Spasmodic Dysphonia Research Articles

Myoneurectomy for Adductor Spasmodic Dysphonia: Long-Term Outcomes, Complications, and Recurrence.

To evaluate the long-term results of endoscopic myoneurectomy (EMN) of the thyroarytenoid (TA) muscle for the treatment of adductor spasmodic dysphonia (AdSD), with an emphasis on vocal outcomes, adverse effects, and recurrence. A total of 48 patients underwent up to three EMNs of the TA muscle and were followed for at least 18 months to evaluate the efficacy, based on patient and examiner assessments, and safety of the procedure(s). Vocal outcomes were evaluated through the use of the 30-item Voice Handicap Index (VHI-30) questionnaire and subjective (patient-reported) assessment. In this group, 38 patients (79.2%) were considered successful. The median VHI-30 score at baseline was 97, decreasing to 26 after treatment, and the median subjective postprocedural improvement was 88.5%. The most common adverse effects were granulomas (in 18 cases), glottic insufficiency (in two), and dyspnea (in one). Although up to three procedures can be needed to achieve a high success rate, EMN of the TA muscle can provide excellent benefits in terms of vocal function with a low rate of complications. 4 Laryngoscope, 2024.

Adductor Laryngeal Dystonia Versus Muscle Tension Dysphonia: Examining the Utility of Automated Acoustic Analysis to Detect Task Dependency as a Distinguishing Feature.

Differentiating adductor laryngeal dystonia (ADLD) and primary muscle tension dysphonia (pMTD) can be challenging. Unlike pMTD, ADLD is described as "task-dependent" with voiced phonemes purportedly provoking greater sign expression than voiceless phonemes. We evaluated the ability of two automated acoustic measures, the Cepstral Spectral Index of Dysphonia (CSID) and creak, to detect task dependency and to discriminate ADLD and pMTD. CSID, % creak, and listener ratings of dysphonia severity were obtained from audio recordings of patients with ADLD (n = 29) or pMTD (n = 33) reading two sentences loaded with either voiced or voiceless phonemes. Group × Sentence Type interaction effects confirmed that both "normalized" CSID and % creak detected task-dependent sign expression in ADLD (i.e., worse symptoms on the voiced- vs. voiceless-loaded sentence). However, a stepwise binary logistic regression analysis with group (ADLD vs. pMTD) as the dependent variable and % creak and normalized CSID variables (voiced, voiceless, and voiced vs. voiceless difference) as covariates revealed that the normalized CSID voiceless-laden sentence z score was the only significant predictor of group membership. Estimates of diagnostic precision from the normalized CSID voiceless sentence z scores were superior to % creak or listener ratings. Finally, the CSID possessed the strongest correlations with listener severity ratings regardless of group or sentence type. Although both normalized CSID and % creak detected task-dependent performance as a distinguishing feature of ADLD, a CSID profile wherein (a) the voiceless sentence z score was less severe than the voiced sentence and (b) the normalized voiceless sentence z score was within approximately 2 SDs (or less) of typical expectations provided the best estimates of diagnostic precision. Automated acoustic measures such as the CSID and creak provide useful information to objectively discriminate ADLD and pMTD.

Impact of Audio-Visual Complexity on Symptomatology of Laryngeal Dystonia: A Virtual Reality Study.

Laryngeal dystonia (LD) is an isolated focal dystonia characterized by involuntary spasms in laryngeal muscles selectively impairing speech production. Anecdotal observations reported the worsening of LD symptoms in stressful or vocally demanding situations. To examine the impact of surrounding audio-visual complexity on LD symptomatology for a better understanding of disorder phenomenology. We developed well-controlled virtual reality (VR) environments of real-life interpersonal communications to investigate how different levels of audio-visual complexity may impact LD symptoms. The VR experiments were conducted over five consecutive days, during which each patient experienced 10 h of 4100 experimental trials in VR with gradually increasing audio-visual complexity. Daily reports were collected about patients' voice changes, as well as their comfort, engagement, concentration, and drowsiness from using VR technology. After a weekly VR exposure, 82% of patients reported changes in their voice symptoms related to changes in background audio-visual complexity. Significant differences in voice symptoms were found between the first two levels of the audio-visual challenge complexity independent of study sessions or VR environments. This study demonstrated that LD symptoms are impacted by audio-visual background across various virtual realistic settings. These findings should be taken into consideration when planning behavioral experiments or evaluating the outcomes of clinical trials in these patients. Moreover, these data show that VR presents a reliable and useful technology for providing real-life assessments of the impact of various experimental settings, such as during the testing of novel therapeutic interventions in these patients. Level 3 Laryngoscope, 2024.

