The Experts below are selected from a list of 873 Experts worldwide ranked by ideXlab platform
Christy L. Ludlow - One of the best experts on this subject based on the ideXlab platform.
-
consensus based attributes for identifying patients with Spasmodic dysphonia and other voice disorders
Archives of Otolaryngology-head & Neck Surgery, 2018Co-Authors: Christy L. Ludlow, Marshall E Smith, Gerald S Berke, H A Jinnah, Christine M Sapienza, Joel H Blumin, Rickie J Domangue, Dinesh Sharma, Joel S Perlmutter, Carrie E KalataAbstract:Importance A roadblock for research on adductor Spasmodic dysphonia (ADSD), abductor SD (ABSD), voice tremor (VT), and muscular tension dysphonia (MTD) is the lack of criteria for selecting patients with these disorders. Objective To determine the agreement among experts not using standard guidelines to classify patients with ABSD, ADSD, VT, and MTD, and develop expert consensus attributes for classifying patients for research. Design, Setting and Participants From 2011 to 2016, a multicenter observational study examined agreement among blinded experts when classifying patients with ADSD, ABSD, VT or MTD (first study). Subsequently, a 4-stage Delphi method study used reiterative stages of review by an expert panel and 46 community experts to develop consensus on attributes to be used for classifying patients with the 4 disorders (second study). The study used a convenience sample of 178 patients clinically diagnosed with ADSD, ABSD, VT MTD, vocal fold paresis/paralysis, psychogenic voice disorders, or hypophonia secondary to Parkinson disease. Participants were aged 18 years or older, without laryngeal structural disease or surgery for ADSD and underwent speech and nasolaryngoscopy video recordings following a standard protocol. Exposures Speech and nasolaryngoscopy video recordings following a standard protocol. Main Outcomes and Measures Specialists at 4 sites classified 178 patients into 11 categories. Four international experts independently classified 75 patients using the same categories without guidelines after viewing speech and nasolaryngoscopy video recordings. Each member from the 4 sites also classified 50 patients from other sites after viewing video clips of voice/laryngeal tasks. Interrater κ less than 0.40 indicated poor classification agreement among rater pairs and across recruiting sites. Consequently, a Delphi panel of 13 experts identified and ranked speech and laryngeal movement attributes for classifying ADSD, ABSD, VT, and MTD, which were reviewed by 46 community specialists. Based on the median attribute rankings, a final attribute list was created for each disorder. Results When classifying patients without guidelines, raters differed in their classification distributions (likelihood ratio, χ2 = 107.66), had poor interrater agreement, and poor agreement with site categories. For 11 categories, the highest agreement was 34%, with no κ values greater than 0.26. In external rater pairs, the highest κ was 0.23 and the highest agreement was 38.5%. Using 6 categories, the highest percent agreement was 73.3% and the highest κ was 0.40. The Delphi method yielded 18 attributes for classifying disorders from speech and nasolaryngoscopic examinations. Conclusions and Relevance Specialists without guidelines had poor agreement when classifying patients for research, leading to a Delphi-based development of the Spasmodic dysphonia Attributes Inventory for classifying patients with ADSD, ABSD, VT, and MTD for research.
-
Spasmodic dysphonia a review part 2 characterization of pathophysiology
Otolaryngology-Head and Neck Surgery, 2017Co-Authors: Justin M Hintze, Christy L. Ludlow, Charles H Adler, Stephen F Bansberg, David G LottAbstract:ObjectiveThe purpose of this review is to describe the recent advances in characterizing Spasmodic dysphonia. Spasmodic dysphonia is a task-specific focal laryngeal dystonia characterized by irregular and uncontrolled voice breaks. The pathophysiology is poorly understood, and there are diagnostic difficulties.Data SourcesPubMed, Google Scholar, and Cochrane Library.Review MethodsThe data sources were searched using the following search terms: (Spasmodic dysphonia or laryngeal dystonia) and (etiology, aetiology, diagnosis, pathogenesis, or pathophysiology).ConclusionThe diagnosis of Spasmodic dysphonia can be difficult due to the lack of a scientific consensus on diagnostic criteria and the fact that other voice disorders may present similarly. Confusion can arise between Spasmodic dysphonia and muscle tension dysphonia. Spasmodic dysphonia symptoms are tied to particular speech sounds, whereas muscle tension dysphonia is not. With the advent of more widespread use of high-speed laryngoscopy and videokymo...
-
Spasmodic dysphonia a review part 1 pathogenic factors
Otolaryngology-Head and Neck Surgery, 2017Co-Authors: Justin M Hintze, Christy L. Ludlow, Charles H Adler, Stephen F Bansberg, David G LottAbstract:ObjectiveThe purpose of this review is to describe the recent advances in identifying possible factors involved in the pathogenesis of Spasmodic dysphonia. Spasmodic dysphonia is a task-specific focal laryngeal dystonia characterized by irregular and uncontrolled voice breaks. Pathogenesis of the disorder is poorly understood.Data SourcesPubMed, Google Scholar, and Cochrane Library.Review MethodsThe data sources were searched using the following search terms: (Spasmodic dysphonia or laryngeal dystonia) and (etiology, aetiology, diagnosis, pathogenesis, or pathophysiology).ConclusionsSeveral potential etiological factors have been proposed by epidemiological, genetic, and neuropathological studies. Spasmodic dysphonia is a rare disorder primarily affecting females beginning in their 40s. Vocal tremor co-occurs in 30% to 60%. Large cohort studies identified risk factors such as a family history of neurological disorders including dystonia and tremor, recent viral illness, and heavy voice use. As none are ra...
-
Cerebral Cortex doi:10.1093/cercor/bhq023 Abnormal Activation of the Primary Somatosensory Cortex in Spasmodic dysphonia: An
2016Co-Authors: Fmri Study, Kristina Simonyan, Christy L. LudlowAbstract: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 in-tensity 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 asymp-tomatic 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
-
abnormal structure function relationship in Spasmodic dysphonia
Cerebral Cortex, 2012Co-Authors: Kristina Simonyan, Christy L. LudlowAbstract:Spasmodic dysphonia (SD) is a primary focal dystonia characterized by involuntary spasms in the laryngeal muscles during speech production. Although recent studies have found abnormal brain function and white matter organization in SD, the extent of gray matter alterations, their structure–function relationships, and correlations with symptoms remain unknown. We compared gray matter volume (GMV) and cortical thickness (CT) in 40 SD patients and 40 controls using voxel-based morphometry and cortical distance estimates. These measures were examined for relationships with blood oxygen level–dependent signal change during symptomatic syllable production in 15 of the same patients. SD patients had increased GMV, CT, and brain activation in key structures of the speech control system, including the laryngeal sensorimotor cortex, inferior frontal gyrus (IFG), superior/middle temporal and supramarginal gyri, and in a structure commonly abnormal in other primary dystonias, the cerebellum. Among these regions, GMV, CT and activation of the IFG and cerebellum showed positive relationships with SD severity, while CT of the IFG correlated with SD duration. The left anterior insula was the only region with decreased CT, which also correlated with SD symptom severity. These findings provide evidence for coupling between structural and functional abnormalities at different levels within the speech production system in SD.
Kristina Simonyan - One of the best experts on this subject based on the ideXlab platform.
-
central voice production and pathophysiology of Spasmodic dysphonia
Laryngoscope, 2018Co-Authors: Niv Mor, Kristina Simonyan, Andrew BlitzerAbstract:Objective Our ability to speak is complex, and the role of the central nervous system in controlling speech production is often overlooked in the field of otolaryngology. In this brief review, we present an integrated overview of speech production with a focus on the role of central nervous system. The role of central control of voice production is then further discussed in relation to the potential pathophysiology of Spasmodic dysphonia (SD). Data Sources Peer-review articles on central laryngeal control and SD were identified from PUBMED search. Selected articles were augmented with designated relevant publications. Review Methods Publications that discussed central and peripheral nervous system control of voice production and the central pathophysiology of laryngeal dystonia were chosen. Results Our ability to speak is regulated by specialized complex mechanisms coordinated by high-level cortical signaling, brainstem reflexes, peripheral nerves, muscles, and mucosal actions. Recent studies suggest that SD results from a primary central disturbance associated with dysfunction at our highest levels of central voice control. The efficacy of botulinum toxin in treating SD may not be limited solely to its local effect on laryngeal muscles and also may modulate the disorder at the level of the central nervous system. Conclusion Future therapeutic options that target the central nervous system may help modulate the underlying disorder in SD and allow clinicians to better understand the principal pathophysiology. Level of Evidence NA.Laryngoscope, 128:177–183, 2018
-
Phenotype- and genotype-specific structural alterations in Spasmodic dysphonia.
Movement disorders : official journal of the Movement Disorder Society, 2017Co-Authors: Serena Bianchi, Steven J Frucht, Andrew Blitzer, Giovanni Battistella, Hailey Huddleston, Rebecca Scharf, Lazar Fleysher, Anna F. Rumbach, Laurie J. Ozelius, Kristina SimonyanAbstract:Background: Spasmodic dysphonia is a focal dystonia characterized by involuntary spasms in the laryngeal muscles that occur selectively during speaking. Although hereditary trends have been reported in up to 16% of patients, the causative etiology of Spasmodic dysphonia is unclear, and the influences of various phenotypes and genotypes on disorder pathophysiology are poorly understood. In this study, we examined structural alterations in cortical gray matter and white matter integrity in relationship to different phenotypes and putative genotypes of Spasmodic dysphonia to elucidate the structural component of its complex pathophysiology. Methods: Eighty-nine patients with Spasmodic dysphonia underwent high-resolution magnetic resonance imaging and diffusion-weighted imaging to examine cortical thickness and white matter fractional anisotropy in adductor versus abductor forms (distinct phenotypes) and in sporadic versus familial cases (distinct genotypes). Results: Phenotype-specific abnormalities were localized in the left sensorimotor cortex and angular gyrus and the white matter bundle of the right superior corona radiata. Genotype-specific alterations were found in the left superior temporal gyrus, supplementary motor area, and the arcuate portion of the left superior longitudinal fasciculus. Conclusions: Our findings suggest that phenotypic differences in Spasmodic dysphonia arise at the level of the primary and associative areas of motor control, whereas genotype-related pathophysiological mechanisms may be associated with dysfunction of regions regulating phonological and sensory processing. Identification of structural alterations specific to disorder phenotype and putative genotype provides an important step toward future delineation of imaging markers and potential targets for novel therapeutic interventions for Spasmodic dysphonia.
-
Polygenic Risk of Spasmodic dysphonia is Associated With Vulnerable Sensorimotor Connectivity
Cerebral Cortex, 2016Co-Authors: Gregory Garbès Putzel, Giovanni Battistella, Anna F. Rumbach, Laurie J. Ozelius, Mert R. Sabuncu, Kristina SimonyanAbstract:Spasmodic dysphonia (SD), or laryngeal dystonia, is an isolated task-specific dystonia of unknown causes and pathophysiology that selectively affects speech production. Using next-generation whole-exome sequencing in SD patients, we computed polygenic risk score from 1804 genetic markers based on a genome-wide association study in another form of similar task-specific focal dystonia, musician's dystonia. We further examined the associations between the polygenic risk score, resting-state functional connectivity abnormalities within the sensorimotor network, and SD clinical characteristics. We found that the polygenic risk of dystonia was significantly associated with decreased functional connectivity in the left premotor/primary sensorimotor and inferior parietal cortices in SD patients. Reduced connectivity of the inferior parietal cortex was correlated with the age of SD onset. The polygenic risk score contained a significant number of genetic variants lying near genes related to synaptic transmission and neural development. Our study identified a polygenic contribution to the overall genetic risk of dystonia in the cohort of SD patients. Associations between the polygenic risk and reduced functional connectivity of the sensorimotor and inferior parietal cortices likely represent an endophenotypic imaging marker of SD, while genes involved in synaptic transmission and neuron development may be linked to the molecular pathophysiology of this disorder.
-
Case Reports Long-term Effect of Sodium Oxybate (XyremH) in Spasmodic dysphonia with Vocal Tremor
2016Co-Authors: Kristina Simonyan, Steven J FruchtAbstract:Background: Symptoms of Spasmodic dysphonia (SD) are usually managed successfully with botulinum toxin injections. Vocal tremor (VT), which accompanies SD, has a poor response to this treatment. Case Report: We report a case of a female with SD and VT who became symptom-free for 10 months after the intake of a single dose of sodium oxybate (XyremH). The long-term treatment effect correlated with attenuated brain activity in the key regions of dystonic brain network. Discussion: Our case demonstrates that the novel treatment of sodium oxybate may hold promise for SD patients, especially those who have associated VT
-
Cerebral Cortex doi:10.1093/cercor/bhq023 Abnormal Activation of the Primary Somatosensory Cortex in Spasmodic dysphonia: An
2016Co-Authors: Fmri Study, Kristina Simonyan, Christy L. LudlowAbstract: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 in-tensity 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 asymp-tomatic 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
Andrew Blitzer - One of the best experts on this subject based on the ideXlab platform.
