Adductor Spasmodic Dysphonia Patients Research Articles

A Novel Acoustic Evaluation Method for the Diagnosis of Adductor Spasmodic Dysphonia

Introduction: Adductor spasmodic dysphonia (ADSD) is characterized by involuntary laryngeal muscle spasms. Due to the lack of a quantitative evaluation method, most measurements have demonstrated difficulty in validity and reliability for diagnosing ADSD. This study aimed to establish a novel indicator for ADSD and determine its diagnostic effects. Methods: We investigated 98 voice samples from 49 patients with ADSD and 49 healthy participants. A sustained vowel was recorded by a high-definition audio recorder. Voice samples underwent regular acoustic evaluation and a novel global dimension (GD) method. GD, Jitter, Shimmer, HNR, Frequency shift, and CPPS were measured for both groups. Results: Statistical analysis revealed that the GD method effectively differentiated ADSD patients from healthy participants (p < 0.001, D′>0.8). Subsequent multiclass receiver operating characteristic analysis demonstrated that GD possessed the most significant classification accuracy (area under the curve = 0.988) compared with other acoustic parameters. Conclusion: GD was an effective metric for objective differentiation between ADSD patients and healthy participants. This metric could assist clinicians in the diagnosis of ADSD patients.

Comparison of Botulinum Toxin Injections and Type 2 Thyroplasty for Adductor Spasmodic Dysphonia.

Injection of botulinum toxin type A (BTX) into intrinsic laryngeal muscles is the current gold standard therapy for adductor spasmodic dysphonia (AdSD). However, a surgical procedure could potentially offer more stable and long-lasting voice quality to AdSD patients. Here, we report the long-term results of type 2 thyroplasty (TP2) with TITANBRIDGE® (Nobelpharma, Tokyo, Japan) compared with those of BTX injections. In total, 73 AdSD patients visited our hospital between August 2018 and February 2022. Patients were provided the option of BTX injections or TP2. They were assessed via the Voice Handicap Index (VHI)-10 before treatments and at scheduled clinical follow-ups at 2, 4, 8, and 12 weeks for BTX and at 4, 12, 26, and 52 weeks for TP2. Overall, 52 patients selected the BTX injection and had a pre-injection mean VHI-10 score of 27.3 ± 8.8. Following injections, the scores significantly improved to 21.0 ± 11.1, 18.6 ± 11.5, and 19.4 ± 11.7 at 2, 4, and 8 weeks, respectively. There were no significant differences between the pre-injection scores and the 12-week scores (21.5 ± 10.7). Alternately, 32 patients opted to be treated with TP2 and had a pre-treatment mean VHI-10 score of 27.7. All patients reported an improvement in their symptoms. Additionally, the mean VHI-10 score significantly improved to 9.9 ± 7.4 at 52 weeks following treatment. There was a significant difference between the two treatment groups at 12 weeks. Some patients received both treatments. These preliminary results provide important insights into the value of TP2 as a potential permanent treatment for AdSD patients. 3 Laryngoscope, 133:3443-3448, 2023.

Durability of Titanium Implants Following Type II Thyroplasty for Adductor Type Spasmodic Dysphonia.

To determine the durability of current titanium implants (TI) used in voice improvement surgery for adductor spasmodic dysphonia (ADSD), which is type II thyroplasty (T2T), and identify the effects of their fractures on vocal functions. A total of 36 ADSD patients who underwent T2T had the following exams: The CT scans of the larynx were performed 1 year after the surgery to assess the fractures of TI. The improvement in the mean voice handicap index 10 (VHI-10) scores and the success rate between nonfractured (NFR) and fractured (FR) groups were compared. It was indicated that TI was broken in 21 cases (58.3%). In one case (2.7%), a fracture on the part of the bridge that connects both sides of the plates was observed, and fractures at holes placed on the plates in the other 35 cases (55.6%). The mean VHI-10 score improved from 27.2 ± 8.1 to 11.4 ± 7.9 in the NFR group and from 26.3 ± 4.9 to 9.7 ± 7.9 in the FR group. The success rates were 66.6% in the NFR group and 71.5% in the FR group. No statistical difference was observed in the improvement in the mean VHI-10 scores, and the success rate between the two groups. However, two cases resulted in failure in the FR group, whereas no worsened case was observed in the NFR group. The current TI used in T2T has low durability and could result in the worsening of vocal symptoms after the surgery. 4 Laryngoscope, 133:3028-3033, 2023.

