Adductor Spasmodic Dysphonia Patients Research Articles

Laryngeal dystonia gravidarum: Sudden onset of adductor spasmodic dysphonia in pregnancy

The purpose of this study was to identify the presence or absence of known factors related to onset of adductor spasmodic dysphonia (ADSD) in a population with sudden onset during or after pregnancy. Retrospective review. A review of 350 patient records identified five patients with sudden onset of ADSD related to pregnancy. An age-matched group with sudden onset of ADSD not related to pregnancy served as controls. All subjects completed a 20-question survey of risk factors relevant to ADSD. The average age of onset in both groups was 31 years. Three had onset of ADSD in the postpartum period, the other two during pregnancy. Significantly increased avocational voice use was found in the pregnant group compared to the control group. There was a significant difference in the two groups regarding cumulative risk factors traditionally associated with ADSD. Sudden onset of ADSD can occur in pregnancy in women with clinical profiles that differ from traditional ADSD patients.

Initial Dosing of Botox A in Adductor Spasmodic Dysphonia

Objective: 1) Assess effect on voice improvement and duration of breathiness based on initial dose of BotoxA in management of adductor spasmodic dysphonia. 2) Compare voice outcomes for initial bilaterally injected doses of 1.25 units Botox A (Group A) versus 2.5 units (Group B). Method: A retrospective chart review was undertaken of all adductor spasmodic dysphonia patients treated at a tertiary care facility between 1990 and 2011. Demographic data (age and sex), voice rating, duration of voice improvement, and breathiness were evaluated and compared between Groups A and B using Student’s t test and chi-square analysis. Results: Of 478 patients identified, 305 (group A: 223; group B: 82) patients met inclusion criteria. The average age of group A was 56.2 years and group B was 57.4 years ( P = .5). The female/male ratio was 2.91 for group A versus 3.56 for group B ( P = .61). Good voice outcomes (grade 3 or 4) were reported by 91% of group A patients versus 94% of group B ( P = .75). The average duration of voice improvement was 99.7 days for group A and 108.3 for group B ( P = .54). The average duration of breathiness was 10.88 days for group A versus 15.42 for group B ( P = .02). Conclusion: Patients injected with 1.25 units bilaterally had a statistically significant shorter duration period of breathiness without a statistically significant difference in clinical effectiveness or voice outcome. It is therefore recommended that a relatively low initial Botox dose be used with subsequent titration to achieve improved voice outcomes.

Endoscopic Laser Thyroarytenoid Myoneurectomy in Patients with Adductor Spasmodic Dysphonia: A Pilot Study on Long-Term Outcome on Voice Quality

Adductor spasmodic dysphonia (ADSD) is a focal laryngeal dystonia, which compromises greatly the quality of life of the patients involved. It is a severe vocal disorder characterized by spasms of laryngeal muscles during speech, producing phonatory breaks, forced, strained and strangled voice. Its symptoms result from involuntary and intermittent contractions of thyroarytenoid muscle during speech, which causes vocal fold to strain, pressing each vocal fold against the other and increasing glottic resistance. Botulinum toxin injection remains the gold-standard treatment. However, as injections should be repeated periodically leading to voice quality instability, a more definitive procedure would be desirable. In this pilot study we report the long-term vocal quality results of endoscopic laser thyroarytenoid myoneurectomy. Prospective study. Surgery was performed in 15 patients (11 females and four males), aged between 29 and 73 years, diagnosed with ADSD. Voice Handicap Index (VHI) was obtained before and after surgery (median 31 months postoperatively). A significant improvement in VHI was observed after surgery, as compared with baseline values (P=0.001). The median and interquartile range for preoperative VHI was 99 and 13, respectively and 24 and 42, for postoperative VHI. Subjective improvement of voice as assessed by the patients showed median improvement of 80%. Because long-term follow-up showed significant improvement of voice quality, this innovative surgical technique seems a satisfactory alternative treatment of ADSD patients who seek a definite improvement of their condition.

