Effectiveness of Voice Therapy on Voice Quality and Function in Individuals with Unilateral Vocal Fold Paralysis: Systematic Review and Meta-Analysis

BACKGROUND

Unilateral vocal fold paralysis (UVFP), characterized by immobility of one vocal fold, results from injuries of recurrent laryngeal nerves. Voice therapy is a conservative intervention aiming to address these symptoms, but standard protocols are lacking. In this study, we provided an updated review of voice therapy for UVFP over the past 3 years and analyzed the effect of voice therapy from the perspective of voice assessment recommended by the guidelines of the European Laryngological Society and the Union of the European Phoniatricians in 2023.

METHODS

Following preferred reporting items for systematic reviews and meta-analyses (PRISMA) 2020 statement, we searched the databases, including PubMed, Embase, Web of Science, the Cochrane Library, and SCOPUS, from their earliest records to December 1, 2023. Quality assessment utilized Cochrane Risk of Bias and Risk Of Bias In Non-randomized Studies of Interventions tools. Data extraction encompassed study design, participant characteristics, therapy protocols, and outcome measures, including subjective and objective assessments. We performed heterogeneity analysis by calculating the I2 statistic and meta-analysis by calculating the standardized difference of means and weighted mean differences.

RESULTS

Our systematic review and meta-analysis included 12 studies encompassing 459 patients. The review revealed a predominance of female participants across studies. Therapy protocols primarily included breathing control, laryngeal manipulation, and resonance training, often supplemented by home exercises. Outcome measures demonstrated significant improvements in subjective parameter: Voice Handicap Index ((standard mean difference) SMD = -1.51, P < 0.001), acoustic parameters: fundamental frequency (SMD = -0.38, P = 0.003), jitter (SMD = -0.97, P < 0.001), shimmer (SMD = -0.94, P < 0.001), and noise-to-harmonic ratio (SMD = -0.89, P < 0.001), and aerodynamic parameters: maximum phonation time (SMD = 1.29, P < 0.001), with early intervention yielding enhanced rate of complete glottal closure.

DISCUSSION

Two randomized controlled trials (RCTs) involved patients aware of their allocation to the treatment group, and the remaining 10 studies were retrospective, leading to bias from deviations in the intended intervention. Subjective and aerodynamic parameter inconsistency was observed, but after excluding studies with the onset of UVFP greater than 12 months, the heterogeneity of VHI scores decreased. The funnel plot was grossly symmetrical in the publication bias test. Significant improvements were noted in subjective, acoustic, and aerodynamic outcomes after intervention. Besides, there were commonalities in protocols, such as breathing control, laryngeal manipulation, and resonance training, often supplemented by home exercises.

SYSTEMATIC REVIEW REGISTRATION

This protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on March 28, 2024, registration number: CRD42024529750.

An eclectic Voice Therapy Program for the Treatment of Hyperfunctional Voice Disorders (HFVD)

PURPOSE

An eclectic voice therapy program includes sequenced and structured set of exercises combining direct and indirect intervention methods. Tailor-made exercise prescription with specific cultural adaptations are needed to provide a holistic change to voice quality.1 This study detailed the construction of an exercise prescription for participants with hyperfunctional voice disorder [HFVD] in the Indian context.

METHOD

The exercise program was developed based on literature related to vocal therapy approaches and delivery methods. Adaptations were introduced to a selected set of exercises. Five voice experts verified the exercises and their prescription for content and feasibility of use in the Indian context. Modification suggested by the experts were included for framing the final version of the exercise program. This structured therapy program was planned for 6 weeks (30 minutes duration/session offered individually twice per week, with a gap of two days between sessions in a week) with the goals to improve voice quality, flexibility, and endurance while speaking. Five participants with HFVD partook in the study for pilot testing. Stroboscopy, perceptual voice analysis, Dysphonia Severity Index (DSI) and Vocal Fatigue Index in Tamil (VFI-T) were used to report the therapy outcomes. Participants' report on the learning process and generalization of the program were documented. Wilcoxon-signed rank test was used to test the pre-post outcome measures.

RESULTS

An eclectic voice therapy program, i.e., Comprehensive Voice Habilitation Program [CVHP] was constructed and it included vocal hygiene instructions, warm-up & cool-down, easy onset, resonant voice, and carry over exercises. Participants completed the program in 14-18 sessions (over 7 to 9 weeks of therapy). All participants showed significant changes in vocal fold movement patterns, reduction in ventricular hyperadduction, overall grade of voice quality, DSI and VFI-T. Participants reported that pictorial illustrations, feedback, and monitoring sheets were useful in learning the exercises.

CONCLUSION

CVHP showed significant change in the voice-related outcome measures and was a viable program for treating HFVD.

