Ultrasound in Causes of Stridor in Children.

Airway ultrasound (US) is an easily available, portable, radiation-free imaging modality for quick, non-invasive, dynamic evaluation of the airway without sedation. This is useful in children with stridor, which is an emergency due to upper airway obstruction requiring immediate management. Several causes of stridor including laryngomalacia, laryngeal cyst, subglottic hemangioma, vocal cord palsy, and lymphatic malformations can be evaluated accurately. Thin musculature and unossified cartilages in children provide a good acoustic window. Thus, airway US is valuable, but underutilized for the evaluation of children with stridor. In this case-based review, we describe the technique, indications, anatomy, and pathologies on airway US.

An automated approach for real-time informative frames classification in laryngeal endoscopy using deep learning.

PURPOSE: Informative image selection in laryngoscopy has the potential for improving automatic data extraction alone, for selective data storage and a faster review process, or in combination with other artificial intelligence (AI) detection or diagnosis models. This paper aims to demonstrate the feasibility of AI in providing automatic informative laryngoscopy frame selection also capable of working in real-time providing visual feedback to guide the otolaryngologist during the examination. METHODS: Several deep learning models were trained and tested on an internal dataset (n = 5147 images) and then tested on an external test set (n = 646 images) composed of both white light and narrow band images. Four videos were used to assess the real-time performance of the best-performing model. RESULTS: ResNet-50, pre-trained with the pretext strategy, reached a precision = 95% vs. 97%, recall = 97% vs, 89%, and the F1-score = 96% vs. 93% on the internal and external test set respectively (p = 0.062). The four testing videos are provided in the supplemental materials. CONCLUSION: The deep learning model demonstrated excellent performance in identifying diagnostically relevant frames within laryngoscopic videos. With its solid accuracy and real-time capabilities, the system is promising for its development in a clinical setting, either autonomously for objective quality control or in conjunction with other algorithms within a comprehensive AI toolset aimed at enhancing tumor detection and diagnosis.

Neural endophenotypes and predictors of laryngeal dystonia penetrance and manifestation.

Focal dystonias are the most common forms of isolated dystonia; however, the etiopathophysiological signatures of disorder penetrance and clinical manifestation remain unclear. Using an imaging genetics approach, we investigated functional and structural representations of neural endophenotypes underlying the penetrance and manifestation of laryngeal dystonia in families, including 21 probands and 21 unaffected relatives, compared to 32 unrelated healthy controls. We further used a supervised machine-learning algorithm to predict the risk for dystonia development in susceptible individuals based on neural features of identified endophenotypes. We found that abnormalities in prefrontal-parietal cortex, thalamus, and caudate nucleus were commonly shared between patients and their unaffected relatives, representing an intermediate endophenotype of laryngeal dystonia. Machine learning classified 95.2% of unaffected relatives as patients rather than healthy controls, substantiating that these neural alterations represent the endophenotypic marker of dystonia penetrance, independent of its symptomatology. Additional abnormalities in premotor-parietal-temporal cortical regions, caudate nucleus, and cerebellum were present only in patients but not their unaffected relatives, likely representing a secondary endophenotype of dystonia manifestation. Based on alterations in the parietal cortex and caudate nucleus, the machine learning categorized 28.6% of unaffected relative as patients, indicating their increased lifetime risk for developing clinical manifestation of dystonia. The identified endophenotypic neural markers may be implemented for screening of at-risk individuals for dystonia development, selection of families for genetic studies of novel variants based on their risk for disease penetrance, or stratification of patients who would respond differently to a particular treatment in clinical trials.

Dual-energy CT for differentiating early glottic squamous cell carcinoma from chronic inflammation and leucoplakia of vocal cord: comparison with simulated conventional 120 kVp CT.