Voice Quality of Life after Type II Thyroplasty for Spasmodic Dysphonia

Objective: 1) Determine the effectiveness of type II thyroplasty for adductor spasmodic dysphonia (AdSD), through perceptual and accoustic analysis. 2) Assess the pre- and postoperative quality of life of AdSD patients using the Voice Handicap Index-10 (VHI-10). Method: Retrospective study. Twelve patients with AdSD underwent type II thyroplasty between March 2007 and December 2010. Measured outcomes included perceptual assessment, acoustic analyses (DVB, SDF0, jitter, shimmer, and HNR), and VHI-10 and were performed prior to and six months or more after surgery. VHI-10 and acoustic evaluation scores were compared. Results: Average follow-up interval was 12.6 months. In perceptual analysis (GRBAS), overall grade and strain significantly improved after surgery ( P = .0017, P = .0002). There were no significant difference in roughness, breathiness, and asthenia. In acoustic analysis, DVB, SDF0, jitter, shimmer, and HNR ( P = .039, P = .0003, P = .0016, P = .0011, P = .0003) improved significantly after surgery. Mean VHI-10 scores significantly improved from a mean of 26.5 to 3.75. Conclusion: Treatment of AdSD with type II thyroplasty significantly improved voice-related quality of life and acoustic findings. The study revealed a significant relationship between the acoustic parameters and the VHI-10. The results confirmed that VHI-10 can be a valuable tool for assessing type II thyroplasty for AdSD.

The point-touch technique for botulinum toxin injection in adductor spasmodic dysphonia: quality of life assessment

Botulinum toxin injection under electromyographic guidance is the 'gold standard' for adductor spasmodic dysphonia treatment. The point-touch technique, an alternative injection method which relies on anatomical landmarks, is cheaper, quicker and more accessible, but has not yet gained widespread acceptance due to concerns about patient satisfaction. To assess swallowing and voice-related quality of life following point-touch botulinum toxin injection in adductor spasmodic dysphonia patients. Stanford University Voice and Swallowing Center. Prospective case series (evidence level four). Consecutive adductor spasmodic dysphonia patients with a stable botulinum toxin dose-response relationship were recruited prospectively. The Eating Assessment Tool and Voice-Related Quality of Life questionnaires were completed pre-treatment and at 10 and 30 per cent completion of the injection cycle, respectively. Thirty-seven patients completed follow up. The mean total botulinum toxin dose was 0.88 units. Pre-treatment Voice-Related Quality of Life questionnaire results reflected the burden of disease. Post-treatment Eating Assessment Tool and Voice-Related Quality of Life questionnaire results were collected at 2.53 and 7.84 weeks, respectively; the former showed an increase in dysphagia, albeit statistically insignificant, while the latter showed significantly improved scores (both domain and total). The point-touch technique is a viable alternative for botulinum toxin injection in the treatment of adductor spasmodic dysphonia.

