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Completed

NCT Number: NCT06111027

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.

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Key information

Conditions

Spasmodic Dysphonia Dysphonia Laryngeal Diseases Laryngeal Dystonia Nervous System Diseases Neurologic Manifestations Otorhinolaryngologic Diseases Pathological Conditions, Signs and Symptoms Respiratory Tract Diseases Signs and Symptoms Voice Disorders

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1 / Phase 2

Primary location

University of Minnesota

Minneapolis, Minnesota, 55414, United States

About this study

Participants with either adductor or abductor-type of spasmodic dysphonia applied VTS at home for a period of 2 months. During the first four weeks they gradually increased their weekly dosage from 3 to 6 days per week. Each application per day lasted 20 minutes.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Diagnosis of spasmodic dysphonia (laryngeal dystonia) for a minimum of 6 months with documented symptom relief after Botox injection.
  • Diagnosis is made by a voice disorder specialist.

Exclusion criteria

  • Regular intake of benzodiazepines
  • Cognitive impairment: score < 27 on Mini-mental state examination
  • Identifies with a neurological or musculoskeletal impairment affecting speech motor function. These impairments may include a form of: Dyskinesia, Dystonia, Essential Tremor, Huntington's Disease, Multiple System Atrophy, Muscle Tension Dysphonia, Parkinsonism, Progressive Supranuclear Palsy, Spasticity, Intracranial Neoplasm (brain tumor), Spinal Neoplasm, Cerebrovascular Accident (Stroke), Mild Traumatic Brain Injury, Intracranial Hemorrhage, Multiple Sclerosis

Treatment and study plan

Vibro-tactile stimulation

Device

Participants received vibro-tactile stimulation (VTS) as a non-invasive treatment option. Stimulators were a pair of light-weight encapsulated cylindrical vibrators applied to both sides of the larynx (voice box). The vibration frequency for VTS was set be to 100Hz. During VTS, participants feel a mild tingling or vibrating sensation at their larynx. They applied VTS at home over a period of 8 weeks with a daily dosage of 20 minutes. During weeks 1-4, the weekly dosage of VTS was gradually increased (week 1: 3 days/wk; week 2: 4 days/wk; week 3: 5 days/wk; week 4: 6 days/wk). During weeks 5-8, participants applied VTS on self-selected days as needed, not exceeding 6 times a week.

Primary outcomes

  1. Perceived Speech Effort (PSE) at Week 4

    Time frame: Week 4

    Perceived Speech Effort was self-rated by participants on a 0-10 scale (0 = no effort, 10 = maximum effort) while reading standardized sentences at habitual pitch and loudness. Ratings were collected immediately before and after each vibro-tactile stimulation session. The PSE value reported here reflects the group mean at week 4.

  2. Perceived Speech Effort (PSE) at Week 8

    Time frame: Week 8

    Perceived Speech Effort was self-rated by participants on a 0-10 scale (0 = no effort, 10 = maximum effort) while reading standardized sentences at habitual pitch and loudness. Ratings were collected immediately before and after each vibro-tactile stimulation session. The PSE value reported here reflects the group mean at week 8.

  3. Voice Quality Change (VQC) at Week 1

    Time frame: Week 1

    Voice Quality Change (VQC) was self-assessed using a 5-point Likert scale (1 = very unnoticeable, 5 = very noticeable; 3 = neutral). Ratings were recorded at the end of each VTS session. VQC at week 1 represents a baseline measure of symptom severity. It was computed as the mean of the first three sessions of VTS of the study.

  4. Voice Quality Change (VQC) at Week 8

    Time frame: Week 8

    Voice Quality Change (VQC) was self-assessed using a 5-point Likert scale (1 = very unnoticeable, 5 = very noticeable; 3 = neutral). Ratings were recorded at the end of each VTS session. The score reflects the overall longitudinal change in symptoms experienced after treatment end. VQC at week 8 was computed as the mean of the last three sessions of the study.

Secondary outcomes

  1. Relative Change in Perceived Speech Effort (rPSE) for VTS Application Method

    Time frame: 8 weeks

    Relative change in PSE (rPSE) was calculated as [(Post - Pre) / Pre] × 100. The between-group difference in mean rPSE comparing VTS received during direct skin contact vs. VTS collar was assessed over the total study period of 8 weeks to understand if the VTS applied directly to the skin was more effective in reducing speech effort than VTS applied via the collar.

  2. Adherence Rate (Feasibility)

    Time frame: Week 1-4

    Number of participants who completed at least 80% of prescribed VTS sessions during the intervention period.

Sponsors and collaborators

Lead sponsor

University of Minnesota

Other

Collaborators

  • National Spasmodic Dysphonia Association

Registry information

Official study title

Usability of Laryngeal Vibro-tactile Stimulation as a Non-invasive Treatment for the Voice Disorder Spasmodic Dysphonia

Important dates

Study start
2023
Primary completion
2024
Study completion
2024
First posted
Nov 1, 2023
Registry last updated
Jul 15, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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