Targeting Personalized Brain States Reflecting Strong and Weak Corticospinal Tract Output in Real-time
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
Status
Conditions
Conditions
Intervention / Treatment
Intervention / Treatment
Study Type
Study Type
Enrollment (Actual)
Enrollment
Phase
Phase
- Not Applicable
Contacts and Locations
Study Locations
-
-
Texas
-
Austin, Texas, United States, 78712
- University of Texas at Austin
-
-
Participation Criteria
Eligibility Criteria
Eligibility Criteria
Ages Eligible for Study
- Adult
- Older Adult
Accepts Healthy Volunteers
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
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
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
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
Sponsor
Sponsor
Collaborators
Collaborators
Publications and helpful links
Helpful Links
Study record dates
Study Major Dates
Study Start (Actual)
Study Start
Primary Completion (Actual)
Primary Completion
Study Completion (Actual)
Study Completion
Study Registration Dates
First Submitted
First Submitted
First Submitted That Met QC Criteria
First Submitted That Met QC Criteria
First Posted (Actual)
First Posted
Study Record Updates
Last Update Posted (Actual)
Last Update Posted
Last Update Submitted That Met QC Criteria
Last Update Submitted That Met QC Criteria
Last Verified
Last Verified
More Information
Terms related to this study
Other Study ID Numbers
Other Study ID Numbers
- STUDY00000608
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
product manufactured in and exported from the U.S.
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