Spasmodic Dysphonia: A Review. Part 1: Pathogenic Factors

Laryngeal dystonia and vocal tremor response to botulinum toxin injection

PURPOSE

The main objective of this study was to compare laryngeal dystonia (LD) and vocal tremor's (VT) response to botulinum toxin injection.

METHODS

Retrospective study including every patient with LD or VT injected with botulinum toxin guided by electromyography, from January 1, 2010, to September 30, 2022, at a tertiary hospital centre. Improvement was assessed with the VHI-10, grade of dysphonia in a visual analogue scale (VAS; 0-10), GRBAS(I) scale (0-3) and maximum phonation time (MPT).

RESULTS

A total of 77 patients were included, 44 patients with LD and 33 with VT. There were no differences between groups on pre-treatment VHI-10, grade of dysphonia in the VAS, MPT and G, R, B, A and I at diagnosis (p > 0.05). S was significantly higher in patients with LD (p < 0.001). After the first injection, both groups showed an increase in the grade of dysphonia on the VAS and a decrease in VHI-10, G, S and I (p < 0.05), with a higher variation in the VAS and S parameters in the LD group compared to VT (p < 0.05). In the 54 patients that performed two or more injections, G, S and I had a higher decrease in patients with LD when compared to patients with VT (p < 0.05).

CONCLUSION

BTX injection was successful in improving the VHI-10, grade of dysphonia on the VAS and G, S and I in the GRBAS-I scale for both DT and VT. LD seems to have a better response to BTX in comparison to VT.

Harnessing machine learning in diagnosing complex hoarseness cases

PURPOSE

Traditional vocal fold pathology recognition typically requires expertise of laryngologists and advanced instruments, primarily through direct visualization. This study aims to augment this conventional paradigm by introducing a parallel diagnostic procedure. Our objective is to harness a machine-learning algorithm designed to discern intricate patterns within patients' voice recordings to distinguish not only between healthy and hoarse voices but also among various specific disorders.

MATERIALS AND METHODS

We employed a machine-learning algorithm, utilizing transfer learning on the HuBERT model with Saarbruecken Voice Database samples. The study was conducted in two stages: a binary classifier distinguishes healthy and hoarse voices, while a subsequent multi-class classifier identifies specific voice disorders. Data from 2103 sessions, including over 25,000 components, representing diverse pathologies and healthy individuals, was analyzed. The models were trained, validated, and tested with a focus on robustness and accuracy in diagnosis.

RESULTS

The binary classifier achieved 82 % accuracy in distinguishing healthy from pathological voices. The multi-class algorithm which aims to identify specific laryngeal disorders obtained the highest accuracy (>93 %) for Laryngeal Dystonia. Noteworthy is the persistent challenge posed by Laryngeal Dystonia, a condition lacking a definitive diagnostic modality.

CONCLUSIONS

Our findings demonstrate the feasibility of utilizing machine-learning algorithms to process voice samples, categorizing them into distinct pathologies. This approach holds potential for enhance patient triage, streamline diagnostics, and elevate overall patient care. Particularly valuable for challenging diagnoses, such as Laryngeal Dystonia, this method underscores the transformative role of machine learning in optimizing healthcare practices.

Central Mechanisms and Pathophysiology of Laryngeal Dystonia: An Up-to-Date Review

OBJECTIVE

Laryngeal dystonia (LD), previously termed spasmodic dysphonia, is an isolated focal dystonia that involves involuntary, uncontrolled contractions of the laryngeal muscles during speech. It is a severely disabling condition affecting patients' work and social lives through prevention of normal speech production. Our understanding of the pathophysiology of LD and available therapeutic options are currently limited. The aim of this short review is to provide an up-to-date summary of what is known about the central mechanisms and the pathophysiology of LD.

METHODS

A systematic review of the literature was performed searching Embase, CINHAL, Medline, and Cochrane with the cover period January 1990-October 2023 with a search strategy (("Laryngeal dystonia" OR "Spasmodic dysphonia") AND ("Central Mechanism" OR "Pathophysiology")). Original studies involving LD patients that discussed central mechanisms and/or pathophysiology of LD were chosen.

RESULTS

Two hundred twenty-six articles were identified of which 27 articles were included to formulate this systematic review following the screening inclusion and exclusion criteria. LD is a central neurological disorder involving a multiregional altered neural network. Affected neural circuits not only involve the motor control circuit, but also the feedforward, and the feedback circuits of the normal speech production neural network, involving higher-order planning, somatosensory perception and integration regions of the brain.

CONCLUSION

Speech production is a complex process, and LD is a central neurological disorder involving multiregional neural network connectivity alteration reflecting this. Neuromodulation targeting the central nervous system could therefore be considered and explored as a new potential therapeutic option for LD in the future, and should assist in elucidating the underlying central mechanisms responsible for causing the condition.

Transcriptome Analysis of Left Versus Right Intrinsic Laryngeal Muscles Associated with Innervation

OBJECTIVES/HYPOTHESIS

Recurrent laryngeal nerve injury diagnosed as idiopathic or due to short-term surgery-related intubation exhibits a higher incidence of left-sided paralysis. While this is often attributed to nerve length, it is hypothesized there are asymmetric differences in the expression of genes related to neuromuscular function that may impact reinnervation and contribute to this laterality phenomenon. To test this hypothesis, this study analyzes the transcriptome profiles of the intrinsic laryngeal muscles (ILMs), comparing gene expression in the left versus right, with particular attention to genetic pathways associated with neuromuscular function.

STUDY DESIGN

Laboratory experiment.

METHODS

RNA was extracted from the left and right sides of the rat posterior cricoarytenoid (PCA), lateral thyroarytenoid (LTA), and medial thyroarytenoid (MTA), respectively. After high-throughput RNA-Sequencing, 88 samples were organized into 12 datasets according to their age (P15/adult), sex (male/female), and muscle type (PCA/LTA/MTA). A comprehensive bioinformatics analysis was conducted to compare the left-right ILMs across different conditions.

