Measuring rTMS-induced Neuroplasticity With EEG Steady-state Visual-evoked Potentials

Inducing and Measuring Visual-evoked Potential Plasticity in Humans With Repetitive Transcranial Magnetic Stimulation

The goals of this study are to 1) use EEG steady-state visual evoked potentials as a noninvasive measure of the neuroplasticity induced by repetitive transcranial magnetic stimulation (rTMS), 2) use visual contrast detection paradigms as a behavioral measure of rTMS effects, and 3) to investigate how visual spatial attention augments or suppresses the neuroplastic impact of rTMS. Participants will observe visual stimuli on a screen while allocating their attention to different parts of the visual field and making responses when they observe changes in the visual stimuli. rTMS is performed to visual cortex using MRI-retinotopy neuronavigation. Then the visual task paradigm is performed again.

Study Overview

• Status: Enrolling by invitation
• Conditions: Repetitive Transcranial Magnetic Stimulation; Visual Attention; Visual Cortical Plasticity
• Intervention / Treatment: Device: repetitive transcranial magnetic stimulation

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Stanford, California, United States, 94306
      • Stanford University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Men and women, ages 18 to 65
• Must comprehend English well to ensure adequate comprehension of the EEG and TMS instructions, and of clinical scales
• Left- or Right-handed
• No current or history of neurological disorders
• No seizure disorder or risk of seizures

Exclusion Criteria:

• Those with a contraindication for MRIs (e.g. implanted metal)

  • Any unstable medical condition
  • History of head trauma with loss of consciousness
  • History of seizures
  • Neurological or uncontrolled medical disease
  • Active substance abuse
  • Diagnosis of psychotic or bipolar disorder
  • Currently taking medications that substantially reduce seizure threshold (e.g., bupropion, olanzapine, chlorpromazine, lithium)
  • Currently pregnant or breastfeeding

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Visual Cortex, 1 Hz rTMS, Attended	Device: repetitive transcranial magnetic stimulation; Repetitive TMS targeted by neuronavigation to left lower visual field of primary visual cortex. Randomized to 10 Hz or 1 Hz on different treatment days. Stimulation at 110% of phosphene threshold, or 110% resting motor threshold if phosphenes not detectable. 1 Hz: 1000 pulses total over 1000 seconds. 10 Hz: 1000 pulses over 10 10 second pulse trains, with 50 second intertrain intervals
Experimental: Visual Cortex, 1 Hz rTMS, Unattended	Device: repetitive transcranial magnetic stimulation; Repetitive TMS targeted by neuronavigation to left lower visual field of primary visual cortex. Randomized to 10 Hz or 1 Hz on different treatment days. Stimulation at 110% of phosphene threshold, or 110% resting motor threshold if phosphenes not detectable. 1 Hz: 1000 pulses total over 1000 seconds. 10 Hz: 1000 pulses over 10 10 second pulse trains, with 50 second intertrain intervals
Experimental: Visual Cortex, 10 Hz rTMS, Attended	Device: repetitive transcranial magnetic stimulation; Repetitive TMS targeted by neuronavigation to left lower visual field of primary visual cortex. Randomized to 10 Hz or 1 Hz on different treatment days. Stimulation at 110% of phosphene threshold, or 110% resting motor threshold if phosphenes not detectable. 1 Hz: 1000 pulses total over 1000 seconds. 10 Hz: 1000 pulses over 10 10 second pulse trains, with 50 second intertrain intervals
Experimental: Visual Cortex, 10 Hz rTMS, Unattended	Device: repetitive transcranial magnetic stimulation; Repetitive TMS targeted by neuronavigation to left lower visual field of primary visual cortex. Randomized to 10 Hz or 1 Hz on different treatment days. Stimulation at 110% of phosphene threshold, or 110% resting motor threshold if phosphenes not detectable. 1 Hz: 1000 pulses total over 1000 seconds. 10 Hz: 1000 pulses over 10 10 second pulse trains, with 50 second intertrain intervals
Sham Comparator: Visual Cortex, Sham, Attended	Device: repetitive transcranial magnetic stimulation; Repetitive TMS targeted by neuronavigation to left lower visual field of primary visual cortex. Randomized to 10 Hz or 1 Hz on different treatment days. Stimulation at 110% of phosphene threshold, or 110% resting motor threshold if phosphenes not detectable. 1 Hz: 1000 pulses total over 1000 seconds. 10 Hz: 1000 pulses over 10 10 second pulse trains, with 50 second intertrain intervals
Sham Comparator: Visual Cortex, Sham, Unattended	Device: repetitive transcranial magnetic stimulation; Repetitive TMS targeted by neuronavigation to left lower visual field of primary visual cortex. Randomized to 10 Hz or 1 Hz on different treatment days. Stimulation at 110% of phosphene threshold, or 110% resting motor threshold if phosphenes not detectable. 1 Hz: 1000 pulses total over 1000 seconds. 10 Hz: 1000 pulses over 10 10 second pulse trains, with 50 second intertrain intervals

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
post-rTMS change in ssVEP Response Amplitude	Change in ssVEP contrast-response amplitude after rTMS	60 minutes
post-rTMS change in visual contrast perceptual sensitivity	change in visual psychometric threshold across contrasts after rTMS	60 minutes

Collaborators and Investigators

• Sponsor: Stanford University
• Collaborators: National Eye Institute (NEI)

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2023
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): May 1, 2027

Study Registration Dates

• First Submitted: May 2, 2023
• First Submitted That Met QC Criteria: May 2, 2023
• First Posted (Actual): May 11, 2023

Study Record Updates

• Last Update Posted (Actual): April 22, 2024
• Last Update Submitted That Met QC Criteria: April 18, 2024
• Last Verified: April 1, 2024

More Information

Terms related to this study

• Keywords: neuroplasticity; TMS; visual-evoked potentials
• Other Study ID Numbers: 62922

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The results of this research will be made available via publication in scientific journals and through scientific meetings where our findings are reported. Publication of data shall occur during the project, if appropriate, or at the end of the project, consistent with normal scientific practices. All publications will be made publicly available consistent with NIH policies. Research data, which documents, supports and validates research findings, will be made available after the main findings from the final research data set have been accepted for publication.
• IPD Sharing Time Frame: Data will be available on reasonable request following completion of data collection.
• IPD Sharing Access Criteria: see above
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes