Neural Facilitation of Stimulation-assisted Movements in People With Spinal Cord Injury
Phase: NA
Conditions: Spinal Cord Injuries
Sponsor: Washington University School of Medicine

Study Title: 
 
Neural Facilitation of Movements in People With SCI 
 
NCT number:  
NCT05354206 
 
IRB ID #: 
 
202111151 (The Washington University in St. Louis IRB) 
 
PI:  
 
Ismael Seáñez 
 
Document Type: 
Protocol 
 
Document Date:  
11/10/2022  
 

 
1 
 
Neural facilitation of stimulation-assisted movements in people with 
spinal cord injury 
 
Principal Investigator: 
Ismael Seáñez, PhD 
Assistant Professor of Biomedical Engineering and Neurosurgery  
Department of Biomedical Engineering 
Washington University McKelvey School of Engineering 
email: ismaelseanez@wustl.edu  
 
Collaborators:  
Rita Haddad, MD 
Instructor of Psychiatry 
Department of Psychiatry 
Washington University School of Medicine 
email: haddad@wustl.edu  
Study team members:  
Lorenzo Lombardi  
John Dean Peiffer 
Kim Walker, OTD, OTR/L, ATP 
Rita Haddad, MD 
Eric C. Leuthardt, MD, FNAI 
 Brenton Pennicooke, MD 
Neringa Jukins, MD 
 Kerri Morgan, PhD, OTR/L, ATP 
Theresa C. Notestine, PT, DPT, NCS 
 
  
Version: November 10, 2022 
                                           
 
 
 
 
          
 
1/10 
Human Research Protection Office  
Box 8089 
(314)633-7400 
Fax (314)367-3041 

 
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Synopsis 
Study title 
Neural facilitation of stimulation-assisted movements in people with 
spinal cord injury 
Objective 
To understand the contribution of individual neural tracts to 
movements facilitated by transcutaneous spinal cord stimulation 
using transcranial magnetic stimulation, loud auditory stimuli, 
wearable sensors, motion tracking, and electromyography. 
Hypothesis 
Previous studies supported a potential role of spinal cord stimulation 
on the excitability of corticospinal and reticulospinal tract. We aim to 
identify the specific contributions of cortico- and reticulospinal 
networks towards reinforcing different types of movements enabled 
by transcutaneous spinal cord stimulation in unimpaired volunteers 
and volunteers with spinal cord injury. The results from this study 
may serve as preliminary data for the development of targeted 
rehabilitation strategies that take advantage of residual connections 
to maximize recovery after spinal cord injury.  
Study period 
Planned enrollment duration: approximately 12 months 
Planned study duration: 1-2 hours per subject, 5 visits 
Number of 
subjects 
112 (100 unimpaired, and 12 volunteers with spinal cord injury) 
Study design 
This study will measure changes in corticospinal and reticulospinal 
excitability associated with spinal cord stimulation during different 
leg movements. 
Inclusion and 
exclusion criteria 
Inclusion Criteria: 
Healthy volunteers 
1. Age between 18 and 65 years 
2. Healthy people with no major comorbidities of any organ 
systems 
Exclusion Criteria: 
1. Subjects younger than 18 or older than 65 years 
2. Subjects not providing consent or not able to consent 
3. Subjects with any acute or chronic pain condition  
4. Subjects with any acute or chronic disease of a major organ 
system 
5. Use of analgesics earlier that 5 half-lives after the latest 
intake prior to study period  
6. The use of caffeinated products within 3 hours prior to study 
period 
7. History of epilepsy 

 
3 
8. Implanted metal 
9. Active medical problems 
 
SCI volunteers 
1. Age between 18 and 65 years 
2. Traumatic injury at the C4-T9 level, complete (ASIA A), or 
incomplete (ASIA B, C, or D) 
3. At least one-year post injury 
4. Stable medical condition 
5. Difficulty independently performing leg movements in routine 
activities of daily living 
6. Able to follow simple commands 
7. Able to speak and respond to questions 
Exclusion Criteria: 
1. Subjects younger than 18 or older than 65 years 
2. Subjects not providing consent or not able to consent 
3. Subjects with any acute or chronic pain condition  
4. Subjects with any acute or chronic disease of a major organ 
system  
5. Use of analgesics earlier that 5 half-lives after the latest 
intake prior to study period  
6. The use of caffeinated products within 3 hours prior to study 
period 
7. Presence of tremors, spasms, and other significant 
involuntary movements 
8. Etiology of SCI other than trauma 
9. Concomitant neurologic disease, such as traumatic brain 
injury that will significantly impact the ability to follow through 
on study directions, multiple sclerosis, stroke, or peripheral 
neuropathy 
10. History of significant medical illness including cardiovascular 
disease or insufficiency, uncontrolled diabetes, uncontrolled 
hypertension, osteoporosis, cancer, chronic obstructive 
pulmonary disease, severe asthma requiring hospitalization 
for treatment, renal insufficiency requiring dialysis, autonomic 
dysreflexia, etc. 
11. Severe joint contractures disabling or restricting lower limb 
movements. 
12. Unhealed fracture, contracture, pressure sore, urinary tract 
infection or other uncontrolled infections, other illnesses that 

 
4 
might interfere with lower extremity exercises or testing 
activities 
13. Depression, anxiety, or cognitive impairment 
14. Deficit of visuo-spatial orientation 
15. Sitting tolerance less than 1 hour 
16. Severe hearing or visual deficiency 
17. Miss more than 3 appointments without notification 
18. Unable to comply with any of the procedures in the protocol 
19. Botulinum toxin injection in lower extremity muscles in the 
prior six months 
20. Any passive implants (osteosynthesis material, metallic 
plates or screws) below T9. 
21. Any implanted stimulator in the body, e.g., pacemaker, vagus 
nerve stimulator, etc. 
22. History of alcoholism or another drug abuse 
23. Pregnancy (or possible pregnancy) 
24. Having an Intrathecal Baclofen Therapy Pump (ITB pump) 
25. History of epilepsy 
Measurements 
Movement kinematics with video, muscle activity, motor evoked 
potentials by transcranial magnetic stimulation, and muscle 
responses after a loud auditory stimulus, before, during, and after 
transcutaneous spinal cord stimulation; depression and anxiety 
evaluation using the Beck Depression Inventory and Beck Anxiety 
Inventory questionnaires.   
 