RESULTS

A total of 774 differentially expressed genes were identified across the 12 experimental groups, revealing age, sex, and muscle-specific differences between the left versus right ILMs. Enrichment analysis of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways implicated several genes with a left-right laryngeal muscle asymmetry. These genes are associated with neuronal and muscular physiology, immune/inflammatory response, and hormone control.

CONCLUSION

Bioinformatics analysis confirmed divergent transcriptome profiles between the left-right ILMs. This preliminary study identifies putative gene targets that will characterize ILM laterality.

LEVEL OF EVIDENCE

N/A Laryngoscope, 134:3741-3753, 2024.

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.

Demographics and Clinical Characteristics Associated with the Spread of New-Onset Laryngeal Dystonia

OBJECTIVES

Adult-onset idiopathic laryngeal dystonia (LD) can be associated with the risk of spread to muscles in the body. Subjects with extralaryngeal onset of dystonia have exhibited spread to the larynx. Previous studies analyze the spread of other dystonias but emphasis has not been placed on LD. The objective was to identify demographic and clinical factors contributing to the spread of dystonia to and from the larynx.

METHODS

Data were obtained from the Dystonia Coalition (DC)-patients from 49 international clinical centers. Clinical and demographic data was taken from 143 out of 409 patients with diagnosed LD. Patient criteria included adult-onset LD diagnosed on exam with no co-morbid neurologic conditions and no dystonia in other locations.

RESULTS

Among the 143 patients, 94 (65.7%) patients were diagnosed with focal laryngeal onset, with the remainder having extralaryngeal onset. Family history and age at study were statistically significant indicators of a patient developing laryngeal versus extralaryngeal onset of dystonia. Among the laryngeal onset group, 21 cases (22.3%) had an average time of 5.81 ± 5.79 years to spread from diagnosis, most commonly to neck (61.9%). Among extralaryngeal onset patients, mean time of larynx spread was 7.92 ± 7.737 years, most commonly to neck (22.7%).

CONCLUSIONS

Our data indicates approximately a quarter of patients with laryngeal-onset dystonia will exhibit spread. There were no demographic or clinical factors that were statistically predictive of the likelihood of spread from larynx. Patients with dystonia elsewhere in the body should be counseled on the possibility of spread to larynx, and vice versa.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:2295-2299, 2024.

Comparison of the efficacy and adverse effects of unilateral or bilateral botulinum toxin injections for adductor spasmodic dysphonia: a systematic review and meta-analysis

PURPOSE

This study aims to aggregate and analyze existing clinical evidence to compare the efficacy and adverse effects of unilateral or bilateral botulinum toxin injections for the treatment of adductor spasmodic dysphonia (ADSD).

METHODS

Reports from non-randomized controlled trials and cohort studies pertaining to the efficacy and adverse effects of unilateral and bilateral botulinum toxin injections for ADSD were identified and retrieved from four electronic databases from inception to July 2023. The meta-analysis employed fixed or random effects models to assess pooled relative risks (RR), mean differences (MDs), and standard mean differences (SMDs) with their corresponding 95% confidence intervals (CIs).

RESULTS

We included two non-randomized controlled trials and seven cohort studies comprising 854 total patients. Meta-analysis of the included studies showed that bilateral botulinum toxin injections associated with a longer duration of vocal improvement (MD =  - 2.89, 95% CI - 3.13 to - 2.65, I2 = 0%, P < 0.00001). However, bilateral botulinum toxin injections associated with an increase in adverse effects, including a longer duration of breathy voice quality (SMD =  - 0.51, 95% CI - 0.79 to - 0.22, I2 = 35%, P = 0.0005) and a higher occurrence of swallowing difficulties (RR = 0.46, 95% CI 0.35 to 0.11, I2 = 0%, P < 0.00001).

CONCLUSION

Bilateral botulinum toxin injections for ADSD showed a longer duration of vocal improvement, a longer breathy voice duration and a higher dysphagia occurrence and duration than unilateral injections.

Improved vocal quality and decreased vocal effort after botulinum toxin treatment for laryngeal dystonia

OBJECTIVES

Laryngeal dystonia (LD) is characterized by irregular and involuntary task-specific spasms of the intrinsic laryngeal muscles. There is no curative treatment for it, however, laryngeal botulinum neurotoxin injections (BoNT-I) are considered the standard of care therapy. This study aims to characterize the population of LD patients and to assess the results of laryngeal BoNT-I.

METHODS

A Retrospective cohort study was conducted. Medical records were reviewed for all the patients with LD diagnosis seen in the Voice Unit of the Red de Salud UCChristus between January 2013 and October 2021. Biodemographic, clinical and treatment data were collected. Additionally, a telephonic survey was completed by the patients that underwent laryngeal BoNT-I, including self-reported voice outcomes and Voice Handicap Index 10 (VHI-10).

RESULTS

Of the 34 patients with LD included in the study, 23 received a total of 93 laryngeal BoNT-I and 19 completed the telephone survey. The majority (97%) of the injections corresponded to patients with adductor LD and 3% to abductor LD. Patients received a median of 3 (1-17) injections, with a more frequent cricothyroid approach (94.4%), while the thyrohyoid approach accounted for 5.6% of cases. Most injections were bilateral (96.8%). A significant improvement in the vocal quality and effort was noted after the last injection and the overall BoNT-I treatment (P < 0.001). Similarly, the VHI-10 score improved from a median of 31 (7-40) to 2 (0-19) (P < 0.001) after the last injection. A post-treatment breathy voice was reported in 95% of patients, and dysphagia to liquids and solids in 68% and 21%, respectively.

CONCLUSIONS

Laryngeal BoNT-I is an effective treatment for LD, achieving an improvement in self-reported vocal quality and VHI-10 scores, and a reduction of the self-reported vocal effort. Adverse effects are mild in the majority of cases, constituting a safe and effective therapy for these patients.

Laryngeal Dystonia, Dystonic Tremor and Vocal Tremor: Three Different Entities

OBJECTIVE

The main objective of this study was to compare the demographic and clinical characteristics of patients with laryngeal dystonia (LD), dystonic tremor (DT), and vocal tremor (VT).

STUDY DESIGN

This was a retrospective longitudinal study.

