Adductor-type Spasmodic Dysphonia Research Articles

Laryngeal Vibrotactile Stimulation as a Non-Invasive Adjunctive Treatment for Spasmodic Dysphonia: A Preliminary Study

Spasmodic dysphonia (SD) is a debilitating condition characterized by involuntary closure of the vocal folds, leading to strained and choked speech. Current treatment options have limitations and require repeated interventions. However, recent studies have shown that high-frequency peripheral somatosensory stimulation is able to modulate neuronal discharge at the somatomotor cortical level and positively influence motor output and therefore SD symptoms. This study investigates the potential of laryngeal vibrotactile stimulation (VTS) as a non-invasive treatment for SD. A custom device was used to apply high-frequency vibrations to the larynx of three female patients with adductor-type SD. The patients underwent VTS treatment once a day for four weeks. Four parameters were used to assess vocal quality: Acoustic Voice Quality Index (AVQI), Cepstral Peak Prominence Smoothed (CPPS), number of voice interruptions (Voice Breaks), and perceptual evaluation using the GIRBAS scale. The results showed improvements in all parameters following VTS treatment, indicating enhanced phonatory function quality and speech stability. These findings highlight the potential of VTS to alleviate symptoms in individuals diagnosed with adductor-type SD.

A Novel Technique: Ultrasonography-Guided Botulinum Toxin Injection in Adductor Type Spasmodic Dysphonia

Spasmodic dysphonia (SD) is a rare disease caused by focal dystonia in the laryngeal muscles. The adductor type SD (AdSD), which affects the thyroarytenoid (TA) muscle, is found in 80% of all SD patients. For them, voice therapy and medication are less effective and definitive surgical treatment has not been established yet. Botulinum toxin injection is considered the gold standard treatment. However, patients require regular injections every 3-6 months whenever the effect of botulinum toxin disappears. Therefore, it is essential that injecting botulinum toxin is safe, comfortable, and accurate. Injections are usually performed under the guidance of electromyography or laryngoscopy. Ultrasonography (US) is a familiar device to otorhinolaryngologists and has recently been used to evaluate the laryngeal structures. While US has been used only for diagnosis, it can also be used for treatment. Here, we describe a novel technique that can be used to inject botulinum toxin into the TA muscle via trans-cartilaginous approach under the guidance of US for the treatment of AdSD.

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.

Usefulness of Water-Resistance Straw Phonation in Discrimination of Adductor-Type Spasmodic Dysphonia and Muscle Tension Dysphonia

Objectives: Although Adductor-type spasmodic dysphonia (AdSD) and Muscle tension dysphonia (MTD) show similar phonetic symptoms, the causes and treatment methods are different. Therefore, discrimination is necessary for the proper treatment of the two diseases. The purpose of this study is to investigate the usefulness of Water-resistance straw phonation (WSP) as a diagnostic therapy for the differentiation of AdSD and MTD. To that end, Both patients with AdSD and MTD performed WSP, and their voices was measured before and after diagnostic therapy.Methods: A total of 27 (18 MTD, 9 AdSD) individuals participated in this study. The MTD group (4 male, 14 female) mean age was 30.01 years and the AdSD (2 male, 7 female) group mean age was 31.03. Both groups were treated with diagnostic therapy using WSP which took approximately 90 seconds. The acoustic analysis and auditory–perceptual assessment were completed after diagnostic therapy.Results: The MTD group was significantly lower in Jitter Percent (Jitter) (p= .003), Pitch Perturbation Quotient (PPQ) (p= .007), Fundamental Frequency Variation (vF0) (p= .004), Shimmer Percent (Shimmer) (p= .010), Amplitude Perturbation Quotient (APQ) (p= .012), Peak to Peak Amplitude Variation (vAm) (p= .005) and auditory–perceptual grade (p= .007). However, the AdSD group was not significantly different for all variables after performing the WSP.Conclusion: WSP is one of the methods that relieve laryngeal hypertension. In this study, the voice improvement of the MTD group after diagnostic therapy using WSP meant that the laryngeal hypertension was relieved. This change indicates a high probability of MTD as opposed to AdSD. Whereas, no improvement or worsening of the voice problem suggests neither the probability of MTD nor no confirmation of AdSD. Therefore, a diagnostic therapy using WSP may be useful as one of the evaluation methods for discrimination between AdSD and MTD.