AIM: To evaluate the value of dual-energy (DE) computed tomography (CT) in discriminating early glottic squamous cell carcinoma (eGSCC) from chronic inflammation and leucoplakia of the vocal cord, and to compare the diagnostic efficiency of DECT with that of simulated conventional 120 kVp CT. MATERIALS AND METHODS: Seventy patients with glottic lesions confirmed by histopathology (38 cases with eGSCC, 11 cases with chronic inflammation, 21 cases with leucoplakia) were enrolled in this prospective study. The DECT-derived parameters were measured and compared using independent sample t-test. Receiver operating characteristic (ROC) curve was performed to evaluate the diagnostic performance, and comparison of the area under the ROC curve (AUC) was made using the Z test to further select the best diagnostic parameters. RESULTS: Significantly higher iodine concentration (IC), normalised IC (NIC), effective atomic number (Zeff), 40-100 keV (20 keV-interval), slope(k), and Mix-0.3 values were found in eGSCC than those in chronic inflammation, leucoplakia, and inflammation + leucoplakia (all p<0.05). Compared with attenuation measurement of simulated conventional 120 kVp CT, the NIC, 60 keV values derived from DECT showed significantly higher AUC in discriminating these glottic lesions (p<0.05). CONCLUSIONS: DECT is more accurate for differentiating eGSCC from chronic inflammation and leucoplakia when compared with simulated conventional 120 kVp CT.

High-Resolution Laryngeal US: Imaging Technique, Normal Anatomy, and Spectrum of Disease.

Although US is one of the most used modalities for head and neck imaging, its use in the diagnosis of laryngeal abnormalities is much less widespread. The standard assessment of laryngeal abnormalities currently involves direct laryngoscopy and cross-sectional imaging (either CT or MRI) but rarely US. US is readily available, noninvasive, and radiation free, and it allows real-time imaging (with video for dynamic assessment), higher resolution than that of cross-sectional imaging, and the performance of targeted fine needle aspiration cytology or biopsy. This modality, particularly with the advent of high-resolution US, has been found to be at least comparable to CT or MRI for diagnosis of malignant lesions and benign abnormalities such as vocal nodules, polyps, cysts, and Reinke edema. Furthermore, it has been found to be more sensitive for diagnosis of abnormalities such as small glottic tumors, and its dynamic capability can be used to identify functional abnormalities such as vocal cord palsy. The authors outline the technique of laryngeal US, which includes strategies to avoid calcified laryngeal cartilage by imaging through the thyrohyoid and cricothyroid membranes with a five-sweep strategy supplemented by cine film of the technique. They also provide US images of common laryngeal abnormalities such as tumors with and without extralaryngeal extension; vallecular, thyroglossal, and vocal cord cysts; laryngeal mucoceles; and vocal cord palsy. Online supplemental material is available for this article. ©RSNA, 2020.

Management of laryngeal candidiasis: an evidence-based approach for the otolaryngologist.

PURPOSE: The authors aim to review available reports regarding laryngeal candidiasis and describe the existing evidence on the demographics, clinical manifestations, diagnosis, therapeutic options, and outcomes of this infection. METHODS: A review of articles on laryngeal candidiasis was conducted using PubMed® database from its inception through July 2019. RESULTS: Patients were mainly females presenting with complaints of dysphonia and associated gastroesophageal reflux history or inhaled corticosteroids use; although local predisposing factors were common, most patients were immunocompetent. The main anatomical affected subsite was the glottis with the presence of leukoplastic lesions. The diagnostic approach remains controversial, since some authors recommend prompt lesion biopsy and others rely on empirical antifungal treatment that showed effective results regarding symptoms and lesions resolution. CONCLUSION: Laryngeal Candida infection is thought to be a rare condition, with limited available literature. The correct diagnosis is difficult for the otolaryngologist and a high level of suspicion is required. The authors emphasize the need to include this condition into the differential diagnosis in patients with predisposing factors presenting with suspected lesions. In addition, the conservative diagnostic approach with antifungal treatment seems to provide effective outcomes, although comparative clinical studies between diagnostic options are lacking.

Prenatal sonographic appearance of laryngeal atresia: A case report.

Detailed assessment of the larynx is not easy because of its complex structures and the associated technical difficulties. We performed sonography in multiple planes to assess the laryngeal anatomy and movements of a fetus with laryngeal atresia. The distended trachea ended abruptly with an echogenic non-structured larynx which showed shallow rapid "flutter-like" movements and up and down but not adduction- abduction movements during swallowing. Shadowing from the chin could be reduced by scanning through fluid in the oral cavity or between the transverse processes of vertebrae in a coronal plane.

Maxillofacial Fractures Associated With Laryngeal Injury: A Craniofacial Surgeon Should be Alert.

OBJECTIVE: Maxillofacial fractures with concomitant laryngeal injuries put both the quality and maintenance of life in jeopardy. Because of its low incidence, it is often overlooked in the clinical setting. The purpose of this study is to review the incidence, clinical presentations, managements, and outcomes of these patients. METHODS: A retrospective analysis of medical records from 2008 to 2015 was conducted at a single institute. A case series (n = 12, which contributed 22.2% of laryngeal injuries in our institute) of these patients was presented, and propensity score matching was applied for further statistical analysis. RESULTS: When comparing patients who sustained maxillofacial fractures with concomitant laryngeal injuries with patients with only maxillofacial fractures and no laryngeal injuries, subcutaneous emphysema (83.3% vs 4.2%, P < 0.001), neck pain (75.0% vs 6.3%, P < 0.001), dyspnea (75.0% vs 0%, P < 0.001), hoarseness (41.7% vs 0%, P < 0.001), neck swelling (66.7% vs 4.2%, P = 0.012), stridor (16.7% vs 0%, P = 0.037), hemoptysis (16.7% vs 0%, P = 0.037), and thoracic trauma (58.3% vs 10.4%, P = 0.001) all showed significant differences. The length of intensive care unit stay (7.42 days vs 3.21 days, P = 0.008), ventilator use (66.7% vs 18.8%, P = 0.002), and tracheostomy (58.3% vs 0%, P < 0.001) were also significantly different. CONCLUSIONS: A significant portion of laryngeal injuries is concurrent with maxillofacial fractures. As a craniofacial surgeon, we should be alert to the signs of laryngeal injury. Diagnosis of laryngeal injuries should be established before definitive surgery for maxillofacial fractures.

Enhanced visualization of the surgical field in pediatric direct laryngoscopy using a three-dimensional endoscopic system.

BACKGROUND: Direct laryngoscopy and rigid bronchoscopy are currently performed using 2-dimensional endoscopic systems. Our objective was to determine whether a 3-dimensional endoscopic system can enhance visualization of the surgical field in pediatric direct laryngoscopy and rigid bronchoscopy. METHODS: A prospective cohort study was conducted. Thirty three children who underwent direct laryngoscopies in a tertiary referral children's hospital were enrolled. Direct laryngoscopy was performed using both 2- and 3-dimensional endoscopic systems, after which the surgeons scored the quality of the images obtained with each system on a scale from 1 (low) to 5 (high). Comparison of the scores obtained with the 2 endoscopic systems was performed. RESULTS: The 33 study children (mean age 2.3 years, M:F ratio 1:1.6) underwent 47 direct laryngoscopies. The mean score for visualization of the glottis was 4.8 for the three-dimensional system compared to 4.0 for the two-dimensional system (P = .025), 4.7 vs. 3.8, respectively, (P = .019) for the subglottis, and 4.6 vs. 3.9, respectively (P = .031) for visualization of the proximal trachea. The mean score for visualization of the distal trachea was 3.0 vs. 3.7, respectively (P = .020). In a child with recurrent type 3 laryngotracheal cleft a residual tracheo-esophageal fistula could not be detected using the 2D system, but was immediately detected using the 3D system. CONCLUSIONS: Visualization of the glottis, subglottis and proximal trachea during direct laryngoscopy using a 3-dimensional endoscopic system was rated by the surgeons as being superior to the conventional 2-dimensional technique. Further outcome studies that will demonstrate the clinical advantage of the 3D technology are highly required. LEVEL OF EVIDENCE: 2b.

Evaluation of vascular features of vocal cords proposed by the European Laryngological Society.

