Brain Activity During Phonation in Women With Muscle Tension Dysphonia: An fMRI Study

Exploring autonomic dysfunction in functional dysphonia: A protocol for a case-control study and a randomized controlled trial

BACKGROUND

Although psychological factors have been implicated in patients with functional dysphonia (FD), conventional voice therapy (CVT) typically targets the aberrant voice symptoms exclusively. Yet, CVT is not always successful, and in view of the significant adverse quality of life impact combined with the financial burden on the healthcare system and society, research is needed to elucidate the underlying psychophysiology of FD and improve treatment outcomes.

OBJECTIVES

The first objective of this research project is to compare the occurrence and frequency of symptoms and/or disorders related to autonomic nervous system (ANS) dysfunction in patients with FD with gender- and age-matched vocally healthy controls, using a case-control study. The second objective is to compare the effects of a novel therapy for FD based on ANS regulation (i.e., ANS therapy: heart rate variability (HRV) biofeedback) on both autonomic function and voice function versus CVT alone or in combination with ANS therapy (i.e., ANS therapy + CVT), using a randomized controlled trial (RCT).

METHODS

Case-control study: Autonomic (dys)function of patients with FD will be compared with gender- and age-matched vocally healthy controls, using both physiological measures (e.g., HRV, skin conductance level) and psychological patient-reported outcome measures (PROMs, e.g., Neuroception of Psychological Safety Scale, Depression Anxiety and Stress Scale). RCT: The FD group will be randomly assigned to the innovative ANS therapy group, the CVT group or the ANS therapy + CVT group. All patients received 1 month of treatment with 20 min of daily practice. Both the autonomic assessment and the voice assessment will be performed pretherapy and immediately after therapy by assessors blinded to group allocation and study phase.

EXPECTED RESULTS

Higher occurrences of symptoms and/or disorders related to autonomic dysfunction are expected in patients with FD compared with vocally healthy controls. Physiological outcomes: lower HRV, lower cardiac pre-ejection period, higher respiration rate and higher skin conductance level are hypothesized in patients with FD compared with vocally healthy controls. Psychological PROMs: higher self-report of feelings/symptoms related to autonomic dysfunction (e.g., perceived stress, anxiety) is expected in patients with FD compared with vocally healthy controls. The autonomic function is hypothesized to improve more after the ANS therapy and the ANS therapy + CVT compared with the CVT only. Voice function is expected to improve more after the ANS therapy + CVT compared with the ANS therapy and the CVT alone.

WHAT THIS PAPER ADDS

What is already known on the subject Autonomic dysfunction is well recognized in the field of psychology but remains understudied in the area of voice. Given that the vagus nerve, innervating the larynx, also helps to regulate the ANS, and psychological symptoms commonly observed in patients with FD may reflect ANS dysregulation, research in this area is needed. There is some preliminary evidence that autonomic dysfunction might indeed be associated with FD. However, physiological ANS measures are needed, as well as validated psychological PROMs. What this paper adds to the existing knowledge The first objective of this study is to investigate the occurrence and frequency of symptoms and/or disorders related to autonomic dysfunction in patients with FD as compared with a gender- and age-matched vocally healthy control group. Autonomic (dys)function will be determined by employing both physiological measures (e.g., HRV, skin conductance level) and psychological PROMs (e.g., Neuroception of Psychological Safety Scale, Depression Anxiety and Stress Scale). The second objective is to compare the effects of a novel therapy for FD based on ANS regulation (HRV biofeedback) versus CVT alone or in combination with ANS therapy. What are the potential or actual clinical implications of this work? Success rates of symptomatic CVT for FD are highly variable. This study is expected to lead to innovative results related to the pathogenesis and psychophysiology of FD, a prevalent voice disorder associated with a significant adverse quality of life impact and a substantial financial burden on the healthcare system and society. The results of this study will lead to crucial new insights into both the diagnosis and treatment of FD, contributing to evidence-based practice in the field of voice.

