Patient perceptions of factors leading to spasmodic dysphonia: a combined clinical experience of 350 patients

Demographic and clinical characteristics of our patients diagnosed with laryngeal dystonia

PURPOSE

Laryngeal dystonia (LD) is a focal dystonia affecting laryngeal musculature with no known etiology or cure. The present study evaluated the sociodemographic and clinical features of patients diagnosed with LD.

MATERIALS AND METHODS

All patients diagnosed with LD at our University Hospital's Ear, Nose, and Throat Department between January 2017 and July 2023 were retrospectively analyzed. The study included 43 patients.

RESULTS

Out of the 43 patients, 19 (44%) were male. At the time of diagnosis, the mean age of the patients was 35.1 years (ranging from 17 to 65 years). The mean elapsed time between the first symptom onset and the first diagnosis was 49.2 months (min. 4 months, max. 240 months). Of the participants, 94% had adductor-type LD. None of the patients had a family history of LD. Of the patients, 9 (20%) experienced a life-altering event or trauma just before the onset of symptoms. All patients who consumed alcohol reported symptom relief with alcohol intake. A total of 67.6% of patients stated that their symptoms were triggered by stress. All of our patients received at least one Botulinum toxin injection, with an average of 2.75 dosages per patient.

CONCLUSION

The gender distribution was approximately equitable between males and females. There was a tendency for men to receive a diagnosis earlier than women following the manifestation of symptoms. A significant number of patients associate the emergence of their symptoms with a stressful event or traumatic experience. This study represents the initial investigation into the sociodemographic characteristics of patients within the Turkish population.

Utility of maximum phonation time in the diagnosis of spasmodic dysphonia (laryngeal dystonia)

OBJECTIVES

Maximum phonation time is a simple test used to assess glottic competency. Our objective was to evaluate any correlation between maximum phonation time and spasmodic dysphonia as adductor spasmodic dysphonia and abductor spasmodic dysphonia have an adductor and abductor overdrive, respectively.

METHODS

A 3-year data-review was performed for patients diagnosed with adductor spasmodic dysphonia, abductor spasmodic dysphonia and mixed spasmodic dysphonia. Maximum phonation time was noted on the first visit and compared with a control group.

RESULTS

Average maximum phonation time in adductor spasmodic dysphonia, abductor spasmodic dysphonia and control group was 25 seconds, 9 seconds and 16 seconds. A significant difference was found for adductor spasmodic dysphonia and abductor spasmodic dysphonia. A receiver operating characteristic curve analysis between adductor spasmodic dysphonia and control groups showed a positive predictive value of 81.3 per cent, negative predictive value of 83.9 per cent, sensitivity of 79.6 per cent and specificity of 85.2 per cent. Level of evidence = 4.

CONCLUSION

We recommend that maximum phonation time be added to the diagnostic armamentarium of spasmodic dysphonia. This correlation between maximum phonation time and spasmodic dysphonia has not been previously published.

Function and dysfunction of the dystonia network: an exploration of neural circuits that underlie the acquired and isolated dystonias

Dystonia is a highly prevalent movement disorder that can manifest at any time across the lifespan. An increasing number of investigations have tied this disorder to dysfunction of a broad "dystonia network" encompassing the cerebellum, thalamus, basal ganglia, and cortex. However, pinpointing how dysfunction of the various anatomic components of the network produces the wide variety of dystonia presentations across etiologies remains a difficult problem. In this review, a discussion of functional network findings in non-mendelian etiologies of dystonia is undertaken. Initially acquired etiologies of dystonia and how lesion location leads to alterations in network function are explored, first through an examination of cerebral palsy, in which early brain injury may lead to dystonic/dyskinetic forms of the movement disorder. The discussion of acquired etiologies then continues with an evaluation of the literature covering dystonia resulting from focal lesions followed by the isolated focal dystonias, both idiopathic and task dependent. Next, how the dystonia network responds to therapeutic interventions, from the "geste antagoniste" or "sensory trick" to botulinum toxin and deep brain stimulation, is covered with an eye towards finding similarities in network responses with effective treatment. Finally, an examination of how focal network disruptions in mouse models has informed our understanding of the circuits involved in dystonia is provided. Together, this article aims to offer a synthesis of the literature examining dystonia from the perspective of brain networks and it provides grounding for the perspective of dystonia as disorder of network function.

