Establishing Functional Biomarkers for Spaced Theta-Burst Stimulation
Phase: NA
Conditions: Healthy Volunteers
Sponsor: Stanford University

Establishing Functional Biomarkers for Spaced 
Theta-Burst Stimulation 
NCT03687892 
October 31, 2021 
a. 
Brief Summary 
We plan to use functional magnetic resonance imaging (fMRI) methods to assess brain 
changes following transcranial magnetic stimulation (rTMS), in 30 healthy participants. 
An additional 30 healthy controls will undergo an MRI scan, without use of rTMS or 
TBS. We will offer these 30 healthy controls an optional component involving 2 sessions 
of 3-10min of TBS, 1 session on the Magventure TMS device and 1 session on the 
Nextstim TMS device, in order to compare participant preference between the 2 TMS 
systems. 
 
For the 30 healthy participants in the MRI+rTMS group, we will assess MRI scans 
following either/both standard rTMS or TBS (theta-burst stimulation- a novel form of 
transcranial magnetic stimulation, in participants.  We will measure the effects of TMS 
applied to the motor cortex, a system that when stimulated produces a readily observable 
behavioral response (e.g., movement of a given body regions). We will also measure the 
effects of TMS applied to the dorsolateral prefrontal cortex, a target recognized for its 
anti-depressant effects. 
 
Our goal is to determine how brain activity and blood flow during tasks and at rest 
change following the applications of TMS to the motor cortex and/or dorsolateral 
prefrontal cortex. 
 
This study will provide an understanding of the functional brain and behavioral changes 
that occur following TMS. 
b. 
Objectives 
Please note TMS/TBS are used interchangeably in this protocol as they refer to different 
settings on the same device, a transcranial magnetic stimulation device, and both types of 
settings will be used for this study.  
 
This study proposes to: 1 - determine the heart rate changes that are seen with TMS 
stimulation. 2- determine the optimal burst frequency for TMS, 3-determine the optimal 
intersession interval for TMS, 4- compare the results of #1 and #2 in the same subjects, 5-
determine the effect of TMS/TBS on the resting state functional connectivity. 6- in 
healthy participants, assess the regulation of neuroplasticity by affective state. 
 
Aim 1: To determine the heart rate changes seen with TMS/TBS. 

October 31, 2021 
 
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Hypothesis 1: Heart rate changes will be observed following stimulation. 
 
Aim 2: To determine the optimal burst frequency. 
 
Hypothesis 2: For cTBS, the optimal frequency will be 30Hz bursts at 6Hz while iTBS 
will be the traditional 50Hz bursts at 5Hz. 
 
Aim 3: To determine the optimal intersession interval for spaced TBS. 
 
Hypothesis 3: For cTBS, the optimal ISI will be 15 min while with iTBS the optimal ISI 
will be 30 min. 
 
Aim 4: To determine the effect of spaced TBS on the resting state functional 
connectivity. 
 
Hypothesis 4: Optimized spaced iTBS and cTBS will produce changes in the resting state 
functional connectivity between pre-motor and motor cortex. Those who have less fc 
change from iTBS will experience maximal cTBS change in fc (correlated with change in 
MEP) and vice versa. 
 
Aim 5: To determine the effect of TMS/TBS on the resting state functional connectivity. 
 
Aim 6: To assess the regulation of neuroplasticity by affective state in healthy control 
participants. 
 
Hypothesis 6: Changes in amplitude and frequency band power of ERP responses to 
emotional faces following iTBS and cTBS will be differentially affected by different 
induced affective states. Changes in MEP amplitude following iTBS and cTBS will be 
differentially affected by different induced affective states. 
 
This study has broad implications ranging from advancing our understanding of the basic 
mechanisms of TBS on brain function, cerebral blood flow, and pain perception and 
therapeutic implications that could impact classical rTMS treatment schedules based on 
the duration of effects of spaced TBS. 
c. 
Rationale for Research in Humans 
We are investigating the neural underpinnings and behavioral effects of brain stimulation 
in humans. As such, only human subjects can be used for this project. 
2. 
STUDY PROCEDURES 
a. 
Procedures 
The study will consist of 4 experiments. 
 
PARTICIPANTS 
 

October 31, 2021 
 
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We will recruit 60 healthy controls for this study 30 participants in MRI+rTMS/TBS 
group and 30 participants in MRI only group. Participants will be 18-80 year-old right 
handed male and female with no history of psychiatric or neurological diagnoses and no 
current use of psychoactive medications. They will be recruited to participate in this 
study, all of whom will be blinded to the purpose of the study. All subjects will be 
screened for any contraindications to TMS and will give their informed written consent 
prior to participation. 
 
