StutteringNCT07668882
Noninvasive Thalamocortical Neuromodulation With Low-Intensity Focused Ultrasound for Persistent Developmental Stuttering
A study testing High DC LIFU in people with Stuttering and Developmental Stuttering, run by University of Michigan at 1 site in United States.
Trial summary
This research is studying the use of low-intensity focused ultrasound (LIFU; a mild, noninvasive acoustic stimulation technique) in a small number of people to learn about its safety as a treatment for stuttering. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Stuttering, Developmental Stuttering
- What is being tested?
- High DC LIFU
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 19 Aug 2026to Aug 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- have normal language, hearing and cognition
- speak English as their primary language
- currently stutter
- score at least 10 (very mild) on the Stuttering Severity Instrument (SSI-4) or exhibit greater than 3% stuttered syllables during at least one of the first 3 speech samples
- have not receive any treatment for stuttering within the past year
Who cannot join
- History of seizures
- Major medical or neurological illness (e.g., stroke, serious head trauma, brain infection, Parkinson's disease, etc.)
- History of closed head injury with loss of consciousness (e.g., concussion)
- Metal or electronic implants such as cochlear implants and pacemakers
- Braids or other hair styling that prevents direct access to the scalp (if removal not possible)
- Current or planned pregnancy
Show all 10Show fewer
- Any active, unstable, or inadequately treated psychiatric condition, including but not limited to psychosis, active major depressive episode, bipolar disorder with recent mood episode, or current suicidal ideation.
- Current use of antipsychotic medications for treatment of a primary psychotic disorder or bipolar disorder; current use of mood stabilizers (e.g., lithium, valproate) or benzodiazepines. Low-dose adjunctive use of atypical antipsychotics (e.g., brexpiprazole, aripiprazole, quetiapine) for treatment-resistant depression or anxiety is not exclusionary if the participant's condition is stable per the existing ≥2-month stability criterion.
- Any condition or medication that lowers seizure threshold, consistent with standard practice across non-invasive brain stimulation protocols.
- Note: participants who cannot undergo MRI may complete the other portions of the study. For participants who cannot undergo MRI can be targeted for LIFU stimulation using a standard T1 scan. Resting state fMRI measures taken before and after stimulation will also be omitted for these cases. But the behavioral and speech measures can still be completed to provide pre and post-stimulation variations.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Michigan
Ann Arbor, Michigan, 48109
Hasini Weerathunge, Ph.D., 734-232-5748, weerathh@umich.edu
Hasini Weerathunge,, Ph.D.
About this study
This research is studying the use of low-intensity focused ultrasound (LIFU; a mild, noninvasive acoustic stimulation technique) in a small number of people to learn about its safety as a treatment for stuttering. LIFU is a small, safe sound signal that produces a gentle, pulsing flow of acoustic waves to help different parts of the brain communicate with each other. Researchers want to understand how the mild, non-invasive brain stimulation affects speech relevant brain areas, which may in turn affect speech fluency and speaking-related brain activity in people who stutter.
Read the detailed description
This study will investigate whether Low-Intensity Focused Ultrasound (LIFU; also known as transcranial ultrasound stimulation, TUS) targeting the ventral intermediate (VIM) nucleus of the thalamus can safely and feasibly modulate neural activity and improve speech fluency in adults with Persistent Developmental Stuttering (PDS).
Adult participants with PDS will be recruited through community advertisements and from existing institutional research registries, including individuals who have previously participated in noninvasive neuromodulation studies and have consented to be re-contacted for future research. All participants will complete an informed consent process prior to any study procedures.
This is a within-subject, sham-controlled study in which participants will attend multiple study visits. Study procedures include: (1) baseline behavioral and speech assessments; (2) magnetic resonance imaging (MRI), including structural imaging and diffusion tractography, to localize individualized stimulation targets; (3) functional MRI (fMRI) to assess brain connectivity; (4) neuronavigation-guided LIFU stimulation targeting the VIM thalamic nucleus; and (5) concurrent and pre/post behavioral tasks assessing speech production, reading, and rhythm perception. Participants will receive both active and sham LIFU stimulation in separate sessions.