METHODS

Data analysis from every patient diagnosed with LD, DT, or VT from January 1, 2010, to September 30, 2022, at a tertiary hospital center. Differential diagnosis between these entities was clinical (clinical history, voice assessment, and endoscopy) and confirmed by laryngeal electromyography.

RESULTS

A total of 87 patients were included in this study: 50 patients with LD, 23 with DT, and 14 with VT. Age at diagnosis was significantly lower in patients with LD, with a mean age of 56.2 years when compared to DT (67.6 years; P = 0.002) and VT (70.5 years; P = 0.009). Furthermore, VT had a higher female prevalence (92.9%) when compared with LD (52%; P = 0.011). LD was mainly adductor, with only two patients diagnosed with abductor LD, and DT was adductor in every case. Tremor direction in patients with VT was horizontal in 50% and mixed (horizontal + vertical) in 50%, while in DT was mixed in 65.2% and horizontal in 34.8%. LD was more commonly an isolated laryngeal movement disorder (78%) when compared to DT (47.8%; P = 0.015) or VT (28.5%; P < 0.001), which were more often secondary to generalized neurological disorders. There were no differences between groups on Voice Handicap Index-10, self-reported grade of dysphonia on a visual analogic scale (0-10), maximum phonation time, and G, R, B, A, and I in the GRBAS-I scale at diagnosis (P > 0.05). S was significantly higher in LD when compared to VT (P < 0.001) and nonsignificantly higher than in DT (P = 0.075).

CONCLUSIONS

LD, DT, and VT seem to be different entities with different demographics and clinical characteristics.

Self-perceived affective, behavioral, and cognitive reactions associated with voice use in people with Parkinson's disease: a pilot study

PURPOSE

This study aimed to compare the affective, behavioral, and cognitive reactions related to vocal function in people with Parkinson's disease (PWPD) and healthy controls using the Behavior Assessment Battery - Voice (BAB-Voice). The test's internal consistency was also described.

METHODS

31 PWPD and 19 healthy controls were recruited from September 2020 to March 2021. Participants completed four BAB-Voice subtests: Speech Situation Checklist - Emotional Reaction (SSC-ER), the Speech Situation Checklist - Speech Disruption (SSC-SD), Behavior Checklist (BCL), and Communication Attitude Test for Adults (BigCAT), describing the experienced negative emotional reaction, voice disruptions, coping behaviors, and negative attitude regarding communication respectively. Subtest scores were calculated and analyzed.

RESULTS

The scores of the PWPD were significantly different from those of the controls (Pillai's Trace = 0.344, F[4] = 5.508, p = .001, ηp2 = .344): PWPD showed more negative emotions and voice problems, more coping behaviors, and more negative speech-related attitude compared to healthy controls. All subtests showed excellent internal consistency.

CONCLUSIONS

The BAB-Voice proved a tool with a good internal consistency that measured different psychosocial reactions in PWPD versus controls. PWPD exhibited significantly more negative emotions and voice problems in specific speech situations, more coping behaviors, and a more negative speech-related attitude. The specificity of information obtained from the BAB-Voice may aid in improving the treatment planning of voice disorders in PWPD.

Spasmodic dysphonia: introductory phonetic analyses

Adductor spasmodic dysphonia (ADSD) is a neurological dystonia characterised by involuntary adductor spasms of the larynx during speech. Spasm frequency is often reported to increase during syllables that begin with voiced speech sounds, especially glottal stops. Because of its underlying physical and acoustic complexities, the voicing contrast in American English (AE) appears unlikely to interact consistently with a singular physical phenomenon like laryngeal spasm. This retrospective study investigated additional phonetic contrasts and their relationship to spasm frequency. Standardised, 144-word recordings of 36 participants with adductor spasmodic dysphonia were analysed. Productions were coded for rater-perceived syllable stress, voiced/voiceless onset, vowel/consonant onset, and word-onset place and manner of production. Phonetic contexts were compared using independent sample t-tests and Kruskal-Wallis statistics. Contexts in which spasm varied significantly included stressed/unstressed syllables, content/function words, and multisyllabic/monosyllabic words. Study results reaffirm the clinical usefulness of standardised ADSD/ABSD sentences during differential diagnosis but conflict with previous studies that report a connection between ADSD spasm and phoneme voicing.

Abnormal Laryngopharyngeal Sensation in Adductor Laryngeal Dystonia Compared to Healthy Controls

BACKGROUND/OBJECTIVES

Laryngeal sensory abnormality has been implicated as a component of adductor laryngeal dystonia (AdLD). The study objective was to assess laryngopharyngeal sensation in AdLD utilizing a calibrated, tactile aesthesiometer to deliver differential stimuli to lateral pyriform sinus (LPS), aryepiglottic fold (AEF), and false vocal fold (FVF).

METHODS

Patients with known Botox-responsive AdLD underwent sensory testing using a previously-validated methodology involving calibrated tactile stimuli (6-0, 5-0, 4.5-0, 4-0 nylon monofilaments). Laryngeal adductor reflex (LAR) and participant-rated perceptual strength of stimulI were evaluated. Responses were compared to normative controls (n = 33). Two-samples, Mann-Whitney and Fisher exact tests compared mean strength ratings and LAR between AdLD and control groups. Mixed-effects logistic regression and linear models assessed association of filament size, stimulus site, age, sex, and LD status on LAR and perceptual strength rating respectively.

RESULTS

Thirteen AdLD patients (nine women, mean age 60+/-15 years) completed testing. Average LAR response rates were higher amongst all filament sizes in AdLD versus controls at LPS (56.3% vs. 35.7%) and AEF (96.1% vs. 70.2%) with comparable rates at FVF (90.2% vs. 91.7%). AdLD had 3.3 times the odds of observed LAR compared to controls (p = 0.005), but differences in subjective detection of stimuli, perceptual strength ratings, and cough/gag rates were insignificant on multivariate modeling (p > 0.05).

CONCLUSIONS

This is the first study to objectively assess laryngopharyngeal sensation in AdLD. Findings demonstrated increased laryngopharyngeal sensation in AdLD compared to controls. The identification of increased laryngeal hypersensitivity in these patients may improve understanding of AdLD pathophysiology and identify future targets for intervention.