HEALTHY CONTROLS: MRI ONLY GROUP 
 
30 healthy controls will undergo an MRI scan, without use of rTMS or TBS. We will 
offer these 30 healthy controls an optional component involving 2 sessions of 3- 10min of 
TBS, 1 session on the Magventure TMS device and 1 session on the Nextstim TMS 
device, in order to compare participant preference between the 2 TMS systems. 
 
EXPERIMENT 1: Heart rate changes 
 
The first experiment will determine what heart rate changes are seen following TMS/TBS 
stimulation. Please note some participants will only be included in experiment 1, 
availability and scheduling permitting. Subjects will attend 2 sessions where they will 
receive TMS/iTBS at 70 -100 of active or resting MT, as determined by the investigator. 
They will receive either active or sham during a session, and the sessions will be in a 
randomly assigned order. 
 
Stimulation may be applied to the vertex, Beam F3 location, or location determined by 
neuronavigation. These are all standard locations for stimulation. Various heart rate 
measurements and cortisol and/or other lab tests will be collected before and after 
stimulation. fMRI will be completed before and after stimulation. Various questionnaires 
(e.g. regarding mood will be collected before/after stimulation). Tasks designed to induce 
mild mental stress (e.g. mental math or similar) will be used during the experiment to 
create equivalent baseline conditions for all subjects. 
 
EXPERIMENT 2: Optimal Burst Frequency 
 
This next experiment will determine the optimal burst frequency for TBS, comparing 
iTBS30, iTBS50, cTBS30, and cTBS50 within the same individual. This experiment is an 
important stepping stone for the overall study, as it will determine how responses to 
cTBS and iTBS are linked. Subjects will attend four sessions no <4 days apart, receiving 
the cTBS50, cTBS30, iTBS50, and iTBS30 applied at 80 of RMT. The order in which 
they will receive each paradigm will be randomized between subjects. In all sessions, 
MEP recruitment curves will be recorded at baseline, as well as at 0, 20, 40, 60, 90, and 
120 min following TBS applications. During the session, the subjects will watch a muted 
video so that they stay alert during the whole experiment. 
 
Each subject will have 4 visits. 
1. MEP----iTBS50----MEP 
2. MEP----iTBS30----MEP 

October 31, 2021 
 
Page 4 of 16 
3. MEP----cTBS50----MEP 
4. MEP----cTBS30----MEP 
 
Stimulation and Recording 
Subjects will be seated in a comfortable chair for all procedures. Single-pulse TMS will 
be used to evoke MEPs from the right first dorsal interosseous FDI muscle target muscle. 
Electromyographic recordings will be made from the right FDI and abductor pollicis 
brevis (APB), which serves as a control muscle, using two Ag–AgCl surface electrodes 
arranged in a belly-tendon montage. Signals will be sampled at a rate of 5 kHz, amplified 
1000 and filtered 20–1000 Hz before we store on a computer for offline analysis. Single-
pulse TMS with monophasic waveform will be applied using a Magventure Magpro 
X100 magnetic stimulator  Magventure, Farum, Denmark connected to a figure-of-eight 
magnetic coil. The optimal scalp site for evoking MEPs in the right FDI will be identified 
from M1 with the help of neuronavigation. The coil direction will be kept perpendicular 
to the nearest sulcus. 
 
The mapping of the optimal location will be done with a supra threshold stimulation 
intensity evoking MEPs of around 1mV. After finding the optimal location, the coil will 
be rotated slightly in the tangential plane to check whether the induced electric field is 
optimal if not, the coil direction will be adjusted. At the optimal location, the rMT will be 
calculated with Motor threshold hunting paradigm, i.e. PEST. Thereafter, a baseline 
recruitment curve will be done 90 rMT-150 rMT, 10 pulses/intensity, interstimulus 
interval 5s and a cortical silent period threshold will be calculated with PEST.  
 
rTMS Stimulation 
rTMS will be applied using a Magventure Magpro. The rMT at the optimal cortical FDI 
representation will be calculated with the PEST. The intensity of TBS application will be 
70-100 active or resting MT, as determined by investigator. 
 
Theta-Burst Stimulation 
TBS will be applied with a biphasic waveform using a Magventure Magpro Magventure, 
Farum, Denmark. The rMT at the optimal cortical FDI representation will be calculated 
with the PEST. The intensity of TBS application will be 80 of rMT. 
 