Aim 1 is to evaluate the safety, feasibility, and precision of individualized, MRI-guided LIFU targeting of the left VIM thalamus using neuronavigation and post-hoc acoustic simulation. Feasibility outcomes include targeting accuracy, protocol adherence, adverse event monitoring, and participant tolerability.
Aim 2 is to characterize the acute neural and behavioral effects of excitatory VIM-LIFU relative to a passive sham condition (reverse direction of transducer; no stimulation) using a within-subjects, double-blind crossover design. Primary outcome is the change in speech fluency (stuttered syllable percentage). Secondary outcomes are motor inhibition (stop-signal reaction time), and beat-based rhythm discrimination (d'). Exploratory neural outcomes include pre-to-post changes in resting-state thalamocortical functional connectivity and task-based (stop-signal fMRI) connectivity between VIM and speech motor regions (IFG, STN, pre-SMA). Exploratory analyses will also examine whether baseline thalamocortical connectivity predicts changes in functional connectivity and behavioral outcomes following stimulation.
The study is noninvasive and does not involve surgical procedures or implantation. Data collected will include neuroimaging, behavioral performance, and speech recordings. The results of this study will inform the feasibility and potential efficacy of noninvasive subcortical neuromodulation for PDS.
- Conditions
- Stuttering, Developmental Stuttering
- Being tested
- High DC LIFU, Sham
- Keywords
- Low Intensity Focused Ultrasound, Thalamus, Neuromodulation
- Medical subject headings
- Stuttering
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
High DC LIFUDevice
Stimulation parameters and target location. Stimulation will be delivered using the BrainSonix BXPulsar 1002 System (BrainSonix Corporation, Sherman Oaks, CA, USA). Sonication Parameters will be as follows. Fundamental frequency: 650 kHz; pulse repetition frequency: 10Hz; pulse duration: 100ms; DC: 70% (yielding pulse width of 70 ms); sonication duration: 30 s; inter-sonication interval: 30s; LIFU-ON epochs per block: 12 epochs (Jang et al., 2025). During active stimulation a total of 4.2 min stimulation will be applied across all LIFU-ON epochs. Both active and sham stimulation sessions will last ~12 mins each. The researchers will be targeting ventral intermediate nucleus (VIM) region of the thalamus for the active stimulation.
ShamDevice
Stimulation parameters and target location. Stimulation will be delivered using the BrainSonix BXPulsar 1002 System (BrainSonix Corporation, Sherman Oaks, CA, USA). Sonication Parameters will be as follows. Fundamental frequency: 650 kHz; pulse repetition frequency: 10Hz; pulse duration: 100ms; DC: 70% (yielding pulse width of 70 ms); sonication duration: 30 s; inter-sonication interval: 30s; LIFU-ON epochs per block: 12 epochs (Jang et al., 2025). During sham stimulation a total of 4.2 min stimulation will be applied across all LIFU-ON epochs. Both active and sham stimulation sessions will last ~12 mins each. The researchers will be reversing the direction of the transducer placed on the head such that no active stimulation will be applied to the participant's head. But the neuronavigation procedures (targeting VIM) and stimulation parameters will be kept identical such that the participant experiences the same procedure across active and sham conditions.
| Study group | Role | What they receive |
|---|---|---|
| High DC LIFU then Sham | Experimental | Not described Receives: Device: High DC LIFU; Device: Sham |
| Sham then High DC LIFU | Sham comparator | Not described Receives: Device: High DC LIFU; Device: Sham |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of stuttered syllables produced during speech sample
The study will calculate the percentage of stuttered syllables (out of total syllables) in two speech samples (one before LIFU and one sample after LIFU) per each stimulation session. Decreased stuttered syllables represents better outcomes (greater reduction in stuttering). Two samples are collected during session 1 and two samples are collected during session 2. An additional baseline sample is collected at the baseline session (on a separate day before the two stimulation sessions).