-
association of laryngeal botulinum neurotoxin injection with work productivity for patients with Spasmodic dysphonia
Archives of Otolaryngology-head & Neck Surgery, 2021Co-Authors: Tanya K Meyer, Andrew Blitzer, Charles Spiekerman, Rachel Kaye, Rouya S Kamizi, Lan Jiang, Edward M WeaverAbstract:Importance A disordered voice can affect an individual across both work and non-work-related life domains. There is insufficient research testing on the effect of Spasmodic dysphonia or its treatment with botulinum neurotoxin (BoNT) injections on work productivity. Objective To assess whether employed patients with Spasmodic dysphonia experience voice-related work productivity impairment before BoNT injection, and had a 10% or greater improvement in productivity 1 month after treatment with BoNT injection. Design, setting, and particpants This prospective case series carried out in 2 laryngology outpatient clinics from November 1, 2015, to August 30, 2018 included a consecutive sample of adult employed patients diagnosed with Spasmodic dysphonia. Analysis was conducted between November 1, 2015, to July 31, 2018. Exposures Treatment with BoNT injection into the intrinsic laryngeal musculature. Main outcomes and measures Eligible participants completed the following validated outcomes instruments immediately before and 1 month after outpatient laryngeal BoNT injection: the Work Productivity and Activity Impairment instrument (WPAI), Voice Handicap Index (VHI), and WorkHoarse. Demographic, comorbidity, and occupational voice use data were also collected at baseline. The changes in outcome measures (primary, WPAI Work Productivity Impairment domain) were tested using a paired 2-tailed t test. Exploratory subgroup analyses were analyzed with multivariable linear regression, adjusting for demographic, comorbidity, and voice use variables. Results Of the 101 patients enrolled, 75 completed the study. The mean (SD) age of the 75 completing participants was 55.7 (11.8) years and 53 (71%) were women. The participants who completed the study had mean (SD) voice-related work productivity impairment of 43% (27%) at baseline and 22% (23%) at 1 month after BoNT injection (difference, 20% [27%] improvement; 95% CI, 14%-27%; effect size, 0.74). Conclusions and relevance This case series study found that employed patients with Spasmodic dysphonia reported voice-related work productivity impairment, which improved significantly 1 month after treatment with BoNT injection. The association of Spasmodic dysphonia with voice-related work productivity appeared greater in women than men with comparable outcomes with BoNT treatment, but this exploratory sex-associated difference requires independent validation.
-
Spasmodic dysphonia and vocal tremor
2021Co-Authors: Diana N Kirke, Andrew BlitzerAbstract:Spasmodic dysphonia is a focal laryngeal dystonia affecting the voice. Several subtypes exist, presenting different diagnostic and treatment challenges. Vocal tremor is a separate disorder characterized by involuntary oscillation of the laryngeal and pharyngeal musculature, resulting in modulation of pitch and loudness. Overall there are many features of Spasmodic dysphonia and vocal tremor that are still poorly understood. This chapter will review the disorders as well as the current levels of evidence for both nonsurgical and surgical management.