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.

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.

Detection of Vocal Fold Image Obstructions in High-Speed Videoendoscopy During Connected Speech in Adductor Spasmodic Dysphonia: A Convolutional Neural Networks Approach

Adductor spasmodic dysphonia (AdSD) is a neurogenic voice disorder, affecting the intrinsic laryngeal muscle control. AdSD leads to involuntary laryngeal spasms and only reveals during connected speech. Laryngeal high-speed videoendoscopy (HSV) coupled with a flexible fiberoptic endoscope provides a unique opportunity to study voice production and visualize the vocal fold vibrations in AdSD during speech. The goal of this study is to automatically detect instances during which the image of the vocal folds is optically obstructed in HSV recordings obtained during connected speech. HSV data were recorded from vocally normal adults and patients with AdSD during reading of the "Rainbow Passage", six CAPE-V sentences, and production of the vowel /i/. A convolutional neural network was developed and trained as a classifier to detect obstructed/unobstructed vocal folds in HSV frames. Manually labelled data were used for training, validating, and testing of the network. Moreover, a comprehensive robustness evaluation was conducted to compare the performance of the developed classifier and visual analysis of HSV data. The developed convolutional neural network was able to automatically detect the vocal fold obstructions in HSV data in vocally normal participants and AdSD patients. The trained network was tested successfully and showed an overall classification accuracy of 94.18% on the testing dataset. The robustness evaluation showed an average overall accuracy of 94.81% on a massive number of HSV frames demonstrating the high robustness of the introduced technique while keeping a high level of accuracy. The proposed approach can be used for efficient analysis of HSV data to study laryngeal maneuvers in patients with AdSD during connected speech. Additionally, this method will facilitate development of vocal fold vibratory measures for HSV frames with an unobstructed view of the vocal folds. Indicating parts of connected speech that provide an unobstructed view of the vocal folds can be used for developing optimal passages for precise HSV examination during connected speech and subject-specific clinical voice assessment protocols.

Quantitative laryngeal electromyography parameters may correlate with improved outcomes following botulinum toxin injection for spasmodic dysphonia

Despite use of qualitative laryngeal electromyography (LEMG) guided botulinum toxin A (BoNT-A) injection for treatment of adductor spasmodic dysphonia (AdSD), unsatisfactory injections and complete "misses" remain problematic. We aimed to determine if the quantitative LEMG measure of number of small segments (NSS) correlates with voice outcomes following (BoNT-A injection for AdSD. Automated quantitative LEMG analysis was performed during electromyography (EMG) -guided BoNT-A injection into the thyroarytenoid-lateral cricoarytenoid muscle complex for treatment of AdSD. Pre-injection phonatory NSS values were correlated with clinical voice outcomes and patient reported injection results. Quantitative LEMG measures were obtained for 45 AdSD patients (28 female, mean age 60.8 ± 12.8 years) during EMG-guided BoNT-A injection. Mean sampled NSS during phonation immediately prior to BoNT-A injection was 524 ± 323 (range: 2-904). Mean follow up was 36.5 ± 9.4 days; one patient was lost to follow-up. In comparison to their previous BoNT-A injection, the current injection was rated as worse, same, and better by 13 (29.5%), 25 (56.8%), and 6 (13.6%) patients, respectively. All 4 (9.1%) patients with NSS < 200 rated their BoNT-A injection result as worse than previous, and change in Voice Handicap Index-10 (VHI-10) scores were worse or without change. Aiming for an NSS value greater than 200 during phonation prior to BoNT-A toxin injection for AdSD may reduce unfavorable voice outcomes.