Machine learning discriminates voice tremor in essential tremor and dysphonia

Patients with essential tremor and adductor-type spasmodic dysphonia may manifest a prominent voice tremor. The diagnosis of voice tremor is currently based on perceptual and qualitative analysis. We have recently demonstrated in two independent studies that advanced voice analysis with machine learning objectively discriminates normal voices from those recorded from patients with essential tremor and dysphonia. The aim of this study is to achieve a direct and objective discrimination between voice samples recoded from patients with essential tremor and dysphonia both manifesting voice tremor.

Altered sensory system activity and connectivity patterns in adductor spasmodic dysphonia

Adductor-type spasmodic dysphonia (ADSD) manifests in effortful speech temporarily relievable by botulinum neurotoxin type A (BoNT-A). Previously, abnormal structure, phonation-related and resting-state sensorimotor abnormalities as well as peripheral tactile thresholds in ADSD were described. This study aimed at assessing abnormal central tactile processing patterns, their spatial relation with dysfunctional resting-state connectivity, and their BoNT-A responsiveness. Functional MRI in 14/12 ADSD patients before/under BoNT-A effect and 15 controls was performed (i) during automatized tactile stimulus application to face/hand, and (ii) at rest. Between-group differential stimulation-induced activation and resting-state connectivity (regional homogeneity, connectivity strength within selected sensory(motor) networks), as well as within-patient BoNT-A effects on these differences were investigated. Contralateral-to-stimulation overactivity in ADSD before BoNT-A involved primary and secondary somatosensory representations, along with abnormalities in higher-order parietal, insular, temporal or premotor cortices. Dysphonic impairment in ADSD positively associated with left-hemispheric temporal activity. Connectivity was increased within right premotor (sensorimotor network), left primary auditory cortex (auditory network), and regionally reduced at the temporoparietal junction. Activation/connectivity before/after BoNT-A within-patients did not significantly differ. Abnormal ADSD central somatosensory processing supports its significance as common pathophysiologic focal dystonia trait. Abnormal temporal cortex tactile processing and resting-state connectivity might hint at abnormal cross-modal sensory interactions.

Voice analysis in adductor spasmodic dysphonia: Objective diagnosis and response to botulinum toxin

IntroductionAdductor-type spasmodic dysphonia is a task-specific focal dystonia characterized by involuntary laryngeal muscle spasms. Due to the lack of quantitative instrumental tools, voice assessment in patients with adductor-type spasmodic dysphonia is mainly based on qualitative neurologic examination. We evaluated patients with cepstral analysis and specific machine-learning algorithms and compared the results with those collected in healthy subjects. In patients, we also used cepstral analysis and machine-learning algorithms to investigate the effect of botulinum neurotoxin type A. MethodsWe investigated 60 patients affected by adductor-type spasmodic dysphonia before botulinum neurotoxin type A therapy and 60 age and gender-matched healthy subjects. A subgroup of 35 patients was also evaluated after botulinum neurotoxin type A therapy. We recorded the sustained emission of a vowel and a sentence by means of a high-definition audio recorder. Voice samples underwent cepstral analysis as well as machine-learning algorithm classification techniques. ResultsCepstral analysis was able to differentiate between healthy subjects and patients, but receiver operating characteristic curve analysis demonstrated that machine-learning algorithms achieved better results than cepstral analysis in differentiating healthy subjects and patients affected by adductor-type spasmodic dysphonia. Similar results were obtained when differentiating patients before and after botulinum neurotoxin type A therapy. Cepstral analysis and machine-learning measures correlated with the severity of voice impairment in patients before and after botulinum neurotoxin type A therapy. ConclusionsCepstral analysis and machine-learning algorithms are new tools that offer meaningful support to clinicians in the diagnosis and treatment of adductor-type spasmodic dysphonia.

