Transcranial Alternating Current Stimulation (tACS) in Stuttering

Not Applicable

Not yet recruiting

• Conditions: Stuttering, Adult; Stuttering, Childhood; Stuttering, Developmental

• Registration Number: NCT06740968
• Lead Sponsor: University of Michigan

Brief Summary

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.

Detailed Description

Participants will have screening and baseline visits that include a variety of tests and procedures (i.e. standardized tests of speech, language, hearing test, music training questionnaire, working memory tests, and speech sample to characterize stuttering, magnetic resonance imaging (MRI) and electroencephalography (EEG)). Following these, participants will have 5 sessions (active and sham conditions) and then a one month follow-up phone call.

Of note, there will be an embedded pilot study to refine the experimental protocol in terms of practicality and feasibility and these participants will not be included in this registration. The only purpose of this embedded study is to refine the protocol and it does not have any health or behavioral outcomes.

Study Timeline

• Study First Submitted: 2024-12-14
• Study First Submitted QC: 2024-12-14
• Study First Posted: 2024-12-18
• Status Verified: 2025-05
• Last Update Submitted: 2025-05-02
• Last Update Posted: 2025-05-07
• Study Start: 2025-06
• Primary Completion: 2029-12
• Study Completion: 2029-12

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 80

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Primary Outcome Measures

Name	Time	Method
Change in Phase Synchronization	Baseline (pre-tACS), approximately 3 hours (post-tACS) (visits 3-7)	The study will compare EEG data recorded before and after stimulation to determine if tACS contributed to any changes. This will be measured by Phase Locking Value (PLV; measured from 0 to 1) between the two regions targeted by stimulation calculated as \[pre(active-sham)\] - \[post(active-sham)\] at each tACS visit.

Secondary Outcome Measures

Name	Time	Method
Percentage of stuttered syllables produced during speech sample	Baseline (before tACS), approximately 3 hours (post-tACS) (visits 3-7)	The study 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).

Trial Locations

Locations (1)

University of Michigan; 🇺🇸 Ann Arbor, Michigan, United States