 
 

 
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TABLE OF CONTENTS 
 
1. Research aims  ................................................................................................... Pg. 6 
 
2. Introduction ......................................................................................................... Pg. 7 
 
3. Background and Significance ........................................................................... Pg. 7 
 
4. Study Objectives ................................................................................................. Pg. 8 
 
5. Selection of Subjects – Inclusion/Exclusion Criteria ...................................... Pg. 8 
 
6. Human Subjects ................................................................................................ Pg. 10 
 
7. Study Design & Methods ................................................................................. Pg. 12 
 
8. Data Analysis and Statistical Plan .................................................................. Pg. 16 
 
9. Management of Intercurrent Events ............................................................... Pg. 17 
 
10. Data Safety and Monitoring Plan ..................................................................... Pg. 21 
 
11. References ........................................................................................................ Pg. 22 
 
 
 

 
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1. Research aims 
Electrical spinal cord stimulation (SCS) combined with exercise training has been shown to 
restore posture, stepping, and voluntary walking in humans with spinal cord injury (SCI). However, 
the neural basis of SCS induced recovery remains poorly understood, presenting significant 
barriers towards maximizing its use in rehabilitation. A better understanding of the specific 
improvements in motor function and potential for cortical and spinal plasticity could allow clinicians 
and physical therapists to personalize SCS mediated therapy according to individual needs. 
Additionally, allowing the brain to play an active role in the delivery of therapy could further 
enhance and accelerate the potential for recovery. In this study, we combine body-machine 
interfaces based on wireless wearable sensors with spinal cord stimulation to determine which 
kinds of SCS-facilitated movements are mediated by the corticospinal and reticulospinal tracts. 
We will evaluate corticospinal and reticulospinal tract excitability via transcranial magnetic 
stimulation (TMS) and loud auditory stimuli respectively. If successful, this study will allow us to 
study whether different types of training used in rehabilitation can be used to enhance the 
excitability of these neural structures and evaluate their role in the learning of skilled motor tasks. 
An understanding of how we can accelerate plasticity through residual cortical and reticulospinal 
connections may enable the development of rehabilitation strategies that take advantage of 
patient-specific residual functions to further augment recovery. 
 

 
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2. Introduction 
Spinal cord injury (SCI) is a life-altering event that leads to long-lasting motor impairment, and 
currently, there is no ‘cure’ for paralysis1–3. Through my work and that of others, electrical spinal 
cord stimulation (SCS) has been gaining momentum as a neuromodulation technique to re-enable 
movement of paralyzed areas4–6. Although regained movements below the injury have enabled 
activity-based interventions to induce unprecedented functional improvements in the chronic 
stage of paralysis7–10, the mechanisms of neurorecovery induced by electrical neuromodulation 
of the spinal cord remain poorly understood11,12. 
 
To better understand SCS-mediated neurorecovery, studies in rodent models of SCI using 
viral tracing13 and optogenetics14 suggest that corticospinal and reticulospinal projections mediate 
the voluntary control of paralyzed areas enabled by SCS, and activity-dependent reorganization 
of these circuits may be a primary contribution towards the restoration of function that has been 
observed in humans7–9. While direct recordings of these neural structures through viral tracing 
and optogenetics are not currently possible in humans, experimental paradigms exist to evaluate 
their involvement and contribution during SCS and motor tasks11,15. Twenty minutes of SCS during 
rest has an excitatory effect at subcortical, but not cortical levels11. However, it remains unclear 
whether this excitatory effect can be further enhanced by combining SCS with active voluntary 
movement. Indeed, despite the motor-enabling effects of SCS having been first observed half a 
century ago16, a major breakthrough in SCI research came from the combination of SCS with 
activity-based training4,5,7–9,17. Moreover, while SCS can immediately enable a broad range of 
behaviors in animal models of paralysis13,18–20, independent stepping without stimulation in 
humans has only been observed after more than a year of intense rehabilitation with SCS8,9,21. In 
this work, we will evaluate corticospinal and reticulospinal tract excitability via transcranial 
magnetic stimulation (TMS) and reaction to a loud auditory stimuli (StartReact) respectively. 
Having a clear understanding of the neural mechanisms that are enhanced by SCS can allow the 
development of therapies that directly target the excitability and plasticity states of these 
structures towards improved and accelerated recovery. 
 
3. Background and Significance  
3.1 Rationale for this study 
This 1-year study will provide the necessary data to prepare a clinical trial investigating whether 
activity-dependent reorganization of cortico- and reticulospinal circuits are primary contributors 
towards the long-lasting improvements in function that have been observed in humans. Moreover, 
we will study whether different types of training used in rehabilitation can be used to enhance the 
excitability of these neural structures and evaluate their role in the learning of skilled motor tasks22–
25. An understanding of how we can accelerate plasticity through residual cortical and 
reticulospinal connections may enable the development of rehabilitation strategies that take 
advantage of patient-specific residual functions to further augment recovery. 
 
 
 

 
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4. Study Objectives 
 
The goal of this project is to generate evidence-based knowledge of changes in the short-term 
excitability of corticospinal and reticulospinal neural structures that may mediate immediate 
improvements in motor function enabled by SCS.  
 
Aim 1. Determine which kinds of SCS-facilitated movements are mediated by the 
corticospinal tract. I will use TMS to test whether SCS can enhance motor evoked potential 
(MEP) response time and amplitude as individuals use their legs to perform motor control tasks 
with different levels of dexterity. 
 
Aim 2. Determine which kinds of SCS-facilitated movements are mediated by the 
reticulospinal tract. Using the same protocol, I will test whether SCS can enhance StartReact 
response time and amplitude. 
 
5. Selection of Subjects – Inclusion/Exclusion Criteria 
We plan to include in this study a total of 100 unimpaired and 12 SCI human volunteers over the 
course of one year.  
 