Impact of an Upper Respiratory Tract Infection on Botulinum Toxin Efficacy in Spasmodic Dysphonia Patients.

To determine whether the presence of a concomitant upper respiratory tract infection (URI) impacts upon Botulinum toxin (BoNT) efficacy in spasmodic dysphonia (SD) patients. Case series and literature review. All SD patients with a concurrent URI, presenting for BoNT therapy at a clinical research center from November 2016 to December 2017 were included. A total of 12 patients were identified. Patients were followed for at least two BoNT treatment cycles (approximately 6 months). The primary outcome measure was efficacy of the initial BoNT injection and the secondary outcome measure was the efficacy of the subsequent BoNT injection. All subjects had adductor type SD (ADSD). There were 10 females and two males with a median age of 55 years (±19.5). All patients were well established on a consistent BoNT treatment regime, with an average administered dose of 1.0 unit (range 0.2-1.80 units). Bilateral injections were administered to 10 patients. Regarding the primary outcome measure, five failed to have any response to BoNT (41.7%), four had a partial response (33.3%), and three had a positive response to treatment (25.0%). When patients had their follow-up injection in the absence of URI symptoms, 11 patients had a positive response to treatment (91.7%). While the interplay between illness and BoNT efficacy is yet to be elucidated, we report that some patients are affected. We recommend that SD patients presenting for BoNT administration with a concomitant URI, should be counseled that their treatment might have decreased effect. 4 Laryngoscope, 130:1746-1749, 2020.

Differentiation of Adductor-Type Spasmodic Dysphonia from Muscle Tension Dysphonia Using Spectrogram

Differentiation of Adductor-Type Spasmodic Dysphonia from Muscle Tension Dysphonia Using Spectrogram

Abnormal motor cortex excitability during linguistic tasks in adductor-type spasmodic dysphonia.

In healthy subjects (HS), transcranial magnetic stimulation (TMS) applied during 'linguistic' tasks discloses excitability changes in the dominant hemisphere primary motor cortex (M1). We investigated 'linguistic' task-related cortical excitability modulation in patients with adductor-type spasmodic dysphonia (ASD), a speech-related focal dystonia. We studied 10 ASD patients and 10 HS. Speech examination included voice cepstral analysis. We investigated the dominant/non-dominant M1 excitability at baseline, during 'linguistic' (reading aloud/silent reading/producing simple phonation) and 'non-linguistic' tasks (looking at non-letter strings/producing oral movements). Motor evoked potentials (MEPs) were recorded from the contralateral hand muscles. We measured the cortical silent period (CSP) length and tested MEPs in HS and patients performing the 'linguistic' tasks with different voice intensities. We also examined MEPs in HS and ASD during hand-related 'action-verb' observation. Patients were studied under and not-under botulinum neurotoxin-type A (BoNT-A). In HS, TMS over the dominant M1 elicited larger MEPs during 'reading aloud' than during the other 'linguistic'/'non-linguistic' tasks. Conversely, in ASD, TMS over the dominant M1 elicited increased-amplitude MEPs during 'reading aloud' and 'syllabic phonation' tasks. CSP length was shorter in ASD than in HS and remained unchanged in both groups performing 'linguistic'/'non-linguistic' tasks. In HS and ASD, 'linguistic' task-related excitability changes were present regardless of the different voice intensities. During hand-related 'action-verb' observation, MEPs decreased in HS, whereas in ASD they increased. In ASD, BoNT-A improved speech, as demonstrated by cepstral analysis and restored the TMS abnormalities. ASD reflects dominant hemisphere excitability changes related to 'linguistic' tasks; BoNT-A returns these excitability changes to normal.

