Clinical Research Directory

EMG-Guided Versus Endoscopic-Catheter Botulinum Toxin Injection for Spasmodic Dysphonia

This randomized, controlled non-inferiority trial will compare two established botulinum toxin injection techniques for adductor spasmodic dysphonia: percutaneous electromyography-guided injection and transnasal endoscopic catheter-guided injection. The study will evaluate whether the endoscopic technique provides voice outcomes that are not inferior to the standard EMG-guided approach, while also assessing treatment-related adverse effects, procedural tolerability, and practical advantages such as direct visualization and suitability for patients with challenging neck anatomy.

Spasmodic Dysphonia Interviews

Previous research has shown that patients with voice disorders often have a lower quality of life and struggle with employment. Spasmodic Dysphonia (SD) is a voice disorder that causes abrupt and uncontrollable spasms of the voice box, often resulting in the person having lifelong changes in their voice and speech pattern. The current mainstay of treatment is injecting botulinum toxin (BT) injections into the vocal cord to ease the spasms. The same research team conducted a pilot study in April 2021 on patients with SD. The pilot study used questionnaires and short interviews to understand the livelihood of 10 SD patients. It displayed that SD may impact patients' quality of life. The investigators now aim to run an official research project, ethically approved, to explore the following questions further: 1. Does SD impact the socio-economic lives of its patients? If so, how? 2. What role does BT play in the socio-economic livelihood of SD patients? To answer these questions, the investigators aim to interview 20 patients with Spasmodic Dysphonia.

Assessment of Laryngopharyngeal Sensation: Cancer Survivor Cohort

A previous study completed in 2022 (NCT05158179) was conducted using cohorts of healthy controls, and adults with general laryngopharyngeal disorders. This study will expand on the previous research to include a separate cohort of adults being seen in clinic for an existing laryngopharyngeal disorder resulting from previous radiation or other cancer treatments.

Zinc Supplementation Prior to Botox Injections for Spasmodic Dysphonia

One initial study has shown that Botulinum Toxin (BT) in combination with zinc supplementation may increase the duration of effects BT treatment. This initial study was in the context of facial aesthetics. The purpose of the present study is to determine the effect, if any, of oral zinc supplementation prior to BT in the treatment of spasmodic dysphonia. If positive effects will be observed, this would help reduce the burden of disease for these patients.

Usability of Vibro-tactile Stimulation to Treat Spasmodic Dysphonia

The general aim of the study was to provide evidence for the usability and feasibility of applying vibro-tactile stimulation (VTS) at home as a non-invasive form of neuromodulation to improve speech in people with spasmodic dysphonia (laryngeal dystonia). This work addresses a clinical need to develop alternative or auxiliary treatments for a rare voice disorder with limited treatment options.

Transcranial Magnetic Stimulation in Laryngeal Dystonia

This randomized clinical trial with a crossover design aims to investigate the effects of neuromodulation through repetitive transcranial magnetic stimulation (rTMS) applied to patients diagnosed with laryngeal dystonia. Participants will undergo three experimental conditions: (1) rTMS alone, (2) rTMS combined with speech-language therapy, and (3) sham rTMS combined with speech-language therapy. The order of the conditions will be randomized. Each phase of the protocol will consist of five consecutive sessions. Outcomes will include acoustic vocal quality parameters, perceptual-auditory voice assessment, self-ratings of vocal effort, smoothed cepstral peak prominence measures, and global perceived change following the intervention. It is expected that the study will contribute to a better understanding of the effects of the intervention on vocal outcomes, supporting the optimization and standardization of therapeutic protocols for laryngeal dystonia.

DaxibotulinumtoxinA Injection for Treatment of Adductor Spasmodic Dysphonia

Spasmodic Dysphonia (SD) is a neurologic condition causing inappropriate contraction of the laryngeal musculature, leading to abnormal voicing. The three types (adductor, abductor, and mixed) affect varying muscle groups which produce characteristic voice patterns. The vast majority of patients with SD have adductor type, which impacts the lateral cricoarytenoid and thyroarytenoid muscle complex. While many treatment modalities have been investigated, the most effective treatment is botulinum toxin injection to these muscle groups, performed transcervically with or without electromyography (EMG) guidance. Patients undergoing this treatment typically require re-injection every 3 months. Due to its specialized nature, the laryngeal injections are not performed routinely outside of academic medical centers; thus, patients may come from a distance to receive this treatment. Both due to the significant impact on voice quality when the injections wear off and the sometimes challenging access to treatment, a longer-acting agent is desired. Injectible daxibotuliumtoxinA (DAXI, Revance Therapeutics Inc., Newark, CA) has been shown in large clinical trials to provide safe, effective treatment for glabellar lines and cervical dystonia and may offer a longer-lasting result when compared with onabotulinumtoxinA. Thus, a study examining the effect of DAXI for patients with adductor spasmodic dysphonia is proposed. This study aims to assess the efficacy of DAXI for transcervical laryngeal injection in patients with adductor spasmodic dysphonia.

Extended-release Sodium Oxybate (Lumryz) in Spasmodic Dysphonia and Voice Tremor

Using a comprehensive approach of clinico-behavioral testing and neuroimaging, the researchers will examine the clinical effects of the extended-release formulation of sodium oxybate on voice symptoms in spasmodic dysphonia in an open-label, proof-of-concept, dose-finding study.

Brain Networks in Dystonia

To date, there is only limited knowledge about the distinct neural abnormalities that lead to the development of different forms of focal dystonia. The goal of this study is to dissect the pathophysiological mechanisms underlying this clinical phenomenon using multi-level brain network analysis in patients with focal dystonia.

Deep Brain Stimulation in Laryngeal Dystonia and Voice Tremor

The goals of this project are 1) to determine the incidence of neurological voice disorders in patients with dystonia and essential tremor undergoing deep brain stimulation (DBS), 2) investigate the neuroimaging and intracranial neurophysiology correlates of voice dysfunction in these subjects, and subsequently 3) determine the effects of DBS on voice function.

Characterization of Clinical Phenotypes of Laryngeal Dystonia and Voice Tremor

The researchers will systematically evaluate current and novel clinical voice assessment tools and measures to elucidate distinct clinical phenotypes of those with laryngeal dystonia and voice tremor.

Understanding Disorder-specific Neural Pathophysiology in Laryngeal Dystonia and Voice Tremor

The researchers will examine functional neural correlates that differentiate between laryngeal dystonia and voice tremor and contribute to disorder-specific pathophysiology using a cross-disciplinary approach of multimodal brain imaging.