A newly proposed classification by the European Laryngological Society (ELS) of glottic lesions by narrow-band imaging (NBI) divides their vascular patterns into longitudinal and perpendicular ones. The latter are further subdivided into the wide and narrow patterns. The longitudinal, wide, and narrow patterns are characteristic of benign disease, papilloma, and malignancy, respectively. The aim of the study was to investigate the diagnostic effectiveness of the classification. Forty patients with glottic lesions underwent microlaryngoscopy. The vascular patterns of all vocal cords were defined with NBI. The affected vocal cords were histologically analysed and comprised the arm (A). Unaffected vocal cords were not histologically analysed but followed-up and comprised the arm (B) and were regarded as true negatives if no suspicious changes appeared during the follow-up. The vocal cords from the arm A were categorised into the benign and malignant group according to the histologic result. The ratio of vascular patterns was determined and the groups were statistically compared using the Chi-square test and Fisher's exact test. Perpendicular changes were observed in 36.6% (9/26) of benign diseases and in 100% (23/23) of cancer conditions (p < 0.001). Wide perpendicular changes appeared only in papillomas (6/6) while narrow ones mostly in malignancies (23/26) and also in benign conditions (3/26) (p < 0.001). The sensitivity, specificity, positive and negative predictive values, and accuracy were 100, 95, 88, 100 and 96%, respectively. The new ELS classification can be used effectively and safely to differentiate malignant from benign disease.

Airway management changes associated with rising radiologic incidence of external laryngotracheal injury.

BACKGROUND: Traumatic laryngeal injuries are uncommon life-threatening injuries that require prompt, rational management of a potentially precarious airway. It is unclear whether the current incidence of laryngotracheal injury is due to enhanced injury detection or increased occurrence. The objective of this study was to evaluate the relations between diagnostic imaging with both initial airway management and surgical treatment in patients with external laryngotracheal injuries (ELTIs) in Alberta. METHODS: In this large-scale population-based analysis, we used regional health databases containing inpatient admissions, emergency department visits and trauma service activations employing International Classification of Diseases diagnostic codes to identify all ELTIs diagnosed from Apr. 1, 1995, to Dec. 31, 2011, in adults (age ≥ 16 yr). We evaluated health records and diagnostic imaging for injury features, airway management, operative interventions and hospital length of stay (LOS). RESULTS: Eighty-nine patients met the inclusion criteria. The incidence of ELTIs increased over time, paralleling a rise in detection during the period incorporating greater computed tomography (CT) use (p = 0.002). Endotracheal tube intubation was performed in 8/30 cases (27%) in the pre-CT era, compared to 38/59 cases (64%) in the post-CT era (p = 0.001); the use of surgical intervention remained consistent. The largest contributors to increased endotracheal tube placements were the emergency department and emergency medical services. No change in survival was detected, but mean LOS among patients admitted for minor, isolated ELTIs increased by 2.3 (95% confidence interval 0.14-4.8) days (p = 0.06), mostly for patients admitted under critical care for mechanical ventilation. CONCLUSION: Management of ELTIs shifted from predominantly conservative airway monitoring to endotracheal tube intubation over the study period in spite of no clinically significant change in injury severity or operative intervention frequency. The location of endotracheal tube placement suggests less comfort with ELTI among first-responder and emergency personnel.