Treatment efficacy of electronic endoscope-guided botulinum toxin injection in adductor spasmodic dysphonia patients

Objective:To investigate the treatment efficacy of electronic endoscope-Guided botulinum toxin injection in Adductor Spasmodic Dysphonia Patients. Method:Clinical characteristics of forty- three cases were retrospectively analyzed. The disease were diagnosed with adductor spasmodic dysphonia and graded according to the severity of the disease by experienced voice specialist. All the cases were treated by electronic endoscope-guided botulinum toxin type A injection in bilateral thyroarytenoid muscles. All the subjects underwent stroboscopic laryngoscope examination and filled in the Voice Handicap Index-10（VHI-10）. They also filled in the VAS score of Voice related symptoms by self evaluation and other evaluation . One month Later, the patients and someone they lived with filled in the VAS score of Voice related symptoms again. Result:After the first injection, the voice-related symptoms of 35 patients improved to varying degrees..All The average onset time of drug was（2.33±1.86） days. The duration of curative effect ranged from 1 to 6 months, the average duration was（2.42±1.65） months. After injection, no one had serious or persistent adverse reactions. There were significant differences in the total score of VHI-10, physiology（P） and function（F） dimensions in VHI-10 of moderate and severe SD patients before and after injection（P<0.05） in all patients. For moderate cases, no significant change in speech articulation（P>0.05）, overall evaluation of voice quality and any other subprojects are statistically significant（P<0.05） in the VAS score of Voice related symptoms; For severe cases, the degree of squeezing and effort during vocalization are no statistically significant（P>0.05）, overall evaluation of voice quality and any other subitems are statistically significant（P<0.05） in the VAS score of Voice related symptoms. Conclusion:In the absence of LEMG, electronic endoscope-guided botulinum toxin injection in adductor spasmodic dysphonia patients can significantly improve the voice quality and quality of life of adductive SD patients. The method is simple to operate, less traumatic, safe and effective, and easy to carry out outpatients service.

Pre- and Postoperative High-Speed Videolaryngoscopy Findings in Adductor Spasmodic Dysphonia Following Transoral CO2 LASER-Guided Thyroarytenoid Myoneurectomy

Vocal cord vibration after transoral CO2 LASER-guided thyroarytenoid (TA) myoneurectomy in adductor spasmodic dysphonia (AdSD) patients is unclear to date. The precise vibratory patterns in AdSD patients are difficult to evaluate with routine videolaryngostroboscopy. High-speed videolaryngoscopy (HSV) is an ideal choice to evaluate such patients. This study was performed to compare pre- and postoperative, after 6 months, vocal fold vibratory onset delay (VFVOD) and closed phase glottal cycle (CPGC) in AdSD patients following transoral CO2 LASER-guided TA myoneurectomy using the HSV. Retrospective study, conducted from January, 2016 to January, 2019, of the AdSD patients who underwent transoral CO2 LASER-guided TA myoneurectomy using the HSV. Patient data were acquired from the hospital database to evaluate VFVOD and CPGC from HSV recordings of the patients. VFVOD was calculated as sum of prephonatory delay (PPD) and steady-state delay (SSD). The PPD and SSD were evaluated and compared separately for each patient. The MedCal Version 19.2.6 was used for data analysis. Paired sample t test was performed to compute the significance of the difference between the mean of the dataset. A P value less than 0.05 was considered significant. A total of nine patients were included in the study, out of which three were females and six were males. The average age was 45.5 ± 6.9 years. The mean of postoperative PPD (166.8 ± 22.1), SSD (76.5 ± 8.6), and CPGC (62.6 ± 4.8) were significantly less than mean of preoperative PPD (222.6 ± 22.1), SSD (97.7 ± 9.5), and CPGC (71.6 ± 5 %), with P values of 0.0007, 0.0001, and 0.0001, respectively. There was a significant decrease in VFVOD and CPGC posttransoral CO2 LASER-guided TA myoneurectomy in AdSD patients after 6 months follow-up. This study also establishes efficiency of the HSV to measure the vocal cord vibration in the patients with AdSD. The primary limitations of the study were the small sample size and its retrospective nature. Future prospective studies with increased sample size can further substantiate the findings of the work performed here.

