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

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to explore how mild, noninvasive electrical brain stimulation can help people who stutter. Researchers hope that transcranial alternating current stimulation (tACS) will improve speech fluency by enhancing communication between brain areas involved in speaking. Participants will receive three sessions, which may include real or placebo (inactive) treatments. Those who currently stutter, speak English as their primary language, and haven't had stuttering treatment in the past year might be a good fit for this study. As an unphased trial, this study offers participants the opportunity to contribute to groundbreaking research that could lead to new treatments for stuttering.

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 prior data suggests that this brain stimulation technique is safe for treating stuttering?

Research has shown that transcranial alternating current stimulation (tACS) is generally safe. In one study with 18 healthy volunteers, using tACS at a frequency of 5 kHz for 10 minutes at a strength of 1 mA did not raise any safety concerns, indicating that the treatment is usually well-tolerated at these settings.

tACS is a noninvasive method, meaning it doesn't involve surgery or cutting into the body. While no major negative effects have been reported, it might cause minor discomforts like a tingling sensation on the skin.

Overall, current studies support the safety of tACS, making it a promising option for exploring its effects on stuttering. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about transcranial alternating current stimulation (tACS) for stuttering because it offers a novel approach to treating this speech disorder. Unlike traditional therapies that often focus on speech techniques and behavioral interventions, tACS uses mild electrical currents to directly stimulate brain activity, potentially targeting the underlying neural pathways associated with stuttering. This method could offer a non-invasive and dynamic way to address stuttering at its source, providing new hope for individuals who have not found success with existing treatments.

What evidence suggests that transcranial alternating current stimulation (tACS) is effective for stuttering?

Research suggests that transcranial alternating current stimulation (tACS), which participants in this trial will receive, might help reduce stuttering. Similar methods, such as transcranial direct current stimulation (tDCS), have significantly lessened stuttering. tACS sends gentle electrical currents to the brain to improve communication between brain areas during speech. This non-invasive method does not involve surgery. While the potential is promising, further research is needed to confirm the effectiveness of tACS for stuttering. ^{1 2 3 6 7}

Who Is on the Research Team?

Soo-Eun Chang, PhD

Principal Investigator

University of Michigan

Are You a Good Fit for This Trial?

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 for a Trial Participant

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)

What Are the Treatments Tested in This Trial?

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.

How Is the Trial Designed?

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

Participants will receive 3 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+

Published Research Related to This Trial

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]

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]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC12509051/

The Effects of tDCS on Speech Fluency in People Who ... The studies reviewed in this study have reported a variable effectiveness of tDCS for enhancing speech fluency in PWS. As a result, it remains ...

2. clinicaltrials.gov clinicaltrials.gov/study/NCT06740968?term=AREA%5BConditionSearch%5D(stuttering)&rank=8

Transcranial Alternating Current Stimulation (tACS) in ... NLM staff identify potential major and advisory issues and provide comments directly to the study sponsor or investigator. Major issues identified in QC review ...

3. sciencedirect.com sciencedirect.com/science/article/pii/S0094730X25000026

The application of non-invasive neuromodulation in stuttering This review aims to report on studies that have utilized neuromodulation methods such as transcranial direct current stimulation (tDCS) and transcranial ...

4. pubs.asha.org pubs.asha.org/doi/10.1044/2025_JSLHR-24-00750

Efficacy of Noninvasive Brain Stimulation Techniques in ... Meta-regression showed that transcranial direct current stimulation (tDCS) had the most significant effect in reducing stuttering severity and frequency among ...

5. frontiersin.org frontiersin.org/journals/human-neuroscience/articles/10.3389/fnhum.2019.00411/full

Stuttering Severity Modulates Effects of Non-invasive Brain ... The group who received active stimulation showed significant decrease in stuttering at 1 week after treatment, compared to the training-only (sham stimulation) ...

6. frontiersin.org frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2024.1419243/full

a systematic review of treatment parameters and outcomes This systematic review aimed to compile human research on tACS for neuropsychiatric disorders to delineate typical treatment parameters for these conditions ...

7. withpower.com withpower.com/trial/brain-stimulation-for-stuttering-1a610

Brain Stimulation for Stuttering 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, ...