Targeting Personalized Brain States Reflecting Strong and Weak Corticospinal Tract Output in Real-time

March 31, 2025 updated by: University of Texas at Austin

Transcranial magnetic stimulation (TMS) interventions could feasibly strengthen residual corticospinal tract (CST) connections and enhance recovery of paretic hand function after stroke. To maximize the therapeutic effects of such interventions, they must be delivered during poststroke brain activity patterns during which TMS best activates the residual corticospinal tract and enhances neural transmission within it (i.e., brain state-dependent TMS). In this study, the investigators will test the feasibility of real-time, personalized brain state-dependent TMS in neurotypical adults.

Participants will visit the laboratory for one day of testing. Upon arrival, participants will provide their informed consent; afterwards, they will complete eligibility screening. The investigators will then place recording electrodes on the scalp using a swim-type cap and on the left first dorsal interosseous, abductor pollicis brevis, and extensor digitorum communis muscles. After determining the location at which TMS best elicits muscle twitches in the left first dorsal interosseous, the investigators will determine the lowest possible intensity at which TMS elicits muscle twitches at least half of the time in this muscle. Then, the investigators will deliver 6 blocks of 100 single TMS pulses while the participant rests quietly with their eyes open; stimulation will be delivered at an intensity that is 20% greater than the lowest possible intensity at which TMS elicits muscle twitches at least half of the time. Afterwards, the investigators will use the muscle and brain activity recordings acquired during these 6 blocks to build a personalized mathematical model that identifies which patterns of brain activity correspond to the largest TMS-evoked muscle twitches. The investigators will then use this model to detect the occurrence of these brain activity patterns in real-time; when these patterns are detected, single TMS pulses will be delivered. Afterwards, all recording electrodes will be removed, participation will be complete, and participants will leave the laboratory.

The investigators will recruit a total of 16 neurotypical adults for this study.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

21

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Texas
      • Austin, Texas, United States, 78712
        • University of Texas at Austin

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Right-hand dominance
  • Willingness to participate
  • Ability to provide informed consent

Exclusion Criteria:

  • History of major neurological, orthopedic, psychiatric, or cardiovascular disease

  • Presence of contraindications to transcranial magnetic stimulation (TMS) or peripheral nerve stimulation (PNS), including:

    • history of adverse reactions to TMS or PNS
    • history of stroke or head injury
    • metal in head, eyes, neck, chest/trunk, or arms, including but not limited to shrapnel,
    • surgical clips, fragments from metalworking, fragments from welding
    • implanted devices
    • history of frequent and severe headaches or migraines
    • immediate family history of seizure or epilepsy
    • personal history of seizure or epilepsy
    • current, suspected, or planned pregnancy
    • current or recent (within the last 3 months) use of medications acting on the central nervous system, including but not limited to: antipsychotic drugs, antidepressants, benzodiazepines, prescription stimulants

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Crossover Assignment
  • Masking: Double

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Motor-evoked Potential (MEP) Amplitudes
Time Frame: single session
Peak-to-peak MEP amplitudes elicited by single transcranial magnetic stimulation (TMS) pulses delivered during personalized strong and weak CST states will be measured from the left first dorsal interosseous muscle. At the individual participant level, all MEP amplitudes will be normalized to the mean MEP amplitude observed in that participant. Mean normalized MEP amplitudes will be compared across CST states.
single session

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
State-targeting Accuracy
Time Frame: single session
An offline version of the real-time EEG analysis algorithm will be used to determine the brain state (i.e., strong or weak CST states, or neither) immediately preceding delivery of each single TMS pulse. The proportion of trials during which the online and offline versions of the real-time EEG analysis algorithm produce the same brain state prediction will be calculated per participant and used as a state-targeting accuracy metric. State-targeting accuracy metrics will be compared to the theoretical chance level (0.5).
single session

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Texas at Austin

Collaborators

Emory University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 27, 2023

Primary Completion (Actual)

January 1, 2025

Study Completion (Actual)

January 1, 2025

Study Registration Dates

First Submitted

April 5, 2024

First Submitted That Met QC Criteria

April 10, 2024

First Posted (Actual)

April 15, 2024

Study Record Updates

Last Update Posted (Actual)

April 17, 2025

Last Update Submitted That Met QC Criteria

March 31, 2025

Last Verified

March 1, 2025

More Information

Terms related to this study

Other Study ID Numbers

  • STUDY00000608

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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