TBS Paradigms 
iTBS and cTBS will be applied with biphasic waveform using a Magventure Magpro  
Magventure, Farum, Denmark. Two cTBS and two iTBS paradigms with varying pulse 
configurations will be employed in this study. cTBS50 consists of a total of 600 stimuli 
applied in bursts of 3 stimuli at 20 ms intervals 50 Hz, with bursts repeated at 200ms 
intervals 5Hz. In the cTBS30 paradigm, bursts consisted of 3 stimuli applied at intervals 
of 33.3 ms 30 Hz, with bursts repeated at 167 ms intervals 6 Hz. As with the cTBS50 
paradigm, cTBS30 will consist of a total of 600 stimuli. iTBS50, consists of a total of 600 
stimuli applied in bursts of 3 stimuli at 20 ms intervals 50 Hz, with bursts repeated at 
200ms intervals 5Hz and an 8 second intertrain interval between triplet. iTBS30 consists 
of bursts consisted of 3 stimuli applied at intervals of 33.3 ms 30 Hz, with bursts repeated 
at 167 ms intervals 6 Hz for three bursts then a 8 second intertrain interval. As with the 
iTBS50 paradigm, iTBS30 will consist of a total of 600 stimuli. The intensity of TBS 

October 31, 2021 
 
Page 5 of 16 
application will be set relative to resting motor threshold (RMT), measured using a 
biphasic pulse waveform with the rTMS coil. RMT will be defined as the minimum 
stimulus intensity sufficient to evoke MEPs in the right FDI at rest with peak-to-peak 
amplitudes of at least 50 lV in five of 10 consecutive trials. After TBS, MEP recruitment 
curves and cortical silent period thresholds will be recorded at 0, 20, 40, 60, 90, and 120 
min following TBS applications. 
 
EXPERIMENT 3: Optimal Intersession Interval 
This experiment builds on previous understanding of the optimal intersession interval for 
spaced TBS which suggests that for cTBS, the optimal ISI is 15 minutes while with iTBS 
the optimal ISI is 30 minutes. We will utilize the burst frequency determined to be 
optimal from experiment 1. We will apply TBS over the left, dominant M1. TBS will be 
repeated two times separated by 15, 30, 45, or 60 min intersession interval. Subjects will 
attend eight sessions no <4 days apart, receiving the cTBSXX-15-cTBSXX, cTBSXX-
30-cTBSXX, cTBSXX-45-cTBSXX, cTBSXX-60- cTBSXX, iTBSXX-15-iTBSXX, 
iTBSXX-30-iTBSXX, iTBSXX-45-iTBSXX, and iTBSXX-60-iTBSXX applied at 80 of 
RMT. The order in which they will receive each paradigm will be randomized between 
subjects. MEP recruitment curves and cortical silent period thresholds will be recorded at 
baseline, and at 0, 20, 40, 60, 90, and 120 min following the second TBS application. 
 
Each subject will have 8 visits. 22 number of participants. 
1. MEP----iTBSXX----15 min----iTBSXX----MEP 
2. MEP----iTBSXX----30 min ----iTBSXX----MEP 
3. MEP----iTBSXX----45 min ----iTBSXX----MEP 
4. MEP----iTBSXX----60 min ----iTBSXX----MEP 
5. MEP----cTBSXX----15 min ----cTBSXX----MEP 
6. MEP----cTBSXX----30 min ----cTBSXX----MEP 
7. MEP----cTBSXX----45 min ----cTBSXX----MEP 
8. MEP----cTBSXX----60 min ----cTBSXX----MEP 
 
XX=optimal burst frequency from experiment  
Motor Evoked Potentials (MEPs) 
 
Subjects will be seated in a comfortable chair for all procedures. Single-pulse TMS will 
be used to evoke MEPs from the right first dorsal interosseous (FDI) muscle. 
Electromyographic recordings will be made from the right FDI using two Ag– AgCl 
surface electrodes arranged in a belly-tendon montage. Signals will be sampled at a rate 
of 5 kHz, amplified ##1000 and filtered 20–1000 Hz before we store on a computer for 
offline analysis. Single-pulse TMS with monophasic waveform will be applied using a 
Magventure Magpro X100 magnetic stimulator Magventure, Farum, Denmark connected 
to a figure-of-eight magnetic coil external wing diameter, 90 mm . The coil will be held 
tangentially to the skull over the left M1, with the handle pointing 45? posterolaterally. 
The optimal scalp site for evoking MEPs in the right FDI will be identified and marked 
using a Watersoluble felt marker, and the intensity of stimulation will be adjusted to 
evoke baseline MEPs of approximately 1 mV amplitude measured peak-to peak. 
 
TBS Paradigms 

October 31, 2021 
 
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iTBS and cTBS will be applied with biphasic waveform using a Magventure Magpro 
Magventure, Farum, Denmark. One of two cTBS and two iTBS paradigms with varying 
pulse configurations will be employed in this study. cTBS50 consists of a total of 600 
stimuli applied in bursts of 3 stimuli at 20 ms intervals 50 Hz, with bursts repeated at 
200ms intervals 5Hz. 
 
In the cTBS30 paradigm, bursts consisted of 3 stimuli applied at intervals of 33.3 ms 30 
Hz, with bursts repeated at 167 ms intervals 6 Hz. 
 