Data collection will be performed at Washington University in St. Louis Danforth and Medical 
campus. Subjects will be referred by Drs. Eric Leuthardt, Brenton Pennicooke, Kerri Morgan, 
Theresa Notestine, and Neringa Jukins, who are co-investigators on this project. 
 
Approximately equal numbers of men and women will be recruited from all ethnic and racial 
groups. The racial composition of the population in St. Louis is approximately 44% Caucasian, 
46% Black or African American, 4% Asian, 4% Hispanic, 2% Other. This will be the expected 
composition of our volunteer pool, of which the minority portion exceeds the national norm. 
5.1 Healthy volunteers  
Inclusion criteria 
1. Age between 18 and 65 years 
2. Healthy people with no major comorbidities of any organ systems 
Exclusion criteria 
1. Subjects younger than 18 or older than 65 years 
2. Subjects not providing consent or not able to consent 
3. Subjects with any acute or chronic pain condition  
4. Subjects with any acute or chronic disease of a major organ system 
5. Use of analgesics earlier that 5 half-lives after the latest intake prior to study period  
6. The use of caffeinated products within 3 hours prior to study period 
7. History of epilepsy 
8. Implanted metal 

 
9 
9. Active medical problems 
 
5.2 SCI volunteers 
Inclusion criteria 
1. Age between 18 and 65 years 
2. Traumatic injury at the C4-T9 level, complete (ASIA A), or incomplete (ASIA B, C, or D) 
3. At least one-year post injury 
4. Stable medical condition 
5. Difficulty independently performing leg movements in routine activities of daily living 
6. Able to follow simple commands 
7. Able to speak and respond to questions 
Exclusion criteria 
1. Subjects younger than 18 or older than 65 years 
2. Subjects not providing consent or not able to consent 
3. Subjects with any acute or chronic pain condition  
4. Subjects with any acute or chronic disease of a major organ system  
5. Use of analgesics earlier that 5 half-lives after the latest intake prior to study period  
6. The use of caffeinated products within 3 hours prior to study period 
7. Presence of tremors, spasms, and other significant involuntary movements 
8. Etiology of SCI other than trauma 
9. Concomitant neurologic disease, such as traumatic brain injury that will significantly impact 
the ability to follow through on study directions, multiple sclerosis, stroke, or peripheral 
neuropathy 
10. History of significant medical illness including cardiovascular disease or insufficiency, 
uncontrolled diabetes, uncontrolled hypertension, osteoporosis, cancer, chronic 
obstructive pulmonary disease, severe asthma requiring hospitalization for treatment, 
renal insufficiency requiring dialysis, autonomic dysreflexia, etc. 
11. Severe joint contractures disabling or restricting lower limb movements. 
12. Unhealed fracture, contracture, pressure sore, urinary tract infection or other uncontrolled 
infections, other illnesses that might interfere with lower extremity exercises or testing 
activities 
13. Depression, anxiety, or cognitive impairment 
14. Deficit of visuo-spatial orientation 
15. Sitting tolerance less than 1 hour 
16. Severe hearing or visual deficiency 
17. Miss more than 3 appointments without notification 
18. Unable to comply with any of the procedures in the protocol 
19. Botulinum toxin injection in lower extremity muscles in the prior six months 
20. Any passive implants (osteosynthesis material, metallic plates or screws) below T9. 
21. Any implanted stimulator in the body, e.g., pacemaker, vagus nerve stimulator, etc. 
22. History of alcoholism or other drug abuse 
23. Pregnancy (or possible pregnancy) 

 
10 
24. Having an Intrathecal Baclofen Therapy Pump (ITB pump) 
25. History of epilepsy 
 
5.3 Withdrawal Criteria 
1. Subjects will be allowed to withdraw from the study at any time upon request 
2. Subjects’ participation will be terminated if any of the inclusion criteria ceases to be valid 
or if any exclusion criteria will manifest after enrollment 
3. Subjects’ participation will be terminated if any significant depression is identified on the 
collected information on depression. Subjects will also be referred to a mental health 
professional. 
 
Prior to scheduling, subjects will be screened over a phone interview to determine whether they 
meet the inclusion and exclusion criteria. All research personnel will have received training in the 
responsible conduct of human research as required by Washington University’s Institutional 
Review Board (IRB).  
 
6. Human Subjects Research 
 
6.1 Protection of Human Subjects 
The study will be performed after proper Washington University Institutional Review Board (IRB) 
approval of the protocol, consent forms, and recruitment materials. This study will include human 
subjects and thus will be conducted in conformity to the Helsinki declaration. The study will be 
conducted under the supervision of the Dr. Ismael Seáñez who is  experienced in the conduct of 
human studies on SCS. The motion tracking, EMG, and TMS data will be analyzed qualitatively 
and quantitively in collaboration with team members with substantial expertise (laboratories of Dr. 
Ismael Seáñez in the Department of Biomedical Engineering and Dr. Rita Haddad in the 
Department of Psychiatry), to identify corticospinal responses associated with movement and 
transcutaneous SCS. 
 
6.2 Recruitment and Informed Consent 
Our recruitment procedure for SCI subjects uses word-of mouth, fliers (posters), and phone calls. 
Healthy subjects that are affiliated with Washington University will be recruited by flyers, and word 
of mouth. We will stress in recruitment and during the study that participation is completely 
voluntary and will not affect their benefits or employment status. 
Subjects with SCI will be referred by Drs. Eric Leuthardt and Brenton Pennicooke 
(Washington University School of Medicine, Neurosurgery), Dr. Neringa Jukins (Barnes-Jewish 
Hospital, Physical Medicine and Rehabilitation, Spinal Cord Injury Medicine), Dr. Theresa 
Notestine (The Rehabilitation Institute of St. Louis), and Kerri Morgan (Paraquad, Stephen A. 
Orthwein Center),  and identified through the EPIC system if they meet the recruitment criteria. 
They will be told about the study in person or contacted by phone and read the “Phone Script”. 
We will make it clear that participation does not imply any certainty for favorable outcome or other 
benefits.  
Recruitment from TRISL and Paraquad will be purely in the form of posting recruitment 
flyers and referrals. No patient database access will be requested or used. 