The Effects of the Use of Protective Face Mask on the Voice and Its Relation to Self-Perceived Voice Changes

OBJECTIVES

The purpose of this study was to investigate the effects that the use of protective face mask has over the voice and to search for associations between the self-reported voice changes and the levels of discomfort experienced by the participants. Also, to detect any change it the phonatory patterns while speaking with face mask.

METHODS

This was a cross-sectional, observational study, conducted by distributing an online questionnaire. From a total of 155 people who participated in the study, 143 of them wore protective face mask during their working hours and qualified. Five groups of questions were used to measure the Speech Difficulties, the Mask Related Behaviors caused by the use of face mask, alterations in the Voice Perceptual Features, the Vocal Tract Discomfort levels and the Greek version of the Voice Handicap Index. The participants self-evaluated their voice and stated the frequency and severity of the symptoms they experienced during the mask usage period.

RESULTS

The results showed that the use of protective face mask increases the self-perception of changes in the voice, especially in the voice-breathing coordination and has great effect on the intelligibility and overall communication. The majority of people stated that they have to speak louder and that they have noticed alterations in the perceptual features of their voice, with hoarseness, and volume being the most frequently affected. Almost every symptom on the Vocal Tract Discomfort Group was present with Dry, Lump in Throat, Tight, and Short Breath being the most severe, and Dry and Short breath being the most common among them. Physical, Functional, and Emotional affectations were also observed through the Voice Handicap Index.

CONCLUSION

The use of protective face mask increases the vocal effort of the speaker, affects the voice-breathing coordination, limits the overall communication, alters the perceptual features of the voice, increases vocal track discomfort levels and results in psychosocial and socioemotional difficulties. All these affectations may result to the establishment of a voice disorder, especially in high-risk population.

Use of a Vortex Whistle for Measures of Respiratory Capacity

OBJECTIVES

A vortex whistle produces a tone which has a frequency proportional to the inlet air flow rate. The objectives of this study were to replicate previous studies demonstrating the use of a vortex whistle as an accurate flow meter, and to assess the degree of relationship between measures of vital capacity (VC) obtained using low-cost methods (vortex whistle and hand-held spirometry) vs. pneumotach-based spirometry.

METHODOLOGY

A vortex whistle was designed using 3D modeling software and manufactured using a 3D printer with non-toxic, biodegradable polylactic acid (PLA). The digitized vortex whistle tone was analyzed using custom software to produce a frequency vs. time contour. As the frequency is proportional to flow, the integral of this curve corresponds to the overall volume by a linear relationship. The accuracy of vortex whistle volume estimates were assessed using (1) controlled flow rates from a consistent volume calibration syringe, and (2) with 66 subjects between the ages of 18-30 yrs. in comparison to hand-held spirometry and two pneumotach systems.

RESULTS

Observations from the calibration syringe experiment confirmed that the vortex whistle and software are able to effectively track the flow rate, with a correlation coefficient between the average flow and the average frequency of r² = 0.9965. Results from the human VC testing showed that measures obtained using both vortex whistles and hand-held spirometry correlated very strongly (r > 0.94) with computerized pneumotach systems, and the strength of correlations obtained via vortex whistles vs. hand-held spirometry were highly comparable.

DISCUSSION & CONCLUSIONS

When coupled with the analysis software described herein, valid and reliable frequency/flow curves and volume estimates may be obtained using a vortex whistle that are highly comparable to the hand-held spirometer. The use of the vortex whistle has the potential to bring measures of basic respiratory function to clinicians and patients alike at a fraction of the cost of currently used spirometric methods.

A novel prognostic system based on clinical and laboratory parameters for childhood Guillain-Barre syndrome

AIM

To develop a score based on clinical and laboratory parameters in acute-phase of GBS to predict outcome at 6 months.

METHODS

Clinical and laboratory assessment at admission including blood neutrophil-to-lymphocyte ratio (NLR), pre and post-immunotherapy serum albumin was prospectively performed in pediatric-GBS cases at a tertiary-care hospital over 1 year. Clinical features and laboratory test results were compared between children with complete (Hughes Disability Score; HDS ≤ 1) and incomplete recovery (HDS > 1) at 6 months from onset, using univariate and multivariate analysis. Area-under-receiver-operating-characteristic-curve (AUC) of predictors of prognosis and their optimal cutoffs were assessed.