116. Functional connectivity between cortical speech network and primary motor cortex is abnormal in spasmodic dysphonia

In healthy humans, the execution of linguistic tasks modifies the excitability of the hand area of the dominant primary motor cortex (M1), as tested by TMS. Our aim was to investigate the effect of linguistic tasks on the excitability of the M1 in patients with adductor type-spasmodic dysphonia (ASD), before and after Botulinum Neurotoxin Type A (BoNT-A) injections. We studied 10 patients with ASD and 10 age-matched healthy subjects. All participants were right handed. The excitability of either M1 hand area was evaluated at the baseline and during different linguistic and non-linguistic tasks: (1) reading aloud of single words; (2) silent reading; (3) looking at meaningless non-letter strings; (4) oral movements without vocalization; (5) producing simple syllabic phonation. In healthy controls, the motor evoked potential (MEP) elicited by TMS of the dominant M1 were significantly larger during reading aloud. In ASD patients, MEP enhancement in the dominant hand emerged not only during reading aloud but also during syllabic phonation. BoNT-A injections restored the neurophysiologic abnormalities. We conclude that ASD is characterized by an abnormal excitability of the hand area of the dominant M1 during specific linguistic tasks. This likely reflects an altered functional connectivity between cortical speech network and M1.

Correlation of self-assessment with expert rating and acoustic analysis for spasmodic dysphonia treatment with botulinum neurotoxin A

ObjectivesObjective and subjective evaluation of botulinum neurotoxin A (BoNTA) treatment for adductor type spasmodic dysphonia is presented. Therefore, a combinatorial approach based on patients’ and speech experts’ assessment of voice impairment, as well as on the acoustic analysis of spoken standardized text was performed. Study designProspective clinical study. Materials and methodsFor 17 patients, the voice quality prior to and 4–8 weeks after BoNTA injection (9 transoral, 8 transcutaneous) was investigated. Voice Handicap Index-12 (VHI-12) questionnaires as well as ratings of the GRB (grade, roughness, breathiness) scale were analyzed. Moreover, objective parameters such as pure speech duration, local jitter, local shimmer and voice breaks were evaluated. ResultsThe pre-post analysis of all patients revealed a significant reduction of the VHI-12 score, the jitter values and the number of voice breaks. Changes in speech duration and breathiness differed significantly for transoral vs. transcutaneous BoNTA injection. ConclusionsWe were able to correlate the questionnaire-based self-assessment with external evaluation of the speech roughness and with acoustic signal analysis parameters, in particular for the jitter. Our data indicated beneficial effects for transoral BoNTA application.

Selective laryngeal adductor denervation-reinnervation surgery for spasmodic dysphonia

Surgical treatment of adductor-type spasmodic dysphonia provides relief from the disabling voice breaks that require repeat botulinum toxin injections. The selective laryngeal adductor denervation-reinnervation surgery is described here. Key points discussed include patient selection, pertinent laryngeal and neural anatomy, and postoperative course.

痙攣性発声障害に対する手術

The injection of botulinum toxin into the thyroarytenoid muscle (BT injection) is the standard therapy used around the world in the treatment of adductor-type spasmodic dysphonia (ADSD) ; however, in Japan BT injection is not approved at all institutions. Thyroarytenoid muscle myectomy-Muta method (TAM) and type 2 thyroplasty (TP2) are the main surgical procedures currently undertaken for treatment of ADSD. The choice between the two procedures is difficult.We reviewed the operative methods of surgical treatment of ADSD. The voice was evaluated preoperatively and postoperatively using the Mora method. The spasmodic ratios (%) were calculated based on the Mora score and then compared. Both operative methods yielded satisfactory results in terms of treatment outcome and satisfaction level of the patients. In surgical therapy for ADSD, TAM and TP2 yield approximately equivalent treatment outcomes. When selecting between the two operative methods, the merits and demerits of each method for each individual patient should be considered.

