An interventional study of High DC LIFU and Sham in Stuttering and Developmental Stuttering, sponsored by University of Michigan. Recruiting at 1 site in United States. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-09-15.
Sponsored by University of Michigan · Not applicable, Interventional, and Treatment
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.
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.
74 studies on the registry are indexed under Stuttering; 23 are open to participants now.
This study's planned enrollment of 20 is below the median of 44 across 57 interventional studies indexed under Stuttering.
Browse Stuttering studies →University of Michigan is the lead sponsor of 1,506 studies on the registry; 192 are open to participants now.
Of its 169 completed or terminated interventional studies of FDA-regulated products, 133 (79%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
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.
Device: High DC LIFU · Device: Sham
Device: High DC LIFU · Device: Sham
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.
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.
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).
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.
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.
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')
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.
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.
Plan to share: No
No publications or documents are linked to this record.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.