RESULTS

Forty-six patients were enrolled (mean age 69.1 ± 35.2 months; male 57.6%). Factors on admission that independently predicted poor-outcome at 6 months were older age, feeble voice, lower NLR and lower post-immunotherapy serum albumin. AUCs and optimal cutoffs of NLR and post-immunotherapy serum albumin for predicting disability at 6 months were 0.729, 0.781 and ≤ 1.65, ≤ 34.5 g/L, respectively. AUCs of clinical parameters such as older age and feeble voice were 0.749 and 0.713 respectively. King GBS outcomescore including all predictors had maximum AUC of 0.971 (95% CI 0.921-1.02). The score at cutoff ≥ 3 demonstrated excellent sensitivity (92.3%) and specificity (96.7%) to determine poor outcome.

CONCLUSIONS

This new prognostic system may be beneficial in recognising children-at-risk of poor prognosis who may benefit from additional treatment.

Enhancing the Vortex Whistle for Measures of Respiratory Capacity via CFD and CAA

A vortex whistle produces a fundamental frequency proportional to the inlet flow rate. Recent investigations using vortex whistles have focused on the use of this relationship to quantify aspects of respiratory function. Despite promising results, there is a lack of understanding of the physical mechanisms underlying vortex whistle function. This paper begins with a principled study of the aero-acoustic properties of the vortex whistle. First a high-fidelity computation fluid dynamics (CFD) simulation was developed to predict the unsteady flow field induced by the vortex whistle when the expiratory flow is applied. A computational aero-acoustic analysis (CAA) was applied to predict the acoustic response of the vortex whistle and to capture the frequency and level of the signature spectral peaks. The CFD is validated against prior experimental data on the vortex whistle. The CFD was used to: (a) determine the source of the vortex whistle harmonics; and (b) investigate the effect of an outlet tube terminator, proposed by Awan and Awan (2020). The CFD and CAA indicated that the harmonics are generated by the cylindrical cavity of the vortex whistle, and the outlet terminator increases harmonic signal-to-noise ratio by increasing the pressure fluctuation within the cylindrical cavity. These results support the addition of the outlet tube terminator and provide insight into future design modifications, that will enhance the reliability of the vortex whistle analyses and enable additional measures of respiratory capacity.

[Vocal tract discomfort and wellbeing of caregivers for the elderly during the pandemic]

BACKGROUND

During the Sars-CoV2-pandemic, people working in healthcare such as caregives for the elderly face additional burden, e.g. by the use of face masks.

METHODS

In a prospective study, the emotional and physical wellbeing as well as the vocal tract discomfort of caregivers of two municipal homes for the elderly were assessed by questionnaires, the Mini-SCL and the Vocal Tract Discomfort Scale (VTDS), and one on personal data (sex, age, lung disease, previous SARS-CoV2-infection) and on voice symptoms.

RESULTS

67% of the questionnaires were answered by 56 women and 11 men aged 45.2 ± 11.5. In the Mini-SCL, increased scores were found in depression in 23.8%, anxiety in 49.3%, somatization in 55.2% and in the global score in 44.7%. 52%. showed increased scores in the VTDS Significant correlations were found in between the subscales of the Mini-SCL and the VTDS as well as to dysphonia symptoms.

DISCUSSION

Psychological problems, somatization and vocal tract discomfort is more frequently reported by caregivers for the elderly than in the normal population. The VTDS, voice symptoms and the Mini-SCL scales are significantly related. Training on vocal hygiene should be included in workplace health promotion during the pandemic.

Effect of Respiratory Muscle Training on Pitch Range and Sound Duration in Brass Instrument Players and Singers

OBJECTIVE

Effective use of respiratory organs is important for musicians. Therefore, the impact of Respiratory Muscle Training (RMT) on phonation is open to research. The aim of this study was to investigate the measurable effects of RMT on blowing in brass instrumental and on voice performance in singers.

METHODS

Thirty musicians were recruited and separated into a four groups. The brass instrumental and singers groups were further subdivided into control and RMT groups for a 4 week RMT intervention giving a total four groups: singers experimental (SE; n:10), singers control (SC; n:10), brass instrument players experimental (BIPE; n:5), and BIPC (n:5). The groups selected from the musicians of Samsun State Opera and Ballet Directorate and Samsun Metropolitan Municipality Band Team participated in the study.

RESULTS

After 4 weeks of RMT application in the study groups, significant increase in all parameters except Forced vital capacity/Forced expiratory volume in 1 second was observed in the values of pulmonary function tests and respiratory muscle strength in subjects with SE and BIPE (P < 0.05). The most significant results of this study are that in addition to changes in the duration of phonation (SE 36%), high-pitch (SE 79%, BIPE 27%) and low-pitch sounds (BIPE 61% and SE 42%), the SE (15%) and BIPE (3%) groups reached higher pitches in the high-pitch notes.

CONCLUSIONS

It was determined that performance of the highest and lowest pitch sounds within a vocal register in a single breath and phonation times can be improved by RMT.