LEVEL OF EVIDENCE

2 Laryngoscope, 133:2271-2278, 2023.

Significance of age and sex in botulinum neurotoxin dosing for adductor spasmodic dysphonia

Objectives

This study aims to analyze the impact of age and sex on botulinum neurotoxin (BoNT-A) dosing and outcomes in adductor spasmodic dysphonia (AdSD).

Methods

A database review of all spasmodic dysphonia patients treated with BoNT from 1989 to 2018 at the Mayo Clinic in Arizona was performed. Only patients who had received ≥4 injections of BoNT-A for AdSD were included. Patients were divided into two cohorts to analyze age, with an age of first treatment cutoff of 60 years. Patients were divided into male and female cohorts to analyze sex.

Results

The final analysis included 398 patients. The mean dose of BoNT-A per treatment was significantly higher in the younger cohort (4.4 vs. 3.9 units, p = 0.048). The mean maximal benefit was similar (72% vs. 70%, p = 0.48); however, the mean length of benefit was significantly shorter in younger patients (3.0 vs. 3.6 months, p < 0.01). The mean BoNT-A dose was significantly higher in the female cohort (4.2 vs. 3.6 units, p = 0.02). The mean maximal benefit was similar (69% vs. 75%, p = 0.58), as was the mean length of benefit (3.2 vs. 3.5 months, p = 0.11).

Conclusions

This study suggests that age and sex influence BoNT-A dosing and outcomes in AdSD.

Comparison of Outcome Measures (Subjective, Objective, and Patient-Based) in Laryngeal Dystonia Treatment With Botulinum Toxin A Injection

BACKGROUND

Outcome assessment in laryngeal dystonia is hindered by lack of consensus on a core set of outcome measures to quantify treatment effect and disease severity on quality of life. Potential outcome measure domains include objective voice, clinician reported, and patient reported outcome measures (PROMs) for determining treatment success and longitudinal disease tracking. We aim to determine correlations between a selections of outcome measure tools following Botulinum toxin injection.

METHODS

A selection of instruments were administered to assess adductor laryngeal dystonia patient outcomes before and after Botulinum toxin injection. Voice samples recorded using a cellular telephone application were used for objective acoustic measures (CPPS, acoustic voice quality index) and speech language pathologist perceptual analysis (CAPE-V). Additionally, patients completed a PROMs battery consisting of the Voice Handicap Index-10, Communicative Participation Item Bank-10, OMNI-Vocal Effort Scale, 3 visual analog scale (VAS) questions. Changes in these outcome measures pre-post treatment were compared between each other and with a global rating of change questionnaire (GRCQ) using Spearman's rank correlation coefficients.

RESULTS

Twenty six patients (20 female, mean age 57.7 years) participated. Using an anchor based GRCQ, patients reported Botox efficacy was the only outcome measure found to have significant correlation (r = 0.54, P = 0.022); all other outcome measures did not meet statistically significant correlation. Amongst the selected outcome tools, several moderate-strong correlations were identified, largely for outcome measures within the same domain. Most notable were correlations between the patient reported OMNI-VES and VAS questions (r > 0.68, P < 0.05), clinician CAPE-V strain and overall severity (r = 0.900, P < 0.001), and acoustic voice quality index with sustained vowel CPPs (r = -0.797, P = 0.002).

CONCLUSION

Correlation between outcome measures instruments used for patients with adductor laryngeal dystonia requires further attention. Weak correlations with an anchor based GRCQ were found for this study's selected outcome instruments. A select number of correlations were found between outcome instruments within each of the individual outcome measure domains (patient perception, clinical perception, objective acoustics), but there was largely a lack of correlation found for instruments between these three separate domains.

Machine Learning Assessment of Spasmodic Dysphonia Based on Acoustical and Perceptual Parameters

Adductor spasmodic dysphonia is a type of adult-onset focal dystonia characterized by involuntary spasms of laryngeal muscles. This paper applied machine learning techniques for the severity assessment of spasmodic dysphonia. To this aim, 7 perceptual indices and 48 acoustical parameters were estimated from the Italian word /a’jwɔle/ emitted by 28 female patients, manually segmented from a standardized sentence and used as features in two classification experiments. Subjects were divided into three severity classes (mild, moderate, severe) on the basis of the G (grade) score of the GRB scale. The first aim was that of finding relationships between perceptual and objective measures with the Local Interpretable Model-Agnostic Explanations method. Then, the development of a diagnostic tool for adductor spasmodic dysphonia severity assessment was investigated. Reliable relationships between G; R (Roughness); B (Breathiness); Spasmodicity; and the acoustical parameters: voiced percentage, F2 median, and F1 median were found. After data scaling, Bayesian hyperparameter optimization, and leave-one-out cross-validation, a k-nearest neighbors model provided 89% accuracy in distinguishing patients among the three severity classes. The proposed methods highlighted the best acoustical parameters that could be used jointly with GRB indices to support the perceptual evaluation of spasmodic dysphonia and provide a tool to help severity assessment of spasmodic dysphonia.

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.

Botulinum Neurotoxin Therapy in the Clinical Management of Laryngeal Dystonia

Laryngeal dystonia (LD), or spasmodic dysphonia (SD), is a chronic, task-specific, focal movement disorder affecting the larynx. It interferes primarily with the essential functions of phonation and speech. LD affects patients' ability to communicate effectively and significantly diminishes their quality of life. Botulinum neurotoxin was first used as a therapeutic agent in the treatment of LD four decades ago and remains the standard of care for the treatment of LD. This article provides an overview of the clinical application of botulinum neurotoxin in the management of LD, focusing on the classification for this disorder, its pathophysiology, clinical assessment and diagnosis, the role of laryngeal electromyography and a summary of therapeutic injection techniques, including a comprehensive description of various procedural approaches, recommendations for injection sites and dosage considerations.

Correlating Perceptual Voice Quality in Adductor Spasmodic Dysphonia With Computer Vision Assessment of Glottal Geometry Dynamics

PURPOSE

This study examined the relationship between voice quality and glottal geometry dynamics in patients with adductor spasmodic dysphonia (ADSD).

