Spasmodic Dysphonia

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.

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.

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.

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.

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.

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.

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.