Spasmodic Dysphonia Research Articles

Spectral Aggregate of the High-Passed Fundamental Frequency and Its Relationship to the Primary Acoustic Features of Adductor Laryngeal Dystonia.

Currently, no clinically feasible objective measures exist that are specific to the signs of adductor laryngeal dystonia (LD), deterring effective diagnosis and treatment. This project sought to establish concurrent validity of a new automated acoustic outcome measure, designed to be specific to adductor laryngeal dystonia (AdLD): the spectral aggregate of the high-passed fundamental frequency contour (SAHf o). Twenty speakers with AdLD read voiced phoneme-loaded (more symptomatic) and voiceless phoneme-loaded (less symptomatic) sentences. LD discontinuities (defined as phonatory breaks, frequency shifts, and creak), the acoustic ramifications of laryngeal spasms, were manually identified. The frequency content of the f o contour was examined as a function of time, and content above 1000 Hz was summed to automatically calculate SAHf o. Multiple linear regression analysis was applied to SAHf o based on LD discontinuities and sentence type (voiced or voiceless phoneme-loaded). The regression model accounted for 41.1% of the variance in SAHf o. Both the LD discontinuities and sentence type were statistically related to SAHf o. Results of this study provide evidence of concurrent validity. SAHf o is an automatic outcome measure specific to acoustic signs of AdLD that may be useful to track treatment progress.

Sign language detection using convolutional neural network for teaching and learning application

Teaching lower school mathematic could be easy for everyone. For teaching in the situation that cannot speak, using sign language is the answer especially someone that have infected with vocal cord infection or critical spasmodic dysphonia or maybe disable people. However, the situation could be difficult, when the sign language is not understandable by the audience. Thus, the purpose of this research is to design a sign language detection scheme for teaching and learning activity. In this research, the image of hand gestures from teacher or presenter will be taken by using a web camera for the system to anticipate and display the image's name. This proposed scheme will detects hand movements and convert it be meaningful information. As a result, it show the model can be the most consistent in term of accuracy and loss compared to others method. Furthermore, the proposed algorithm is expected to contribute the body of knowledge and the society.

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

This study examined the relationship between voice quality and glottal geometry dynamics in patients with adductor spasmodic dysphonia (ADSD). 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. 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. We found specific glottal geometry dynamics that correspond to voice quality in ADSD.

Optimizing Botox regimens in patients with adductor spasmodic dysphonia and essential tremor of voice: A 31-year experience.

ObjectiveThe purpose of this study was to quantitatively compare the effectiveness of unilateral and bilateral botulinum toxin A (BTX‐A) injections for mitigating undesirable weak/breathy voice quality and dysphagia for patients with adductor spasmodic dysphonia and/or essential tremor of voice (ETV).MethodsData were collected from the medical records of 319 patients, yielding three treatment cohorts: patients who received an equal dose bilateral injection regimen (BL=) throughout their course of treatment at VUMC, patients who switched to a unilateral injection regimen (UL), and patients who switched to an unequal dose bilateral injection regimen (BL≠). Changes in length of improvement, duration of weak/breathy voice, and dysphagia severity were compared.ResultsThe BL = treatment group reported the longest duration of improved voice. Shorter periods of improved voice were reported at baseline by patients who later switched to UL or BL ≠ injection regimens. Patients receiving UL injections reported significantly reduced weak/breathy voice and dysphagia. Patients receiving BL ≠ injections reported increased length of improved voice; however, dysphagia symptoms increased. Ninety‐two percent of patients with ETV switched to a UL regimen, with 61% of patients transitioning within the first three injections.ConclusionsPatients with pronounced dysphagia and extended periods of weak/breathy voice may benefit from a UL injection approach to mitigate side effects from BTX‐A without sacrificing improved voice outcomes. For patients seeking to extend their length of improved voice, a BL ≠ injection regimen may be effective provided the adverse side effects from BTX‐A are minimal. Patients with ETV may benefit from a UL injection approach at the outset of their course of treatment with BTX‐A.Level of evidenceIII.