CONTEXTE: Les lésions traumatiques du larynx sont des blessures rares qui peuvent être mortelles et nécessitent une prise en charge rapide et efficiente, en raison de l'état potentiellement précaire des voies respiratoires. On ignore si l'incidence actuelle des lésions laryngo-trachéales est attribuable à une amélioration de la détection ou à une augmentation de la fréquence réelle. Cette étude avait pour but d'évaluer le lien entre l'imagerie diagnostique, et la prise en charge initiale des voies respiratoires ainsi que le traitement chirurgical chez des patients ayant subi des lésions laryngo-trachéales externes (LLTE) en Alberta. MÉTHODES: Dans le cadre de cette analyse de grande envergure basée sur une population, nous avons interrogé des bases de données régionales sur les hospitalisations, les consultations aux services d'urgence et la prestation de services de traumatologie. Nous nous sommes servis des codes diagnostiques de la Classification statistique internationale des maladies pour repérer tous les cas de LLTE diagnostiqués entre le 1er avril 1995 et le 31 décembre 2011 chez des adultes (16 ans et plus). Nous avons examiné les dossiers de santé et les résultats d'imagerie diagnostique pour en extraire des données sur les caractéristiques des lésions, la prise en charge des voies respiratoires, les interventions chirurgicales et la durée de séjour à l'hôpital. RÉSULTATS: Au total, 89 patients répondaient aux critères d'inclusion. L'incidence des LLTE a augmenté au fil du temps; en parallèle, l'utilisation répandue de la tomographie par ordinateur a entraîné une augmentation de la détection de ces lésions (p = 0,002). Une intubation trachéale a été réalisée chez 8/30 patients (27 %) pendant la période prétomographie, et chez 38/59 patients (64 %) pendant la période post-tomographie (p = 0,001); le recours à la chirurgie est demeuré constant. L'augmentation du nombre d'intubations est principalement attribuable aux interventions effectuées par le personnel ambulancier et par les services d'urgence. Aucun changement du taux de survie n'a été enregistré; toutefois, la durée de séjour moyenne des patients hospitalisés en raison de LLTE mineures et isolées a augmenté de 2,3 jours (intervalle de confiance à 95 % : 0,14-4,8; p = 0,06), surtout pour les patients admis aux soins intensifs pour recevoir une ventilation mécanique. CONCLUSION: Durant la période à l'étude, la prise en charge des LLTE est passée d'un suivi essentiellement conservateur des voies respiratoires à la prépondérance de l'intubation trachéale, bien qu'aucun changement significatif n'ait été observé quant à la gravité des lésions ou à la fréquence des interventions chirurgicales. Le contexte où ont lieu les intubations laisse croire que le personnel ambulanciers et les premiers intervenants sont moins à l'aise de prendre en charge les LLTE.

Evaluation of the combined use of narrow band imaging and high-speed imaging to discriminate laryngeal lesions.

BACKGROUND AND OBJECTIVE: Laryngeal lesions are usually investigated by microlaryngoscopy, biopsy, and histopathology. This study aimed to evaluate the combined use of Narrow Band Imaging (NBI) and High-Speed Imaging (HSI) in the differentiation of glottic lesions in awake patients. STUDY DESIGN: Prospective diagnostic study. MATERIALS AND METHODS: Thirty-six awake patients with 41 glottic lesions were investigated with both NBI and HSI, and the suspected diagnoses were compared to the histopathological results of tissue biopsies taken during subsequent microlaryngoscopies. Of the 41 lesions, 28 were primary lesions and 13 recurrent lesions after previous laryngeal pathologies. RESULTS: Sensitivity, specificity, positive predictive value, and negative predictive value in the differentiation between benign/premalignant and malignant lesions with both NBI and HSI accounted to 100.0%, 79.4%, 50.0%, and 100.0%. Sensitivities and specificities were 100.0% and 85.7% for HSI alone, and 100.0% and 79.4% for NBI alone. Regarding only primary lesions the results were generally better with sensitivities and specificities of 100% and 81% for NBI, 100% and 84.2% for HSI and 100% and 85.7% for the combination of both methods, respectively. CONCLUSION: NBI and HSI both seem to be promising adjunct tools in the differentiation of various laryngeal lesions in awake patients with high sensitivities. Specificities, however, were moderate but could be increased when using NBI and HSI in combination in a subgroup of patients with only primary lesions. Although both methods still have limitations they might ameliorate the evaluation of suspicious laryngeal lesions in the future and could possibly spare patients from repeated invasive tissue biopsies. Lasers Surg. Med. 49:609-618, 2017. © 2017 Wiley Periodicals, Inc.

The use of narrow band imaging for the detection of benign lesions of the larynx.

In the cases of uncertainty, even if the patient has no complaints about his voice quality, sometimes, benign vocal fold mass lesions are removed to exclude malignancy with the risk of resultant dysphonia. Narrow Band Imaging (NBI) enables a specific visualization of vessel structures in the superficial tissue. Benign lesions of the larynx are frequently characterized by abnormal vessel configuration or an absence of vessels in the area of the lesion. It was hypothesized that, in the primary diagnosis of patients with these benign lesions, the combination of white light and NBI endoscopy enables a better detection compared with white light endoscopy alone. Twenty-nine patients (eight patients with a cyst on a vocal fold, eight with a polyp, seven with a Reinke´s edema, two with a leukoplakia, one with a carcinoma, one with a granuloma, and two without any pathologic finding) were examined with normal white light and NBI endoscopy. 87 video sequences (29 white, 29 NBI, and 29 white/NBI) were generated and randomized and presented to 20 otolaryngologists who rated the videos in terms of the suspected diagnosis. Results were compared with the histopathologic findings of microlaryngoscopy. The probability of detecting benign lesions of the vocal folds was higher using NBI in combination with white light endoscopy compared with white light endoscopy alone. For vocal fold cysts, this difference was statistically significant. NBI endoscopy in combination with normal white light endoscopy improves the detection rate of benign lesions of the larynx, especially of vocal fold cysts.