Laryngeal Sensory Symptoms in Spasmodic Dysphonia

OBJECTIVE

The purpose of this research was to determine whether an association between laryngeal hypersensitivity (LH) and spasmodic dysphonia (SD) exists using the LH Questionnaire (LHQ). This study also explored the prevalence of self-reported upper respiratory infection (URI) at the time of SD onset across SD phenotypes.

METHODS

Individuals with and without SD were recruited to complete an online survey measure. All respondents provided demographic information and completed the LHQ. Participants with SD were also asked to provide information about their diagnosed SD subtype and pattern of onset, including whether onset was associated with a URI. The percentage of respondents with and without SD who were classified with LH was determined based on the LHQ. Scores on the LHQ were also compared between the non-SD and the SD groups, as well as between SD phenotypes (adductor SD, abductor SD, and mixed)).

RESULTS AND CONCLUSIONS

Significant associations were found between ADSD and LH, mixed SD and LH, and URI at time of SD onset and increased severity of LH symptoms. These findings suggest that laryngeal sensory symptoms may potentially contribute to or result from motor spasms in SD and/or have implications for its pathophysiology.

Simultaneous Botox and Augmentation Injection Laryngoplasty in Patients With Adductor Spasmodic Dysphonia (ASD) and Tremor

OBJECTIVE

Although Botulinum Toxin (BOTOX) is effective for adductor spasmodic dysphonia (ASD) and essential vocal tremor (EVT), the side effects of breathy dysphonia may result in reluctance to pursue BOTOX treatment. We sought to improve results in selected elderly tremor patients with EVT and in professional voice users with ASD by simultaneous BOTOX injection and injection laryngoplasty using Hyaluronic acid (HA/Botox).

MATERIAL AND METHODS

Between July 2018 and March 2022, 23 simultaneous HA/Botox using LEMG control were done in eight patients with ASD and EVT (23 of 406 Botox Injections). All eight patients have previously reported unwanted side effects with poor voice results with Botox. Three patients had tremor with presbyphonia. Injection of Botox is performed first using LEMG control, followed by bilateral LEMG guided injection of 0.1 cc of HA.

RESULTS

All HA/Botox injections were tolerated well. All patients reported some improved voice. Two patients did not go on to further HA injections while the others six have requested ongoing simultaneous HA/Botox injections. Patients with EVT and presbyphonia noted greater stability of voice than Botox alone. It lasted through the injection cycle. The professional voice users reported less breathy voice that allowed them to work right after the BOTOX injection.

CONCLUSION

Simultaneous BOTOX injection with injection laryngoplasty using HA may be helpful in patients with tremor and presbyphonia. It also may be considered in professional voice users with ASD to reduce side effects of BOTOX.

How can we make better decisions about dystonic voice management?

PURPOSE OF REVIEW

The optimal diagnosis and management of dystonic voice disorders are rooted in the nuanced understanding of their phenomenology. Distinguishing between subtypes of vocal dystonia is challenging, not only because the audible and physical presentations of these dystonia's can seem similar, but also because there is a lack of scientific consensus regarding the diagnostic criteria for these conditions. To help improve the clinician's acumen we focus on outlining the classification of the top three neurological voice disorders, notably: spasmodic dysphonia, (2) spasmodic dysphonia with tremor, and essential tremor of the voice. We also provide an algorithmic approach based on current evidence-based literature to guide practitioners through the clinical diagnosis and management of each possible etiology.

RECENT FINDINGS

Much remains unknown about the subtypes of vocal dystonia, and this gap in our knowledge likely limits our ability to advance clinical management. Still, continued experience evaluating and treating these patients yields refined clinical evaluations and decision making.

SUMMARY

Improvements in our clinical decision-making can be made by acknowledging that our limited understanding of vocal dystonia may hinder what therapeutic interventions we can offer, yet our ability to accurately diagnose the dystonia is central to providing optimal patient management.

Laryngeal Dystonia: Multidisciplinary Update on Terminology, Pathophysiology, and Research Priorities

OBJECTIVE

To delineate research priorities for improving clinical management of laryngeal dystonia, the NIH convened a multidisciplinary panel of experts for a 1-day workshop to examine the current progress in understanding its etiopathophysiology and clinical care.

METHODS

The participants reviewed the current terminology of disorder and discussed advances in understanding its pathophysiology since a similar workshop was held in 2005. Clinical and research gaps were identified, and recommendations for future directions were delineated.

