Brain Stimulation for Stuttering

Overseen By Soo-Eun Chang, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Michigan

Disqualifiers: Seizures, Neurological illness, Head injury, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 8

Duration: 5 sessions

80 Participants Needed

Trial Summary

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

What data supports the effectiveness of the treatment Transcranial Alternating Current Stimulation (tACS) for stuttering?

Research shows that a similar treatment, transcranial direct current stimulation (tDCS), can improve speech fluency in adults who stutter when combined with speech fluency training. Additionally, 10-Hz tACS has been found to improve verbal fluency in healthy individuals, suggesting potential benefits for language-related conditions. ^{1 2 3 4 5}

Is transcranial alternating current stimulation (tACS) safe for humans?

Research indicates that transcranial alternating current stimulation (tACS) is a safe technique for humans, as it is a non-invasive method of brain stimulation that has been used in studies without significant safety concerns. ^{1 3 4 6 7}

How does the treatment Transcranial Alternating Current Stimulation (tACS) for stuttering differ from other treatments?

Transcranial Alternating Current Stimulation (tACS) is unique because it uses electrical currents to modulate brain activity, potentially improving speech fluency by targeting specific brain areas involved in language processing. Unlike traditional behavioral therapies, tACS offers a non-invasive approach that may enhance fluency by synchronizing brain activity, similar to how reading in unison with a metronome can temporarily improve speech. ^{1 2 3 5 7}

What is the purpose of this trial?

The purpose of this study is to investigate how mild, noninvasive electrical brain stimulation affects speech relevant brain areas, which may in turn affect speech fluency and speaking-related brain activity in people that stutter. The long-term goal of this study is to test the therapeutic potential of transcranial alternating current stimulation (tACS) for the treatment of stuttering. The study team hypothesizes that if stuttering involves impaired initiation of motor programs, delta-tuned tACS will strengthen communication between brain regions and decrease stuttering. Therefore, the study team delta-tuned sensorimotor tACS will be paired with fluency-induced speech (choral reading), which is hypothesized to decrease stuttering via improved auditory motor integration. However, if the primary impairment lies in planning of motor programs, the study team hypothesizes that theta-tuned tACS will strengthen communication between prefrontal and temporal brain regions and decrease stuttering.

Research Team

Soo-Eun Chang, PhD

Principal Investigator

University of Michigan

Eligibility Criteria

This trial is for adults who stutter, including those whose stuttering began in childhood or adulthood. Participants must be able to undergo noninvasive brain stimulation and participate in speech tasks. Specific medical conditions or treatments that could interfere with the study are reasons for exclusion.

Inclusion Criteria

Currently stutter

Score (per protocol) a certain value on the Stuttering Severity Instrument (SSI-4)

I haven't had stuttering treatment in the last year.

Exclusion Criteria

Currently pregnant

I have a history of seizures.

Metal or electronic implants such as cochlear implants and pacemakers anywhere in the body

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

1 visit (in-person)

Baseline

Participants undergo baseline assessments including standardized tests of speech, language, hearing, and working memory, as well as MRI and EEG

1-2 weeks

1 visit (in-person)

Treatment

Participants receive 5 sessions of tACS, which can be active or sham, paired with fluency-induced speech (choral reading)

5 sessions

5 visits (in-person)

Follow-up

Participants are monitored for changes in speech fluency and brain activity after treatment, with a follow-up phone call one month later

1 month

1 call (phone)

Treatment Details

Interventions

• Transcranial Alternating Current Stimulation (tACS)

Trial Overview The trial is testing transcranial alternating current stimulation (tACS), a mild electrical brain stimulation, to see if it can improve speech fluency in people who stutter by enhancing communication between brain areas involved in speech production.

Participant Groups

Group I: transcranial alternating current stimulation (tACS) Experimental Treatment 1 Intervention

Participants will receive 5 sessions of tACS. Each session can be active or sham. The stimulation parameters regarding the active and sham will not be disclosed at this time to maintain blind to participants. At the end of the trial the study will be updated to list these.

Who Is Running the Clinical Trial?

University of Michigan

Lead Sponsor

Trials

1,891

Recruited

6,458,000+

Findings from Research

In a study involving 14 adults who stutter, high-definition transcranial direct current stimulation (HD-tDCS) was tested to see if it could improve speech fluency during synchronized reading, but no significant differences were found between active and sham stimulation.

However, the results indicated that for individuals with more severe stuttering, active stimulation reduced the abnormal brain activity associated with their condition, suggesting that HD-tDCS may have potential for enhancing fluency in stuttering and warrants further investigation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stuttering Severity Modulates Effects of Non-invasive Brain Stimulation in Adults Who Stutter. Garnett, EO., Chow, HM., Choo, AL., et al.[2020]

In a study involving 18 healthy volunteers, sinusoidal transcranial alternating current stimulation (tACS) at 5 kHz for 10 minutes at 1 mA was found to be safe, as indicated by stable neuron-specific enolase (NSE) levels and no significant changes in EEG or MRI results.

The findings suggest that tACS does not cause structural or pathological changes in the brain, supporting its safety for use under the tested conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety of 5 kHz tACS. Chaieb, L., Antal, A., Pisoni, A., et al.[2022]

References

1. Switzerland pubmed.ncbi.nlm.nih.gov

Stuttering Severity Modulates Effects of Non-invasive Brain Stimulation in Adults Who Stutter. [2020]

2. Netherlands pubmed.ncbi.nlm.nih.gov

Investigating the feasibility of using transcranial direct current stimulation to enhance fluency in people who stutter. [2019]

3. England pubmed.ncbi.nlm.nih.gov

Transcranial direct current stimulation over left inferior frontal cortex improves speech fluency in adults who stutter. [2023]

4. United States pubmed.ncbi.nlm.nih.gov

Investigation of the effect of delayed auditory feedback and transcranial direct current stimulation (DAF-tDCS) treatment for the enhancement of speech fluency in adults who stutter: A randomized controlled trial. [2022]

5. England pubmed.ncbi.nlm.nih.gov

10-Hz tACS over the prefrontal cortex improves phonemic fluency in healthy individuals. [2022]

6. Switzerland pubmed.ncbi.nlm.nih.gov

Effects of cerebellar transcranial alternating current stimulation in cerebellar ataxia: study protocol for a randomised controlled trial. [2023]

7. United States pubmed.ncbi.nlm.nih.gov

Safety of 5 kHz tACS. [2022]