Botulinum toxin - an overview of applications in otorhinolaryngology

Background: Botulinum toxin (BT) is primarily known for its aesthetic applications, but there are many opportunities to use the toxin for the prevention and treatment of various other conditions. BT is not very widespread in otolaryngology practice, but can be effective in many diseases. The TB mechanism is related to the blockade of the muscular plate or the glandular one and is therefore effective in various muscular disorders and autonomic secretory disorders. Aim: The purpose of this work is to review the applications of botulinum toxin in otolaryngology. Material and methods: Scientific publications on the Pubmed platform were reviewed using the keywords: botulinum toxin and otolaryngology, and time descriptors were set for 20122022. Results: Botulinum toxin is an effective and safe treatment that causes minor and transient side effects, and its duration of action varies depending on the condition for which it is used (from 36 months on average, up to several years in Lucia Frey syndrome). This is the first-line treatment in Lucia Frey syndrome, laryngeal dystonia and synkinesis. The most common otorhinolaryngological indications, discussed in the following paper, in which botulinum toxin is one component of treatment include Lucia Frey syndrome, salivary fistulas, excessive salivation syndromes, laryngeal dystonia, vocal tremor, vocal granuloma, synkinesis in facial nerve palsy, dysphagia, and an interesting new indication for the use of the toxin in the treatment of resistant rhinitis. The following paper reviews the treatment protocols with botulinum toxin for the aforementioned indications and includes information such as management, dosage, injection sites. The study provides an introduction for ENTs interested in introducing botulinum toxin into their practice, as well as updates practical information for those already practicing. Conclusions: Botulinum toxin is a safe and effective treatment for a wide range of non-aesthetic indications in otorhinolaryngology.

Deep-Learning-Based Representation of Vocal Fold Dynamics in Adductor Spasmodic Dysphonia during Connected Speech in High-Speed Videoendoscopy

Adductor spasmodic dysphonia (AdSD) is a neurogenic dystonia, which causes spasms of the laryngeal muscles. This disorder mainly affects production of connected speech. To understand how AdSD affects vocal fold (VF) movements and hence, the speech signal, it is necessary to study VF kinematics during the running speech. This paper introduces an automated method for analysis of VF vibrations in AdSD using laryngeal high-speed videoendoscopy (HSV) in running speech. A monochrome HSV system was used to obtain video recordings from vocally normal individuals and AdSD patients during production of the six CAPE-V sentences and the "Rainbow Passage." A deep neural network was designed based on the UNet architecture. The network was developed for glottal area segmentation in HSV data providing a tool for quantitative analysis of VF vibrations in both norm and AdSD. The network was trained and validated using the manually labeled HSV frames. After training the network, the segmentation quality was quantitatively evaluated against visual analysis results of a test dataset including segregated HSV frames and a short sequence of VF vibrations in consecutive frames. The developed convolutional network was successfully trained and demonstrated an accurate segmentation on the testing dataset with a mean Intersection over Union (IoU) of 0.81 and a mean Boundary-F1 score of 0.93. Moreover, the visual assessment of the automated technique showed an accurate detection of the glottal edges/area in the HSV data even with challenging image quality and excessive laryngeal maneuvers of AdSD patients during the running speech. The introduced automated approach provides an accurate representation of the glottal edges/area during connected speech in HSV data for norm and AdSD patients. This method facilitates the development of HSV-based measures to quantify VF dynamics in AdSD. Using HSV to automatically analyze VF vibrations in AdSD can allow for understanding AdSD vocal mechanisms and characteristics.

