Non-invasive Brain Stimulation in Adults Who Stutter

Study Overview
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Brief Summary
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Research studies in stuttering have shown that activity patterns in certain brain areas differ in people who stutter compared to people who do not stutter when speaking. The purpose of this study is to investigate how mild, non-invasive brain stimulation applied consecutively for five days affects speech relevant brain areas, which may in turn affect speech fluency and speaking-related brain activity in people who stutter.

Official Title
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Non-invasive Brain Stimulation in Adults Who Stutter

Conditions
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Stuttering, Developmental

Intervention / Treatment
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* Device: Anodal tDCS
* Behavioral: Fluency training
* Device: Sham tDCS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: history of persistent developmental stuttering stuttering severity ranging from mild to very severe, specifically Stuttering Severity Instrument (SSI) total score of 20 (mild) or higher and stuttering rates of 3% or higher scores within 1 standard deviation of the norm on the standardized tests for the study Exclusion Criteria: received any treatment for stuttering within the past year other neurological conditions such as Tourette's syndrome or post-traumatic stress disorder taking any medications/drugs that affect brain function history of past or current mental illness for example, schizophrenia that may affect brain development and function history of serious medical or neurological illness such as epilepsy and Parkinson's disease history of closed head injury (e.g., concussion) history of reading disorders hearing loss taking any medication, prescription or non-prescription with any psychotropic effects at the time of the study metal or electronic implants such as cochlear implants, and pacemakers

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Active tDCS and fluency training<br>Participants will receive anodal tDCS at 2milliampere (mA) intensity for 20 minutes during speech fluency training (5 consecutive days). | Device: Anodal tDCS<br>* 20 minutes of 2mA anodal stimulation.<br>Behavioral: Fluency training<br>* Speaking along with a metronome and/or speaking along with another person (choral speech) for 20 minutes<br>|
| Sham Comparator: Sham tDCS and fluency training<br>Participants will receive sham tDCS. Sham stimulation will involve 30 seconds of stimulation at the beginning of the 20 minutes of speech fluency training (5 consecutive days). | Behavioral: Fluency training<br>* Speaking along with a metronome and/or speaking along with another person (choral speech) for 20 minutes<br>Device: Sham tDCS<br>* For sham stimulation, current is ramped up and back down over 30 seconds.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in Brain Activation as Assessed by fMRI Images | Investigators will use the fMRI images taken from before and after tDCS to determine if the treatment intervention contributed to any changes within brain regions associated with speech production. This will be measured by Blood-Oxygen-Level-Dependent (BOLD) signal change (arbitrary units). Images from scans are preprocessed. Changes in BOLD signal are modeled for contrasts within a group for [post-pre] and [follow up-pre] (e.g., active group reading condition post visit MINUS active group reading pre visit). Results are reported for reading condition. | Baseline, 1 week (post), 4 weeks (follow up) | 
| Change in Percentage of Stuttered Syllables Produced During Speech Sample | Investigators will calculate the percentage of stuttered syllables (out of total syllables) in a speech sample. Decreased stuttered syllables represents better outcomes (greater reduction in stuttering). | Baseline, 1 week (post), 4 weeks (follow up) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes From Baseline on the Overall Assessment of Speakers Experience of Stuttering (OASES) | The OASES is a standardized assessment of the functional impact of stuttering on a person's life. There are 4 sub-tests: general information about speech, your reactions to stuttering, communication in daily situations, quality of life. Each one has a score from 1 to 5 with regard to impact (1 least, 5 most negative impact). These are combined to give a total impact score between 1 and 5, with 5 representing the highest negative impact on person's life. The change on the total impact score will be used. Changes are shown in the table below by comparison between the measurements at the three points in time. | Baseline, 1 week (post), 4 weeks (follow up) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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transcranial direct current stimulation, MRI, Speech, fluency, tDCS