Structural and functional brain alterations in laryngeal dystonia: A coordinate-based activation likelihood estimation meta-analysis.

Laryngeal dystonia (LD) is an isolated, task-specific, focal dystonia characterized by intermittent spasms of laryngeal muscles impairing speech production. Although recent studies have demonstrated neural alterations in LD, the consistency of findings across studies is not well-established, limiting their translational applicability. We conducted a systematic literature search to identify studies reporting stereotactic coordinates of peak structural and functional abnormalities in LD patients compared to healthy controls, followed by a coordinate-based activation likelihood estimation meta-analysis. A total of 21 functional and structural neuroimaging studies, including 31 experiments in 521 LD patients and 448 healthy controls, met the study inclusion criteria. The multimodal meta-analysis of these studies identified abnormalities in the bilateral primary motor cortices, the left inferior parietal lobule and striatum, the right insula, and the supplementary motor area in LD patients compared to healthy controls. The meta-analytical findings reinforce the current view of dystonia as a neural network disorder and consolidate evidence for future investigations probing these targets with new therapies.

How Do I Examine Laryngeal Dystonia?

Laryngeal dystonia is a potentially disabling task specific dystonia primarily affecting speech. The evaluation and diagnosis of laryngeal dystonia remain challenging, and often require a multi-disciplinary approach, involving collaboration among speech language pathologists, neurologists and laryngologists (1-5). It is crucial to correctly differentiate between the types of laryngeal dystonia due to the distinct therapeutic approaches and responses to botulinum toxin therapy or speech therapy. For educational purposes, we have divided laryngeal dystonia into two main types: adductor and abductor dystonia. In this article, we describe a series of examination techniques that can assist movement disorders neurologists diagnosing this condition, and appropriately differentiating the most common forms of laryngeal dystonia.

Supraglottic Laryngeal Maneuvers in Adductor Laryngeal Dystonia During Connected Speech

ObjectiveAdductor laryngeal dystonia (AdLD) disrupts fine motor movements of vocal folds during speech, resulting in a strained, broken, and strangled voice. Laryngeal high-speed videoendoscopy (HSV) in connected speech enables the direct visualization of detailed laryngeal dynamics, hence, it can be effectively used to study AdLD. The current study utilizes HSV to investigate supraglottic laryngeal tissue maneuvers obstructing the view of the vocal folds, in AdLD and normophonic speakers during connected speech. Characterizing the laryngeal maneuvers in these groups can facilitate a deeper understanding of the normophonic voice physiology and AdLD voice pathophysiology. MethodsHSV data were obtained from six normophonic speakers and six patients with AdLD during production of connected speech. Three experienced raters visually analyzed the data to determine laryngeal tissues leading to obstructions of vocal folds in HSV images. The raters recorded the duration of each obstruction and indicated the specific tissue(s) leading to the obstruction After the completion of their individual visual analysis, the raters came to consensus about their observations and measurements. ResultsStatistical analysis indicated that AdLD patients exhibited higher occurrences of vocal fold obstructions and longer durations of obstructions compared to the normophonic group. Similar obstruction types were found in both groups, with the epiglottis being the primary site of obstruction for both. Participants with AdLD displayed significantly elevated occurrences of sphincteric compression resulting in vocal fold obstruction. ConclusionHSV can be used to study the movements of laryngeal tissues in detail during connected speech. The analysis of supraglottic laryngeal tissue dynamics in speech can help us characterize the AdLD pathophysiology. The study's findings regarding the tissues implicated in obstructions may potentially inform the development of patient-specific therapeutic strategies targeting individual control over specific laryngeal muscles during phonation and speech production.

A Preliminary Study on Effect of Vocal Aerobic Treatment on Voice Improvement in Patients With Adductor Spasmodic Dysphonia

A Preliminary Study on Effect of Vocal Aerobic Treatment on Voice Improvement in Patients With Adductor Spasmodic Dysphonia

The Clinical Utility of Botulinum Toxin in the Field of Otolaryngology

Botulinum toxin, originally identified in relation to botulism, has evolved from being considered a perilous pathogen to an invaluable therapeutic agent. First utilized by Alan Scott in 1977 to treat strabismus under the commercial name, Oculinum, the toxin received Food and Drug Administration approval in 1989 and was subsequently rebranded as Botox. Its clinical applications have expanded notably, especially in the field of otolaryngology, proving effective in managing conditions such as spasmodic dysphonia, essential vocal tremor, and chronic salivary gland disorders. Moreover, botulinum toxin has shown promising results in treating persistent chronic rhinitis, objective tinnitus, and synkinesis following facial palsy, significantly improving involuntary facial movements. This paper details the diverse applications and methodologies of botulinum toxin across various ENT disorders, illustrating its growing scope and significance in medical practice.