Measured: Baseline, and immediately before and after LIFU stimulation during Stimulation Session 1 and Stimulation Session 2 (sessions occurring a minimum of 2 days apart and a maximum of 1 week apart), for a total of 5 assessments over an estimated 2-3 weeks.
Secondary outcomes (2)
Stop signal response time (SSRT)
The study will measure the Stop signal response time (SSRT) from the stop signal fMRI task (one before LIFU and one sample after LIFU) per each stimulation session. Two SSRT outcomes are collected during session 1 and two SSRT outcomes are collected during session 2. An additional baseline SSRT is collected at the baseline session (on a separate day before the two stimulation sessions). SSRT will be measured 5 times total.
Measured: Baseline, and immediately before and after LIFU stimulation during Stimulation Session 1 and Stimulation Session 2 (sessions occurring a minimum of 2 days apart and a maximum of 1 week apart), for a total of 5 assessments over an estimated 2-3 weeks.
Rhythm discrimination score (d')
The study will compare the rhythm discrimination behavioral task from before and after LIFU during both session 1 and 2 for a total of 4 measurements. This is measured by the signal direction measures d' that will be calculated to quantify perceptual sensitivity (d'). Apart from the stimulation sessions, the baseline session will also collect this measure. Thus, assessed 5 times in total, considering the baseline session and stimulation sessions 1 and 2.
Measured: Baseline, and immediately before and after LIFU stimulation during Stimulation Session 1 and Stimulation Session 2 (sessions occurring a minimum of 2 days apart and a maximum of 1 week apart), for a total of 5 assessments over an estimated 2-3 weeks.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Jun 2026
- Study start19 Aug 2026
- Primary completionAug 2027 (estimated)
- Study completionAug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for StutteringStudies of the same condition, open and under way.
- More trials run by University of MichiganThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- This is a two-period, two-sequence crossover design. All participants receive both active LIFU and sham stimulation across two sessions. Participants pseudo randomized to Arm 1 receive High duty cycle (DC) LIFU in Session 1 followed by Sham in Session 2; those pseudo randomized to Arm 2 receive Sham in Session 1 followed by High DC LIFU in Session 2. The order is counterbalanced across participants to control for order effects. Participants also complete a baseline session where a T1 MRI structural image will be collected for VIM-LIFU targeting, and baseline versions of the outcome measures will also be collected.
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Outcomes assessor
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Michigan
- Sponsor type
- University, hospital or other
- Collaborators
- Michigan Pioneer Fellowship
- Responsible party
- Principal investigator, Hasini Weerathunge, University of Michigan
- Investigators
- Hasini Weerathunge, Ph.D., Principal investigator, University of MichiganSoo-Eun Chang, Ph.D., Principal investigator, University of Michigan
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07668882
- Sponsor's protocol ID
- HUM00274381
- Status last verified
- Aug 2026
- First submitted
- 11 Jun 2026
- Last updated
- 15 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Noninvasive Thalamocortical Neuromodulation With Low-Intensity Focused Ultrasound for Persistent Developmental Stuttering
- ClinicalTrials.gov ID
- NCT07668882
- Acronym / sponsor ID
- HUM00274381
- Conditions
- Stuttering, Developmental Stuttering
- Keywords
- Low Intensity Focused Ultrasound, Thalamus, Neuromodulation
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- University of MichiganUniversity, hospital or other
- Collaborators
- Michigan Pioneer Fellowship
- Study start
- 19 Aug 2026 (actual)
- Primary completion
- Aug 2027 (estimated)
- Study completion
- Aug 2027 (estimated)
- First posted
- 25 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This research is studying the use of low-intensity focused ultrasound (LIFU; a mild, noninvasive acoustic stimulation technique) in a small number of people to learn about its safety as a treatment for stuttering. LIFU is a small, safe sound signal that produces a gentle, pulsing flow of acoustic waves to help different parts of the brain communicate with each other. Researchers want to understand how the mild, non-invasive brain stimulation affects speech relevant brain areas, which may in turn affect speech fluency and speaking-related brain activity in people who stutter.