Patient Experience Contributing to Outcomes of Laryngeal Botulinum Toxin Injection

Laryngeal Botulinum Toxin injection (LBTX) in the adductor musculature is the current therapy for Adductor Spasmodic Dysphonia. This study explores nonbiological factors that can affect the patient experience during this procedure and their association with better or worse self-reported effectiveness. A 14 item survey was used to evaluate the patient experience in patients who had undergone LBTX in Mayo Clinic Jacksonville, Florida, during 2019. Information from the survey, previous medical history, and demographic data were collected, and a descriptive analysis was performed. Of the 36 patients who participated, the mean age was 65 years and a female predominance was found (66%). The average age at onset of symptoms was 57 years, and voice tremor was associated with 36.1% of patients. Preprocedure education was recognized as a factor affecting outcomes in 87% of patients; 11 patients reported that body position used during the injection could affect the results. Pain or stress experienced at the time of procedure was referred in one-third of patients as an influencing factor too. This study has shown that nonpharmacological factors such as education before the procedure, body position, pain, and stress sensation before LBTX may have a role in the botulinum toxin effect on Adductor Spasmodic Dysphonia patients. This study is the first to describe these variables qualitatively, and further studies may help to improve the patient experience and outcome of LBTX around the world.

Retrospective review of dosing trends in botulinum toxin injections for the treatment of adductor spasmodic dysphonia in a long-term cohort

BackgroundBotulinum toxin A (BT) is the gold standard treatment for adductor spasmodic dysphonia (AdSD) with established use for greater than thirty years. The spasmodic dysphonia (SD) literature would benefit from additional long-term cohort data, especially in the Canadian population. The goals of this study were to evaluate whether BT dosage required to achieve acceptable voice shifts over time and to elucidate differences in the subgroups of patients receiving unilateral vocal fold (UVF) injections.MethodsPatient records were retrospectively reviewed at the regional tertiary Voice Clinic for AdSD patients from 1996 to 2017 to identify AdSD patients treated with serial BT injections. Descriptive statistics, paired t-tests for time between treatments and ANOVA tests were used to evaluate trends in subgroup age.ResultsOne-hundred and twenty-six patients (61% female, mean age = 53 ± 15.5 years) met inclusion criteria and received laryngeal EMG-guided BT injections for up to twenty-two years and as many as 79 treatments. The mean total BT dosage for our population was 1.54 ± 0.35 Units per side. The majority of subjects had decreasing doses over time with a small subgroup having slowly increasing doses. Comparing treatment dosages between unilateral and bilateral injection groups, injection dosage per vocal fold was 1.65 ± 0.62 with time between injections was significantly shorter for the unilateral injection group (mean = 105 days, SD ± 19.8 days, p = 0.005) compared to the bilateral injection subgroup (137 ± 35.7 days, p < 0.005). The mean age of the unilateral injection population as younger at 42.4 ± 11.8 years (p = 0.004).ConclusionThe majority of patients in this study had decreasing BT injection dosages over time, with a smaller proportion having slowly increasing doses, thought to be likely relating to disease severity. The unilateral vocal fold injections were well tolerated despite needing more frequent injections, and found to be more prevalent in the younger age group.

Vibratory Onset of Adductor Spasmodic Dysphonia and Muscle Tension Dysphonia: A High-Speed Video Study✰

Adductor spasmodic dysphonia (AdSD) is a challenging voice disorder to diagnose, often erroneously diagnosed as muscle tension dysphonia (MTD) or vocal tremor, due to its similarity in auditory and perceptual presentation. Assessments using laryngoscopy or strobolaryngoscopy procedures have demonstrated limited utility in the diagnosis of spasmodic dysphonia. High-speed videoendoscopy (HSV) provides visualization of the precise vibratory pattern of phonatory onset and thus, offers an alternative to previous diagnostic strategies for visual diagnosis of AdSD. The purpose of this study was to examine vibratory onset of patients with AdSD and patients with MTD using HSV methodology. HSV of six adults with AdSD and five adults with MTD were captured during sustained phonation. Digital kymography was used to obtain precise vibrogram data at the mid-membranous region of the vocal fold prior to and at the onset of phonation. Voice onset delay was examined by (1) quantifying timing of prephonatory delay and steady state delay and (2) describing vocal fold onset movements qualitatively in each diagnosis. HSV adequately captured the phonatory onset of the vocal folds. Voice onset delay was not significantly different between AdSD and MTD. However, there were distinct differences in voice onset gestures. Both AdSD and MTD patients presented with vocal hyperfunction during the onset of phonation. In a subset of AdSD patients, a rapid sustained adduction occurred following the initial vibratory motion. Vocal fold vibration then continued until steady phonation was achieved. This oscillatory break pattern was not observed in patients with MTD. Therefore, there appears to be differences in vocal fold vibratory onset motion between MTD and AdSD. HSV captures the precise vibratory onset in patients with MTD and AdSD. Differences were most notable after vibratory onset as opposed to vibratory delay measurements. Examination of voice onset gesture may offer an additional laryngeal parameter to assist in the differential diagnosis of spasmodic dysphonia.