IncobotulinimtoxinA (Xeomin) for the treatment of adductor laryngeal dystonia: A prospective, open-label clinical trial

ObjectivesDemonstrate an understanding of incobotulinumtoxinA efficacy in the treatment of adductor spasmodic dysphonia (SD). Understand that incobotulinumtoxinA can successfully be used as an alternative to onabotulinumtoxinA and for secondary non-responders. MethodsWe conducted a prospective open-label trial from 2016 until 2019 regarding the use of incobotulinimtoxinA for the treatment of adductor spasmodic dysphonia. Exclusion criteria included pregnant/nursing women, botulinum toxin for other indications, known allergy, neuromuscular or systemic diseases, use of aminoglycoside antibiotics, substance abuse, litigation regarding prior therapy, or other confounding conditions. Sixty-four injection sessions with completed with sixteen patients who were enrolled in the study and underwent EMG-guided incobotulinumtoxinA injections to the thyroarytenoid (TA) muscle using a hollow monopolar Teflon-coated needle via a trans-cricothyroid membrane approach. Dosages to each TA muscle were recorded and patients completed a Voice Handicap Index-10 (VHI-10), a validated worksheet regarding their perceived percent of normal function (PNF) following treatment, and a side effect profile. Outcomes were analyzed using the paired t-test. ResultsFor primary transitioners to incobotulinimtoxinA, VHI-10 scores and best percent normal function did not significantly change. For non-responders, VHI-10 decreased from 32.5 on Botox to 19.5 on incobotulinimtoxinA and best PNF increased from 37.6 to 90 %, which was statistically significant. Transient side effects included breathiness. ConclusionsOur study demonstrates that incobotulinimtoxinA may be used successfully for adductor SD either as first line treatment or in secondary non-responders to onabotulinumtoxinA.

The Prevalence of Idiopathic or Inherited Isolated Dystonia: A Systematic Review and Meta‐Analysis

ABSTRACTBackgroundA systematic review of epidemiological studies of primary dystonia from 1985 and 2010 found an overall prevalence of 16.43 per 100,000 (95% CI = 12.09–22.32).MethodsWe performed a systematic review of studies from 2010 and 2022 to determine if there are important differences in epidemiology between these time periods.ResultsNineteen studies were included. Incidence of cervical dystonia, blepharospasm, and oromandibular dystonia were each reported in one study; one study reported incidence for all adult onset idiopathic focal dystonias combined. Using data from 11 studies, we performed random effects meta‐analyses of the prevalence of cervical dystonia (9.95 per 100,000; 95% CI = 3.51–28.17), blepharospasm (2.82 per 100,000; 95% CI = 1.12–7.12), laryngeal dystonia (0.40 per 100,000; 95% CI = 0.09–1.83), upper limb dystonia (1.27 per 100,000; 95% CI = 0.36–4.52), oromandibular dystonia (0.57 per 100,000; 95% CI = 0.15–2.15), and idiopathic or inherited isolated dystonia all subtypes combined (30.85 per 100,000; 95% CI = 5.06–187.74). All studies reported more cases of dystonia in females. There was no significant difference in prevalence by subgroup analysis based on time of study publication (1985–2010 vs. 2010–2022). Subgroup analysis of differences in prevalence by dystonia subtype by continent using all studies published (1985–2022) revealed significant regional differences in the prevalence of cervical and laryngeal dystonia.ConclusionThe incidence and prevalence of idiopathic or inherited isolated dystonia in the last decade was not significantly different from earlier reports. Population‐based studies across multiple geographic areas are needed to obtain a clearer understanding of the epidemiology of this condition.

Validity of intraoperative voice monitoring undergoing type 2 thyroplasty with titanium bridges for adductor spasmodic dysphonia.