-
central voice production and pathophysiology of Spasmodic dysphonia
Laryngoscope, 2018Co-Authors: Niv Mor, Kristina Simonyan, Andrew BlitzerAbstract:Objective Our ability to speak is complex, and the role of the central nervous system in controlling speech production is often overlooked in the field of otolaryngology. In this brief review, we present an integrated overview of speech production with a focus on the role of central nervous system. The role of central control of voice production is then further discussed in relation to the potential pathophysiology of Spasmodic dysphonia (SD). Data Sources Peer-review articles on central laryngeal control and SD were identified from PUBMED search. Selected articles were augmented with designated relevant publications. Review Methods Publications that discussed central and peripheral nervous system control of voice production and the central pathophysiology of laryngeal dystonia were chosen. Results Our ability to speak is regulated by specialized complex mechanisms coordinated by high-level cortical signaling, brainstem reflexes, peripheral nerves, muscles, and mucosal actions. Recent studies suggest that SD results from a primary central disturbance associated with dysfunction at our highest levels of central voice control. The efficacy of botulinum toxin in treating SD may not be limited solely to its local effect on laryngeal muscles and also may modulate the disorder at the level of the central nervous system. Conclusion Future therapeutic options that target the central nervous system may help modulate the underlying disorder in SD and allow clinicians to better understand the principal pathophysiology. Level of Evidence NA.Laryngoscope, 128:177–183, 2018
-
gender differences in onabotulinum toxin a dosing for adductor Spasmodic dysphonia
Laryngoscope, 2017Co-Authors: Michael Z Lerner, Benjamin A Lerner, Amit A Patel, Andrew BlitzerAbstract:Objectives/hypothesis The objective of this study was to determine the influence of gender on onabotulinum toxin A dosing for the treatment of adductor Spasmodic dysphonia symptoms. Study design Retrospective review. Methods A chart review of the senior author's database of botulinum toxin injections was performed. Patients diagnosed with adductor Spasmodic dysphonia who received onabotulinum toxin A (BoNTA) injections to the thyroarytenoid muscle for at least 5 years were included for study. Patients who received alternate formulations of botulinum toxin (Myobloc, Dysport, or Xeomin) and patients with alternate diagnoses, such as abductor Spasmodic dysphonia, tremor, and oromandibular dystonia, were excluded. The average BoNTA dose was calculated for each patient and statistical analysis was performed comparing the male and female groups. Results A total of 201 patients (52 males and 149 females) met inclusion criteria. The average follow-up times for the male and female groups were 10.2 ± 3.6 and 11.1 ± 4 years, respectively. The average BoNTA doses for the male and female groups were 0.6 ± 0.42 U and 1.3 ± 1.1 U, respectively. Statistical analysis was performed using an independent samples two-tailed t test yielding a P value of .0000000002. A large effect size was noted with Cohen's d = 0.85. Conclusions The data from this retrospective chart review reveal a statistically and clinically significant correlation between female gender and higher average BoNTA dose for symptom control in adductor Spasmodic dysphonia. Explanations for this observation are speculative and include a possible inverse relationship between optimal BoNTA dose and vocal fold mass and possibly greater neutralizing antibody formation among female patients. Level of evidence 4. Laryngoscope, 127:1131-1134, 2017.
-
Phenotype- and genotype-specific structural alterations in Spasmodic dysphonia.
Movement disorders : official journal of the Movement Disorder Society, 2017Co-Authors: Serena Bianchi, Steven J Frucht, Andrew Blitzer, Giovanni Battistella, Hailey Huddleston, Rebecca Scharf, Lazar Fleysher, Anna F. Rumbach, Laurie J. Ozelius, Kristina SimonyanAbstract:Background: Spasmodic dysphonia is a focal dystonia characterized by involuntary spasms in the laryngeal muscles that occur selectively during speaking. Although hereditary trends have been reported in up to 16% of patients, the causative etiology of Spasmodic dysphonia is unclear, and the influences of various phenotypes and genotypes on disorder pathophysiology are poorly understood. In this study, we examined structural alterations in cortical gray matter and white matter integrity in relationship to different phenotypes and putative genotypes of Spasmodic dysphonia to elucidate the structural component of its complex pathophysiology. Methods: Eighty-nine patients with Spasmodic dysphonia underwent high-resolution magnetic resonance imaging and diffusion-weighted imaging to examine cortical thickness and white matter fractional anisotropy in adductor versus abductor forms (distinct phenotypes) and in sporadic versus familial cases (distinct genotypes). Results: Phenotype-specific abnormalities were localized in the left sensorimotor cortex and angular gyrus and the white matter bundle of the right superior corona radiata. Genotype-specific alterations were found in the left superior temporal gyrus, supplementary motor area, and the arcuate portion of the left superior longitudinal fasciculus. Conclusions: Our findings suggest that phenotypic differences in Spasmodic dysphonia arise at the level of the primary and associative areas of motor control, whereas genotype-related pathophysiological mechanisms may be associated with dysfunction of regions regulating phonological and sensory processing. Identification of structural alterations specific to disorder phenotype and putative genotype provides an important step toward future delineation of imaging markers and potential targets for novel therapeutic interventions for Spasmodic dysphonia.
Mark Hallett - One of the best experts on this subject based on the ideXlab platform.