METHOD

An objective computer vision and machine learning system was developed to extract glottal geometry dynamics from nasolaryngoscopic video recordings for 78 patients with ADSD. General regression models were used to examine the relationship between overall voice quality and 15 variables that capture glottal geometry dynamics derived from the computer vision system. Two experts in ADSD independently rated voice quality for two separate voice tasks for every patient, yielding four different voice quality rating models.

RESULTS

All four of the regression models exhibited positive correlations with clinical assessments of voice quality (R ²s = .30-.34, Spearman rho = .55-.61, all with p < .001). Seven to 10 variables were included in each model. There was high overlap in the variables included between the four models, and the sign of the correlation with voice quality was consistent for each variable across all four regression models.

CONCLUSION

We found specific glottal geometry dynamics that correspond to voice quality in ADSD.

Acupuncture and the Otolaryngology-Head & Neck Surgery Patient

The use of acupuncture among US adults was estimated at nearly 40% in 2012. A study from the United Kingdom in 2010 found 60% of otolaryngologic patients had used a form of complementary or integrative medicine, with greater than a third in the last year alone. Acupuncture, a therapeutic modality of traditional Chinese medicine, has been used for millennia in Asian countries. Within otolaryngology, acupuncture has been used for a variety of conditions encompassing otology, laryngology, rhinology, and pediatrics. Herein, we review the current literature on the applications of acupuncture for a range of ENT disorders.

Transoral radiofrequency of the terminal branches of the recurrent nerve in the treatment of adductor spasmodic dysphonia: our experience over 11 patients

PURPOSE

Spasmodic dysphonia (SD) or laryngeal dystonia is as a rare vocal disorder characterized by involuntary action-induced endolaryngeal contraction. In the last decade, botulin toxin injection has become the standard treatment in adductor spasmodic dysphonia necessitating repetitive injections. The purpose of this study is to analyze retrospectively data from patients treated with the minimal-invasive transoral radiofrequency-induced thermotherapy (RFITT) of the terminal branches of the recurrent nerve.

METHODS

Between 2009 and 2015, 11 patients (six females and five males aged from 32 to 91 years) with adductor SD were treated with RFITT. Pre-operative and post-operative vocal assessments (VHI-30, GRBASI, and acoustic-aerodynamics measurements), number of surgical revisions, delay between procedures, and post-operative complications were recorded. Statistical analyses were carried out on the first vocal assessment performed 2-8 weeks after the first procedure.

RESULTS

Based on available data from ten patients, voice handicap index (VHI) showed improvement with a mean value of -17.7 points (p-value (pval) = 0.014, adjusted p-value (adj pval) = 0.21); instability has also revealed improvement in six patients (pval = 0.05, adj pval = 0.31). Four patients underwent only one procedure including one patient showing still long-term beneficial results after 5 years of follow-up. Other patients required one to three new procedures with an average time between procedures of 15.3 months. Over 24 surgeries performed on a total of 11 patients, one definitive treatment-related severe adverse event was reported.

CONCLUSION

Thanks to long-lasting effect, repetitive treatments are less frequent compared to botulin toxin therapy. In our opinion, RFITT is a promising alternative to botulin toxin as a second-step procedure in case of toxin resistance or patient's lack of compliance.

Globus Pallidus Interna and Ventral Intermediate Nucleus of the Thalamus Deep Brain Stimulation for Adductor Laryngeal Dystonia: a Case Report of Blinded Analyses of Objective Voice Outcomes in 2 Patients

BACKGROUND

Adductor laryngeal dystonia (ADLD) is a substantially debilitating focal progressive neurological voice disorder. Current standard of care is symptomatic treatment with repeated injections of botulinum toxin into specific intrinsic laryngeal muscles with extremely variable and temporary benefits. We report the use of bilateral deep brain stimulation (DBS) of globus pallidus (GPi) for long-term improvement of ADLD voice symptoms.

OBJECTIVE

To investigate the effects of bilateral DBS of the GPi and ventral intermediate nucleus (VIM) of the thalamus on vocal function in 2 patients with ADLD associated with voice and hand tremor.

METHODS

Blinded objective and quantitative analyses of voice were conducted before and after treatment in 2 female patients (70 and 69 years). Paired t-tests were conducted to compare voice measurements pre-GPi and post-GPi and VIM-DBS. A 2-way analysis of variance was conducted to determine the interaction between target (GPi/VIM) and time (pre/post) for each voice measure.

RESULTS

Although the follow-up period differed between patients, the GPi-DBS implanted patient had notable improvement in vowel voicing (%), extent of tremor intensity (%), and overall speech intelligibility (%), compared with preoperative status. GPi-DBS also resulted in significant improvement in cepstral peak prominence (dB). VIM-DBS resulted in a significantly greater change in the tremor rate (Hz).

CONCLUSION

Changes in phonatory function provide preliminary support for the use of bilateral GPi-DBS for treatment of ADLD and bilateral VIM-DBS for vocal tremor predominant ADLD. Future studies with larger sample sizes and standardized follow-up periods are needed to better assess the role of DBS for ADLD.

Second hit hypothesis in dystonia: Dysfunctional cross talk between neuroplasticity and environment?

One of the great mysteries in dystonia pathophysiology is the role of environmental factors in disease onset and development. Progress has been made in defining the genetic components of dystonic syndromes, still the mechanisms behind the discrepant relationship between dystonic genotype and phenotype remain largely unclear. Within this review, the preclinical and clinical evidence for environmental stressors as disease modifiers in dystonia pathogenesis are summarized and critically evaluated. The potential role of extragenetic factors is discussed in monogenic as well as adult-onset isolated dystonia. The available clinical evidence for a "second hit" is analyzed in light of the reduced penetrance of monogenic dystonic syndromes and put into context with evidence from animal and cellular models. The contradictory studies on adult-onset dystonia are discussed in detail and backed up by evidence from animal models. Taken together, there is clear evidence of a gene-environment interaction in dystonia, which should be considered in the continued quest to unravel dystonia pathophysiology.