Auditory Perception of Roughness and Breathiness by Dysphonic Women

OBJECTIVE

To investigate the auditory perception of roughness and breathiness by dysphonic women.

METHODS

Twenty-two dysphonic native Brazilian Portuguese women participated in this research. All participants underwent audiological evaluation and laryngeal examination to confirm the diagnosis. During the tests, they recorded the sustained vowel /Ɛ/. A speech-language pathologist performed the auditory-perceptual judgment of voice quality for these vocal samples, categorizing the general degree of vocal deviation (mild, moderate, and severe degree) and the predominant type of deviation (roughness or breathiness). Thirty-two (32) stimuli were selected from a voice database, including twenty-four (24) dysphonic voice samples and eight (8) voice samples from vocally healthy women. The authors conducted five perception experiments, being three categorization tasks (normal vs. deviated, breathy vs. nonbreathy, rough vs. nonrough) and two tasks for discriminating the degree of deviation (roughness degree and breathiness degree).

RESULTS

The experiments showed a difference between the answers for presence/absence of deviation, presence/absence of breathiness, and presence/absence of roughness in the stimuli, and a difference in the proportion of similar answers of dysphonic women (P < 0.001) regarding the identification of the deviation. Participants classified a large part of the deviated (57.9%), breathy (63.13%), and rough (65.31%) voices as normal. The degree of vocal deviation (P = 0.008) and the degree of roughness in the stimuli correlated positively with the proportion of similar answers of the participants. As for the discrimination of breathiness degrees, less deviated (normal and mild) voices were less discriminated, and more deviated (moderate and severe) voices were better discriminated. Regarding the discrimination of roughness degrees, only the voices with severe deviations showed good discrimination.

CONCLUSION

Dysphonic women had a high rate of not similar answers in the identification of normal and deviated voices. They identified more than half of the deviated voices as normal. Samples with more severe deviations were proportionally more identified as deviated by the participants. The greater the vocal deviation of the participants' voices, the smallest the number of similar answers. Participants had a high rate of not similar answers in the identification of normal and breathy voices. Dysphonic women show less ability to perceive mildly and moderately breathy voices in the breathy category. Participants had a high rate of similar answers in the identification of normal and rough voices. Dysphonic women show less ability to perceive mildly and moderately breathy voices in the breathy category. Participants show less ability to perceive only mildly roughness voices with similar responses. Dysphonic women could discriminate between voices with adjacent degrees of roughness but had a low percentage of similar answers for discrimination between voices with adjacent degrees of breathiness.

Neural Correlates of Healthy Sustained Vowel Phonation Tasks: A Systematic Review and Meta-Analysis of Neuroimaging Studies

OBJECTIVE

This review of the methodology and results of studies involving a sustained vowel phonation task during functional Magnetic Resonance Imaging (fMRI) aims to contribute to the identification of brain regions involved in phonation for healthy subjects.

DATA SOURCES

This review was performed using the PubMed electronic database.

REVIEW METHODS

A review was conducted, according to PRISMA guidelines, between September and November 2020, using the following search term pairs: "fMRI and Phonation" and "fMRI and Voice." Activation likelihood estimation analysis was performed. A qualitative analysis was also performed to specify the frequency of activation of each region, as well as the various activation clusters within a single region.

RESULTS

Seven studies were included and analyzed. Five of the seven studies were selected for the activation likelihood estimation meta-analysis which revealed significant convergent activation for only one cluster located in the left precentral gyrus (BA4). A qualitative review provides an overview of brain activation. Primary motor and premotor areas were the only activated areas in all studies included. Other regions previously considered to be implicated in phonation were often activated in sustained vowel phonation tasks. Additionally, areas generally associated with articulation or language also showed activation.

CONCLUSION

Methodological recommendations are suggested to isolate the phonatory component and reduce variability between future studies. Based on the qualitative analysis, this review does not support a distinction between regions more related to phonation and regions more related to articulation. Further research is required seeking to isolate the vocal component and to improve insight into human brain network involved in phonation.