Multimodality imaging of pediatric airways disease: indication and technique.

Congenital and acquired airway anomalies represent a relatively common albeit diagnostic and therapeutic challenge, even for the most skilled operators in dedicated centers. Airway malformations encompass a wide spectrum of pathologies involving the larynx, trachea and bronchi, esophagus, mediastinal vessels. These developmental lesions are often isolated but the association of two or more anomalies is not infrequent. From the traditional chest X-ray to the newest applications of Optical Coherence Tomography, non- or mini-invasive diagnostic techniques represent useful tools to integrate invasive procedures. Comprehensive knowledge of the characteristics of each diagnostic test is mandatory for its useful application. The aim of our paper is to analyze the clinical indications for Imaging the Airway disease in pediatric population, and describe the diagnostic techniques. Only by a close interaction between all the operators involved in diagnosis and treatment of pediatric airway, as it happens in Multidisciplinary Airway Team, the non- or mini-invasive imaging is effective.

[Narrow band imaging for evaluation of laryngeal mucosal lesions]. / "Narrow band imaging" zur Beurteilung laryngealer Schleimhautläsionen.

The use of narrow band imaging (NBI) and further technological achievements concerning the resolution and magnification of endoscopic images have revolutionized laryngology in the past 10 years. The diagnosis and therapy of dysplasia and early laryngeal carcinoma have become significantly easier. There are also clear benefits for benign laryngeal lesions. Central to these techniques is the assessment of epithelial, connective tissue and vascular changes caused by diverse diseases.

Computed tomography virtual bronchoscopy: normal variants, pitfalls, and spectrum of common and rare pathology.

A broad spectrum of pathologies that involve the laryngotracheobronchial airway and imaging plays a crucial role in evaluating these abnormalities. Computed tomography with virtual bronchoscopy has been found to be very helpful in defining the location, extent, and nature of these lesions, and is increasingly being used even in patients with contraindications for fiberoptic bronchoscopy and laryngoscopy. Ionizing radiation, associated with virtual bronchoscopy, can be minimized by using low-dose multidetector computed tomography and hybrid iterative reconstruction techniques. Furthermore, retrospectively generated virtual bronchoscopy from a routinely acquired computed tomography data set eliminates additional cost and radiation. In the future, virtual bronchoscopy assisted with advanced navigational techniques will broaden the diagnostic and therapeutic landscape. This article presents the characteristic features of common and rare laryngotracheobronchial pathologies seen with virtual bronchoscopy.

Fatal laryngeal angioedema: a case report and a workup of angioedema in a forensic setting.

Angioedema is an episodic swelling of the deep dermis, subcutis, and/or submucosal tissue due to an increase in local vascular permeability. Swelling may involve skin, respiratory, and gastrointestinal tracts. The most commonly involved areas are the periorbital region and the lips. Here we report a case of a fatal laryngeal obstruction due to angioedema likely caused by an angiotensin-converting-enzyme inhibitor. The decedent, a 58-year-old man, was witnessed developing sudden facial swelling and acute respiratory difficulties quickly followed by unresponsiveness. His past medical history suggested that this was his second episode of angioedema without urticaria. Postmortem examination revealed a complete laryngeal obstruction in the absence of infection, neoplasm, or autoimmune disease. Postmortem computed tomography of the head and neck showed a complete obstruction of the upper airway. Based on the current understanding of the pathophysiology of different types of angioedema, we will suggest a workup of angioedema without urticaria in the forensic setting and offer readers resources they can use in their practice.

Abnormal striatal dopaminergic neurotransmission during rest and task production in spasmodic dysphonia.

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 [(11)C]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.