-
Neurobiology of Disease Abnormal Striatal Dopaminergic Neurotransmission during Rest and Task Production in Spasmodic dysphonia
2016Co-Authors: Kristina Simonyan, Peter Herscovitch, Brian D. Berman, Mark HallettAbstract:Spasmodic dysphonia is a primary focal dystonia characterized by involuntary spasms in the laryngeal muscles during speech produc-tion. The pathophysiology of Spasmodic dysphonia is thought to involve structural and functional abnormalities in the basal ganglia– thalamo-cortical circuitry; however, neurochemical correlates underpinning these abnormalities as well as their relations to Spasmodic dysphonia symptoms remain unknown. We used positron emission tomography with the radioligand [11C]raclopride (RAC) to study striatal dopaminergic neurotransmission at the resting state and during production of symptomatic sentences and asymptomatic finger tapping in Spasmodic dysphonia patients. We found that patients, compared to healthy controls, had bilaterally decreased RAC binding potential (BP) to striatal dopamine D2/D3 receptors on average by 29.2%, which was associated with decreased RAC displacement (RAC BP) in the left striatum during symptomatic speaking (group average difference 10.2%), but increased RAC BP in the bilateral striatum during asymptomatic tapping (group average difference 10.1%). Patients with more severe voice symptoms and subclinically longer reaction time to initiate the tapping sequence had greater RACBPmeasures, while longer duration of Spasmodic dysphonia was associatedwithadecrease in task-inducedRACBP.Decreaseddopaminergic transmissionduring symptomatic speechproductionmay represent adisorder-specific pathophysiological trait involved in symptomgeneration,whereas increaseddopaminergic functionduring unaffected task performance may be explained by a compensatory adaptation of the nigrostriatal dopaminergic system possibly due t
-
abnormal striatal dopaminergic neurotransmission during rest and task production in Spasmodic dysphonia
The Journal of Neuroscience, 2013Co-Authors: Kristina Simonyan, Brian Berman, Peter Herscovitch, Mark HallettAbstract:Spasmodic dysphonia is a primary focal dystonia characterized by involuntary spasms in the laryngeal muscles during speech production. The pathophysiology of Spasmodic dysphonia is thought to involve structural and functional abnormalities in the basal ganglia–thalamo-cortical circuitry; however, neurochemical correlates underpinning these abnormalities as well as their relations to Spasmodic dysphonia symptoms remain unknown. We used positron emission tomography with the radioligand [11C]raclopride (RAC) to study striatal dopaminergic neurotransmission at the resting state and during production of symptomatic sentences and asymptomatic finger tapping in Spasmodic dysphonia patients. We found that patients, compared to healthy controls, had bilaterally decreased RAC binding potential (BP) to striatal dopamine D2/D3 receptors on average by 29.2%, which was associated with decreased RAC displacement (RAC ΔBP) in the left striatum during symptomatic speaking (group average difference 10.2%), but increased RAC ΔBP in the bilateral striatum during asymptomatic tapping (group average difference 10.1%). Patients with more severe voice symptoms and subclinically longer reaction time to initiate the tapping sequence had greater RAC ΔBP measures, while longer duration of Spasmodic dysphonia was associated with a decrease in task-induced RAC ΔBP. Decreased dopaminergic transmission during symptomatic speech production may represent a disorder-specific pathophysiological trait involved in symptom generation, whereas increased dopaminergic function during unaffected task performance may be explained by a compensatory adaptation of the nigrostriatal dopaminergic system possibly due to decreased striatal D2/D3 receptor availability. These changes can be linked to the clinical and subclinical features of Spasmodic dysphonia and may represent the neurochemical basis of basal ganglia alterations in this disorder.
-
research priorities in Spasmodic dysphonia
Otolaryngology-Head and Neck Surgery, 2008Co-Authors: Christy L. Ludlow, Steven Bielamowicz, Mark Hallett, Charles H Adler, Gerald S Berke, Andrew Blitzer, Susan Bressman, H A Jinnah, Uwe Juergens, Sandra B MartinAbstract:Objective To identify research priorities to increase understanding of the pathogenesis, diagnosis, and improved treatment of Spasmodic dysphonia. Study Design and Setting A multidisciplinary working group was formed that included both scientists and clinicians from multiple disciplines (otolaryngology, neurology, speech pathology, genetics, and neuroscience) to review currently available information on Spasmodic dysphonia and to identify research priorities. Results Operational definitions for Spasmodic dysphonia at different levels of certainty were recommended for diagnosis and recommendations made for a multicenter multidisciplinary validation study. Conclusions The highest priority is to characterize the disorder and identify risk factors that may contribute to its onset. Future research should compare and contrast Spasmodic dysphonia with other forms of focal dystonia. Development of animal models is recommended to explore hypotheses related to pathogenesis. Improved understanding of the pathophysiology of Spasmodic dysphonia should provide the basis for developing new treatment options and exploratory clinical trials. Significance This document should foster future research to improve the care of patients with this chronic debilitating voice and speech disorder by otolaryngology, neurology, and speech pathology.