Differentiation of adductor-type spasmodic dysphonia from muscle tension dysphonia by spectral analysis

To determine the utility of spectral analysis in the differentiation of adductor-type spasmodic dysphonia (AdSD) from muscle tension dysphonia (MTD). Prospective blinded study. Forty-seven samples of AdSD-connected speech spectrograms from 27 subjects and 17 samples of MTD-connected speech spectrograms from 15 subjects were selected from clinical charts and de-identified. These spectrograms were reviewed independently and blindly by two speech language pathologists experienced in spectrography. The speech language pathologists designated the spectrogram as consistent with AdSD and MTD, and these designations were compared with actual clinical diagnoses. The ability to differentiate AdSD from MTD with spectral analysis was 94% for rater #1 and 98% for rater #2. No MTD subjects were incorrectly diagnosed as having SD (100% specificity). This study suggests that experienced speech language pathologists can distinguish AdSD from MTD with a high degree of sensitivity and specificity based on spectral analysis. Spectral analysis is especially useful in cases where perceptual analysis and clinical evaluation alone are insufficient.

Treatment of Adductor-Type Spasmodic Dysphonia by Surgical Myectomy: A Preliminary Report

Treatment of Adductor-Type Spasmodic Dysphonia by Surgical Myectomy: A Preliminary Report

Treatment of Adductor-Type Spasmodic Dysphonia by Surgical Myectomy: A Preliminary Report

Despite the belief that it represents a central neurologic dysfunctional process, adductor-type spasmodic dysphonia without tremor is usually effectively treated by injection of botulinum toxin A; however, in most cases such injections must be repeated every few months. A promising new surgical procedure is herein reported. Under local anesthesia with intravenous sedation, a large laryngoplasty window is created, and under direct vision with intraoperative voice monitoring, fibers from the thyroarytenoid and lateral cricoarytenoid muscles are removed until breathiness occurs. The two sides are staged; that is, one side is done at a time, with surgery on the second side being performed 3 to 6 months after that on the first side, if needed. This was a retrospective, unblinded study of 5 patients who underwent myectomy of the thyroarytenoid and lateral cricoarytenoid muscles. The preliminary results show improved voice fluency in all patients at 5 to 19 months of follow-up. There was no period of prolonged breathiness or dysphagia in any of the patients, and there were no surgical complications. Myectomy of the thyroarytenoid and lateral cricoarytenoid muscles is a promising new surgical treatment for adductor-type spasmodic dysphonia that may effectively mimic "permanent" botulinum toxin injections.

Historical approaches to the treatment of Adductor-Type Spasmodic Dysphonia (ADSD): Review and tutorial

Adductor-type spasmodic dysphonia (ADSD) is a voice disorder of uncertain, though likely neurogenic origin. Symptoms of the disorder include mild to profound "strain and strangle" sensations during voiced speech tasks that, in the most severe form, are physically and psychologically debilitating. Over the years, treatment approaches have evolved from behavioral attempts at voice modification, to surgical and, most recently, pharmacological treatments involving partial and temporary paralysis of muscle fibers within the larynx following injection of botulinum toxin or Botox. The most current research hints at the potential benefits of a multi-faceted approach to symptom management, combining behavioral with pharmacological treatments. The following is intended as a review and tutorial of treatment approaches for ADSD. The tutorial is intended for practicing clinical professionals with an interest in the treatment of neurogenic disorders of voice and speech.

Cortical dysfunction of the supplementary motor area in a spasmodic dysphonia patient

The etiology of spasmodic dysphonia (SD) is still unknown. In the present study, cortical function of a 59-year-old male patient with adductor type SD was examined during phonation with positron emission tomography (PET). Magnetic resonance imaging showed no organic abnormality in the brain. However, PET showed remarkable activities during phonation in the left motor cortex, Broca's area, the cerebellum, and the auditory cortices, whereas the supplementary motor area (SMA) was not activated. The SMA is known to function for motor planning and programming and is usually activated in normal phonation. Several previous reports have shown that the damage of the SMA caused a severe disturbance of voluntary vocalization. In the present case, it was suggested that the functional deficit of the SMA might be related to SD. (Am J Otolaryngol 2001;22:219-222. Copyright © 2001 by W.B. Saunders Company)

Differential diagnosis of adductor-type spasmodic dysphonia, vocal tremor, and muscle tension dysphonia

Differential diagnosis of adductor-type spasmodic dysphonia, vocal tremor, and muscle tension dysphonia