As with the cTBS50 paradigm, cTBS30 consists of a total of 600 stimuli. iTBS50, 
consists of a total of 600 stimuli applied in bursts of 3 stimuli at 20 ms intervals 50 Hz, 
with bursts repeated at 200ms intervals 5Hz and an 8 second intertrain interval between 
triplets. iTBS30 consists of bursts consisted of 3 stimuli applied at intervals of 33.3 ms 30 
Hz, with bursts repeated at 167 ms intervals 6 Hz for three bursts then an 8 second 
intertrain interval.  
 
In Experiment 1, the optimal burst frequency for both cTBS and iTBS will be determined 
and that optimal cTBS and 
iTBS frequency will be utilized in this portion of the study. 
 
EXPERIMENT 4: Neuroimaging 
This experiment will form the bulk of the study and involves determining the rs fc MRI 
changes seen with spaced TBS, as well as determining how these rs fc MRI changes 
correlate with iTBS/cTBS response. Functional connectivity between pre-motor and 
motor cortex will be assessed. MRIs will be done at the Center for Cognitive and 
Neurobiological Imaging at Stanford University, or at the Richard Lucas Center for 
Imaging. All scans will be governed by each respective imaging center's safety protocols. 
 
Resting state functional MRI and MR spectroscopy may be performed. The experimental 
procedures TBS applications of the fMRI sessions will be timed equivalent to the time 0 
post spaced theta-burst stimulation of the MEP sessions from Experiment 2. In addition 
to the MEP acquisition, resting-state fMRI time series will be acquired at baseline and 
after the second application of cTBS and iTBS. Before the baseline fMRI measurements, 
the "hotspot" and RMT will be assessed using the neuronavigation setup.Subjects will 
attend two sessions no <4 days apart, receiving the cTBSXXYY-cTBSXX, and iTBSXX-
YY-iTBSXX applied at 80 of RMT. The order in which they will receive each paradigm 
will be randomized between subjects. The fMRI sessions will start with a baseline 
resting-state scan duration 10 min where subjects will be instructed to lie motionless in 
the scanner with open eyes fixating a red cross, which was presented on a screen visible 
through a mirror attached to the MR head coil. After completion of the resting-state MRI, 
subjects will be asked to perform an active motor task, which will serve as a functional 
localizer for determining coordinates of M1 and other motor related regions for 
subsequent analyses. 
 
This "activity" condition will be acquired after the resting state scan. After completion of 
the baseline fMRI session, subjects will be transported from the scanner to the anteroom 
of the MR console again sitting in the MR wheelchair without moving their right arm. 

October 31, 2021 
 
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After coregistration with the neuronavigation system, spaced TBS will be applied 
separated by YY min controlled by a stopwatch. After the TBS, there will be another 
resting-state fMRI. The time protocol in the fMRI sessions will be identical to the one 
used in the MEP sessions. 
 
Each subject will have 2 visits. 
1. MRI-----iTBSXX----YY min----iTBSXX----MRI 
2. MRI-----cTBSXX----YY min ----cTBSXX----MRI 
XX=optimal burst frequency from experiment 1 
YY=optimal intersession interval from experiment 2 
 
Motor Evoked Potentials MEPs) 
Subjects will be seated in a comfortable chair for all procedures. Single-pulse TMS will 
be used to evoke MEPs from the right first dorsal interosseous FDI muscle. 
Electromyographic recordings will be made from the right FDI using two Ag–AgCl 
surface electrodes arranged in a belly-tendon montage. Signals will be sampled at a rate 
of 5 kHz, amplified ##1000 and filtered 20–1000 Hz before we store on a computer for 
offline analysis. 
 
Single-pulse TMS with monophasic waveform will be applied using a Magventure 
Magpro X100 magnetic stimulator Magventure, Farum, Denmark connected to a figure-
of-eight magnetic coil external wing diameter, 90 mm. The coil will be held tangentially 
to the skull over the left M1, with the handle pointing 45 posterolaterally. The optimal 
scalp site for evoking MEPs in the right FDI will be identified and marked using a 
watersoluble felt marker, and the intensity of stimulation will be adjusted to evoke 
baseline MEPs of approximately 1 mV amplitude measured peak-to peak . 
 
TBS Paradigms 
iTBS and cTBS will be applied with biphasic waveform using a Magventure Magpro 
Magventure, Farum, Denmark. One of two cTBS and two iTBS paradigms with varying 
pulse configurations will be employed in this study. cTBS50 consists of a total of 600 
stimuli applied in bursts of 3 stimuli at 20 ms intervals 50 Hz, with bursts repeated at 
200ms intervals 5Hz. 
 