Does sex influence the natural history of idiopathic adult-onset dystonia?

BackgroundSeveral earlier studies showed a female predominance in idiopathic adult-onset dystonia (IAOD) affecting the craniocervical area and a male preponderance in limb dystonia. However, sex-related differences may result from bias...

Expanding the phenotypic and genotypic spectrum of DYT-TUBB4A with seven patients from India

BackgroundVariants in the TUBB4A gene are associated with dystonia (DYT-TUBB4A), Hypomyelination with Atrophy of the Basal Ganglia and Cerebellum (H-ABC) and spastic paraplegia. Phenotypes intermediate to these three broad phenotypes are also observed. These are rare disorders, and data from diverse populations remains limited. We report seven Indian cases with dystonia phenotype related to TUBB4A mutation. CasesAmong these seven patients, age at onset ranged from 5 to 48 years. Five patients had cranio-cervical onset of dystonia. One patient had prominent parkinsonism with dystonia. Patients responded well to botulinum toxin injected for laryngeal, cervical and jaw dystonia. The patient with parkinsonism responded well to levodopa, albeit with development of dyskinesias. Apart from the common p.Arg2Gly variant in three patients with DYT-TUBB4A, other variants included p.Arg262Pro, p.Arg39Cys and p.Asp245Asn. ConclusionsWe report the first collection of cases with TUBB4A mutation from India. We expand the phenotype to include levodopa-responsive parkinsonism. Indian patients, consistent with global literature, harbor prominent adductor dysphonia, cervical and jaw dystonia, which responds well to botulinum treatment.

"Lombard Effect" and Voice Changes in Adductor Laryngeal Dystonia: A Pilot Study.

The aim was to describe the acoustic, auditory-perceptive, and subjective voice changes under the Lombard effect (LE) in adductor laryngeal dystonia (AdLD) patients. Subjective perception of vocal effort (OMNI Vocal Effort Scale OMNI-VES), Maximum Phonation Time (MPT), and the perceptual severity of dysphonia (GRBAS scale) were assessed in condition of stillness and under LE in 10 AdLD patients and in 10 patients with typical voice. Speakers were asked to produce the sustained vowel /a/ and to read a phonetically balanced text aloud. Using the PRAAT software, the following acoustic parameters were analyzed: Mean Pitch (Hz), Minimum and Maximum Intensity (dB), the Fraction of Locally Unvoiced Frames, the Number of Voice Breaks, the Degree of Voice Breaks (%), the Cepstral Peak Prominence-Smoothed (CPPS) (dB). Under LE, the AdLD group showed a decrease of both G and S parameters of GRBAS and subjective effort, mean MPT increased significantly; in the controls there were no significant changes. In both groups under LE, pitch and intensity of the sustained vowel /a/ significantly increased consistently with LE. In the AdLD group the mean gain of OMNI-VES score and the mean gain of each parameter of the speech analysis were significantly greater than the controls' ones. Auditory feedback deprivation obtained under LE improves subjective, perceptual-auditory, and acoustics parameters of AdLD patients. These findings encourage further research to provide new knowledge into the role of the auditory system in the pathogenesis of AdLD and to develop new therapeutic strategies. 4 Laryngoscope, 134:3754-3760, 2024.

Demographic and clinical characteristics of our patients diagnosed with laryngeal dystonia

PurposeLaryngeal 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 MethodsAll 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.ResultsOut 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.ConclusionThe 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.