Chronic respiratory failure negatively affects speech function in patients with bulbar and spinal onset amyotrophic lateral sclerosis: retrospective data from a tertiary referral center

Background: Although dysarthria and respiratory failure are widely described in literature as part of the natural history of Amyotrophic lateral sclerosis (ALS), the specific interaction between them has been little explored.Aim: To investigate the relationship between chronic respiratory failure and the speech of ALS patients.Materials and methods: In this cross-sectional retrospective study we reviewed the medical records of all patients diagnosed with ALS that were accompanied by a tertiary referral center. In order to determine the presence and degree of speech impairment, the Amyotrophic Lateral Sclerosis Functional Rating Scale-revised (ALSFRS-R) speech sub-scale was used. Respiratory function was assessed through spirometry and through venous blood gasometry obtained from a morning peripheral venous sample. To determine whether differences among groups classified by speech function were significant, maximum and mean spirometry values of participants were compared using multivariate analysis of variance (MANOVA) with Tukey's post hoc test.Results: Seventy-five cases were selected, of which 73.3% presented speech impairment and 70.7% respiratory impairment. Respiratory and speech functions were moderately correlated (seated FVC r = 0.64; supine FVC r = 0.60; seated FEV1 r = 0.59 and supine FEV1 r = 0.54, p < .001). Multivariable logistic regression revealed that the following variables were significantly associated with the presence of speech impairment after adjusting for other risk factors: seated FVC (odds ratio [OR] = 0.862) and seated FEV1 (OR = 1.106). The final model was 81.1% predictive of speech impairment. The presence of daytime hypercapnia was not correlated to increasing speech impairment.Conclusion: The restrictive pattern developed by ALS patients negatively influences speech function. Speech is a complex and multifactorial process, and lung volume presents a pivotal role in its function. Thus, we were able to find that lung volumes presented a significant correlation to speech function, especially in those with bulbar onset and respiratory impairment. Neurobiological and physiological aspects of this relationship should be explored in further studies with the ALS population.

Functional and structural abnormalities of the speech disorders: a multimodal activation likelihood estimation meta-analysis

Speech disorders are associated with different degrees of functional and structural abnormalities. However, the abnormalities associated with specific disorders, and the common abnormalities shown by all disorders, remain unclear. Herein, a meta-analysis was conducted to integrate the results of 70 studies that compared 1843 speech disorder patients (dysarthria, dysphonia, stuttering, and aphasia) to 1950 healthy controls in terms of brain activity, functional connectivity, gray matter, and white matter fractional anisotropy. The analysis revealed that compared to controls, the dysarthria group showed higher activity in the left superior temporal gyrus and lower activity in the left postcentral gyrus. The dysphonia group had higher activity in the right precentral and postcentral gyrus. The stuttering group had higher activity in the right inferior frontal gyrus and lower activity in the left inferior frontal gyrus. The aphasia group showed lower activity in the bilateral anterior cingulate gyrus and left superior frontal gyrus. Across the four disorders, there were concurrent lower activity, gray matter, and fractional anisotropy in motor and auditory cortices, and stronger connectivity between the default mode network and frontoparietal network. These findings enhance our understanding of the neural basis of speech disorders, potentially aiding clinical diagnosis and intervention.

Relations Between Dysphonia and Personality: An Approximation From Gray' Theories

Our study sought to show the relation between dysphonia and personality traits as explained by Gray's theories. Personality traits were analyzed in a patient group of 141 patients who showed functional and congenital voice disorders. The results were compared to the control group made up of 99 vocally healthy individuals. Their objective voice quality was measured by using the Dysphonia Severity Index, Voice Handicap level was measured using the VHI-10, and a perceptive analysis was conducted with a listening jury. The results showed significant differences in Introversion and Neuroticism and a greater tendency for activating the behavioral inhibition system in the patient group. Such an influence was also evident in voice quality measures. The results were similar to specialized literature.

Risk of Fibromyalgia in Patients with Primary Muscle Tension Dysphonia: A Prospective Pilot Study

OBJECTIVE

To investigate the risk of fibromyalgia in patients with primary muscle tension dysphonia (MTD) in comparison to subjects with no dysphonia.