In the cTBS30 paradigm, bursts consisted of 3 stimuli applied at intervals of 33.3 ms 30 
Hz, with bursts repeated at 167 ms intervals 6 Hz. As with the cTBS50 paradigm, 
cTBS30 consists of a total of 600 stimuli. iTBS50, consists of a total of 600 stimuli 
applied in bursts of 3 stimuli at 20 ms intervals 50 Hz, with bursts repeated at 200ms 
intervals 5Hz and an 8 second intertrain interval between triplets. iTBS30 consists of 
bursts consisted of 3 stimuli applied at intervals of 33.3 ms 30 Hz, with bursts repeated at 
167 ms intervals 6 Hz for three bursts then an 8 second intertrain interval. In Experiment 
1, the optimal burst frequency for both cTBS and iTBS will be determined and that 
optimal cTBS and iTBS frequency will be utilized in this portion of the study. 
 
EXPERIMENT 5: AFFECTIVE STATE 
This experiment will investigate the effect of TMS-induced neuroplasticity on evoked-
related potential ERP responses to emotional and neutral faces, and motor-evoked 

October 31, 2021 
 
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potential MEP responses to motor cortex 1 stimulation, as measured by 
electroencephalogram EEG and electromyogram EMG, respectively. ERP and MEP 
measurements will be taken prior to and following thetaburst TMS. 
 
Evoked Related Potentials (ERPs) 
Subjects will be seated in a comfortable chair for all procedures. EEG recordings will be 
made while subjects view emotional and neutral faces displayed on a computer screen. 
Subjects will then undergo the iTBS or cTBS protocol 
(see below). ERP and MEP responses will be measured again following TBS and 
compared to pre-TBS ERPs to measure the amount and valence of plasticity induced by 
TBS, and how this was modulated by the induced affective state. 
 
Motor Evoked Potentials (MEPs) 
Subjects will be seated in a comfortable chair for all procedures. Single-pulse TMS will 
be used to evoke MEPs from the right first dorsal interosseous (FDI) muscle. 
Electromyographic recordings will be made from the right FDI using two Ag–AgCl 
surface electrodes arranged in a belly-tendon montage. Signals will be sampled at a rate 
of 5 kHz, amplified ##1000 and filtered 20–1000 Hz before we store on a computer for 
offline analysis. Single-pulse TMS with monophasic waveform will be applied using a 
Magventure Magpro X100 magnetic stimulator Magventure, Farum, Denmark connected 
to a figure-of-eight magnetic coil external wing diameter, 90 mm. The coil will be held 
tangentially to the skull over the left M1, with the handle pointing 45 posterolaterally. 
The optimal scalp site for evoking MEPs in the right FDI will be identified and marked 
using a watersoluble felt marker, and the intensity of stimulation will be adjusted to 
evoke baseline MEPs of approximately 1 mV amplitude measured peak-to peak. 
 
TBS Paradigms 
iTBS and cTBS will be applied with biphasic waveform using a Magventure Magpro 
Magventure, Farum, Denmark. One of two cTBS and two iTBS paradigms with varying 
pulse configurations will be employed in this study. cTBS50 consists of a total of 600 
stimuli applied in bursts of 3 stimuli at 20 ms intervals 50 Hz, with bursts repeated at 
200ms intervals 5Hz. In the cTBS30 paradigm, bursts consisted of 3 stimuli applied at 
intervals of 33.3 ms 30 Hz, with bursts repeated at 167 ms intervals 6 Hz.  
 
As with the cTBS50 paradigm, cTBS30 consists of a total of 600 stimuli. iTBS50, 
consists of a total of 600 stimuli applied in bursts of 3 stimuli at 20 ms intervals 50 Hz, 
with bursts repeated at 200ms intervals 5Hz and an 8 second intertrain interval between 
triplets. iTBS30 consists of bursts consisted of 3 stimuli applied at intervals of 33.3 ms 30 
Hz, with bursts repeated at 167 ms intervals 6 Hz for three bursts then an 8 second 
intertrain interval.  
 
In Experiment 1, the optimal burst frequency for both cTBS and iTBS will be determined 
and that optimal cTBS and iTBS frequency will be utilized in this portion of the study. 
Subjects will view movie clips tailored to induce primary affective states during the iTBS 
or cTBS protocol targeted to either dlPFC or area M1. 
 

October 31, 2021 
 
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TMS-EEG 
TMS-EEG recordings may be collected at various points throughout the study. During 
TMS-EEG recordings, subjects will be instructed to listen to white noise. 
 
BIOMARKERS 
Cortisol and other biomarkers may be collected at points during the study. 
 
OTHER TASKS/QUESTIONNAIRES: 
Participants will be asked to perform the critical feedback task CFT at various points in 
the study. This is a simple computer-based question and answer task that asks the 
participant to perform mental math and provides them with accurate or bogus feedback 
on their performance. 
 
