individuals and 98 pathological cases of mass lesions of vocal fold and 50 cases of unilateral vocal fold paralysis. Overall, all items reflecting perturbations of pitch and amplitude as well as glottal noise were significantly higher in the groups of patients compared with the normal group. The measurement of normalized noise energy (NNE) was found to be an optimum parameter for discrimination of normal/abnormal voices. The voices of patients with vocal fold nodules and vocal fold polyps were analyzed before endolaryngeal phonomicrosurgery (EPM) and 2 weeks after. Statistically significant (p < 0.01) improvement was achieved both in perceptual and acoustic analysis. EPM resulted in a significant decrease of mean jitter, shimmer, and NNE. Clinically, these measures provided documentable and measurable evidence of vocal function and were helpful for comparing patients with normal speakers. They also were useful for a thorough documentation of patient's voice pathology and for evaluation of the presurgical and postsurgical voice status.

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.

Perspectives on medialization laryngoplasty

Medialization laryngoplasty has become the new gold standard for the permanent management of patients with vocal fold paralysis and paresis. This article reviews the conceptual developments of the diagnosis and management of patients with vocal fold paresis and paralysis. We identify the specifics of operative decision-making as well as surgical complications associated with medializationlaryngoplasty. The role of revision surgery is detailed. We suggest a standardized evaluation using both objective and subjective data for analysis of surgical outcomes.

Evidence-based treatment of paralytic dysphonia: making sense of outcomes and efficacy data

The criteria used to determine the success or failure of a given treatment for vocal fold paralysis are fundamental components of routine clinical practice and treatment outcomes research for the surgeon and voice therapist. The purpose of this article is to offer a guide to the critical interpretation of available measures of out-come and efficacy for this patient population. Such data form the basis for the practice of evidence-based medicine and voice therapy,essential if the standard of care is to evolve to the benefit of the patient. A better understanding of the potentials and limitations of each measure is important for treatment planning and patient counseling and, ultimately, for the conception of future well-designed clinical research. The complex issues regarding outcomes measurement are addressed here within the context of current treatment literature on vocal fold paralysis. Particular emphasis is placed on realistic data gathering within clinical practice.

Tracking outcomes after phonosurgery for sulcus vocalis: a case report

Outcomes data after a surgical or behavioral intervention should be tracked until stability is reached. Often it is unclear how long patients should be followed and at what point an outcome can be considered stable. These issues have implications for treatment decision making, efficacy measurement, and the design of research studies. Vocal function data were collected 24 hours before and at 1, 6, and 12 months after phonosurgery for sulcus vocalis. One data series was collected daily during the first month after surgery, providing a unique opportunity to study voice changes in the immediate postoperative period. The different vocal function indices (acoustic, perceptual, videostroboscopic, aerodynamic, psychosocial) demonstrated a general pattern of improvement after intervention; however, they appeared to reach stability at different times. This report reinforces the value of following patients until complete outcome stability.