Defining differences in patient characteristics between spasmodic dysphonia and laryngeal tremor.

To compare presenting characteristics of patients with adductor spasmodic dysphonia (ADSD), ADSD with laryngeal tremor (ADSD + LT), and laryngeal tremor without ADSD (LT). Cross-sectional analysis. Patients treated for laryngeal movement disorders (1990-2016) were included. Analysis of variance and chi square tests measured differences in patient characteristics across the three disease groups. Using ADSD as the referent, multivariable logistic regression models were used to determine whether potential risk factors including patient demographics, family history, presence of potential inciting events prior to disease onset, and coprevalent movement disorders were associated with ADSD + LT or LT. In all, 652 patients with ADSD (n = 377), ADSD + LT (n = 98), and LT (n = 177) were included. ADSD patients were significantly younger than those with ADSD + LT and LT (52.5 ± 13.4, 63.9 ± 11.3, and 69.3 ± 10.5 years, respectively; P < 0.001). Coprevalent movement disorders were more common in ADSD + LT (38.7%) and LT (57.1%) groups than in the ADSD group (11.5%; P < 0.001). Compared to ADSD, patients with ADSD + LT and LT were more likely to develop an additional movement disorder during follow-up. In multivariable analyses, increasing age, female gender, and having a movement disorder at presentation were associated with significantly greater odds of having ADSD + LT or LT when compared to ADSD. ADSD + LT patients demonstrate intermediate gender composition and age distributions between those with ADSD and LT. These findings suggest that ADSD + LT may be a distinct phenotype in the spectrum of laryngeal movement disorders. 4 Laryngoscope, 129:170-176, 2019.

Factors Associated With Patient-perceived Hoarseness in Spasmodic Dysphonia Patients

The American Academy of Otolaryngology-Head and Neck Surgery Clinical Practice Guidelines on Hoarseness distinguishes between hoarseness, which is a symptom perceived by the patient, and dysphonia, which is a diagnosis made by the clinician. Our objective was to determine factors that are associated with patient-perceived hoarseness in spasmodic dysphonia (SD) patients. Retrospective study. Adductor SD patients who presented for botulinum toxin injections from September 2011 to June 2012 were recruited. The main outcome variable, Voice Handicap Index-10 (VHI-10), was used to quantify patient-perceived hoarseness. Clinical data, Hospital Anxiety and Depression Scale (HADS), and VHI-10 were collected. Clinician-perceived dysphonia was measured by a speech-language pathologist with Consensus Auditory Perceptual Evaluation of Voice (CAPE-V). Statistical analysis included univariate analyses and multiple linear regression. One hundred thirty-nine SD patients had VHI-10 score of 26.0 ± 7.2 (mean ± standard deviation), disease duration of 10.5 + 7.0 years, CAPE-V overall score of 43.2 ± 21.8, HADS anxiety score of 6.7 ± 3.8, and HADS depression score of 3.6 ± 2.8. In univariate analyses, there were positive correlations (P < 0.05) between VHI-10 and female gender, CAPE-V overall, older age, HADS anxiety, and depression. There was no correlation with professional voice use and disease duration. In multiple linear regression (R2 = 0.178, P < 0.001), age, HADS anxiety, female gender, and CAPE-V were significant. Older age, higher anxiety levels, female gender, and clinician-perceived dysphonia are associated with higher levels of patient-perceived hoarseness in SD patients. Hoarseness is a very personal symptom. Multiple factors determine its self-perception.