- Hamilton rating scale for depression (HAMD) 
-Montgomery–Asberg Depression Rating Scale 
- Beck depression inventory 
- Inventory of depressive symptoms 
- Other mood questionnaires 
- Emotion Induction task 
- Emotional identification task 
 
Video Recording 
-Video recordings will be conducted during clinical assessments and interviews for 
participants who consent to video recordings. More details are indicated in section 2d. 
b. 
Procedure Risks 
These methods are the least risky because the intervals of treatment have been shown to 
be appropriate for theta burst stimulation in the motor system with no adverse outcomes. 
c. 
Use of Deception in the Study 
No deception will be used.  
d. 
Use of Audio and Video Recordings 
We will offer study participants the option of videotaping the clinical assessments 
conducted with them while enrolled in the study. They will have to sign a separate 
consent for this to occur. The video recordings will be recorded using Zoom video from 
an encrypted Stanford owned laptop. The recordings will be available for training 
purposes for study personnel only. We will not use or distribute the videos to outside 
personnel or scientific meetings etc. unless directly indicated by the participant on the 
video consent form attached in section 13. 
e. 
Alternative Procedures or Courses of Treatment 
N/A 

October 31, 2021 
 
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f. 
Will it be possible to continue the more (most) appropriate therapy for the 
participant(s) after the conclusion of the study? 
N/A 
g. 
Study Endpoint(s) 
Because this is a mechanistic study and not a clinical trial, the primary endpoint is an 
assessment of the duration of effect of an application of TBS. We will assess the findings 
of the trial after all subjects have been run. We will not be performing interim analysis as 
this is not a treatment study and the risks of the TMS intervention are either minor or 
very rare. 
3. 
BACKGROUND  
a. 
Past Experimental and/or Clinical Findings 
Theta-Burst Stimulation 
There is early indication that utilizing TBS, which mimics natural brain rhythms, is an 
effective stimulation method for modulation of human cortex Huang, Edwards, Rounis, 
Bhatia, & Rothwell, 2005. While first utilized in the motor cortex, TBS has been since 
utilized in the limbic and cognitive areas with some early success in treating depression 
Chung, Hoy, & Fitzgerald, 2015. The benefits of this form of stimulation is that it 
appears to allow for a reduction in the time of treatment while maintaining a similar 
efficacy to traditional 40 min 10Hz rTMS stimulation in an early comparison study 
Bakker et al., 2015. Stimulation of the primary motor cortex M1 specifically, can 
influence both motor output and pain perception in both healthy and chronic pain 
populations Zaghi et al., 2010; Sacco et al., 2014. Associated changes in brain activity 
can be detected using functional magnetic resonance imaging MRI methods. There is 
emerging evidence from the motor system that the spacing or timing between theta burst 
trains is important in long-term potentiation/depression LTP/LTD. If the train goes on for 
two long without a necessary time interval, there is a reversal of the initial direction LTP 
or LTD Gamboa, Antal, Moliadze, & Paulus, 2010. 
 
TBS Burst frequency 
Originally, the TBS burst frequency was determined to be 50Hz at 5Hz intervals. 
Recently, a modified version of the inhibitory form of TBS continuous---cTBS was 
demonstrated to produce more consistent suppression of the motor evoked potential MEP 
than the traditional form of cTBS. This modified form has been used in treatment 
applications with success. For the excitatory form of TBS intermittent---iTBS, iTBS30 
has demonstrated a similar change in the MEP as iTBS50. Modifications to the burst 
frequency have been described to potentially affect clinical outcome in TBS for MDD. 
While single experiments have been performed demonstrating differences between 
TBS30 and TBS50, there has yet to be a study comparing iTBS and cTBS in the same 
participants between these two burst frequency conditions. 
 
Spaced Theta-Burst Stimulation 
Spaced theta-burst stimulation (sTBS) is a patterned application of TBS that was studied 
initially in animal models. It has been demonstrated that en masse stimulation with TBS 

October 31, 2021 
 
Page 11 of 16 
produces effects that are opposite to the intended effect. Spaced, patterned theta-burst is 
therefore required. sTBS was assessed in healthy controls with MEP change and it has 
been demonstrated that RMT70 produces 2 hours of suppression of the MEP which is 
affected by preceding hand activation. This approach has been assessed for saccade 
induction with non-linear increases in saccades. Recently, the technique has been applied 
to disease conditions such as hemispatial neglect and depression. 
 
Intersession Interval of Spaced TBS 
The optimal ISI is unknown for iTBS and cTBS. It appears that 15 minutes as has 
previously used by one group for depression, may be too short for late stage LTP 
induction in the case of iTBS. For cTBS, 10-15 min has been most regularly used, but 
longer ISI have yet to be explored.  
 
TBS-induced Change to Resting State Functional Connectivity  
It has been demonstrated that rTMS and more specifically TBS are functional 
connectivity (fc) modulators that are stimulation parameter specific (excitatory or 
inhibitory). Furthermore, it has been demonstrated that patterned TBS application 
produces changes in fc MRI that are correlated with changes in MEP. It has been 
demonstrated that optimized ISI can produce an optimized change in the fc. Furthermore, 
it has been demonstrated that relative amounts of fc within the targeted neural network is 
correlated with change or no change in the fc and change or no change in the MEP. This 
property has been reflected in treatment application as well. 
 