STUDY DESIGN

Prospective cohort study.

METHODS

The medical records and video recordings of all patients presenting to the Voice and Swallowing unit at a tertiary referral center between October 2022 and October 2023 and who were diagnosed with primary MTD were prospectively reviewed. The risk of fibromyalgia was assessed using the "Fibromyalgia Rapid Screening Tool" (FiRST). Demographic data included age, gender, history of smoking, and history of high vocal load. The impact of dysphonia on quality of life was also analyzed using the Voice Handicap Index-10 (VHI-10).

RESULTS

A total of 42 patients who had filled the FiRST questionnaire were enrolled in this study. These included 20 patients diagnosed with primary MTD and 22 healthy subjects with no history of dysphonia and normal laryngeal examination. Forty percent of the study group tested positive using the FiRST questionnaire as compared to only 9.1% in the control group. The difference between the two groups was statistically significant (P = 0.03). The risk of having fibromyalgia was 6.67 times among patients with primary MTD in comparison to controls (RR=6.67; 95% CI [1.21-36.74]).

CONCLUSION

The results of this investigation indicate that the risk of fibromyalgia is significantly higher in patients with primary MTD vs controls. A holistic approach in the diagnosis and treatment of MTD is advocated.

[Voice disorders associated with novel coronavirus infection]

OBJECTIVE

To evaluate the features of voice disorders associated with novel coronavirus infection and to develop the clinical algorithm for diagnostic and treatment these patients.

MATERIAL AND METHODS

A prospective observational study was conducted in patients with dysphonia after COVID-19 (n=60). All patients underwent a comprehensive voice assessment before and after the proposed treatment. The follow-up period was 1 month.

RESULTS

Functional dysphonia or aphonia with a stable (refractory) or recurrent course was diagnosed in 58 (97%) patients. A tendency to an increase in the value of the latent period of the P300 and MMN in patients with voice disorder was revealed. There was a significant decrease in supraglottic constriction and glottal insufficiency before and after the treatment. The mean VHI-10 decreased from 25.4 before treatment to 15.3 after treatment. The DSI which is based on the set of voice measurements, statistically significant improved from -5.2 to 2.6 in patients as a result of treatment. The average value of MFI-20 improved from 65.4 (8.7) at the beginning of the study to 20.3 (5.3) after treatment.

CONCLUSION

In patients with dysphonia or aphonia associated with COVID-19 are indicated a refractory type of dysphonia. This was indicated by the study of AEPs of the brain. The clinical algorithm for treatment and diagnostic patients with voice disorders after COVID-19 has been developed. The treatment of this group of patients should be adjunct by the drug therapy, kinesiotaping method and psychotherapy.

Lombard Effect in Individuals With Nonphonotraumatic Vocal Hyperfunction: Impact on Acoustic, Aerodynamic, and Vocal Fold Vibratory Parameters

PURPOSE

This exploratory study aims to investigate variations in voice production in the presence of background noise (Lombard effect) in individuals with nonphonotraumatic vocal hyperfunction (NPVH) and individuals with typical voices using acoustic, aerodynamic, and vocal fold vibratory measures of phonatory function.

METHOD

Nineteen participants with NPVH and 19 participants with typical voices produced simple vocal tasks in three sequential background conditions: baseline (in quiet), Lombard (in noise), and recovery (5 min after removing the noise). The Lombard condition consisted of speech-shaped noise at 80 dB SPL through audiometric headphones. Acoustic measures from a microphone, glottal aerodynamic parameters estimated from the oral airflow measured with a circumferentially vented pneumotachograph mask, and vocal fold vibratory parameters from high-speed videoendoscopy were analyzed.

RESULTS

During the Lombard condition, both groups exhibited a decrease in open quotient and increases in sound pressure level, peak-to-peak glottal airflow, maximum flow declination rate, and subglottal pressure. During the recovery condition, the acoustic and aerodynamic measures of individuals with typical voices returned to those of the baseline condition; however, recovery measures for individuals with NPVH did not return to baseline values.