The Mayo Clinic Arizona Spasmodic Dysphonia Experience: A Demographic Analysis of 718 Patients.

Analyze demographic data collected over a 25-year experience of 718 patients with spasmodic dysphonia (SD) who have been treated with botulinum toxin-A (BoNT-A) and compare our data with previously published studies. Seven hundred eighteen patients with SD were treated with 6621 BoNT-A injections at Mayo Clinic Arizona between 1989 and 2014. All patients were treated by the same physician team. Background demographic data for each patient were recorded. Of 718 patients, 557 patients were female (77.6%). Six hundred sixty of 718 (91.8%) patients had adductor SD (AdSD), and 58 of 718 (8.1%) patients had abductor SD (AbSD). Average age of onset was 51 years. Of 718 patients, 378 (52.6%) had vocal tremor (VT); VT was present in 54.4% of AdSD patients and 32.1% of AbSD patients. Thirty-seven of 718 (5.2%) patients had other dystonias, including cervical dystonia (2.3%), blepharospasm (1.4%), limb dystonia (1.1%), and oromandibular dystonia (0.3%). A positive family history of SD was present in only 6 of 718 patients (0.8%) and of other dystonias in 11 of 718 patients (1.5%). Spasmodic dysphonia is a chronic and potentially disabling focal laryngeal dystonia. The Mayo Clinic Arizona SD experience compares to prior reports and reveals a female preponderance, onset in middle age, infrequent hereditary pattern, high co-occurrence of VT, and low co-occurrence of other dystonias.

Voice Onset Time for the Word-Initial Voiceless Consonant /t/ in Japanese Spasmodic Dysphonia—A Comparison With Normal Controls

Voice onset time (VOT) for word-initial voiceless consonants in adductor spasmodic dysphonia (ADSD) and abductor spasmodic dysphonia (ABSD) patients were measured to determine (1) which acoustic measures differed from the controls and (2) whether acoustic measures were related to the pause or silence between the test word and the preceding word. Forty-eight patients with ADSD and nine patients with ABSD, as well as 20 matched normal controls read a story in which the word "taiyo" (the sun) was repeated three times, each differentiated by the position of the word in the sentence. The target of measurement was the VOT for the word-initial voiceless consonant /t/. When the target syllable appeared in a sentence following a comma, or at the beginning of a sentence following a period, the ABSD patients' VOTs were significantly longer than those of the ADSD patients and controls. Abnormal prolongation of the VOTs was related to the pause or silence between the test word and the preceding word. VOTs in spasmodic dysphonia (SD) may vary according to the SD subtype or speaking conditions. VOT measurement was suggested to be a useful method for quantifying voice symptoms in SD.

Relationship of Laryngeal Botulinum Toxin Dosage to Patient Age, Vitality, and Socioeconomic Issues

Chemical denervation with botulinum toxin A is the current standard of treatment for spasmodic dysphonia, but dosage is determined individually after a titration period that can take months to years. The objective of this study was to determine if age, body mass index (BMI), overall health, and socioeconomic factors were associated with a patient's optimal dose of botulinum toxin. This retrospective chart review looked at 32 patients with stabilized doses of botulinum toxin. Age and BMI were obtained from patient charts, and overall health was assessed by the Short-Form 36 survey. Analysis showed that BMI was positively correlated with botulinum toxin dose (r=0.42, P=0.02). Overall health showed a positive but nonsignificant association with dose, but subgroup analysis found that adductor spasmodic dysphonia (ADSD) patients without tremor had a significant positive correlation between overall health and dose (r=0.50, P=0.04), whereas tremor-only and mixed dystonia showed a negative nonsignificant correlation. Age was found to have no significant association with dose. Although socioeconomic factors were found to impact the number and frequency of injections, they had no significant impact on the ultimate dosage. BMI and overall health are positively correlated with higher effective dose and may be useful in guiding clinicians during the titration period.

Treatment efficacy of electromyography versus fiberscopy-guided botulinum toxin injection in adductor spasmodic dysphonia patients: a prospective comparative study.