RESULTS

The panel unanimously agreed to adopt the term "laryngeal dystonia" instead of "spasmodic dysphonia" to reflect the current progress in characterizations of this disorder. Laryngeal dystonia was recognized as a multifactorial, phenotypically heterogeneous form of isolated dystonia. Its etiology remains unknown, whereas the pathophysiology likely involves large-scale functional and structural brain network disorganization. Current challenges include the lack of clinically validated diagnostic markers and outcome measures and the paucity of therapies that address the disorder pathophysiology.

CONCLUSION

Research priorities should be guided by challenges in clinical management of laryngeal dystonia. Identification of disorder-specific biomarkers would allow the development of novel diagnostic tools and unified measures of treatment outcome. Elucidation of the critical nodes within neural networks that cause or modulate symptoms would allow the development of targeted therapies that address the underlying pathophysiology. Given the rarity of laryngeal dystonia, future rapid research progress may be facilitated by multicenter, national and international collaborations.

Demographics and coexisting tremor, cervical dystonia and vocal fold disorders in a group of patients with spasmodic dysphonia

The primary aim of this study is to describe the demographic and clinical characteristics of a group of patients with spasmodic dysphonia (SD). As a secondary aim, we examined associations of age at SD diagnosis and sex with co-existing cervical dystonia and nonvocal tremor; as well as association of vocal tremor with sex and nonvocal tremor. Seventy-four consecutive patients who were treated for SD at the Mayo Clinic in Jacksonville, Florida between October 1, 2015 and March 31, 2018 were included in this retrospective study. Information was collected regarding sex, age at SD diagnosis, BMI, SD diagnosis type, recent history of major stress/depression, recent history of upper respiratory tract infection (URTI), co-existing neurological diseases, and co-existing vocal disorders. The majority of patients were female (75.7%) and median age at SD diagnosis was 61 years (range: 17 – 80 years). The median BMI was 25.7 (range: 16.9 – 63.7). The most common diagnostic combinations were adductor dysphonia only (52.7%), adductor dysphonia and MTD (18.9%), and adductor dysphonia and tremor (17.6%). Co-existing tremor was present in 36.6% of patients and cervical dystonia was present in 15.5%. Co-existing vocal disorders were observed as follows: paresis/paralysis (3.1%), cyst (3.1%), mass (4.7%), polyp (1.6%), and anterior glottis web (1.6%). Sex was not notably associated with either cervical dystonia or nonvocal tremor (all P ≥ 0.30). Older age at SD diagnosis was significantly associated with cervical dystonia (P = 0.049), but not nonvocal tremor (P = .22). Other than co-existing tremor, most patients had no co-existing neurological diseases or vocal disorders. Additionally, patients who were older at SD diagnosis were significantly more likely to have co-existing cervical dystonia.

The Effects of Self-Esteem, Coping, and Voice-Related Quality of Life on Communicative Participation Before and After BOTOX® Treatment for Spasmodic Dysphonia

OBJECTIVES/HYPOTHESIS

The purpose of this study was to (1) investigate the percent change in communicative participation in individuals with spasmodic dysphonia (SD) pre- and post-BOTOX® treatment; and (2) to investigate if percent change in communicative participation is predicted by change in self-esteem, coping, and/or Voice-Related Quality of Life (V-RQOL) pre- and post-BOTOX® treatment.

STUDY DESIGN/METHODS

A cross-sectional study of 49 patients was conducted across three clinics, with each participant completing the Rosenberg Self-Esteem Scale, the Voice Disability Coping Questionnaire (VDCQ), the V-RQOL instrument, and the Communication Participation Item Bank (CPIB) before BOTOX® treatment and 10-14 days following BOTOX® treatment.

DATA ANALYSIS

For Research Question 1, a paired t test was applied to test the equality of means for CPIB and to test the pre-post changes among other composite measurements before and after the BOTOX® treatment. For Research Question 2, a multivariable linear regression model was applied with percent change in CPIB as a main outcome, and change in Rosenberg Self-Esteem Scale, VDCQ, and the V-RQOL as independent variables (or covariates) in order to test the associations.

RESULTS

The results indicated that pre- and post-BOTOX® measures of communicative participation are not statistically significantly different among the participants with SD. There was a strong positive correlation between change in coping and voice-related QOL.

CONCLUSIONS

A better understanding of the relationship between communicative participation and voice-related QOL is warranted. Item analysis of the V-RQOL and the VDCQ may illustrate coping strategies and functional impairments and provide further information regarding highly variable communicative participation among individuals with SD.

