NCT07121582 · University of North Carolina, Chapel Hill
Modulation of Brain Rhythms in Stroke
What this study is about
The goal of this research study is to examine communication between brain and muscle in individuals with stroke and determine if applying non-invasive brain stimulation to different parts of the brain improves this communication and performance on a hand squeezing task.
View original scientific description
The goal of this research study is to examine communication between brain and muscle in individuals with stroke and determine if applying non-invasive brain stimulation to different parts of the brain improves this communication and performance on a hand squeezing task. The investigators will fit participants with an electroencephalography (EEG) cap and place electromyography (EMG) stickers on participants hand and arm muscles to record brain and muscle activity, respectively. Participants will complete a single research visit lasting approximately 3 hours. During this visit, participants will receive two different types of non-invasive brain stimulation: \[1\] stimulation to the motor part of the brain and \[2\] stimulation to the visual part of the brain. Participants will be randomized so that half will receive stimulation to the motor part of the brain first followed by stimulation to the visual part of the brain second and vice versa. Participants will complete three blocks of hand squeezing trials using the stroke-affected (weak) hand. During the first block of squeezing trials, no brain stimulation will occur. During the second and third blocks, participants will receive stimulation just before each hand squeezing trial. The investigators will record participants' brain and muscle activity during these blocks of hand squeezing trials. Additionally, participants will also complete screening tests and exams looking at mood, motor function, and cognition.
Interventions
OTHER
Motor Brain Stimulation
For each grip trial (20 grip trials per block), participants will receive visual cues that signify the onset and offset of squeezing. Just prior to the start of the visual cue representing the onset of squeezing, participants will receive a burst of repetitive transcranial magnetic stimulation (rTMS) to their primary motor hotspot region. Motor brain stimulation will involve 3 bursts of 5 pulses/burst with a 20 Hz inter-pulse interval delivered at 90% of their resting or active motor threshold.
OTHER
Visual Brain Stimulation
For each grip trial (20 grip trials per block), participants will receive visual cues that signify the onset and offset of squeezing. Just prior to the start of the visual cue representing the onset of squeezing, participants will receive a burst of repetitive transcranial magnetic stimulation (rTMS) to their ipsilesional occipital cortex region. Visual brain stimulation will involve 3 burst of 5 pulses/burst with a 20 Hz inter-pulse interval delivered at 90% of their resting or active motor threshold.
Primary outcome measures
Corticomuscular Coherence Change
Time frame: Immediately (within 5 minutes) before and after (within 5 minutes) each stimulation block.
Investigators will compute pre/post changes in brain-muscle functional connectivity (i.e., corticomuscular coherence, CMC) following across each block (20 trials/block). Specifically, investigators are focused on CMC in the beta (13-30 Hz) frequency range between the ipsilesional motor cortex (M1) and the affected first dorsal interossei muscle. Investigators will calculate CMC at two distinct phases during the squeezing task that correspond to the ramp/recruitment phase (i.e., squeezing to the target) and the hold/sustain phase (when participant's reach the target and sustain their grip).
Grip Precision
Time frame: Immediately (within 5 minutes) before and after (within 5 minutes) each stimulation block.
The variance of participants' force output from a visual target
Reaction Time
Time frame: Immediately (within 5 minutes) before and after (within 5 minutes) each stimulation block.
The time delay between the grip signal onset (visual cue provided to participants) and the realized force.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Chronic (≥ 6 months) unilateral cortical/subcortical ischemic or hemorrhagic stroke as confirmed by medical records
- Upper extremity weakness (hemiparesis) contralateral to the stroke
- Sufficient cognitive capacity (Montreal Cognitive Assessment ≥ 21 points), communication function, and English proficiency to understand and safely comply with all study procedures
- Ipsilesional motor-evoked potential response
- Able to perform isometric grip task by making a fist with their stroke-affected hand (hand contralateral to the stroke)
Exclusion criteria
- Contraindications to TMS (seizure activity within past 2 years, pregnancy, indwelling metal)
- Cognitive deficits (Montreal Cognitive Assessment \< 21 points)
- Concurrent physical/occupational therapy and/or clinical trial participation related to stroke
- Injury or conditions that impact affected extremity-use beyond stroke (e.g., arthritis)
- Impaired vision despite use of aid (e.g. glasses, contacts, etc.)
- Cerebellar stroke
- Major medical/neurological/psychiatric condition impacting physical function in the opinion of the physician co-investigator
- Absent ipsilesional motor-evoked potential response
Where
- Chapel Hill, North Carolina
Collaborators
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Apr 27, 2026 · Source of record for eligibility and locations