 
11 
Subjects will be given verbal (initially) and then written descriptions of the study aims, 
procedures, risks, and benefits, and will be required to give written informed consent. A member 
of the investigative team provides all study descriptions, informed consent, and answers all 
questions. Subjects are informed verbally and in writing that participation is voluntary, and they 
may refuse to participate and may withdraw from the study at any time without penalty. 
 
6.3 Potential benefits of the proposed research to the subjects and others 
There is no expected direct benefit to study subjects. If this study is able to identify specific neural 
tracts that are involved in movements enhanced by spinal cord stimulation, we may implement 
this knowledge for the development of patient-specific rehabilitation strategies towards 
improvement of movement after SCI. Society may benefit from a novel paradigm for restoration 
of function after SCI. 
 
6.4 Compensation 
There will be no costs to participants for being in this study. Participants with SCI will be paid $20 
for every hour of participation during this research study. Unimpaired participants will be paid $10 
for every hour of participation. A prorated rate of $5 dollars for every completed 15 and 30 minutes 
for SCI and Control participants respectively will be used to account for incomplete hours or 
participation. If they withdraw from the study, they will be paid for a percentage of the experiment 
that they participated. The maximum amount of money that they can receive for a visit to the lab 
is $60. Transportation expenses from home to the hospital will be reimbursed when needed. 
Transportation expenses from home to the hospital will be reimbursed upon receipt. These funds 
are provided to help support participants with time and travel associated with participation.  
 
6.5 Inclusion of women 
Studies actively encourage the participation of women in the research. Our studies routinely and 
deliberately attempt to include equivalent numbers of women and men. However, due to a small 
size of the study, we may not be able to enroll equal number of male and female subjects. 
Pregnant or possibly pregnant women are excluded from our research protocols. 
 
6.6 Inclusion of minorities 
All of our studies actively encourage the participation of minorities in the research.  Our minority 
recruiting of healthy subjects typically matches the demographic composition of the Washington 
University community from which subjects will be recruited (78% white, 21% Black, <1 % 
Hispanic). The racial composition of the population in St. Louis is approximately 44% Caucasian, 
46% Black or African American, 4% Asian, 4% Hispanic, 2% Other. This will be the expected 
composition of our SCI volunteer pool, of which the minority portion exceeds the national norm. 
 
6.7 Inclusion of children 
Due to the newly identified rare risk of autonomic dysreflexia, children will not be included in the 
study. 
 
7. Study design and methods 
 

 
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7.1 Procedure Schedules – Full Protocol 
SCI and Controls – Complete protocol 
 
7.2 INITIAL EVALUATION 
7.3 AIM 1 
7.4 AIM 2 
PROCEDURE 
Visit #1 
Functional Mapping 
Visit #2 
Range of Motion 
Visit #3 
Familiarization 
Visit #4 
TMS 
Visit #5 
StartReact 
Kinematic recordings 
 
 
 
 
 
EMG recordings 
 
 
 
 
 
Transcutaneous SCS 
 
 
 
 
 
BoMI  
 
 
 
 
 
Motor tasks 
 
 
 
 
 
TMS 
 
 
 
 
 
StartReact 
 
 
 
 
 
 
7.2 Initial evaluation: Determine the effect of SCS on motor responses and range of motion 
To determine an initial baseline for each participant, we will evaluate motor responses elicited by 
transcutaneous SCS in the initial evaluation phase. Participants will visit the lab for 1) a functional 
mapping where we measure spinal responses elicited by SCS, 2) a range of motion evaluation 
where we measure the range of motion on different joints with and without SCS, and 3) a 
familiarization phase where participants learn to control the body-machine interface using their 
leg movements supported by SCS. 
Participants: 100 unimpaired participants and 12 participants with spinal cord injury (spinal cord 
injury level C4-T9) with motor impairments in the legs (complete ASIA A, or incomplete ASIA B, 
C, or D) and in the chronic stage of SCI (>6 months postinjury) will participate in this experiment, 
which will be submitted for review and approval to Washington University School of Medicine 
Institutional Review Board. Unimpaired participants will be recruited to perform either one of the 
five potential visits (Visits# 1-5) or all five visits. Approximately 16 unimpaired participants are 
expected to complete each type of protocol. SCI participants will be recruited for the five visits in 
total.  
Experiments with unimpaired, control participants will be used to refine collection procedures and 
instruments and to prepare an improved, more refined research design that will ensure effective 
and high-quality data collection with SCI participants. Data collected on control subjects will also 
be used to establish baseline behavior for comparison of SCI participant task performance and 
may be used to generate generalizable knowledge. 
Kinematic recordings: Kinematic recordings will be obtained at a 100 Hz sampling rate using a 
3D markerless motion capture system (Miqus-Hybrid, Qualisys, Sweden) consisting of 10 HD 
cameras covering the entire workspace. Head, trunk, and bilateral upper and lower extremity 
kinematics will be captured by these 2MP cameras or by infrared cameras and positioning virtual 
markers over standardized anatomical landmarks.  
Muscle activity recordings (EMG): Muscle activity (EMG) will be acquired bilaterally at 1 kHz 