CONCLUSIONS

As expected, individuals with NPVH and participants with typical voices exhibited a Lombard effect in the presence of elevated background noise levels. During the recovery condition, individuals with NPVH did not return to their baseline state, pointing to a persistence of the Lombard effect after noise removal. This behavior could be related to disruptions in laryngeal motor control and may play a role in the etiology of NPVH.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.20415600.

Integrative Review and Framework of Suggested Mechanisms in Primary Muscle Tension Dysphonia

PURPOSE

Despite the high prevalence of primary muscle tension dysphonia (MTD-1), its underlying mechanisms and their interrelationships have yet to be fully identified. The objectives of this integrative review were (a) to describe and classify the suggested underlying mechanisms for MTD-1, (b) to appraise the empirical evidence supporting each of the proposed mechanisms, and (c) to summarize the information in an integrative model.

METHOD

PubMed, Scopus, and CINAHL were searched for all publications pertaining to muscle tension dysphonia. Papers were retained if they included theoretical or empirical data pertaining to underlying mechanisms of MTD-1. A total of 921 papers initially qualified for screening, of which 100 remained for consideration in this review. Underlying mechanisms of MTD-1 were extracted using a consensus approach.

RESULTS

Seven broad categories of putative mechanisms involved in MTD-1 were identified: psychosocial, autonomic, sensorimotor, respiratory, postural, inflammatory, and neuromuscular. These categories were further divided into 19 subcategories detailed in the body of this review article. Based on the reviewed evidence, our proposed integrative model presents MTD-1 as an idiosyncratic motor adaptation to physiological perturbation or perceived threat. Under this model, physiologically or psychologically aversive stimuli can instigate a series of motor adaptations at multiple levels of the nervous system, ultimately disturbing muscle activation patterns and their biomechanical outcomes. Importantly, these adaptations appear to have the potential to become chronic even after threatening stimuli are withdrawn.

CONCLUSIONS

The proposed model highlights the importance of personalized rehabilitation in MTD-1 treatment. Limitations of the literature are discussed to provide guidance for future research aimed at improving our understanding of MTD-1.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19586065.

An Updated Theoretical Framework for Vocal Hyperfunction

Purpose The purpose of this viewpoint article is to facilitate research on vocal hyperfunction (VH). VH is implicated in the most commonly occurring types of voice disorders, but there remains a pressing need to increase our understanding of the etiological and pathophysiological mechanisms associated with VH to improve the prevention, diagnosis, and treatment of VH-related disorders. Method A comprehensive theoretical framework for VH is proposed based on an integration of prevailing clinical views and research evidence. Results The fundamental structure of the current framework is based on a previous (simplified) version that was published over 30 years ago (Hillman et al., 1989). A central premise of the framework is that there are two primary manifestations of VH-phonotraumatic VH and nonphonotraumatic VH-and that multiple factors contribute and interact in different ways to cause and maintain these two types of VH. Key hypotheses are presented about the way different factors may contribute to phonotraumatic VH and nonphonotraumatic VH and how the associated disorders may respond to treatment. Conclusions This updated and expanded framework is meant to help guide future research, particularly the design of longitudinal studies, which can lead to a refinement in knowledge about the etiology and pathophysiology of VH-related disorders. Such new knowledge should lead to further refinements in the framework and serve as a basis for improving the prevention and evidence-based clinical management of VH.