Current opinion on laryngeal electromyography

PurposeThis study evaluates expert opinion on laryngeal electromyography (LEMG). MethodsA cross-sectional design was used to conduct an online survey of LEMG experts in 2021. They were questioned about the number LEMG performed annually, type of electrodes used, sector worked in, pain during the test, placement of the needle electrodes, interpretation of electrical muscle parameters, diagnosis of neuromuscular injury, prognostic sensitivity in vocal fold paralysis (VFP), laryngeal dystonia, tremor and synkinesis and quantifying LEMG. ResultsThirty-seven professionals answered (23 Spanish and 14 from other countries), with a response rate of 21.56%. All physicians used LEMG. 91.9% had one- or two-years’ experience and 56.8% performed 10–40 LEMG per year. 70.3% were otolaryngologists and 27%, neurologists. In 89.1% of cases, a team of electrodiagnostic physician and otolaryngologist performed LEMG. 91.3% of Spanish respondents worked in Public Health, 7.14% of other nationalities; 37.8% in a university department. Bipolar concentric needles electrodes were used by 45.9% and monopolar concentric by 40.5%. 57% professionals considered good patients’ tolerance to the test. LEMG sensitivity was regarded as strong, median and interquartile range were 80.0 [60.0;90.0] to diagnose peripheral nerve injuries, less for other levels of lesions, and strong to evaluate prognosis, 70.0 [50.0;80.0]. Respondents believe locate the thyroarytenoid and the cricothyroid muscles with the needle, 80.0 [70.0;90.0], as opposed to 20.0 [0.00;60.0] the posterior cricoarytenoid. The interpretation of the electrical parts of the LEMG was strong, 80.0 [60.0;90.0]. LEMG identify movements disorders, 60.0 [20.0;80.0], and synkinesis, 70.0 [30.0;80.0]. The professionals prefer quantitative LEMG, 90.0 [60.0;90.0]. ConclusionsThe experts surveyed consider LEMG that is well tolerated by patients. The insertional and spontaneous activity, recruitment and waveform morphology can be assessed easily. LEMG is mainly useful in the study of peripheral nerve injuries, and its value in VFP prognosis is considered strong.

BOTOX’s Mechanism, Diversity Considerations, and Therapeutic Potential in Cosmetic, Medical, and Dental Practice

This review provides a comprehensive overview of the societal pressures of maintaining a youthful appearance and the increasing popularity of BOTOX injections for aesthetic purposes. It discusses the motivation behind BOTOX use for personal psychological gains, partly driven by social media pressure and societal expectations. Ethical considerations and potential psychosocial consequences of cosmetic BOTOX are also addressed.The article delves into the explanation of what BOTOX is and how it works, emphasizing its use for cosmetic and medical purposes, such as treating spasmodic dysphonia and hyperhidrosis. When used appropriately, it highlights the rarity of complications and adverse effects associated with BOTOX. BOTOX’s historical use and development, from its initial medical applications to its widespread adoption in cosmetic procedures, are outlined. Further explored is the prevalence of BOTOX use among different socioeconomic classes, races/ethnicities, ages, and genders, highlighting disparities and emerging trends. It summarizes the effectiveness and safety of BOTOX injections for facial wrinkles and its non-cosmetic uses (e.g., treating migraines, hyperhidrosis, and pain management). The review describes BOTOX’s uses in dentistry, including its therapeutic benefits and safety considerations.It also discusses the possible therapeutic advantages of BOTOX injections in managing psychological conditions, including depression, anxiety, and body dysmorphic disorder (BDD). The diagnostic applications of BOTOX and its mechanism of action are briefly explained.The article concludes with a summary of BOTOX’s beneficial and adverse effects and the constraints on access to and use of BOTOX treatments. It acknowledges the limitations of BOTOX research and the need for further investigation to address these limitations.Abbreviations: BDD: Body Dysmorphic Disorder; FDA: U.S. Food and Drug Administration; QoL: Quality of Life; ROM: Range of Motion; SES: Socioeconomic Status; SNAP-25: Synaptosomal-Associated Protein 25; TMD: Temporomandibular Joint Disorder

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

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. 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. 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. 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.

Blood-Based Proteomics for Adult-Onset Focal Dystonias.

The adult-onset focal dystonias are characterized by over-active muscles leading to abnormal movements. For most cases, the etiology and pathogenesis remain unknown. In the current study, unbiased proteomics methods were used to identify potential changes in blood plasma proteins. A large-scale unbiased proteomics screen was used to compare proteins (N = 6,345) in blood plasma of normal healthy controls (N = 49) with adult-onset focal dystonia (N = 143) consisting of specific subpopulations of cervical dystonia (N = 45), laryngeal dystonia (N = 49), and blepharospasm (N = 49). Pathway analyses were conducted to identify relevant biological pathways. Finally, protein changes were used to build a prediction model for dystonia. After correction for multiple comparisons, 15 proteins were associated with adult-onset focal dystonia. Subgroup analyses revealed some proteins were shared across the dystonia subgroups while others were unique to 1 subgroup. The top biological pathways involved changes in the immune system, metal ion transport, and reactive oxygen species. A 4-protein model showed high accuracy in discriminating control individuals from dystonia cases [average area under the curve (AUC) = 0.89]. These studies provide novel insights into the etiopathogenesis of dystonia, as well as novel potential biomarkers. ANN NEUROL 2024;96:110-120.

Does Vocal Fold Pathology Play a Role in Determining the Timeline of Presentation to an Ear, Nose, and Throat Surgeon?