Adductor Spasmodic Dysphonia – Changes in dosing after prolonged injections

CONTACT OBJECTIVES: Botulinum toxin therapy (BTX) for adductor spasmodic dysphonia (ADSD) requires re-injection. The dosing effects after prolonged treatment are not well reported. We report our ten-year experience in the utilization of BTX in ADSD STUDY DESIGN: Retrospective chart review METHODS: From a database of 182 ADSD patients from 1997-2008 treated with BTX, we pulled a subset of 87 patients receiving BTX for greater than 3 visits (average 10.27 visits, range 3-40). We analyzed duration of effect, dosing effects and changes in administration technique. RESULTS: This study group was predominantly female (3:1), presenting at mean age 60. All BTX was administered with laryngeal electromyographic guidance. The average starting dose was 2.28 units (range 1.25 – 3.75). The average dose per injection was 2.15 units (range 0.25-12.5) with an average time interval of 5.6 months between visits. Patients reached a stable dosing regimen at an average of 1.34 months, with 75% optimized after the first visit. There was a trend towards increased average dosage for patients during their 15th treatment visit and up (p=0.14), with increased variation in effect (SD 0.95 vs 1.36). Average time interval between visits tended to decrease over time. Patients who began treatment at older ages in the 6th and 7th tended to require decreasing dosages over time. 10 out of 87 patients progressed to unilateral injections after an average of 12.5 treatment visits, with 70% efficacy. CONCLUSIONS: Botulinum therapy in ADSD is stable and safe. Prolonged treatment over 15 visits may require changes in dosing and technique. Unilateral injections provide an effective alternative to bilateral injection. Name: Nina Chinosornvatana, MD Organization: Mount Sinai Hospital Email: nchinos@gmail.com •Patient positioned supine with neck slightly extended. Laryngeal electromyography (LEMG) ground and reference electrodes are placed. Neck prepped. •Botulinum toxin diluted to 100 units per 4cc of injectable bacteriostatic saline. 1cc tuberculin syringe fixed to LEMG monopolar electrode injector needle. •Needle inserted through the skin just off of midline at the level of the cricothyroid membrane. Needle advanced superolaterally towards the targeted thyroarytenoid muscle. •LEMG used to verify placement of needle into thyroarytenoid muscle, showing increased muscle action potential complexes with phonation and cough. •Starting dosage administered is 2.5 units to each side. Subsequent dosing is determined dependent on prior dosage and its effectiveness. • Botulinum therapy was shown to have prolonged efficacy, with successful injections administered at upper limits of 80 injections, 40 visits, and 10 years. This is consistent with BTX’s proven record of safety and efficacy in the literature. To date, there are no reports of mortality attributed to BTX treatment in the literature. 7 The most common adverse effect has been temporary excessive breathiness from overinjection. •We recommend 2.5 units to each thyroarytenoid muscle as an effective starting dose with use of laryngeal electromyographic guidance. Reported rates of starting dosage administration vary; our 70% efficacy rate after the first visit compares favorably to other reported series. 6,7 •We saw an increase in dosage variability in patients receiving prolonged treatment beyond 15 visits, with a trend towards increased average dosing. Other series have reported decreases in dosing requirements over time without resistance. 7 We therefore recommend vigilant attention to changes in dosing requirement or technique in patients over 15 visits, with consideration of unilateral injections as an alternative to bilateral injection. •Unilateral injections have been reported to be successful in a wide range of doses, from 2.5u – 30u. 9 Comparisons to bilateral injections have shown similar efficacy, with some reports of decreased side effect profiles. 10 Our experience confirms unilateral administration as a useful and effective alternative to bilateral injection. •Adductor spasmodic dysphonia (ADSD) is an idiopathic focal dystonia of the intrinsic laryngeal adductor musculature. Spasms most frequently affect the thyroarytenoid muscles, but can also involve the lateral cricoarytenoid and interarytenoids, resulting in overforceful vocal fold closure. •Clinically, ADSD presents with strangulated strained vocal quality, and is characterized by repetitive breaks in phonation and pitch, requiring increased effort during speech. ADSD is triggered by speech, in particular, voiced sounds. 1 •Treatment options for ADSD include speech therapy, recurrent laryngeal nerve sectioning2,3 , partial thyroarytenoid myectomy4, anterior commissure release, and botulinum administration. The use of botulinum remains the gold standard treatment due to its effectiveness, reliability, and high safety profile.5 •Chemodenervation with botulinum requires reinjection. Because there is significant variability in patient response and toxin delivery, individualization of treatment is necessary for optimal effect. Adductor Spasmodic Dysphonia

A Comparison of the VHI, VHI-10, and V-RQOL for Measuring the Effect of Botox Therapy in Adductor Spasmodic Dysphonia

Although disease-specific quality-of-life (QOL) instruments are an invaluable outcome measure in spasmodic dysphonia, there is no consensus on which QOL instrument should be used. To determine the responsiveness of the Voice Handicap Index (VHI), Voice Handicap Index-10 (VHI-10), and Voice-Related Quality of Life (V-RQOL) to the treatment effect of botulinum toxin (Botox) in adductor spasmodic dysphonia (ADSD). Stanford University Voice and Swallowing Center. Prospective case series (level of evidence=4). Consecutive ADSD patients with a stable Botox dose-response relationship were recruited prospectively. VHI, VHI-10, and V-RQOL scores were obtained pretreatment and during the middle third of the posttreatment injection cycle. Thrity-seven patients completed the follow-up. The average total Botox dose was 0.88 units. The average follow-up time after injection was 7.84 weeks. The pretreatment QOL scores reflected the burden of the disease. All the three instruments were highly correlated in subscale and total scores. After treatment, all three instruments showed significant improvement. The VHI, VHI-10, and V-RQOL all reflected the morbidity associated with ADSD and were significantly responsive to the effect of Botox therapy. The choice of instrument should be based on physician preference.