TBS-induced Change to IL TMS-fMRI  
IL TMS-BOLD has been demonstrated to reflect inherent network properties of the TMS 
targeted neural network. It has been demonstrated that pharmacology or TBS can changes 
these properties as reflected by the differential BOLD activation. One group has 
demonstrated that TBS to a targeted neural network can change the BOLD activation 
after IL TMS-BOLD as compared to pre TBS IL TMS-BOLD. 
b. 
Findings from Past Animal Experiments 
None 
4. 
DEVICES USED IN THE STUDY 
a. 
Investigational Devices (Including Commercial Devices Used Off-Label) 
Investigational Device 1 
Name: 
MagPro X100 
Description: 
Transcranial Magnetic Stimulation Device with theta burst stimulation 
Significant Risk? (Y/N) 
N 
Rationale for Non-Significant Risk 
The 'traditional 10Hz TMS' is on label and the theta burst stimulation is 
off label. It is the same device for both. The Magventure is about to be 
approved by the FDA for depression in 2 weeks. When that happens, the 
'traditional 10Hz' stimulation will be on label with an approved 
device.The theta burst stimulation is minimal risk because the risk of 
seizure is very low only reported once in literatureand there is no 
other risk other than minimal scalp irritation. We will be using an 
approved device 'off label' stimulation parameters which has a lower risk 
profile than the on label approved parameters. 
Investigational Device 2 

October 31, 2021 
 
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Investigational Device 1 
Name: 
MRI-safe infrared diode laser stimulator 
Description: 
MRI-safe infrared diode laser stimulator 
Significant Risk? (Y/N) 
N 
Rationale for Non-Significant Risk 
Does not fulfill the definition of a significant risk device. 
Investigational Device 3 
Name: 
NextStim 
Description: 
NextStim TMS device 
Significant Risk? (Y/N) 
N 
Rationale for Non-Significant Risk 
NextStim is an FDA-approved TMS device for treatment of depression 
 
5. 
PARTICIPANT POPULATION 
a. 
Planned Enrollment 
we will recruit 60 healthy participants only at Stanford-affiliated sites 
b. 
Age, Gender, and Ethnic Background 
Participants will be 18-80 year-old right handed male and female subjects with no history 
of psychiatric or neurological diagnoses and no current use of psychoactive medications. 
They will be recruited to participate in this study, all of whom will be blinded to the 
purpose of the study. All subjects will be screened for any contraindications to TMS (23) 
and will give their informed written consent prior to participation. This study is approved 
by the Stanford University Institutional Review Board and performed in accordance with 
the Declaration of Helsinki 
c. 
Vulnerable Populations 
We will not include children, pregnant women, decisionally impaired. We will include 
economically/educationally disadvantaged and homeless. We will also include employees 
and students rTMS is a low-risk procedure, but we will ensure all safety measures are 
taken for these participants.  
d. 
Rationale for Exclusion of Certain Populations 
Women and minorities are included. Children are not because they are typically excluded 
from rTMS studies.  
e. 
Stanford Populations 
Employees, students and lab personnel may sign up for this study in compliance HIPAA 
policy.  
f. 
Healthy Volunteers 
All participants are healthy volunteers. 
g. 
Recruitment Details 
We intend to recruit 30 healthy subjects. We will obtain IRB approval for flyers 
advertising the study.  
 

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We will be utilizing social media to reach potential participants. We have a Facebook 
page for our research group that we will use to promote the study. We will do so using 
only IRB approved language.  
 
We will also begin utilizing the Stanford Research Registry (protocol 25422) to recruit 
study participants. The research registry is a list of individuals who have consented to be 
contacted by research at Stanford and at present includes over 1,000 volunteers.  
h. 
Eligibility Criteria 
i. 
Inclusion Criteria 
1. Age 18-80 years old 
2. Right-handed 
3. Agree to having fMRI scan 
4. Willingness to suspend use of analgesic drugs or cough suppressants for 24 hours 
prior to the scans 
5. Proficiency in English sufficient to complete questionnaires/follow instructions 
during fMRI assessments 
6. US Citizen or resident able to receive payment legally 
ii. 
Exclusion Criteria 
1. A medical condition that would contraindicate the use of rTMS 
2. Any condition that would contraindicate MRI (like ferromagnetic metal in the 
body) 
3. Pregnancy or breast feeding 
4. Any significant neurologic disease, including dementia, multi-infarct dementia, 
Parkinson’s or Huntington’s disease, brain tumor, progressive supranuclear 
palsy, seizure disorder, subdural hematoma, multiple sclerosis, history of 
significant head trauma.  
5. Current antidepressant use (must be washed out for two weeks prior to starting 
protocol). 
6. Inability to stop taking medication contraindicated with treatment. 
7. Motor threshold is unable to attained. 
i. 
Screening Procedures 
The principal investigator (PI) and/or study staff will:  
 