Introduction. This study prospectively evaluates and compares the treatment efficacy of botulinum toxin injection under electromyography guidance (EMG group) and percutaneous botulinum toxin injection under flexible fiberscopic guidance (fiberscopy group). Methods. Thirty patients with adductor spasmodic dysphonia (ADSD), who had never received treatment, were randomly allocated into EMG- or fiberscopy-guided botulinum toxin injections between March 2008 and February 2010. We assessed acoustic and aerodynamic voice parameters, and the voice handicap index (VHI) before injection and at 1, 3, and 6 months after injection. Results. The mean total dosage of botulinum toxin was similar for both groups: 1.7 ± 0.5 U for the EMG group and 1.8 ± 0.4 U for the fiberscopy group (P > 0.05). There were no significant differences in outcomes between the two groups in either the duration of effectiveness or complications such as breathy voice and aspiration. Conclusion. Botulinum toxin injection under fiberscopic guidance is a viable alternative to EMG-guided botulinum toxin injection for the treatment of adductor spasmodic dysphonia when EMG equipment is unavailable.

Brain activity related to phonation in young patients with adductor spasmodic dysphonia

This study investigated the brain activities during phonation of young patients with adductor spasmodic dysphonia (ADSD) of relatively short disease duration (<10 years). Six subjects with ADSD of short duration (mean age: 24. 3 years; mean disease duration: 41 months) and six healthy controls (mean age: 30.8 years) underwent functional magnetic resonance imaging (fMRI) using a sparse sampling method to identify brain activity during vowel phonation (/i:/). Intragroup and intergroup analyses were performed using statistical parametric mapping software. Areas of activation in the ADSD and control groups were similar to those reported previously for vowel phonation. All of the activated areas were observed bilaterally and symmetrically. Intergroup analysis revealed higher brain activities in the SD group in the auditory-related areas (Brodmann's areas [BA] 40, 41), motor speech areas (BA44, 45), bilateral insula (BA13), bilateral cerebellum, and middle frontal gyrus (BA46). Areas with lower activation were in the left primary sensory area (BA1-3) and bilateral subcortical nucleus (putamen and globus pallidus). The auditory cortical responses observed may reflect that young ADSD patients control their voice by use of the motor speech area, insula, inferior parietal cortex, and cerebellum. Neural activity in the primary sensory area and basal ganglia may affect the voice symptoms of young ADSD patients with short disease duration.

The Mayo Clinic Arizona Spasmodic Dysphonia Experience: 24 Years and 686 Patients

Objectives: 1) Outline onabotulinumtoxinA (onaBTX-A) injection dose and frequency trends in adductor spasmodic dysphonia (AdSD) patients. 2) Assess correlations between onaBTX-A injection dose, duration of breathiness, time to therapeutic onset, percent maximal benefit obtained, and duration of benefit. Methods: Retrospective chart review. Setting: Tertiary academic care center. Subjects and Methods: 686 patients with spasmodic dysphonia (SD) were treated with 6345 BTX injections between 1989 and 2013. This included 630 AdSD and 56 AbSD patients further subdivided into subgroups based on presence of vocal tremor (VT) and injection laterality. Injection frequency, dosing, laterality, and background demographic data were recorded in addition to subjective onaBTX-A injection responses. Results: AdSD patients’ symptom onset and injections began at an older age than AbSD patients (52.5; 60.6 years vs. 43.7; 50.0 years respectively; P = 0.0008) and had VT more frequently ( P= 0.0012). For the 380 AdSD patients (+/- VT) receiving over six injections, the average total onaBTX-A dose was 5.0 units, which remained stable up to 15 years (year 15 dose mean= 5.29, std dev= 5.07). Using Pearson’s correlation coefficients, there was no significant positive or negative correlation between onaBTX-A dose and percent maximal benefit (p=0.760), duration of breathiness ( P = 0.618), dysphagia duration ( P = 0.142), benefit duration ( P = 3622), or time to therapeutic onset ( P = 0.618). Conclusions: Spasmodic dysphonia is effectively treated according to patient subjective response; however, more refined longitudinal analysis is needed to show if any objective correlation between injection dose and outcomes are present. Treatment methods and outcomes as described should aid others in developing best practice patterns.