The extrinsic risk and its association with neural alterations in spasmodic dysphonia

INTRODUCTION

Spasmodic dysphonia (SD) is an isolated focal dystonia characterized by laryngeal spasms during voluntary voice production. Environmental factors have been assumed to play a role in SD pathophysiology; however, the exact extrinsic risk factors and their association with neural alterations remain unknown.

METHODS

A total of 186 SD patients and 85 healthy controls completed a structured 177-question survey, consisting of questions on general biographical information, medical history, symptomatology of dystonia. Data were imputed in a stepwise regression model to identify extrinsic risk factors for SD. In addition, functional MRI data from a subset of this cohort were analyzed to determine brain activation abnormalities associated with the SD extrinsic risk.

RESULTS

We found that (1) recurrent upper respiratory infections, gastroesophageal reflux, and neck trauma, all of which influence sensory feedback from the larynx, represent extrinsic risk factors, likely triggering the manifestation of SD symptoms, and (2) neural alterations in the regions necessary for sensorimotor preparation and integration are influenced by an extrinsic risk in susceptible individuals.

CONCLUSIONS

These findings provide evidence for the extrinsic risk in SD development and demonstrate the link with alterations in the sensorimotor preparatory network that collectively contribute to the multifactorial pathophysiology of SD.

OnabotulinumtoxinA for adductor spasmodic dysphonia (ADSD): Functional results and the role of dosage

OBJECTIVE

To report the results of functional outcome, dose trend and relationship between onabotulinumtoxinA (onabotA) dosage and the severity of disease or time between therapy sessions in patients affected by adductor spasmodic dysphonia (ADSD).

PATIENTS AND METHODS

Thirty-two patients underwent 193 EMG-guided intracordal injections of a starting dose of 2 MU of onabotA. At enrollment, each subject was administered the VHI. The response was evaluated using a subjective rating scale (0-100% of normal phonation).

RESULTS

The quality of voice improved significantly after 1 month and stabilized by 3 months. The percentage of normal voice improved 33.34 ± 11.5% (min 26 - max 68). The functional gain was significantly worse in patients presenting with ADSD associated with dystonias in other body regions (31% vs 45% - p < 0.05). The mean dose employed was 3.64 MU (min 1 - max 6) with a trend of increasing dosages up to the 5th treatment after which the doses stabilized over time. The pre-treatment VHI showed a weakly positive correlation with the cumulative dose at the 5th and 10th injections. Benefit duration and the mean between treatment interval were 103 and 136 days respectively. The correlation between dose and inter-injection time is weakly negative (r = -0.22, p < 0.05), however, this is influenced predominantly by the first-to-second injection. After this initial treatment effect, the correlation becomes weakly positive (r = 0.12).

CONCLUSIONS

Our data confirm the efficacy of onabotA to improve the quality of voice in cases of ADSD. The trial period for optimal dosage lasted up to a mean of five injections. The dosage of onabotA impacted the length of response and was influenced by the severity of ADSD. Finally the efficacy of onabotA did not change significantly after repeated administrations.

Phenomenology, genetics, and CNS network abnormalities in laryngeal dystonia: A 30-year experience

OBJECTIVE

Laryngeal dystonia (LD) is a functionally specific disorder of the afferent-efferent motor coordination system producing action-induced muscle contraction with a varied phenomenology. This report of long-term studies aims to review and better define the phenomenology and central nervous system abnormalities of this disorder and improve diagnosis and treatment.

METHODS

Our studies categorized over 1,400 patients diagnosed with LD over the past 33 years, including demographic and medical history records and their phenomenological presentations. Patients were grouped on clinical phenotype (adductor or abductor) and genotype (sporadic and familial) and with DNA analysis and functional magnetic resonance imaging (fMRI) to investigate brain organization differences and characterize neural markers for genotype/phenotype categorization. A number of patients with alcohol-sensitive dystonia were also studied.

RESULTS

A spectrum of LD phenomena evolved: adductor, abductor, mixed, singer's, dystonic tremor, and adductor respiratory dystonia. Patients were genetically screened for DYT (dystonia) 1, DYT4, DYT6, and DYT25 (GNAL)-and several were positive. The functional MRI studies showed distinct alterations within the sensorimotor network, and the LD patients with a family history had distinct cortical and cerebellar abnormalities. A linear discriminant analysis of fMRI findings showed a 71% accuracy in characterizing LD from normal and in characterizing adductor from abductor forms.