Detailed description
This study will investigate whether Low-Intensity Focused Ultrasound (LIFU; also known as transcranial ultrasound stimulation, TUS) targeting the ventral intermediate (VIM) nucleus of the thalamus can safely and feasibly modulate neural activity and improve speech fluency in adults with Persistent Developmental Stuttering (PDS).
Adult participants with PDS will be recruited through community advertisements and from existing institutional research registries, including individuals who have previously participated in noninvasive neuromodulation studies and have consented to be re-contacted for future research. All participants will complete an informed consent process prior to any study procedures.
This is a within-subject, sham-controlled study in which participants will attend multiple study visits. Study procedures include: (1) baseline behavioral and speech assessments; (2) magnetic resonance imaging (MRI), including structural imaging and diffusion tractography, to localize individualized stimulation targets; (3) functional MRI (fMRI) to assess brain connectivity; (4) neuronavigation-guided LIFU stimulation targeting the VIM thalamic nucleus; and (5) concurrent and pre/post behavioral tasks assessing speech production, reading, and rhythm perception. Participants will receive both active and sham LIFU stimulation in separate sessions.
Aim 1 is to evaluate the safety, feasibility, and precision of individualized, MRI-guided LIFU targeting of the left VIM thalamus using neuronavigation and post-hoc acoustic simulation. Feasibility outcomes include targeting accuracy, protocol adherence, adverse event monitoring, and participant tolerability.
Aim 2 is to characterize the acute neural and behavioral effects of excitatory VIM-LIFU relative to a passive sham condition (reverse direction of transducer; no stimulation) using a within-subjects, double-blind crossover design. Primary outcome is the change in speech fluency (stuttered syllable percentage). Secondary outcomes are motor inhibition (stop-signal reaction time), and beat-based rhythm discrimination (d'). Exploratory neural outcomes include pre-to-post changes in resting-state thalamocortical functional connectivity and task-based (stop-signal fMRI) connectivity between VIM and speech motor regions (IFG, STN, pre-SMA). Exploratory analyses will also examine whether baseline thalamocortical connectivity predicts changes in functional connectivity and behavioral outcomes following stimulation.
The study is noninvasive and does not involve surgical procedures or implantation. Data collected will include neuroimaging, behavioral performance, and speech recordings. The results of this study will inform the feasibility and potential efficacy of noninvasive subcortical neuromodulation for PDS.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, care provider, outcomes assessor)
- Number of arms
- 2
- Model description
- This is a two-period, two-sequence crossover design. All participants receive both active LIFU and sham stimulation across two sessions. Participants pseudo randomized to Arm 1 receive High duty cycle (DC) LIFU in Session 1 followed by Sham in Session 2; those pseudo randomized to Arm 2 receive Sham in Session 1 followed by High DC LIFU in Session 2. The order is counterbalanced across participants to control for order effects. Participants also complete a baseline session where a T1 MRI structural image will be collected for VIM-LIFU targeting, and baseline versions of the outcome measures will also be collected.
| Arm | Type | Receives |
|---|---|---|
| High DC LIFU then Sham | Experimental | Device: High DC LIFU, Device: Sham |
| Sham then High DC LIFU | Sham comparator | Device: High DC LIFU, Device: Sham |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- have normal language, hearing and cognition
- speak English as their primary language
- currently stutter
- score at least 10 (very mild) on the Stuttering Severity Instrument (SSI-4) or exhibit greater than 3% stuttered syllables during at least one of the first 3 speech samples
- have not receive any treatment for stuttering within the past year
Key exclusion criteria (10 listed)
- History of seizures
- Major medical or neurological illness (e.g., stroke, serious head trauma, brain infection, Parkinson's disease, etc.)