Abnormal Activation of the Primary Somatosensory Cortex in Spasmodic Dysphonia: An fMRI Study

Spasmodic dysphonia (SD) is a task-specific focal dystonia of unknown pathophysiology, characterized by involuntary spasms in the laryngeal muscles during speaking. Our aim was to identify symptom-specific functional brain activation abnormalities in adductor spasmodic dysphonia (ADSD) and abductor spasmodic dysphonia (ABSD). Both SD groups showed increased activation extent in the primary sensorimotor cortex, insula, and superior temporal gyrus during symptomatic and asymptomatic tasks and decreased activation extent in the basal ganglia, thalamus, and cerebellum during asymptomatic tasks. Increased activation intensity in SD patients was found only in the primary somatosensory cortex during symptomatic voice production, which showed a tendency for correlation with ADSD symptoms. Both SD groups had lower correlation of activation intensities between the primary motor and sensory cortices and additional correlations between the basal ganglia, thalamus, and cerebellum during symptomatic and asymptomatic tasks. Compared with ADSD patients, ABSD patients had larger activation extent in the primary sensorimotor cortex and ventral thalamus during symptomatic task and in the inferior temporal cortex and cerebellum during symptomatic and asymptomatic voice production. The primary somatosensory cortex shows consistent abnormalities in activation extent, intensity, correlation with other brain regions, and symptom severity in SD patients and, therefore, may be involved in the pathophysiology of SD.

Transoral laser ventricular fold resection and thyroarytenoid myoneurectomy for adductor spasmodic dysphonia: Long‐term outcome

A transoral approach to laser myoneurectomy of the thyroarytenoid muscles was recently reported as an effective technique for treatment of adductor spasmodic dysphonia (ASD). The short-term results were encouraging. In this study, a long-term surgical outcome of this technique is investigated. A prospective clinical series. Fifty-two patients with ASD underwent transoral laryngomicrosurgery with a CO(2) laser to resect the ventricular folds followed by myoneurectomy of the thyroarytenoid muscles. The nerve fibers of recurrent laryngeal nerve terminating at the thyroarytenoid muscle, which were frequently found branching deeply among the posterior belly of this muscle, were vaporized. Care was taken not to damage the vocal ligaments, lateral cricoarytenoid muscles, or arytenoid cartilages. Pre- and postoperative subjective voice assessments, and acoustic and aerodynamic measurements, were performed and statistically analyzed. Twenty-nine of the 52 patients who were followed up for more than 12 months (range, 12-63 months; mean, 31 months) were studied. Moderate and marked vocal improvement was achieved in 90% (26/29) of the patients. Three patients had 30% improvement, which was reported as unsuccessful. Eight of the 26 patients who were satisfied with their postoperative voice still had a mild strain during phonation. Of the eight patients, seven achieved normal or nearly normal voice quality after revision laser surgery. No significant vocal deficit or paralysis was observed in any patient. After long-term follow-up of 31 months on average, approximately 90% of the ASD patients obtained moderate to marked improvement of vocal performance after transoral laser surgery. The long-lasting outcome is encouraging.

Outcomes of type II thyroplasty for adductor spasmodic dysphonia: analysis of revision and unsatisfactory cases

Conclusion. The factors responsible for the observed failures can be broken into two major groups: (1) a wrong indication and (2) an inadequate technique to achieve relief from an excessively tight glottal closure. The use of a titanium bridge in place of a silicone shim was found to be essential. Type II thyroplasty can relieve the symptoms of adductor spasmodic dysphonia (AdSD) when implemented with a modern technique using titanium bridges. Objectives. To identify the factor or factors that necessitated revision surgery in type II thyroplasty for AdSD, detailed analytical examinations were made of individual cases with unsatisfactory outcomes. Patients and methods. A retrospective analysis of a case series with follow-up periods of 2–5 years. Results. Ninety AdSD patients underwent type II thyroplasty. The results in one patient were limited because a pathological mechanism other than AdSD was also involved. One patient, a singer, who wanted a more intense voice for singing was dissatisfied with the results. In three patients, the material used for fixation was inadequate. In two other patients, the method of application of the fixative material was found to be insufficient as it did not include both the upper and lower sides.