ObjectivesThe success of type 2 thyroplasty (TP2) for adductor spasmodic dysphonia (AdSD) depends on the selection of optimally sized titanium bridges, which requires accurate assessment of intraoperative vocal changes. While this procedure has traditionally been performed according to the laryngologist's experience, the most appropriate method for voice monitoring and selection of titanium bridge size remains to be determined. This study aimed to investigate evaluation parameters useful for voice monitoring, as these may allow less experienced surgeons to perform TP2 properly.MethodsIn this prospective study, voice monitoring was performed in 18 patients with AdSD patients undergoing TP2. Evaluations were performed preoperatively, intraoperatively, 13 weeks postoperatively, and 52 weeks postoperatively using GRBAS (grade, roughness, breathiness, asthenia, and strain), as well as perceptual judgment and acoustic analyses.ResultsPreoperative and intraoperative assessments of the G, R, B, and S parameters, perceptual judgment, and harmonic‐to‐noise ratio (HNR) were in moderate or better agreement. Intraoperative and 13‐ or 52‐week postoperative measurements of the R, B, and G parameters and strangulation, tremor, and HNR were also in high agreement. When two different sizes of titanium bridges were compared (unselected vs. selected), ratings for G, R, S, strangulation, tremor, jitter, shimmer, HNR, standard deviation of F0, and degree of voice breaks were better for the selected width than the unselected width.ConclusionThe candidate items for intraoperative voice monitoring during TP2 for AdSD are G, R, strangulation, tremor, and HNR. The use of these items may help to ensure successful TP2 and contribute to the advancement of laryngeal framework surgery.Level of evidenceLevel 4.

The epidemiology of dystonia: the Hannover epidemiology study

The prevalence of dystonia has been studied since the 1980s. Due to different methodologies and due to varying degrees of awareness, resulting figures have been extremely different. We wanted to determine the prevalence of dystonia according to its current definition, using quality-approved registries and based on its relevance for patients, their therapy and the health care system. We applied a service-based chart review design with the City of Hannover as reference area and a population of 525,731. Barrier-free comprehensive dystonia treatment in few highly specialised centres for the last 30 years should have generated maximal dystonia awareness, a minimum of unreported cases and a high degree of data homogeneity. Prevalence [n/1mio] and relative frequency is 601.1 (100%) for all forms of dystonia, 251.1 (42%) for cervical dystonia, 87.5 (15%) for blepharospasm, 55.2 (9%) for writer’s cramp, 38.0 (6%) for tardive dystonia, 32.3 (5%) for musician’s dystonia, 28.5 (5%) for psychogenic dystonia, 26.6 (4%) for generalised dystonia, 24.7 (4%) for spasmodic dysphonia, 20.9 (3%) for segmental dystonia, 15.2 (3%) for arm dystonia and 13.3 (2%) for oromandibular dystonia. Leg dystonia, hemidystonia and complex regional pain syndrome-associated dystonia are very rare. Compared to previous meta-analytical data, primary or isolated dystonia is 3.3 times more frequent in our study. When all forms of dystonia including psychogenic, generalised, tardive and other symptomatic dystonias are considered, our dystonia prevalence is 3.7 times higher than believed before. The real prevalence is likely to be even higher. Having based our study on treatment necessity, our data will allow better allocation of resources for comprehensive dystonia treatment.

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

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). 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. 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. 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.

Deep Brain Stimulation for Spasmodic Dysphonia: A Phase I Randomized Controlled Trial

Adductor spasmodic dysphonia (SD) is a dystonia of the vocal folds causing difficulty with speech. The current standard of care is repeated botulinum toxin injections to weaken the adductor muscles. We sought to ameliorate the underlying neurological cause of SD with a novel therapy—deep brain stimulation (DBS). This phase I trial was designed to assess the safety of DBS in SD and to quantify the magnitude of any benefit. It is the first RCT in the new field of DBS for voice.