Deep Learning Application for Vocal Fold Disease Prediction Through Voice Recognition: Preliminary Development Study

Background

Dysphonia influences the quality of life by interfering with communication. However, a laryngoscopic examination is expensive and not readily accessible in primary care units. Experienced laryngologists are required to achieve an accurate diagnosis.

Objective

This study sought to detect various vocal fold diseases through pathological voice recognition using artificial intelligence.

Methods

We collected 189 normal voice samples and 552 samples of individuals with voice disorders, including vocal atrophy (n=224), unilateral vocal paralysis (n=50), organic vocal fold lesions (n=248), and adductor spasmodic dysphonia (n=30). The 741 samples were divided into 2 sets: 593 samples as the training set and 148 samples as the testing set. A convolutional neural network approach was applied to train the model, and findings were compared with those of human specialists.

Results

The convolutional neural network model achieved a sensitivity of 0.66, a specificity of 0.91, and an overall accuracy of 66.9% for distinguishing normal voice, vocal atrophy, unilateral vocal paralysis, organic vocal fold lesions, and adductor spasmodic dysphonia. Compared with the accuracy of human specialists, the overall accuracy rates were 60.1% and 56.1% for the 2 laryngologists and 51.4% and 43.2% for the 2 general ear, nose, and throat doctors.

Conclusions

Voice alone could be used for common vocal fold disease recognition through a deep learning approach after training with our Mandarin pathological voice database. This approach involving artificial intelligence could be clinically useful for screening general vocal fold disease using the voice. The approach includes a quick survey and a general health examination. It can be applied during telemedicine in areas with primary care units lacking laryngoscopic abilities. It could support physicians when prescreening cases by allowing for invasive examinations to be performed only for cases involving problems with automatic recognition or listening and for professional analyses of other clinical examination results that reveal doubts about the presence of pathologies.

Sulcus vocalis in spasmodic dysphonia-A retrospective study

BACKGROUND

Spasmodic dysphonia (SD) is a neurological condition of the larynx characterised by task specific, involuntary spasms of the intrinsic laryngeal muscles causing frequent voice breaks during speech. The current treatment modality involves Botulinum Toxin injections into the affected group of muscles. This has yielded satisfactory results in Adductor SD (ADSD) and mixed SD but not in Abductor SD (ABSD). Sulcus vocalis is a morphological condition of the vocal folds with invagination of the superficial epithelium into the lamina propria or deeper layers. It is characterised by breathiness in voice and hypophonia. In our voice clinic, patients diagnosed with SD were occasionally found to have a sulcus on flexible stroboscopy. Studies have revealed an asymmetric stimulation of both the adductor and abductor group of muscles in ABSD and a predominant possibly symmetric stimulation of the adductor group of muscles in ADSD. Our objective was to study any significant association between vocal fold sulcus and two groups within SD; group one being ADSD and group two being both ABSD and Mixed SD. A literature review did not reveal any studies suggesting an association between SD and vocal fold sulcus to date.

METHODS

A retrospective review of the stroboscopic video recordings as well as file records of all patients diagnosed with SD between January 2016 and September 2019 was conducted at our voice clinic. The first author was the laryngologist who had diagnosed SD and its type on the basis of hearing the voice and making the patient perform various vocal tasks with and without flexible videostroboscopy. The SD patients were divided into two groups with the first group consisting of ADSD patients and the second group consisting of ABSD as well as Mixed SD patients. The presence or absence of vocal fold sulcus was noted in all the SD patients. Odds ratio was used to establish statistical significance of the presence of vocal fold sulcus in the two SD groups.

RESULTS

Among the 106 patients of SD, 62 patients were males and 44 were females. A total of 84 patients were diagnosed as ADSD, 10 as ABSD and 12 as Mixed SD patients. Vocal fold sulcus was noted in 5 out of 84 patients of ADSD, 4 out of 10 patients of ABSD, and in 3 out of 12 patients of mixed SD. Odds Ratio of 7.37 (C.I. = 2.063-26.35) was obtained for the second group of patients i.e. ABSD and Mixed SD.

CONCLUSION

Our study revealed a significant association between patients of SD having an abductor component (ABSD and mixed SD) and vocal fold sulcus. The two hypothesis proposed for this are the possibility of asymmetrical adductor and abductor muscle stimulation in SD being responsible for the development of a vocal fold sulcus or the primary presence of a vocal fold sulcus contributing to altered sensory feedback resulting in SD. Further study to evaluate this, as well as a study of the vocal response to medialisation procedures for patients of ABSD with sulcus is recommended.

Coagulation of posterior cricoarytenoid muscles for abduction spasmodic dysphonia

INTRODUCTION

Spasmodic dysphonia (SD), a form of focal dystonia, has been defined as a neurogenic, task-specific disorder characterized by abrupt spasms of intrinsic laryngeal muscles that result in phonatory breaks. There are three classic types of SD: adductor SD, abductor (ABSD) and mixed SD. Compared with the more common adductor form, treatment of ABSD with botulinum toxin injection is related to a shorter efficacy and improvement in only about 70% of patients [Blitzer et al. in Laryngoscope 108:1435-1441, 1998]. Moreover, due to the possible loss of efficacy over time or patient refusal for repeated injections, surgical solutions for permanent or at least long-term results must be considered.

METHOD

The surgical technique we propose is based on transoral bilateral posterior cricoarytenoid muscle (PCA) coagulation by radiofrequency (Celon, pro surg 250-T30, Olympus, Germany, 10 W, in 3 spots, each side) under a microscope or rigid scope control. The procedure is performed in two sessions distant of 2-3 weeks to avoid the risk of bilateral vocal fold temporary paralysis in adduction. A 52-year-old female patient with no audible voicing, resistant to botulinum toxin and after failure of relaxation thyroplasty type III according to lssihki [Saito et al. in Case Rep Otolaryngol 2018:4280381, 2018] showed an improvement of the Voice Handicap Index (VHI-10) from 35/40 to 19/40. The patient was rated G2R3B2A1S2 according to GRABS scale.