 
13 
using a 16-channel wireless system (Trigno Avanti, Delsys, Natick, MA). The area around 
muscles will be shaved and cleaned with an abrasive cream and alcohol. Bipolar surface 
electrodes will be placed over the form of the iliopsoas, rectus femoris, vastus lateralis, 
semitendinosus, biceps femoris, tibialis anterior, medial gastrocnemius, and soleus muscles. 
Prior to electrode placement, the area around each muscle will be shaved and cleaned with an 
abrasive cream and alcohol. EMG signals will be processed according to the SENIAM (Surface 
Electromyography for the Non-Invasive Assessment of Muscles) standards for EMG recordings 
and band-passed filtered between 10 and 450 Hz using a 4th order Butterworth filter. A moving 
average of the rectified EMG signal within a centered 250 ms time window will be used to generate 
normalized EMG envelopes for quantification. 
Transcutaneous spinal cord stimulation (SCS): During the stimulation phases of the study, 
non-invasive transcutaneous electrical stimulation will be delivered to the lumbar segments of the 
spinal cord below the injury using a DSR8 biphasic constant-current stimulator (Digitimer, UK) 
with a range of 0-1,000 mA. Stimulation will be administered using two pairs of conductive self-
adhesive electrodes with a diameter of 3.2 cm placed on the skin over the spinal midline between 
the spinous processes of the L4 and L5 vertebrae to act as cathodes. The center of the cathodes 
will be located ~2 cm left and right of the midline. Two additional 5x10 cm electrodes will be placed 
symmetrically on the skin over the abdomen to be used as anodes56,57. The stimulation waveform 
will be biphasic, rectangular, with 1 ms pulses at a frequency of 1-100 Hz. As an additional 
alternative, the stimulation will be filled with a carrier frequency of 5 KHz. It is thought that a 5-10 
KHz carrier frequency is beneficial for improving muscle strength58 and for suppressing the 
sensitivity of pain receptors59, and is therefore more comfortable for human participants11,60,61.  
Functional mapping: Recordings will be performed with single-pulse, graded stimulation 
amplitudes as subjects lay supine on a table in order to compute the degree of recruitment of 
each muscle with increasing stimulation amplitudes as previously described in my work7.  
Range of motion: Kinematic recordings will be performed to quantify the range of motion at the 
different joints with and without transcutaneous SCS. 
Body-machine interface: Participants will be fitted with a body-machine interface to control a 
computer cursor using the legs. Leg movements will be recorded using non-invasive, wireless 
inertial measurement unit (IMU) motion sensors (YostLabs, Portsmouth, OH) attached with 
Velcro® to adjustable straps around the legs or with double-sided skin tape. User-specific body 
motions will be decoded and converted into the two coordinates of the cursor in real-time as 
previously described in my work62.  
Familiarization: Participants will have the opportunity to familiarize themselves with the control 
of the BoMI using SCS and perform different types of game-like activities like center-out reaching, 
pong, solitaire, Tetris, and other flash games, as well as the motor tasks (described below). 
7.1 Aim 1: Determine which kinds of SCS-enabled movements are mediated by the 
corticospinal tract 

 
14 
An increasing number of studies supports the view that SCS can restore posture, stepping, and 
voluntary walking in humans with SCI4,7,17. The prevailing view is that by elevating the functional 
state of spared spinal sensory-motor networks below the lesion, residual descending pathways 
can transmit activity that enables and amplifies voluntary motor control15. Although epidural SCS 
can enable force production in paralyzed muscles7, whether motor improvements are mediated 
by the corticospinal tract or the reticulospinal remains unknown. 
 
In a 45-min session, we will deliver non-invasive transcutaneous SCS to the lumbosacral 
enlargement as participants use their SCS-facilitated leg movements to control a non-invasive 
body-machine interface (BoMI) on a computer screen and perform game-like activities62,63. To 
determine which kinds of SCS-enabled movements are mediated by corticospinal networks, 
participants will perform two motor tasks before and after training requiring different degrees of 
dexterity: precision control vs. maximum range of motion; using two types of movements: hip vs. 
ankle flexion. To quantify changes in neural excitability of the corticospinal tract, we will compare 
motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation of the leg motor 
cortex64 as participants perform the motor tasks. We postulate that MEP responses will be 
enhanced for the precision-control task in distal muscles (tibialis anterior), which are thought to 
require a high involvement from the corticospinal tract. Our hypothes is that SCS will further 
enhance the MEP response for these movements, but not for range-of-motion movements, or 
movements with proximal muscles (rectus femoris). 
Transcranial magnetic stimulation (TMS): Motor evoked potentials (MEPs) in the tibialis 
anterior and rectus femoris muscles will be evoked by TMS of the contralateral motor cortical leg 
area using a Magstim 2002 stimulator (Magstim, UK) through a double cone coil and a 
monophasic current waveform delivered at 4-s intervals. The motor threshold for both muscles 
will be identified65 and that intensity will be used to elicit and average twenty MEPs at each 
timepoint24. Average MEP response amplitude will be used to quantify changes in corticospinal 
tract excitability15. If no motor threshold is detected at 100% device stimulation intensity due to 
SCI (and interrupted circuits), the 100% stimulation intensity or the maximum tolerable intensity 
will be used. MEP responses will be measured during rest and during an active contraction (Motor 
Tasks, see below) before and after BoMI training, as well as with and without SCS. To estimate 
changes in MEPs, response amplitudes under different conditions will be normalized to the 
baseline (before training, resting) response. 
Motor tasks: Immediately before after the BoMI session, participants will wear a VR headset 
(Oculus Quest 2, Facebook, CA) to block their view. The IMUs on the legs will measure and 
digitize their leg joint angles. A real-time virtual representation of one of their joint angles will be 
presented through the VR. Participants will be asked to perform two tasks requiring different types 
of motor control. In the range-of-motion task, participants will be instructed to flex or extend their 
legs to surpass a virtual target of a specified amplitude. In the precision-control task, participants 
will have to move their joint and hold the position within a target range of a specified amplitude 
for 1 second. We will examine motor-evoked potentials elicited by TMS (Aim 1) and the StartReact 
response (Aim 2) as individuals perform the task under two conditions: with SCS and without SCS 
using the knee and ankle joints. As an alternative to the VR headset, a wall projector will be used 
to perform the motor tasks. 