A novel phenotype in an Italian family with a rare progranulin mutation

IntroductionProgranulin (PGRN) is a secreted glycoprotein encoded in humans by the GRN gene, located on chromosome 17q21. Several nonsense and missense pathogenetic GRN mutations have been described.ObjectiveWe herein describe two sisters carrying a rare GRN mutation with extremely different clinical features and family history of dementia and behavioral disorders, with a novel presentation with stridor and dysphonia.MethodsPatients underwent a multidimensional assessment including neurological and neuropsychological evaluation, structural and functional imaging, and genetic screening.ResultsThe younger sister presented at the age of 64 with inspiratory stridor, dysphonia and exercise-induced dyspnea. Transnasal fiberoptic laryngoscopy showed bilateral adduction of the vocal cords at rest and paradoxical further adduction of the vocal cords during forced inspiration, suggesting the hypothesis of an adductor laryngeal dystonia. The older sister presented at the age of 63 with a rapidly progressive corticobasal syndrome. The only clinical feature common to both sisters was a dysexecutive syndrome. The c.893G > A mutation in exon 9 of GRN was found in heterozygosis in both sisters, causing a missense Arginine to Histidine substitution in position 298 of the protein (p.R298H).ConclusionsOur report supports the pathogenicity of the GRN p.R298H mutation, which is first detected in two members from the same family, showing an extremely different phenotypes. Moreover, we report the first case of an FTD-associated mutation presenting with inspiratory stridor and dysphonia linked to adductor laryngeal dystonia, thus expanding the clinical spectrum of GRN-related disorders.

Spasmodic dysphonia: introductory phonetic analyses

ABSTRACT 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.

Botulinum Toxin Therapy for Spasmodic Dysphonia in Japan: The History and an Update.

Spasmodic dysphonia (SD) is a rare neurological disorder that impairs phonatory function by triggering involuntary and intermittent contractions of the intrinsic laryngeal muscles. SD is classified into three types: adductor SD (AdSD), abductor SD (AbSD), and mixed SD. Of these, AdSD accounts for 90–95% of disease; younger females are predominantly affected. Botulinum toxin injection into the laryngeal muscles is safe, minimally invasive, and very effective. Here, we review the history of clinical research for SD conducted in Japan. The first use of botulinum toxin injection therapy to treat SD in Japan was by Kobayashi et al. in 1989. The group developed an objective mora (syllable) method to evaluate SD severity. Recently, we conducted a placebo-controlled, randomized, double-blinded clinical trial of botulinum toxin therapy for AdSD and an open-label trial for AbSD to obtain the approval of such therapy by the Japanese medical insurance system. The mora method revealed significant voice improvement and the evidence was of high quality. Additionally, a clinical trial of type 2 thyroplasty using titanium bridges confirmed the efficacy and safety of such therapy. These studies broadened the SD treatment options and have significantly benefited patients.

Short- and Long-term Central Action of Botulinum Neurotoxin Treatment in Laryngeal Dystonia.

Background and ObjectivesLaryngeal dystonia (LD) is isolated task-specific focal dystonia selectively impairing speech production. The first choice of LD treatment is botulinum neurotoxin (BoNT) injections into the affected laryngeal muscles. However, whether BoNT has a lasting therapeutic effect on disorder pathophysiology is unknown. We investigated short-term and long-term effects of BoNT treatment on brain function in patients with LD.MethodsA total of 161 participants were included in the functional MRI study. Statistical analyses examined central BoNT effects in patients with LD who were stratified based on the effectiveness and duration of treatment.ResultsPatients with LD who were treated and benefited from BoNT injections had reduced activity in the left precuneus compared with BoNT-naive and treatment nonbenefiting patients. In addition, BoNT-treated patients with adductor LD had decreased activity in the right thalamus, whereas BoNT-treated abductor patients with LD had reduced activity in the left inferior frontal cortex. No statistically significant differences in brain activity were found between patients with shorter (1–5 years) and longer (13–28 years) treatment durations. However, patients with intermediate treatment duration of 6–12 years showed reduced activity in the right cerebellum compared with patients with both shorter and longer treatment durations and reduced activity in the right prefrontal cortex compared with patients with shorter treatment duration.DiscussionOur findings suggest that the left precuneus is the site of short-term BoNT central action in patients with LD, whereas the prefrontal-cerebellar axis is engaged in the BoNT response in patients with intermediate treatment duration of 6–12 years. Involvement of these structures points to indirect action of BoNT treatment on the dystonic sensorimotor network through modulation of motor sequence planning and coordination.

The Patho-Neurophysiological Basis and Treatment of Focal Laryngeal Dystonia: A Narrative Review and Two Case Reports Applying TMS over the Laryngeal Motor Cortex.

