Laryngeal Dystonia, Spasmodic Dysphonia
Conditions
Keywords
in-home therapy, vibration, vibro-tactile, laryngeal dystonia
Brief summary
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.
Detailed description
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.
Interventions
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.
Sponsors
University of Minnesota
National Spasmodic Dysphonia Association
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
Usability study
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Perceived Speech Effort (PSE) at Week 4 | 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. |
| Perceived Speech Effort (PSE) at Week 8 | 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. |
| Voice Quality Change (VQC) at Week 1 | 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. |
| Voice Quality Change (VQC) at Week 8 | 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
| Measure | Time frame | Description |
|---|---|---|
| Relative Change in Perceived Speech Effort (rPSE) for VTS Application Method | 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. |
| Adherence Rate (Feasibility) | Week 1-4 | Number of participants who completed at least 80% of prescribed VTS sessions during the intervention period. |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORJuergen Konczak, PhD
University of Minnesota
Participant flow
Recruitment details
Data collection occurred between the 21st November 2023 and the 28th October 2024. Recruitment ended on 29th October 2024. A total of 40 participants were enrolled. Of these, 34 participants began study procedures and 32 participants completed the study.
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 16 Participants |
| Age, Categorical Between 18 and 65 years | 16 Participants |
| Age, Continuous | 62.3 Years STANDARD_DEVIATION 15.2 |
| Perceived Speech Effort | 5.5 Score on a scale of 1-10 STANDARD_DEVIATION 1.3 |
| Race (NIH/OMB) American Indian or Alaska Native | 1 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 31 Participants |
| Sex: Female, Male Female | 21 Participants |
| Sex: Female, Male Male | 11 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 32 |
| other Total, other adverse events | 2 / 32 |
| serious Total, serious adverse events | 0 / 32 |
Outcome results
None listed