1. Obtain signed informed consent from the potential participant before any study-
specific procedures are performed.  
2. Assign potential participant a unique enrollment number.  
3. Determine participant eligibility. 
j. 
Participation in Multiple Protocols 
We will not enroll participants that are involved in any other treatment trial. We will 
coordinate with any ongoing biomarker studies to ensure that the treatment follows the 

October 31, 2021 
 
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biomarker study. The consent form clearly asks patients if they are participating in any 
other studies. The PI and/or research coordinator will also ask the patient.  
k. 
Payments to Participants 
Participants will be paid $25 per visit.  
 
Added 30 additional health controls who will undergo an MRI scan, without use of rTMS 
or TBS. These participants will be compensated a total of $150 USD for their 
participation in the study. 
l. 
Costs to Participants 
None. 
m. 
Planned Duration of the Study 
This research study is expected to take approximately 8 months to complete with 4 days 
of active participation by each participant.  
6. 
RISKS 
a. 
Potential Risks 
i. 
Investigational devices 
N/A 
ii. 
Investigational drugs 
N/A 
iii. 
Commercially available drugs, biologics, reagents or chemicals 
N/A 
iv. 
Procedures 
Receiving rTMS may cause minor discomfort at the site of stimulation, occurring only 
during the time of stimulation.  
 
Participants may experience a localized twitching sensation due to the magnetic field 
changes during the MRI scan. This should not be painful.  
v. 
Radioisotopes/radiation-producing machines 
N/A 
vi. 
Physical well-being 
Participants will have all measures exerted to reduce the chances of seizure and 
discomfort from stimulation of rTMS. Receiving rTMS may cause minor discomfort at 
the site of stimulation, occurring only during the time of stimulation. 
 

October 31, 2021 
 
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Participants may experience a localized twitching sensation due to the magnetic field 
changes during the MRI scan. This should not be painful.  
vii. 
Psychological well-being 
Participants will be placed in a relaxing environment to help reduce any psychological 
well being.  
 
Patients may find the study visits to be inconvenient. 
viii. 
Economic well-being 
Study should not effect economic well-being. 
ix. 
Social well-being 
No risk to social well-being is anticipated. 
x. 
Overall evaluation of risk 
Low – innocuous procedures such as phlebotomy, urine or stool collection, no therapeutic 
agent, or safe therapeutic agent such as the use of an FDA approved drug or device. 
b. 
Procedures to Minimize Risk 
We will have a trained rTMS treater in the room at all times monitoring for changes in 
level of consciousness. We will eliminate any offending agents that may increase risk of 
seizure. The protocol directors will monitor all physiological data obtained for adverse 
effects. A physician (Dr. Nolan Williams, Dr. Spiegel, or medical backup) will be in the 
building and on call in case of any seizures or other adverse events.  
 
If suicidal tendencies are indicated during completion of the MINI, the participant will be 
evaluated in more detailed by Dr. Nolan Williams or Dr. David Spiegel who are both 
trained psychiatrists. They will decide on the best course of action or treatment to ensure 
the participant’s safety.  
c. 
Study Conclusion 
The experiment will terminate when the final participant has completed their treatment 
and all data has been analyzed. 
d. 
Data Safety Monitoring Plan (DSMC) 
i. 
Data and/or events subject to review 
The study’s data and safety monitor will be the Protocol Director. In addition, 
participants can always call with questions or concerns. Serious Adverse Events, if 
any, will be reported ot the Protocol Director within 24 hours and to the FDA within 
48 hours. An events that occur will be reported to the IRB per the prompt reporting 
guidelines.  
ii. 
Person(s) responsible for Data and Safety Monitoring 
The Protocol Director will perform this function.  

October 31, 2021 
 
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iii. 
Frequency of DSMB meetings 
The Protocol Director will perform this function. 
iv. 
Specific triggers or stopping rules 
We will report all SAE. 
v. 
DSMB Reporting 
Monthly  
vi. 
Will the Protocol Director be the only monitoring entity? (Y/N) 
Yes 
vii. 
Will a board, committee, or safety monitor be responsible for study monitoring? 
(Y/N) 
No 
7. 
BENEFITS 
Participants will most likely not benefit from this study. Understanding the duration of effect of 
this new type of rTMS treatment will serve as necessary knowledge for designing future TBS 
treatment studies.  
8. 
PRIVACY AND CONFIDENTIALITY 
All participant information and specimens are handled in compliance with the Health Insurance 
Portability and Accountability Act (HIPAA) and privacy policies of Stanford University, Stanford 
Health Care, and Stanford Children’s Health.