Reliability of the Perceptual Evaluation of Adductor Spasmodic Dysphonia

Although perceptual assessment by experienced voice clinicians remains the gold standard for the diagnosis and assessment of severity of adductor spasmodic dysphonia (ADSD), the interrater reliability of voice experts for this task has not been assessed. In addition, it is unknown whether telephone-recorded or -transmitted voice samples could be used for this task. The aims of this study were (1) to assess the reliability of perceptual analysis of ADSD severity by voice experts and (2) to compare the results between digitally recorded voice samples and those recorded over the telephone. Five laryngologists randomly selected voice samples from 46 ADSD patients and rated the severity of ADSD on a 5-point rating scale. A set of digital voice recordings and a set of telephone voice recordings made from filtering the digital set via the telephone were rated, and each voice set was rated twice. Measures of intrarater and interrater reliability, as well as a measure of the probability of agreement among the raters, were calculated. There was a high level of agreement on ADSD severity, with excellent interrater and intrarater reliability (Cronbach's alpha, .93 to .96). The probabilities of rater agreement on the digitally recorded and telephone-filtered voice samples were similar (chi2, p = .07). The ratings of digital versus telephone voice samples were highly correlated (Pearson r, 0.99; p < .001). These results demonstrate that voice experts are reliably able to judge and agree on the severity of ADSD. Telephone-filtered voices appear to convey adequate ADSD perceptual cues for expert listeners to judge the severity of spasmodic dysphonia.

Longitudinal Follow‐Up of Adductor Spasmodic Dysphonia Patients After Botulinum Toxin Injection: Quality of Life Results

Botulinum toxin injections are used routinely to treat patients with adductor spasmodic dysphonia. After an initial "breathy phase," most patients experience improvement for a few weeks to months and then a gradual decline until their next injection. In this study, voice-related quality of life (VRQOL) data were collected at 4 week intervals through one to three injection cycles in an attempt to quantify the proportion of each cycle during which patients experience meaningful benefit. Prospective, nonrandomized case series. Patients receiving stable-dose botulinum injections for adductor spasmodic dysphonia were invited to participate. Voice recordings and clinical outcomes data were collected by telephone every 4 weeks throughout each injection cycle. Quality of life data were normalized for cycle length and interpolated to generate composite curves. Twenty-two patients completed data collection for at least one full injection cycle. The average cycle was 25.9 weeks; the mean age was 59.8 years. On a 100-point scale, the total VRQOL scores peaked at 77.4, at 30% of the cycle, then gradually declined. The social-emotional (SE) subscale scores were significantly better than the physical subscale scores (P < .05). The total VRQOL score exceeded 75 during only 14% of the cycle (52.6% for SE subscores, 0% for physical subscores). If the threshold is lowered to 70, the total VRQOL exceeded this level during 54.6% of the cycle (69.6% for SE subscores, 44.1% for physical subscores). For the 11 patients completing three full injection cycles, there were no significant differences between the three cycles, and the mean VRQOL scores were similar to the values given above. At the beginning and end of each cycle, the total VRQOL scores averaged 52.8 (56.0 for SE subscale, 50.7 for physical subscale). Although botulinum toxin injections provide significant improvement for these patients, the initial breathy phase and the late declining phase add up to a significant proportion of each cycle spent with a reduced quality of life. At best, the total VRQOL averaged below 80%. This longitudinal study provides a unique look at the effect of this condition and its treatment on these patients' lives. A suitable long-term treatment for this condition is needed to eliminate the cyclical voice results experienced with the botulinum toxin injection approach.

Relationship of botulinum dosage to duration of side effects and normal voice in adductor spasmodic dysphonia

Objective evaluation of botulinum toxin A (BTX-A) dosing by determination of the statistical relationship between injection amount and duration of side effects and normal voice in adductor spasmodic dysphonia (SD) patients. From this information, to provide a rational guide to determine the initial and follow-up BTX-A amounts for injection. Private laryngology clinic. Statistical analysis was performed on data obtained from 101 patients with SD. Significant and predictable positive correlations were found between duration of side effects and duration of normal voice after BTX-A injection in patients with SD. Dose of BTX-A injected also appeared to have a significant positive correlation with duration of side effects, but a negative correlation with duration of normal voice. A trend toward more severe side effects was seen with larger doses of BTX-A injections. Increased understanding of the response of the human voice over time after BTX-A injection at various doses suggests new ideas to further increase clinical efficacy with the use of lower BTX-A doses.