- History of closed head injury with loss of consciousness (e.g., concussion)
- Metal or electronic implants such as cochlear implants and pacemakers
- Braids or other hair styling that prevents direct access to the scalp (if removal not possible)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| High DC LIFUStimulation parameters and target location. Stimulation will be delivered using the BrainSonix BXPulsar 1002 System (BrainSonix Corporation, Sherman Oaks, CA, USA). Sonication Parameters will be as follows. Fundamental frequency: 650 kHz; pulse repetition frequency: 10Hz; pulse duration: 100ms; DC: 70% (yielding pulse width of 70 ms); sonication duration: 30 s; inter-sonication interval: 30s; LIFU-ON epochs per block: 12 epochs (Jang et al., 2025). During active stimulation a total of 4.2 min stimulation will be applied across all LIFU-ON epochs. Both active and sham stimulation sessions will last ~12 mins each. The researchers will be targeting ventral intermediate nucleus (VIM) region of the thalamus for the active stimulation. | Device | High DC LIFU then Sham, Sham then High DC LIFU |
| ShamStimulation parameters and target location. Stimulation will be delivered using the BrainSonix BXPulsar 1002 System (BrainSonix Corporation, Sherman Oaks, CA, USA). Sonication Parameters will be as follows. Fundamental frequency: 650 kHz; pulse repetition frequency: 10Hz; pulse duration: 100ms; DC: 70% (yielding pulse width of 70 ms); sonication duration: 30 s; inter-sonication interval: 30s; LIFU-ON epochs per block: 12 epochs (Jang et al., 2025). During sham stimulation a total of 4.2 min stimulation will be applied across all LIFU-ON epochs. Both active and sham stimulation sessions will last ~12 mins each. The researchers will be reversing the direction of the transducer placed on the head such that no active stimulation will be applied to the participant's head. But the neuronavigation procedures (targeting VIM) and stimulation parameters will be kept identical such that the participant experiences the same procedure across active and sham conditions. | Device | High DC LIFU then Sham, Sham then High DC LIFU |
Primary outcome
Percentage of stuttered syllables produced during speech sample
Time frame: Baseline, and immediately before and after LIFU stimulation during Stimulation Session 1 and Stimulation Session 2 (sessions occurring a minimum of 2 days apart and a maximum of 1 week apart), for a total of 5 assessments over an estimated 2-3 weeks.
The study will calculate the percentage of stuttered syllables (out of total syllables) in two speech samples (one before LIFU and one sample after LIFU) per each stimulation session. Decreased stuttered syllables represents better outcomes (greater reduction in stuttering). Two samples are collected during session 1 and two samples are collected during session 2. An additional baseline sample is collected at the baseline session (on a separate day before the two stimulation sessions).
2 secondary outcomes
Stop signal response time (SSRT)
Time frame: Baseline, and immediately before and after LIFU stimulation during Stimulation Session 1 and Stimulation Session 2 (sessions occurring a minimum of 2 days apart and a maximum of 1 week apart), for a total of 5 assessments over an estimated 2-3 weeks.
Rhythm discrimination score (d')
Time frame: Baseline, and immediately before and after LIFU stimulation during Stimulation Session 1 and Stimulation Session 2 (sessions occurring a minimum of 2 days apart and a maximum of 1 week apart), for a total of 5 assessments over an estimated 2-3 weeks.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Sep 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Hasini Weerathunge, Ph.D. principal investigator
University of Michigan
Soo-Eun Chang, Ph.D. principal investigator
University of Michigan
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing High DC LIFU in people with Stuttering and Developmental Stuttering, run by University of Michigan at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 15 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Hasini Weerathunge, Ph.D. (734-232-5748, weerathh@umich.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Percentage of stuttered syllables produced during speech sample (time frame: Baseline, and immediately before and after LIFU stimulation during Stimulation Session 1 and Stimulation Session 2 (sessions occurring a minimum of 2 days apart and a maximum of 1 week apart), for a total of 5 assessments over an estimated 2-3 weeks.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Sep 2026; AzTrials last refreshed its copy on 26 Oct 2026.