CONCLUSION

PCA coagulation for ABSD is a safe and reusable surgical option. It is less invasive than other techniques described before. To the best of our knowledge, this technique was never reported before in this type of SD.

Factors influencing long-term treatment response to botulinum toxin injection for spasmodic dysphonia

OBJECTIVE

The purpose of this study was to evaluate the outcomes of long-term botulinum toxin type A (BoNTA) treatment for adductor spasmodic dysphonia (AdSD) and to determine the factors predictive of treatment response by investigating dose stability and average intervals.

DESIGN

Retrospective cohort study.

SETTING

Academic tertiary medical centre.

EXPOSURES

A total of 470 patients with adductor spasmodic dysphonia, who received electromyography-guided BoNTA injections over 12 years, were retrospectively enrolled in this study.

MAIN OUTCOMES AND MEASURES

The patients' demographic data, baseline voice dynamics and treatment profiles (dose, frequency and intervals) were evaluated. Factors correlating with the dose adjustment ratio (number of increasing dosing/total number of BoNTA toxin injections) and changes in intervals between injections were statistically analysed.

RESULTS

A total of 122 patients, who received ≥ 4 injections and whose average treatment interval was < 240 days, were finally evaluated. Of them, 115 (94.3%) were female and seven (5.7%) were male, and the mean age at initial treatment was 34.89 ± 13.07 and 41.14 ± 12.71 years, respectively. On average, patients received 18.00 ± 13.33 injections (1.67 ± 0.60 U/injection) to alternating unilateral vocal folds. The treatment period was 65.07 ± 43.28 months and the mean interval between injections was 4.16 ± 1.28 months. The mean dose adjustment ratio among patients who received ≥ 4 injections was 0.15 ± 0.13, and dose changes occurred 4.36 times/patient. The patients' age and gender significantly affected the treatment response, where younger or female patients showed greater dosing variability and shorter intervals between injections. However, the baseline voice dynamics (voice handicap index, fundamental frequency, jitter, shimmer, noise-to-harmonic ratio, maximum phonation time and degree of voice breaks) did not predict the dose adjustment ratio or interval changes. In addition, patients with fluctuating doses showed lower age and higher VHI subscale scores, and patients with short-treatment interval (< 100 days) showed higher SDF0.

CONCLUSIONS

Almost all patients received stable low doses of BoNTA over time, irrespective of the baseline results. Patients' age, gender and VHI scores were correlated with poor treatment responses, such as frequent dose changes and shorter intervals between injections.

Sex differences in movement disorders

A number of studies reported the possible differences between men and women in movement disorders. Evidence shows that estrogens may have a neuroprotective effect and may modulate the neurodevelopment of the different brain structures. Movement disorders including Parkinson's disease, dementia with Lewy body, Huntington's disease, Tourette's syndrome, and dystonia among others display significant clinical differences between sexes, with structural differences in the dopaminergic pathways between men and women. Here we summarize the most relevant clinical aspects of some of the most common movement disorders, highlighting the differences in disease onset, clinical presentation, therapy, and outcomes. Increased recognition of these differences may help physicians better understand the pathophysiology of these conditions and provide a tailored therapeutic approach.

Alternating Unilateral Versus Bilateral Injections of Botulinum Toxin for the Treatment of Adductor Spasmodic Dysphonia

OBJECTIVE

This study aimed to compare the long-term efficacy, durability, and dose and interval stability between alternating unilateral and bilateral injections of botulinum neurotoxin type A for the treatment of adductor spasmodic dysphonia.

STUDY DESIGN

Retrospective cohort study.

SETTING

Academic tertiary medical center.

METHODS

A total of 137 patients (105 alternating unilateral and 32 bilateral injections) who were administered ≥5 injections of botulinum neurotoxin type A were included in this study. The mean dosage change, dose adjustment ratio (number of dose increases/total number of injections), and stability of treatment responses were compared between the alternating unilateral and bilateral injection groups.

RESULTS

Long-term changes in the mean dosages for alternating unilateral (mean ± SD, -0.010 ± 0.048 IU) and bilateral (-0.042 ± 0.142 IU) injections did not differ between groups (P = .225), suggesting that both methods follow a decreasing dosing trend over time. The dose adjustment ratio also did not differ between groups (P = .077), although a longer average treatment interval (P < .001) and duration of hoarse voice (P = .045) were found in the bilateral injection group. The proportion of stable patients who did not increase injection dose and had regular follow-up did not differ between the groups.

CONCLUSION

Both alternating unilateral and bilateral injection methods showed a long-term decreasing dosing trend, with comparable levels of efficacy, durability, and stability for treating adductor spasmodic dysphonia. Our findings indicate that alternating unilateral injections can be routinely performed with fewer side effects, albeit at shorter treatment intervals, than bilateral injections.

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.

Deep Brain Stimulation for Spasmodic Dysphonia: A Blinded Comparison of Unilateral and Bilateral Stimulation in Two Patients

Deep brain stimulation (DBS) is a promising new therapy for patients with spasmodic dysphonia (SD). The preliminary results from our randomized controlled trial showed good clinical effects with unilateral left thalamic stimulation in 6 right- handed patients. This suggests that the pathological process underpinning SD may have a "hemisphere dominant" pathway. We describe 2 patients with concurrent essential tremor and SD who had previously undergone bilateral thalamic DBS for their limb tremor. Both patients experienced an unanticipated improvement of their SD symptoms. One patient was right-handed, and the other was mixed left-handed. To investigate the amount of SD improvement following DBS therapy in each hemisphere, 4 different settings were tested: both sides on, left side on, right side on, and both sides off. Both patients most improved following bilateral stimulation. There was, however, a powerful unilateral benefit in both patients with only a small additional benefit from bilateral stimulation. The right-handed patient improved most with left-hemisphere stimulation whereas the mixed left-handed patient improved most with right hemisphere stimulation. There was some discrepancy between the two tests applied in the second patient reflecting the known difficulties to evaluate vocal symptom improvement in SD. We discuss the possible correlation of handedness and speech hemisphere dominance as well as the need for more reliable tests to measure SD severity. Ultimately, we recommend a bilateral approach for future studies, using a patient perception test as the primary outcome and functional imaging to further investigate the correlation of handedness and the amount of hemisphere dominance in SD.