Spectral Amplitude Measures of Adductor Spasmodic Dysphonic Speech

Spectral amplitude measures are sensitive to varying degrees of vocal fold adduction in normal speakers. This study examined the applicability of harmonic amplitude differences to adductor spasmodic dysphonia (ADSD) in comparison with normal controls. Amplitudes of the first and second harmonics (H1, H2) and of harmonics affiliated with the first, second, and third formants (A1, A2, A3) were obtained from spectra of vowels and /i/ excerpted from connected speech. Results indicated that these measures could be made reliably in ADSD. With the exception of H1(*)-H2(*), harmonic amplitude differences (H1(*)-A1, H1(*)-A2, and H1(*)-A3(*)) exhibited significant negative linear relationships (P < 0.05) with clinical judgments of overall severity. The four harmonic amplitude differences significantly differentiated between pre-BT and post-BT productions (P < 0.05). After treatment, measurements from detected significant differences between ADSD and normal controls (P < 0.05), but measurements from /i/ did not. LTAS analysis of ADSD patients' speech samples proved a good fit with harmonic amplitude difference measures. Harmonic amplitude differences also significantly correlated with perceptual judgments of breathiness and roughness (P < 0.05). These findings demonstrate high clinical applicability for harmonic amplitude differences for characterizing phonation in the speech of persons with ADSD, as well as normal speakers, and they suggest promise for future application to other voice pathologies.

Botulinum toxin management of adductor spasmodic dysphonia after failed recurrent laryngeal nerve section.

This study examined botulinum toxin type A (BTX-A) treatment of adductor spasmodic dysphonia patients who had previously undergone recurrent laryngeal nerve section that failed to control symptoms. Information was retrieved from records of patients treated by our group between 1984 and 1999. Complete records with standardized outcome measurements were available for 181 BTX-A injection sessions in 16 patients who had had nerve section. These were compared to previously published information regarding 4,621 sessions in 639 adductor spasmodic dysphonia patients also treated by our group. Treatment with BTX-A resulted in significant improvement in voice function in the studied patients (change, 38.2% +/- 24.5%; p < .0001). The onset of effect took place approximately 2.3 days after treatment, and the peak effect about 10.0 days after treatment. The therapeutic effect lasted 14.1 weeks on the average. These features were not significantly different from those observed in adductor spasmodic dysphonia patients as a whole. The incidence of complications was also comparable. However, lower baseline and peak posttreatment perceptions of voice function in the nerve section group were statistically significant (baseline, 45.6% +/- 23.0% versus 52.4% +/- 22.0%; peak, 83.8% +/- 16.4% versus 89.7% +/- 13.0%; both p < .001). We conclude that BTX-A is effective in the treatment of adductor spasmodic dysphonia in patients who have had recurrent nerve section. However, nerve section may adversely affect perceived voice function and may make botulinum toxin therapy less satisfactory. Because of this finding, and because of the unusual pathological features of the focal dystonias, irreversible means of treating adductor spasmodic dysphonia should be approached with caution.

Laryngeal Muscle Activity During Speech Breaks in Adductor Spasmodic Dysphonia

To determine the laryngeal muscle activation abnormalities that are associated with speech symptoms in adductor spasmodic dysphonia (ADSD), electromyographic measures of extrinsic and intrinsic laryngeal muscles during speech compared 1) muscle activity when ADSD patients had breaks in words with when they produced the same words without breaks; and 2) muscle activity in ADSD patients during speech without voice breaks with normal control producing phonetically similar words. Simultaneous electromyographic recordings were made from the thyroarytenoid (TA), cricothyroid (CT), sternothyroid (ST), thyrohyoid (TH) and the posterior cricoarytenoid (PCA) muscles during speech testing in 11 ADSD patients and 10 control subjects. Speech breaks were identified and mean muscle activity measured starting 100 ms preceding a voice break and for the remainder of the word. Mean muscle activity level was significantly greater on break than non break words in ADSD patients only for the thyroarytenoid muscle (p<.001). No significant differences were found between the ADSD and control subjects during non break words for any of the laryngeal muscles studied. The results demonstrated that 1) only the thyroarytenoid, of the muscles tested, was affected in ADSD, 2) that muscle activation abnormalities were spasmodic, only appearing when symptoms occurred and 3) no imbalances of muscle tone were evident when speech disruptions did not appear.