CONCLUSION

Continuous studies of LD patients over 30 years has led to an improved understanding of the phenomenological characteristics of this neurological disorder. Genetic and fMRI studies have better characterized the disorder and raise the possibility of making objective rather than subjective diagnoses, potentially leading to new therapeutic approaches. Laryngoscope, 128:S1-S9, 2018.

Spasmodic Dysphonia: A Review. Part 1: Pathogenic Factors

Objective The purpose of this review is to describe the recent advances in identifying possible factors involved in the pathogenesis of spasmodic dysphonia. Spasmodic dysphonia is a task-specific focal laryngeal dystonia characterized by irregular and uncontrolled voice breaks. Pathogenesis of the disorder is poorly understood. Data Sources PubMed, Google Scholar, and Cochrane Library. Review Methods The data sources were searched using the following search terms: ( spasmodic dysphonia or laryngeal dystonia) and ( etiology, aetiology, diagnosis, pathogenesis, or pathophysiology). Conclusions Several potential etiological factors have been proposed by epidemiological, genetic, and neuropathological studies. Spasmodic dysphonia is a rare disorder primarily affecting females beginning in their 40s. Vocal tremor co-occurs in 30% to 60%. Large cohort studies identified risk factors such as a family history of neurological disorders including dystonia and tremor, recent viral illness, and heavy voice use. As none are rare events, a complex interactive process may contribute to pathogenesis in a small proportion of those at risk. Consequences to pathogenesis are neurological processes found in spasmodic dysphonia: loss of cortical inhibition, sensory processing disturbances, and neuroanatomical and physiological differences in the laryngeal motor control system. Implications for Practice Diagnosis of spasmodic dysphonia usually includes speech and laryngoscopic assessment. However, as diagnosis is sometimes problematic, measurement of neurophysiological abnormalities may contribute useful adjuncts for the diagnosis of spasmodic dysphonia in the future.

The Mayo Clinic Arizona Spasmodic Dysphonia Experience

Objective:

Analyze demographic data collected over a 25-year experience of 718 patients with spasmodic dysphonia (SD) who have been treated with botulinum toxin-A (BoNT-A) and compare our data with previously published studies.

Methods:

Seven hundred eighteen patients with SD were treated with 6621 BoNT-A injections at Mayo Clinic Arizona between 1989 and 2014. All patients were treated by the same physician team. Background demographic data for each patient were recorded.

Results:

Of 718 patients, 557 patients were female (77.6%). Six hundred sixty of 718 (91.8%) patients had adductor SD (AdSD), and 58 of 718 (8.1%) patients had abductor SD (AbSD). Average age of onset was 51 years. Of 718 patients, 378 (52.6%) had vocal tremor (VT); VT was present in 54.4% of AdSD patients and 32.1% of AbSD patients. Thirty-seven of 718 (5.2%) patients had other dystonias, including cervical dystonia (2.3%), blepharospasm (1.4%), limb dystonia (1.1%), and oromandibular dystonia (0.3%). A positive family history of SD was present in only 6 of 718 patients (0.8%) and of other dystonias in 11 of 718 patients (1.5%).

Conclusions:

Spasmodic dysphonia is a chronic and potentially disabling focal laryngeal dystonia. The Mayo Clinic Arizona SD experience compares to prior reports and reveals a female preponderance, onset in middle age, infrequent hereditary pattern, high co-occurrence of VT, and low co-occurrence of other dystonias.

Spasmodic dysphonia: let's look at that again

G. Paul Moore influenced the study of spasmodic dysphonia (SD) with his 1960 publication that examined the neurological, medical, and vocal fold behavior in a group of patients with adductor spasmodic dysphonia (ADSD). This review of advances in the diagnosis and treatment of SD follows a time line of research that can be traced in part to the early work of Moore et al. This article reviews the research in ADSD over the past 50 plus years. The capstone events that brought SD to its present day level of management by laryngologists and speech-language pathologists are highlighted. A look to the future to understand more of the disorder is offered for this debilitating disorder.

Epidemiologic Advances in Spasmodic Dysphonia

Recently research offers new insights into the pathogenesis, pathophysiology, and socioemotional implications of spasmodic dysphonia (SD). Among these advances are epidemiologic studies clarifying (1) SD onset and course, (2) SD risk factors, and (3) the relationships among SD course, treatment, and psychosocial impact. In this paper, I will provide a summary of recent epidemiologic and socioemotional research advances involving the onset, course, risk factors, and psychosocial impact of SD.