Focal laryngeal dystonia (LD) is a rare, idiopathic disease affecting the laryngeal musculature with an unknown cause and clinically presented as adductor LD or rarely as abductor LD. The most effective treatment options include the injection of botulinum toxin (BoNT) into the affected laryngeal muscle. The aim of this narrative review is to summarize the patho-neuro-physiological and genetic background of LD, as well as the standard recommended therapy (BoNT) and pharmacological treatment options, and to discuss possible treatment perspectives using neuro-modulation techniques such as repetitive transcranial magnetic stimulation (rTMS) and vibrotactile stimulation. The review will present two LD cases, patients with adductor and abductor LD, standard diagnostic procedure, treatments and achievement, and the results of cortical excitability mapping the primary motor cortex for the representation of the laryngeal muscles in the assessment of corticospinal and corticobulbar excitability.

Analysis of vocal fold vibration characteristics of spasmodic dysphonia by laryngeal high speed photography combined with glottis area wave

Objective: To analyze the characteristics of vocal fold vibration of normal people and patients with spasmodic dysphonia (SD) using laryngeal high speed videoendoscopy combined with glottal area wave analysis. Methods: This prospective study examined twenty healthy subjects (10 males and 10 females), 12 patients with adductor spasmodic dysphonia(AdSD) (2 males,10 females)as AdSD group and 2 patients with abductor spasmodic dysphonia(AbSD) (2 males) as AbSD group. Twelve of healthy subjects (2 males,10 females) were selected as control group according to AdSD group gender match. All the subjects were recruited from the Department of Voice, Zhongshan Hospital, Xiamen University from October 2019 to December 2020. All subjects underwent laryngeal high speed videoendoscopy and 10 vibration periods were selected from each recording and were used to quantitatively analyze the change of glottal area and vocal fold vibration parameters (Speed Quotient (SQ), Open Quotient (OQ) and Close Quotient (CQ)). Results: 1. There were statistically significant differences in SQ, CQ and OQ between males and females in the healthy subjects (t=12.28, 5.59, 5.59, P<0.05). The change of the glottal area during each vibration period in healthy subjects was relatively stable(0.19-0.42). 2. The change of the glottal area during each vibration period in AdSD subjects had larger fluctuations, with the glottal area change index fluctuating in the range of 0.31 to 0.62. The SQ value of the AdSD group was significantly lower than that of control group (t=4.246, P<0.05). There were no significant differences in OQ and CQ between AdSD group and normal group (t=1.064, 1.332, P>0.05); The SQ value of the AbSD group tended to increase compared to normal group. Conclusions: Laryngeal high speed videoendoscopy combined with glottal area wave analysis has a certain reference value in the studying the vibration characteristics of SD patients. SQ has good specificity.

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

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. Between 2009 and 2015, 11 patients (six females and five males aged from 32 to 91years) 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 2-8weeks after the first procedure. 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 5years of follow-up. Other patients required one to three new procedures with an average time between procedures of 15.3months. Over 24 surgeries performed on a total of 11 patients, one definitive treatment-related severe adverse event was reported. 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.

Classification, diagnosis and treatment of spasmodic dysphonia

痉挛性发声障碍（spasmodic dysphonia，SD）是一种由局灶性喉肌张力障碍引起的发声困难，以不规则和非控制性的发声中断为特征性表现，伴有发声费力。有报道其患病率约为1/100 000，中年女性多见，我国男女性发病性别比为1∶10.3，高发年龄段为30~49岁。根据受累肌群和临床特点，SD可分为3个类型，其中内收型（adductor spasmodic dysphonia，AdSD）最常见，约占SD患者的80％，外展型（abductor spasmodic dysphonia，AbSD）和混合型（mixed spasmodic dysphonia，MSD）较少见。目前，对SD的研究主要集中在治疗上，而对病理生理学的探索相对有限，临床诊断也因缺乏标准而具有挑战性，通常需要喉科医师、言语病理师及神经科医师的多学科合作。.