-
perioral reflexes in orofacial dyskinesia and Spasmodic dysphonia
Muscle & Nerve, 1992Co-Authors: Helge Topka, Mark HallettAbstract:In order to assess the clinical utility of trigemino-facial reflexes in lower facial muscles, we studied perioral reflexes to mechanical and electrical stimulation in 13 patients with Spasmodic dysphonia and orofacial dyskinesia and in 7 healthy subjects. Mechanical stimulation of the upper lip of the all patients and electrical stimulation of the infraorbital nerve of patients with orofacial dyskinesia elicited larger perioral reflexes than in controls. In the majority of patients, hyperexcitable perioral were accompanied by increased gain of the blink reflex. In 4 patients, however, trigemino-facial reflexes were enhanced selectively in either the perioral muscles or orbicularis oculi. Our findings suggest that the quantitive assessment of perioral reflexes may provide information about the excitability of brainstem interneurons in cranial dystonia that is complementary to blink reflex studies. © John Wiley & Sons, Inc.
Ayoub Daliri - One of the best experts on this subject based on the ideXlab platform.
-
auditory feedback control mechanisms do not contribute to cortical hyperactivity within the voice production network in adductor Spasmodic dysphonia
Journal of Speech Language and Hearing Research, 2020Co-Authors: Ayoub Daliri, Elizabeth Heller S Murray, Pieter J Noordzij, Alfonso Nietocastanon, Jason A Tourville, Anne J Blood, James A Burns, Frank H GuentherAbstract:Purpose Adductor Spasmodic dysphonia (ADSD), the most common form of Spasmodic dysphonia, is a debilitating voice disorder characterized by hyperactivity and muscle spasms in the vocal folds during...
-
auditory feedback control mechanisms do not contribute to cortical hyperactivity within the voice production network in adductor Spasmodic dysphonia
Journal of Speech Language and Hearing Research, 2020Co-Authors: Ayoub Daliri, Elizabeth Heller S Murray, Pieter J Noordzij, Alfonso Nietocastanon, Jason A Tourville, Anne J Blood, James A Burns, Frank H GuentherAbstract:Purpose Adductor Spasmodic dysphonia (ADSD), the most common form of Spasmodic dysphonia, is a debilitating voice disorder characterized by hyperactivity and muscle spasms in the vocal folds during speech. Prior neuroimaging studies have noted excessive brain activity during speech in participants with ADSD compared to controls. Speech involves an auditory feedback control mechanism that generates motor commands aimed at eliminating disparities between desired and actual auditory signals. Thus, excessive neural activity in ADSD during speech may reflect, at least in part, increased engagement of the auditory feedback control mechanism as it attempts to correct vocal production errors detected through audition. Method To test this possibility, functional magnetic resonance imaging was used to identify differences between participants with ADSD (n = 12) and age-matched controls (n = 12) in (a) brain activity when producing speech under different auditory feedback conditions and (b) resting-state functional connectivity within the cortical network responsible for vocalization. Results As seen in prior studies, the ADSD group had significantly higher activity than the control group during speech with normal auditory feedback (compared to a silent baseline task) in three left-hemisphere cortical regions: ventral Rolandic (sensorimotor) cortex, anterior planum temporale, and posterior superior temporal gyrus/planum temporale. Importantly, this same pattern of hyperactivity was also found when auditory feedback control of speech was eliminated through masking noise. Furthermore, the ADSD group had significantly higher resting-state functional connectivity between sensorimotor and auditory cortical regions within the left hemisphere as well as between the left and right hemispheres. Conclusions Together, our results indicate that hyperactivation in the cortical speech network of individuals with ADSD does not result from hyperactive auditory feedback control mechanisms and rather is likely related to impairments in somatosensory feedback control and/or feedforward control mechanisms.