 
15 
BoMI Training: Participants will perform visuo-spatial motor tasks over a 45min session with 
SCS. The tasks will consist of different types of game-like activities like center-out reaching, pong, 
solitaire, Tetris, and other flash games. 
Expected outcomes, potential problems, and alternative strategies: Based on previous 
studies by other groups, it is our expectation that MEP responses will be enhanced for the 
precision-control task in distal muscles (tibialis anterior), which are thought to require a high 
involvement from the corticospinal tract. We hypothesize that SCS will further enhance the MEP 
response for these movements, but not for range-of-motion movements, or movements with 
proximal muscles (rectus femoris. 
The main challenge in this study will be the recruitment of a sufficiently large group of 
volunteers with spinal cord injuries in the C4-T9 level. If this will not be feasible, we will extend 
the study to individuals with lesions at the C2-C3 level that have complete or partial paralysis in 
the legs. Furthermore, we can seek to further extend the study to other hospitals in the St. Louis 
region like the Barnes Jewish Hospital, the Rehabilitation Institute of St. Louis, SSM Rehabilitation 
Hospital, and the VA Medical Center Spinal Cord Injury Program. Another potential difficulty may 
arise because of the high expected attrition with severely disabled volunteers. As a consequence, 
some evaluations might be interrupted. To preserve uniformity of statistical power across the 
study, we will retain the results of participants with an incomplete number of sessions in separate 
data sets. The analysis of incomplete data sets will take explicitly into account the causes for 
abandoning the study (e.g. dissatisfaction with the methodology, change in medical condition, 
etc). 
Our approach will have –by design an objective—a degree of customization based on each 
individual’s specific mobility and potential for movement restoration with SCS. Therefore, there 
might be a small initial difference in performance. However, our previous studies have 
demonstrated an improvement in performance with training independent of differences in the 
BoMI map between subjects22,62,66,67. 
 
One possibility is that 45 minutes of BoMI training is not sufficient to observe changes in 
corticospinal and reticulospinal tract excitability within a single session. If this is the case, we will 
increase the duration of BoMI training to 2 hours. Twenty minutes to 2 hours of SCS and motor 
training have been shown to be sufficient to observe changes in motor function61,68,69 as well as 
spinal15, cortical24, and subcortical11 excitability in human subjects.  
 
Support of limb weight may introduce a force production confound when participants have 
to generate torque to move their foot compared to their whole leg. If this is the case, we will 
perform the motor task evaluations as participants lay on their side as manual support is provided 
to counter the effects of gravity. 
7.2 Aim 2: Determine which kinds of SCS-enabled movements are mediated by the 
reticulospinal tract 
Using the same protocol as Aim 1, we will test whether SCS can enhance the StartReact response 
time and amplitude. To quantify changes in neural excitability of the reticulospinal tract, we will 
compare the StartReact response70 (a shortening in response time after a startling auditory 
stimulus) as participants perform the motor tasks before and after BoMI training. 

 
16 
StartReact response: Participants will be instructed to reach the target as fast as possible after 
it is presented. Response time will be identified from EMG activity71 and measured when the target 
is presented alone (visual reaction time), when it is paired with a soft auditory stimulus (80 dB, 
500 Hz, 50 ms, visual-auditory reaction time), or with a startling acoustic stimulus (120 dB, 500Hz, 
50ms, visual-startle react time) presented through audio speakers (T-15, Polk Audio). To quantify 
changes in StartReact responses, response times under different conditions will be normalized to 
the baseline response. 
Expected outcomes: Based on previous studies by other groups47,71,72, I expect the StartReact 
response time to be the shortest for the startle response, where the reticulospinal tract is engaged. 
Furthermore, I expect that SCS will have an additional enhancement of this response, but only 
for tasks that require a high involvement from the reticulospinal tract. We hypothesize that SCS 
will enhance the StartReact response for the range-of-motion task in proximal muscles (rectus 
femoris), but not for precision-control movements, or movements with distal muscles (tibialis 
anterior). 
8. Data Analysis and Statistical Plan 
Average MEP and StartReact responses (of 20 responses) will be used to quantify changes in 
corticospinal and reticulospinal tract excitability15. A paired sample t-test of response amplitude 
and latency (time from stimulation to muscle response) will be used to test the hypothesis that 
BoMI training with SCS results in enhanced corticospinal tract excitability during precision-control 
movements and reticulospinal tract excitability during range-of-motion movements. In addition, a 
Student’s t-test with a Holm-Sidak adjustment for multiple comparisons will be performed to 
compare the difference between changes in corticospinal excitability induced by the type of motor 
task (precision control vs. range-of-motion), joint (ankle vs. hip), and group (control vs. SCI).  
8.4 Sample Size 
We plan to include in this study a total of 100 unimpaired and 12 SCI human volunteers over the 
course of two years. We expect that only 90% of unimpaired and 70% of SCI subjects initially 
recruited will conclude the experiment. Therefore, we will need to recruit 110 unimpaired and 16 
SCI volunteers in order to reach the recruitment targets. 
 
The number of subjects has been powered from the results of previous studies using similar 
methods to investigate structural changes in the brain after BoMI practice22,73. Although the power 
is adequate, it might be possible that we are unable to detect significant changes in motor 
capacity. If no within-subject significant changes are found in preliminary experiments, we can 
extend the duration of training within one session, or extend the protocol to several sessions. If 
no significant group changes are found, we can recruit six more SCI participants for the study (a 
50% increase). 
9. Management of Intercurrent Events 
9.1 Adverse Experiences  

 
17 
The investigators will monitor the subjects closely for any local or systemic adverse events from 
the study. If any such events are noted, they will be managed appropriately and reported. Subjects 
will be followed until satisfactory resolution. The description of the adverse event will include time 
of onset, duration, severity, etiology, relationship to the study (none, unlikely, probably, highly 
probable) and treatment that was required. 
9.2 Premature Discontinuation 
Subjects may be discontinued from the study if the investigators decide that it is in the best interest 
of the subject, or the subject requests to be withdrawn. Subjects’ participation will be terminated 
if any significant depression is identified on the collected information on depression. Subjects will 
also be referred to a mental health professional.  
 