Spasmodic Dysphonia: Standardized Spanish Tool for Ambulatory Consult Diagnosis

INTRODUCTION

Spasmodic dysphonia (SD) is a focal dystonia of the larynx where involuntary spasms of its intrinsic muscles are triggered by specific phonemes. The diagnosis is challenging and is performed by listening to the patient's voice, supported by nasolaryngoscopy. There is no diagnostic tool in Spanish for SD. The objective of our study is to establish phonetically studied vocal tasks in Spanish language to diagnose patients with SD.

MATERIAL AND METHOD

This is a prospective study in three groups of patients: 11 with SD, 11 with another vocal disease, and 11 with no vocal disease, recruited in the Voice Unit of Hospital Clínico Universidad Católica. Of the patients with SD, 10 (90.9%) had adductor SD and 1 (9.1%) abductor SD. Vocal tasks phonetically studied by a speech language pathologist as laryngeal spasm triggers were recorded. The audio recordings were randomized and analyzed by nine evaluators: three experts and six otolaryngology residents. The correlation between the different professionals for the correct diagnosis was analyzed.

RESULTS

The audio recordings were analyzed and patients with SD presented irregular voice breaks that occurred during the trigger phonemes. Evaluators classified the audio recordings: the expert group presented 100% sensitivity, 95-100% specificity and individual consistency of κ=0.73-0.82. The interrater agreement was 81.8%. The resident group presented 55-100% sensitivity, 58-95% specificity, and individual consistency of κ=0.36-0.82. The interrater agreement was 67.0%.

DISCUSSION AND CONCLUSIONS

We obtained a strong to almost perfect interrater agreement in experts and fair to almost perfect in residents. This study shows that the established list of phonetically studied and standardized words can be a useful tool for the diagnosis of SD.

Sex differences in movement disorders

In a range of neurological conditions, including movement disorders, sex-related differences are emerging not only in brain anatomy and function, but also in pathogenesis, clinical features and response to treatment. In Parkinson disease (PD), for example, oestrogens can influence the severity of motor symptoms, whereas elevation of androgens can exacerbate tic disorders. Nevertheless, the real impact of sex differences in movement disorders remains under-recognized. In this article, we provide an up-to-date review of sex-related differences in PD and the most common hyperkinetic movement disorders, namely, essential tremor, dystonia, Huntington disease and other chorea syndromes, and Tourette syndrome and other chronic tic disorders. We highlight the most relevant clinical aspects of movement disorders that differ between men and women. Increased recognition of these differences and their impact on patient care could aid the development of tailored approaches to the management of movement disorders and enable the optimization of preclinical research and clinical studies.

An Appraisal of Printed Online Education Materials on Spasmodic Dysphonia

OBJECTIVE

The use of the Internet for seeking health-related information has increased exponentially. We aimed to comprehensively appraise the readability, understandability, actionability, and quality of printed online education materials (POEMs) pertaining to Spasmodic Dysphonia (SD).

STUDY DESIGN

Descriptive, correlational study.

METHODS

POEMs were identified using the Google search engine with the phrase "spasmodic dysphonia." The first 50 websites meeting criteria were included. Accreditation of POEMs was evaluated using Health on the Net Foundation Code of Conduct (HONcode) toolbar. Readability of the content was analyzed using the Flesch-Kincaid Grade Level (FKGL) and Flesch Reading Ease (FRE) tests. Understandability and actionability was evaluated using the Patient Education Material Assessment Tool for Printed Materials. Overall quality of POEMs was appraised using the DISCERN instrument.

RESULTS

The overall mean [SD] FKGL and mean [SD] FRE score was 11.5 [2.5] and 42.1 [12.8], respectively. The mean understandability score was 65% [14], while the mean [SD] actionability score was only 17% [12]. The overall mean [SD] quality score for all websites was 43.5 [13]. Only four websites (8%) were HONcode certified. A moderately positive correlation was discovered between understandability and overall quality of POEMs (r = 0.38, P 0.01) CONCLUSIONS: POEMs pertaining to SD are written above recommended reading levels with subsequent poor understandability and actionability. We recommend that authors assess POEMs prior to publication to ensure alignment with the needs of the target audience.

Laboratory Evaluation of Spasmodic Dysphonia

OBJECTIVES

To evaluate the utility of comprehensive laboratory evaluation in patients with spasmodic dysphonia (SD).

STUDY DESIGN

Retrospective chart review.

METHODS

A review of the medical records of 40 patients diagnosed with spasmodic dysphonia from 2009-2018 was preformed to evaluate abnormal test results that were significant when compared with abnormal results of the general population and for any other clinically relevant pathology.

RESULTS

Erythrocyte sedimentation rate, ceruloplasmin levels, and anti-AChR were found to be elevated at levels considered statistically significant (p <0.05). Furthermore, we found levels of cholesterol, thyroid-stimulating hormone (TSH), T3, fasting blood glucose, creatine kinase, immunoglobulin, antinuclear antibody (ANA), and alpha-fetoprotein (AFP) levels to be abnormal at a greater rate in our population, but these were not statistically significant. Workup revealed several underlying conditions including thyroid neoplasms, hypothyroidism, and laryngopharyngeal reflux. Additionally, brain MRI revealed age-related ischemic pathology in an elevated number of patients, but with no obvious clinical sequalae.

CONCLUSION

There is an association between serological values and spasmodic dysphonia that can aid in diagnosing pathology, as well as establishing a directed workup. Additionally, our study shows the utility of comprehensive evaluation in identifying undetected disease.

Movement Disorders and Voice

The primary movement disorders affecting the voice are laryngeal dystonia (including spasmodic dysphonia), essential voice tremor, and Parkinson disease. Diagnosis of these conditions is clinical and based on a detailed history, voice evaluation, and physical and laryngoscopic examination. Laryngeal dystonia and essential voice tremor are hyperfunctional disorders and are treated most commonly with botulinum toxin injections. Parkinson disease is a hypofunctional disorder that may affect the voice and most commonly is treated with Lee Silverman Voice Treatment.