Abstract Background: The primary objective is to study the average time duration between the onset of vocal symptoms and presentation to an ear, nose, and throat (ENT) surgeon, in different vocal pathologies. Our second objective is to study gender distribution among various pathologies. Methods: Our voice clinic records were retrospectively reviewed for 1 year, from August 2022, for details regarding gender, and the average time taken for presentation (ATTFP) in months, to an ENT surgeon. Disorders were grouped into vocal fold nodules, polyps, cysts, paralysis/paresis, sulcus, spasmodic dysphonia (SD), and premalignant and malignant conditions. Results: A total of 17 patients of vocal fold nodules (15 females), 47 vocal fold polyp patients (45 males), 40 vocal fold cyst patients (24 females), 64 paralysis/paresis patients (44 males), 41 sulcus patients (31 males), 35 SD patients (22 females), and 65 premalignant and malignant condition patients (51 males) presented to us. The ATTFP for nodules was 8.1 months, 6.8 months for polyps, 10.2 months for cysts, 22.8 months for idiopathic and 6 months for other causes of paralysis/paresis, 32.4 months for sulcus, 26.1 months for SD, and 10.2 months for premalignant and malignant conditions. Conclusion: Sulcus patients took the longest time to present to an ENT surgeon, followed by SD patients, both groups averaging over 2 years. Vocal fold paralysis/paresis patients with a nonidiopathic diagnosis were the earliest to present. A high male preponderance in vocal fold polyps (96%) as opposed to a high female preponderance in vocal fold nodules (88%), both considered phonotraumatic lesions, warrants further research into possible varying etiopathogenesis.

Comparison study of Endoscopic-guided versus Electromyography-guided Botulinum toxin injection treatments in Adductor spasmodic dysphonia

Comparison study of Endoscopic-guided versus Electromyography-guided Botulinum toxin injection treatments in Adductor spasmodic dysphonia

Intensive Voice Treatment following Botulinum Neurotoxin Injection for a Speaker with Abductor Laryngeal Dystonia: An Exploratory Case Study.

Abductor laryngeal dystonia (ABLD) is a rare neurological voice disorder which results in sporadic opening of the vocal folds during speech. Etiology is unknown, and to date there is no identified effective behavioral treatment for it. It is hypothesized that LSVT LOUD®, which was developed to treat dysphonia secondary to Parkinson's disease, may have application to speakers with ABLD to improve outcomes beyond that with botulinum neurotoxin (BoNT) treatment alone. The participant received one injection of BoNT in each vocal fold 2 to 3 months prior to initiating intensive voice therapy via teletherapy. Objective measures of vocal loudness (dB sound pressure level), maximum phonation time, and high/low pitch frequency (Hz) were recorded in all treatment sessions and follow-up sessions. Over the course of treatment, the participant showed steady gains in phonation time, volume, pitch range, and vocal quality with a substantial reduction in aphonic voice breaks by the end of the treatment program. Perceptual symptoms of ABLD were nearly undetectable by the participant and the clinicians up to 12 months posttreatment, with no additional BoNT injections. The results suggest that LSVT LOUD® following BoNT was effective, with long-lasting improvement in vocal function, for this speaker with ABLD.

Central Autonomic Mechanisms Involved in the Control of Laryngeal Activity and Vocalization.

In humans, speech is a complex process that requires the coordinated involvement of various components of the phonatory system, which are monitored by the central nervous system. The larynx in particular plays a crucial role, as it enables the vocal folds to meet and converts the exhaled air from our lungs into audible sounds. Voice production requires precise and sustained exhalation, which generates an air pressure/flow that creates the pressure in the glottis required for voice production. Voluntary vocal production begins in the laryngeal motor cortex (LMC), a structure found in all mammals, although the specific location in the cortex varies in humans. The LMC interfaces with various structures of the central autonomic network associated with cardiorespiratory regulation to allow the perfect coordination between breathing and vocalization. The main subcortical structure involved in this relationship is the mesencephalic periaqueductal grey matter (PAG). The PAG is the perfect link to the autonomic pontomedullary structures such as the parabrachial complex (PBc), the Kölliker-Fuse nucleus (KF), the nucleus tractus solitarius (NTS), and the nucleus retroambiguus (nRA), which modulate cardiovascular autonomic function activity in the vasomotor centers and respiratory activity at the level of the generators of the laryngeal-respiratory motor patterns that are essential for vocalization. These cores of autonomic structures are not only involved in the generation and modulation of cardiorespiratory responses to various stressors but also help to shape the cardiorespiratory motor patterns that are important for vocal production. Clinical studies show increased activity in the central circuits responsible for vocalization in certain speech disorders, such as spasmodic dysphonia because of laryngeal dystonia.