Limbic and cortical control of phonation for speech in response to a public speech preparation stressor

Knowledge on brain networks subserving vocalization in vocally healthy individuals under various task conditions is scarce but paramount to understand voice disorders. The aims of our study were to determine (1) the effect of social-evaluative stress on the central neural control of phonation underlying speech production; and (2) the neural signature, personality profile, and aerodynamic vocal function in relation to salivary cortisol responses. Thirteen vocally healthy females underwent an event-related sparse-sampling fMRI protocol consisting of voiced and whispered sentence productions with and without exposure to the social-evaluative stressor public speaking anticipation. Participants completed a personality questionnaire, rating scales of negative emotional state, and provided salivary cortisol samples. In the total sample, the task contrast of voiced productions revealed that stressor exposure resulted in a peak activation in the right caudate with concomitant deactivations in the bilateral pgACC and aMCC, and right IFG, BA 9, BA 10, insula, putamen, and thalamus. There were individual differences in stressor-induced brain activations as a function of stress reactivity with greater cortisol reactivity linked with lower laryngeal motor cortex activity and lower scores on aspects of extraversion. Our data confirm that stress alters the phonatory control for speech production through limbic-motor interactions. The findings support the Trait Theory of Voice Disorders (Roy and Bless 2000) and help provide critical insights to the study of voice disorders such as primary muscle tension dysphonia.

Brain Activity in Patients With Unilateral Vocal Fold Paralysis Detected by Functional Magnetic Resonance Imaging

OBJECTIVES

Understanding brain activity in response to unilateral vocal fold paralysis is essential to determine the neural compensatory mechanism underlying adaptation to voice disorders and to develop novel and improved rehabilitation programs for these disorders. We aimed to clarify brain activity during phonation (prolonged vowel, |i:|) in patients with chronic left vocal fold paralysis (LVFP) and compare with that in normal controls.

STUDY DESIGN

Case-control study.

METHODS

This functional magnetic resonance imaging (fMRI) study of an event-related task comprised 12 individuals with LVFP of more than 6 months duration and 12 healthy controls. The experimental task alternated phonation (prolonged vowel, |i:|) and no phonation (rest) conditions. The functional images obtained were single-shot gradient-echo echo-planar imaging. The volumes were acquired parallel to the anterior-posterior commissure plane and were sensitive to BOLD contrast. Data sets were processed and statistically analyzed using Statistical Parametric Mapping 8 software. Within-group analyses were conducted by applying the one-sample t test (P < 0.001, uncorrected). A random-effects analysis was used for group comparison.

RESULTS

The LVFP group showed significantly higher brain activity in the right premotor areas, left parietal lobule, right primary somatosensory areas, and bilateral supplementary motor area and lower brain activity in the auditory-related areas of the superior temporal gyrus. There were no significant correlations of the percent signal change on fMRI with disease duration, maximum phonation time, or age.

CONCLUSION

Patients with chronic unilateral vocal fold paralysis have stronger activity during voluntary phonation in various central networks. More detailed information on the central nervous system regions related to voluntary phonation from early to chronic phase is needed to understand the compensatory mechanisms in vocal fold paralysis and to establish an effective rehabilitation program. This is the first report to investigate brain activity in chronic unilateral vocal fold paralysis.

Neural Correlates of Esophageal Speech: An fMRI Pilot Study

OBJECTIVES

The esophageal speech is one of the possible alaryngeal voices resulting after total laryngectomy. Its production is made by the regurgitation of the air coming from the esophagus, sonorized through the passage from the walls of the upper esophageal sphincter. The neural correlates of this voice have never been investigated, while the neural control of laryngeal voice has been already documented by different studies.

METHODS

Four patients using esophageal speech after total laryngectomy and four healthy controls underwent functional magnetic resonance imaging. The fMRI experiment was carried out using a "Block Design Paradigm."

RESULTS

Comparison of the phonation task in the two groups revealed higher brain activities in the cingulate gyrus, the cerebellum and the medulla as well as lower brain activities in the precentral gyrus, the inferior and middle frontal gyrus and the superior temporal gyrus in the laryngectomized group.

CONCLUSIONS

The findings in this pilot study provide insight into neural phonation control in laryngectomized patients with esophageal speech. The imaging results demonstrated that in patients with esophageal speech, altered brain activities can be observed. The adaptive changes in the brain following laryngectomy reflect the changes in the body and in the voice modality. In addition, this pilot study establishes that a blocked design fMRI is sensitive enough to define a neural network associated with esophageal voice and lays the foundation for further studies in this field.