Magnetic brain stimulation for voice problems in laryngeal dystonia

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults with laryngeal dystonia, a condition causing voice spasms. It tests rTMS, a magnetic brain stimulation, against a sham (fake) version.

Age

21 to 85 years

Sex

All sexes

Disease stage

A diagnosis of laryngeal dystonia (LD). People getting botulinum toxin injections must have symptoms at their worst severity.

Earlier treatment

People who had surgery on the larynx (voice box) cannot join.

Main reasons for not taking part

• Other forms of dystonia, essential tremor, or vocal fold disease or paralysis
• Laryngeal cancer, or other nerve conditions treated with medicines that act on the brain
• A seizure in the last 2 years
• Any reason rTMS cannot be used safely
• Not able to give consent or complete the tests and treatment

The registry criteria, word for word

Check if you might fit

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

• Are you between 21 and 85 years old?YesNo

What the trial wants to find out

Laryngeal dystonia (LD) causes excessive vocal fold abduction (opening) or adduction (closing) leading to decreased voice quality, job prospects, self-worth and quality of life. Individuals with LD often experience episodic breathy voice, decreased ability to sustain vocal fold vibration, frequent pitch breaks and in some cases, vocal tremor. While neuroimaging investigations have uncovered both cortical organization and regional connectivity differences in structures in parietal, primary somatosensory and premotor cortices of those with LD, there remains a lack of understanding regarding how the brains of those with LD function to produce phonation and how these might differ from those without LD. Intervention options for people with LD are limited to general voice therapy techniques and Botulinum Toxin (Botox) injections to the posterior cricoarytenoid (PCA) and/or TA (thyroarytenoid) often bilaterally, to alleviate muscle spasms in the vocal folds. However, the effects of injections are short-lived, uncomfortable, and variable. To address this gap, the aim of this study is to investigate the effectiveness of repetitive transcranial magnetic stimulation (rTMS), a non-invasive neuromodulation technique, in assessing cortical excitability and inhibition of laryngeal musculature. Previous work conducted by the investigator has demonstrated decreased intracortical inhibition in those with adductor laryngeal dystonia (AdLD) compared to healthy controls. The investigators anticipate similar findings in individuals with with other forms of LD, where decreased cortical inhibition will likely be noted in the laryngeal motor cortex. Further, following low frequency (inhibitory) rTMS to the laryngeal motor brain area, it is anticipated that there will be a decrease in overactivation of the TA muscle. To test this hypothesis, a proof-of-concept, randomized study to down-regulate cortical motor signal to laryngeal muscles will be compared to those receiving an equal dose of sham rTMS. Previous research conducted by the investigator found that a single session of the proposed therapy produced positive phonatory changes in individuals with AdLD and justifies exploration in LD.

The 2 groups in the trial

• repetitive transcranial magnetic stimulation (rTMS)Existing treatment, for comparison

  5 consecutive days of rTMS to the individualized, targeted, left laryngeal motor cortex associated with laryngeal function to down-regulate cortical motor signal to intrinsic laryngeal muscles and improve vocal function of individuals with LD.

• Sham rTMSSham treatment, for comparison

  5 consecutive days of sham rTMS to the individualized, targeted, left laryngeal motor cortex associated with laryngeal function to down-regulate cortical motor signal to intrinsic laryngeal muscles and improve vocal function of individuals with LD.