Analysis of factors affecting botulinum toxin results in spasmodic dysphonia.

This study was designed to investigate how variations in patterns of injection could improve the efficacy of botulinum toxin injections in relieving the symptoms of adductor spasmodic dysphonia. A total of 64 adductor spasmodic dysphonia patients who were injected using indirect laryngoscopic localization (for a total of 426 injections) were analyzed retrospectively using their own subjective data on duration of voice improvement, optimal voice improvement, breathiness side effects, and intervals between treatments. Injection to both the thyroarytenoid (TA) and the lateral cricoarytenoid (LCA) simultaneously gave the best voice results; the overall improvement from baseline was the longest lasting, and the period during which the voice was the best was the longest lasting. TA+LCA also gave the shortest duration of undesirable breathiness side effect. On the basis of these data, it seems reasonable to recommend that initial botulinum toxin therapy for adductor spasmodic dysphonia patients should be a single unilateral injection placed strategically at the posterior portion of the TA and directed toward the LCA so that both muscle groups are affected.

The Swallowing Side Effects of Botulinum Toxin Type A Injection in Spasmodic Dysphonia

Botulinum toxin type A (BOTOX) injection of the thyroarytenoid muscle is used to control speech symptoms in patients with adductor spasmodic dysphonia. Transient difficulty in swallowing liquids is a common treatment side effect. Laryngeal movement durations were measured during swallowing in 13 adductor spasmodic dysphonia patients undergoing treatment and in 6 normal control subjects in order to determine the following: 1. whether, prior to the injection, laryngeal movement durations were longer in the spasmodic dysphonia patients than in the control subjects; 2. whether movement durations increased following the injections; 3. whether preinjection swallowing difficulties related to postinjection swallowing measurements and postinjection patient reports of swallowing problems. A piezoelectric movement transducer was shown to be accurate for noninvasive measurement of laryngeal movement duration in relation to muscle onset and offset for hyoid elevation and relaxation. Before botulinum toxin type A injection, no significant differences in swallowing duration were found between the patient and control groups. Four patients with swallowing complaints prior to injection had longer laryngeal movement durations than the other spasmodic dysphonia patients and the control subjects. Following injection, laryngeal movement durations increased in the patients with spasmodic dysphonia, and eight patients reported dysphagia for an average of 2 weeks. Relationships were found between the patients' initial reports of swallowing problems and increased laryngeal movement durations before and after botulinum toxin type A injection. Those patients initially reporting swallowing difficulties had severe dysphagia for 2 weeks after the injection. Patient reports of dysphagia prior to injection may indicate a greater likelihood of significant dysphagia following thyroarytenoid injection with botulinum toxin type A.

Analytical study of pathologic tremulous voices of Japanese-speaking patients

This study was undertaken to clarify the major characteristics of voices of the Japanese-speaking patients of the adductor spasmodic dysphonia. The mechanism of the tremulous voice was also studied. For Japanese-speaking patients, to make a proper diagnosis of adductor spasmodic dysphonia, an evaluation method of the grade of the disease is needed. Sound spectrographic analysis was applied. First, the voices of the adductor spasmodic dysphonia patients were compared with the voices of other tremulous voice disease patients. Second, the voices of the different stages of adductor spasmodic dysphonia were analyzed. In the first study, results revealed that adductor spasmodic dysphonia voices showed irregularity of the fluctuation frequency in both pitch and intensity, while the voices with essential voice tremor showed a periodic fluctuation in pitch and intensity. In the second study, it was indicated that the cessation and fine flutter of the voice have a major role in the grade of the disease. With those results, phonological measurement and clinical feature can be matched. By evaluation of the irregularity of the voice, the diagnosis of tremulous voices might be confirmed. It was suggested that contributing factors to the voice symptom were not uniform.