9.3 Potential Risks 
Use of motion sensors. There are no known risks associated with the use of the instrumented 
motion sensors. The trunk and leg motions made in the proposed research are well within the 
normal range of motion of adult subjects, and there are no physical injuries expected from the use 
of the motion sensors. Fatigue from the repeated movement of legs, or dizziness from the 
computer screen are a possibility. 
Surface electrodes. Surface electrodes for recording of muscle activity via electromyography 
(EMG) and transcutaneous spinal cord stimulation are widely used and present a low-risk to the 
subject. Skin redness, dryness, or irritation is possible from the shaving and skin cleaning required 
for the application of the surface EMGs. Skin lacerations from shaving due to dry contact or 
repeated shaves are possible. Subjects are instructed that they may stop any procedure at any 
time with no adverse consequences.  
Transcutaneous spinal cord and peripheral nerve stimulation. Unpleasant or even painful 
paresthesia could be experienced during stimulation. In most cases, stimulation parameters can 
be adapted to be tolerated by the subject. However, there is a likelihood that stimulation cannot 
be tolerated by a subject. Subjects are instructed that they may stop any procedure at any time 
with no adverse consequences. 
Autonomic dysreflexia (AD) is an acute episodic hypertension resulting from sympathetic 
hyperactivity46 and is typically defined as increased systolic blood pressure greater than 20 to 30 
mmHg47. AD may be experienced by individuals with injuries above the 6th thoracic level (T6), 
most commonly triggered by noxious irritation of urinary bladder or bolon48, although it can also 
be triggered by nonnoxious or noxious stimuli47,49. A recent study testing the use of tSCS for 
upright posture in children with SCI detected an episode of AD in one participant (5% occurrence), 
rating it as "very unlikely to occur"50. The stimulation was immediately stopped, and, within 3 min, 
the episode resolved, and blood pressure returned to baseline levels. Although a study specifically 
investigating the incidence of AD by spinal cord stimulation in people with SCI failed to observe 
an adverse event51, and numerous other studies have not reported incidences of AD10,11,32,52–55, 

 
18 
we found two other studies reporting signs of AD in SCI while using SCS56,57. In one study, one 
out of nine participants was observed to experience symptoms of AD, but was later found to have 
an injury to the left calf, likely due to the sit-to-stand training paradigm57. Although the other study 
mentions that there were no confirmed incidents of AD, one out of fifteen participants 
demonstrated an elevation of systolic blood pressure greater than 60 mmHg, and the stimulation 
was stopped.  
History of AD is already an exclusion criteria of our study, and participants with SCI typically have 
experience in identifying the onset of AD symptoms. However, we believe that although the risk 
of inducing AD through tSCS may be rare, it is important to monitor blood pressure and other 
signs of AD (decreased heart rate, face flushing, headache, and sweating) to manage it in time 
should it occur. 
Transcranial magnetic stimulation. The TMS device to be used is the MagStim 2002 with a 110mm 
double cone coil and an EMG interface module. The TMS devices are non-significant risk devices. 
The principal component of the TMS is a “figure-8” coil made of insulated copper bus bar and 
capacitor-containing booster modules. The flow of electricity through the coil is regulated by a 
control module and a computer. When electricity flows through the coil, a magnetic field pulse is 
generated according to Faraday’s law. This magnetic pulse in turn causes nearby neurons to 
discharge in a physiological variant of the Hall effect. No electrical current is ever passed between 
the machine and the participant. Currently, this MagStim 2002 machine has FDA approval for 
peripheral nerve stimulation, but we will use it for cortical stimulation to evoke motor evoked 
potentials from the motor cortex15,24,71,72.  
Generally, TMS is considered safe and well-tolerated. Patients receiving repetitive TMS, 
which has increased risks compared to single-pulse TMS74 (Table 1), are able to drive home or 
return to work immediately after a repetitive TMS session. In this study, we will only use single-
pulse TMS. The single-pulse TMS techniques performed in this study have been used extensively 
in thousands of research studies and on tens of thousands of participants in the United States 
and around the world. Single-pulse TMS techniques are considered remarkably safe74 if the 
appropriate guidelines are followed 75.  

 
19 
Table 1
 
Adapted from 76. 
In general, the risks associated with single-pulse TMS are very minimal. Some of the risks 
that may be associated with TMS include unpleasant temporary side effects including headache, 
scalp discomfort at the site of stimulation, paresthesia, toothache, hearing changes, spasms, or 
twitching of facial muscles, and lightheadedness.  
Studies suggest that the loud clicking noise produced by the TMS discharge may exceed 
140 dB of sounds pressure level, and can cause hearing loss 74. However, a majority of studies 
report no change in hearing after TMS when hearing protection is used 74.  
There is a very small risks of seizures in repetitive TMS done with very intense, high-frequency 
stimulation or stimulations separated by less than 1 second. Such intensities and frequencies will 
not be used in this study, as only single-pulse TMS will be employed. A questionnaire77 sent to 
2510 authors in 174 groups using a variety of coils and protocols in TMS reported over 16 seizures 
apparently caused by TMS in over 200,000 sessions for a standardized risk of 8/100,000. 
However, 13 of these occurred in high-risk subjects. The other 3 had no known risk factors 74.  
Loud auditory stimulus. Loud noises can cause temporary side effects including headache, and 
discomfort in the ear.  
Loss of confidentiality. There is a risk of loss of confidentiality with participation in this study. 
Investigators will aim to keep the identity of the subjects confidential to the extent permitted by 
law. However, it is possible that others may become aware of the subject’s participation in this 
study and may inspect and copy records pertaining to this research. Some of these records could 
contain information that personally identifies subjects. 

 
20 
This is an observational study, and no treatments will be tested in this study. Treatment for SCI 
will be directed by the participant’s physician. 
9.4 Procedures to minimize potential risks 
This study will be conducted at Washington University under the supervision of the PI. The PI is 
trained and well-experienced in performing human subject research. Study subjects will be 
monitored throughout the experiment by a co-investigator. Inclusion and exclusion criteria and 
monitoring are designed to ensure that the risks are minimal. Subjects are informed that 
participation is voluntary, and they may refuse to participate and may withdraw from the study at 
any time without penalty.  
 
The responses to the Beck Depression Inventory questionnaire will be reviewed in real time 
by team members. If, based on the questionnaires, a participant is suspected of having suicidal 
intent, the PI will be notified immediately and referrals will be made as needed for further 
evaluation.  
 
Study staff complete training in HIPPA regulations and do not divulge confidential 
information regarding participants. Participant records are kept confidential with paper records in 
a secure location and computer records password-protected, available only to the study staff, and 
with subject identifiers removed. 
 
Use of motion sensors. To avoid fatigue, experiments will be self-paced by the subject. Subjects 
will be instructed that they may ask to have the procedure stopped if they have any discomfort or 
other concerns. 
Muscle activity sensors (EMG). Washing the electrode gel from the skin surface and applying 
unscented skin lotion after the experiments will be applied to minimize skin irritation. Shaving 
cream will be used to reduce the likelihood of lacerations. In case of lacerations, first aid will be 
applied as necessary and the EMG application will be discontinued in that area. 
Transcutaneous spinal cord and peripheral nerve stimulation. Stimulation will always start at a 
minimum amplitude and slowly increased as subjects are instructed to give feedback on their 
comfort levels. Amplitudes will be chosen as the level at which a subject feels paresthesia (tingling 
sensation) or a motor response is elicited. These amplitudes are normally way below pain 
thresholds. If a subject feels discomfort at a certain stimulation amplitude, the amplitude will be 
lowered to a comfortable level, or stopped. 
To identify potential incidences of autonomic dysreflexia, blood pressure and heart rate will be 
monitored before, during, and after the use of continuous SCS. A baseline measurement will be 
recorded at the beginning of the experiment. A second recording will be performed as soon as 
the continuous stimulation has reached the amplitude necessary for the experiment. A final 
recording will be performed at the end of the experiment. Signs of autonomic dysreflexia will 
include an increase in systolic blood pressure by more than 20 mmHg, absolute pressure greater 
than 140 mmHg systolic or 100 mmHg diastolic,  a decrease in heart rate by more than 40 bpm, 
face flushing, sweating, and headache. If a sign of autonomic dysreflexia is detected, stimulation 

 
21 
will be immediately stopped, participants will be moved to an upright position to induce an 
orthostatic hypotension response, and blood pressure and heart rate will be monitored once every 
5 minutes until they return to baseline levels.  
Transcranial magnetic stimulation. Stimulation will always start at a minimum device amplitude 
and slowly increase as subjects are instructed to give feedback on their comfort levels. Stimulation 
amplitudes will be chosen as the level at which muscle responses are elicited. These amplitudes 
are normally below pain thresholds. If a subject feels discomfort at a certain stimulation amplitude, 
the amplitude will be lowered to a comfortable level, or stopped. 
All participants in our study will be required to wear approved hearing protection (earplugs or 
earmuffs) during TMS evaluations as recommended by TMS safety guidelines. 
Loud auditory stimulus. When delivered continuously for prolonged times (longer than 2 minutes), 
noises above 110dB can result in temporary or permanent hearing loss. Noises in our experiment 
will have a short 1/5 second duration to prevent adverse consequences. Subjects will be 
instructed that they may stop any procedure at any time with no adverse consequences. 
Loss of confidentiality. Upon enrollment in this study, 1) all subjects will be assigned a study ID 
number, 2) The link to identifiers will be destroyed at the end of the study, 3) Data will be stored 
under lock and key (office, file cabinet) and only the investigators and research team will have 
access.  If data are published, there will be no link to identifiers.  Study data will not be revealed 
to any organization or individuals other than the subjects themselves, 4) Study data will not be 
entered in subjects' medical records. 
Adverse experiences. The investigators will monitor the subjects closely for any local or systemic 
adverse events from the study. If any such events are noted, they will be managed appropriately 
and reported to the HRPO and QASMC according to institutional guidelines. Subjects will be 
followed until satisfactory resolution. The description of the adverse event will include time of 
onset, duration, severity, etiology, relationship to the study (none, unlikely, probably, highly 
probable) and treatment that was required. 
Premature discontinuation. Subjects may be discontinued from the study if the investigators 
decide that it is in the best interest of the subject, or the subject requests to be withdrawn. 
Subjects’ participation will be terminated if any significant depression is identified on the collected 
information on depression. Subjects will also be referred to a mental health professional.  
 
10. Data Safety and Monitoring Plan 
 
The specific monitoring plan for this investigation is commensurate with the risks and the size and 
complexity of the investigations planned. This study involves a single site (Washington University 
in St. Louis) and a single intervention (behavioral tasks), with minimal risks. Therefore, we have 
selected the monitoring authority of: Dr. Ismael Seáñez and Washington University 

 
22 
Institutional Review Board. 
 
Dr. Ismael Seáñez, the Principal Investigator, will take primary responsibility for monitoring 
participant safety. He will review all serious adverse events (SAEs), adverse events (AEs), and 
unanticipated problems (UPs) on an ongoing basis, and ensure that that the Washington 
University Institutional Review Board (IRB) receives reports via its online reporting system 
following the IRB's required timeframes. Specifically: 
• 
All SAEs, regardless of relatedness or expectedness, will be reported to the safety officer 
within two working days of becoming aware of the event.  
• 
AEs and SAEs that meet the definition of a UP, including breach of confidentiality, will be 
reported to the safety officer within two working days and to the IRB within 10 working 
days of becoming aware of the event. 
• 
All other AEs and SAEs that do not meet criteria as a UP will be reported to the IRB at the 
time of continuing review in accordance with its policy.  
• 
Any major deviations from protocol will be reported within 10 working days, and changes 
to protocol initiated without IRB approval to alleviate immediate hazards will be reported 
within 24 hours.  
• 
Participant complaints (which do not rise to the level of UP) and minor deviations from 
protocol will be reported annually, but any pattern/series of minor deviations will be 
reported within 10 working days.  
 
In addition, the following records will be added to the study regulatory binder: 
• 
For all reports to the IRB, the Coordinator will retain a copy of the notification to the IRB 
• 
Each SAE and UP will be recorded individually in an Adverse Event Form  
• 
AEs will be recorded as part of the AE Tracking Log. 
Dr. Seáñez will ensure that all study personnel are adequately trained and provisioned to work 
with participants to resolve complaints, trained to identify and respond to expected AEs (e.g. 
intolerability of spinal cord stimulation or headaches or seizures after transcranial magnetic 
stimulation), and otherwise trained to ensure compliance with the protocol.  
During quarterly whole-study meetings, Dr. Seáñez and the clinical research coordinator will lead 
a review of any issues related study data and safety with all members of the team. 
  
 
 

 
23 
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