Study of Postural Stability in Subjects With Myelopathy Using a Portable Virtual Reality Balance Protocol
Conditions: Cervical Spondylotic Myelopathy
Sponsor: VA Office of Research and Development

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Study of Postural Stability in Subjects with Myelopathy using a Portable 
Virtual Reality Balance Protocol 
 
NCT03810781 
Principal Investigator:  
 
Richard Servatius, PhD 
Version Date:   
 
 
 
9/5/19 
 
 
 
 

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Abstract 
Veterans are at heightened risk of developing cervical spondylotic myelopathy (CSM) from rigors of 
military service. Diagnosis of CSM involves a set of clinical findings and is confirmed by imaging the 
spine.  
Gait impairment and disturbances of stance control are hallmarks of CSM and are a consequence of 
abnormalities in proprioception due to dorsal column tract damage of the spine. Currently, gait and 
balance deficits rely on clinical level assessments and judgement for detection. An objective measure of 
posturography has the benefit of: a) quantifying balance-related disability in CSM, b) facilitating 
structure-functional assessments in CSM, and c) quantifying the degree surgical interventions affect 
posturography and recovery of function in CSM. 
Objective and sensitive means for assessing balance and posturography exist, but are not routinely 
incorporated in diagnosis or functional tracking of progress after interventions such as surgery. A barrier 
may be accessibility of posturography and ease of assessments. The Virtual Environment TBI Screen 
(VETS) was devised using Army Rapid Innovation Development funding to objectively assess balance 
and posturography in a cost effective, but sensitive manner. VETS involves virtual environments and 
computerized posturography and is proving to be a sensitive system facilitating diagnosis, treatment, and 
mitigation of balance dysfunction associated with mTBI. 
Our working hypothesis is VETS testing will enhance clinical judgements regarding CSM. This study is 
designed to provide data critical to a more extensive program of research incorporating posturography 
into treatment and rehabilitation of CSM. First, a limited comparative study of standing balance will be 
conducted of 20 veterans being evaluated for cervical spine surgery to treat CSM and 20 otherwise 
healthy veterans. Second, posturography of the 20 veterans undergoing surgery to treat CSM will be 
tracked during their scheduled follow up visits to determine the degree VETS scores are affected by 
surgery and to track recovery from CSM. 
 
 
 
 
 
 
 
 
 
 

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List of Abbreviations 
ALS  
amyotrophic lateral sclerosis  
ANOVA  
analysis of variance  
AUC  
area under the curve  
COP  
center of pressure  
CSM  
cervical spondylotic myelopathy  
CT  
computed tomography  
DYN  
Dynamic  
EC  
Eyes Closed  
EO  
Eyes Open  
mJOA  
modified Japanese Orthopaedic Association scale  
ML  
medio-lateral  
MMT  
manual muscle test  
MRI  
magnetic resonance imaging  
MRSR  
Medical Research Surveillance Reports  
MS  
multiple sclerosis  
MSE  
multiscale entropy  
mTBI  
mild traumatic brain injury  
NDI  
Neck Disability Index  
PTSD  
posttraumatic stress disorder  
ROC  
receiver operating characteristic  
SF-36  
Short Form-36  
SOT  
Sensory Organization Test  
SVAMC  
Syracuse Veterans Affairs Medical Center  
TBI  
traumatic brain injury  
VETS  
Virtual Environment TBI Screen  
VR  
virtual reality  
WBB  
Wii balance board  
 
 
 

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Contents 
Protocol Title: ............................................................................................................................................... 5 
1.0 
Study Personnel ................................................................................................................................ 5 
2.0 
Introduction ....................................................................................................................................... 5 
3.0 
Objectives ......................................................................................................................................... 9 
4.0 
Resources and Personnel ................................................................................................................... 9 
5.0 
Study Procedures .............................................................................................................................. 9 
5.1 Study Design ....................................................................................................................................... 9 
5.2 Recruitment Methods ........................................................................................................................ 10 
5.3 Informed Consent Procedures ........................................................................................................... 11 
5.4 Inclusion/Exclusion Criteria ............................................................................................................. 11 
5.5 Study Evaluations ............................................................................................................................. 12 
5.6 Data Analysis .................................................................................................................................... 13 
5.7 Withdrawal of Subjects ..................................................................................................................... 14 
6.0 
Reporting ......................................................................................................................................... 15 
7.0 
Privacy and Confidentiality ............................................................................................................ 15 
8.0 
Communication Plan ....................................................................... Error! Bookmark not defined. 
9.0 
References ..................................................................................................................................... 16 
 
 
 
 
 
 
 
 
 
 
 
 
 

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Protocol Title:  Study of Postural Stability in Subjects with Myelopathy using 
a Portable Virtual Reality Balance Protocol 
 
1.0 
Study Personnel 
 
Principal Investigator/Study Chair:  
• 
Richard Servatius, PhD. SVAMC. Research Scientist, Director of the SMBI. 
Co-Investigators: 
• 
Steven Brose, DO. SVAMC. Chief of Spinal Cord Injury Unit.  
• 
Aiga Rakhesh, MD. SVAMC. Neurologist, Spinal Cord Injury Unit 
• 
Satyajit Marawar, MD. SVAMC. Chief of Spine Surgery. 
• 
William Geoffrey Wright, PhD. SVAMC. WOC.  
Coordinator: 
• 
Amanda Haskell. SVAMC. WOC.  
• 
Labeeby Servatius. SVAMC. WOC 
 
2.0 
Introduction 
 
Cervical Spondylotic Myelopathy (CSM), also known as degenerative cervical myelopathy, encapsulates 
a cascade of events leading to significant degenerative changes in discs, formation of osteophytes, facet 
hypertrophy, calcification of the posterior longitudinal ligament and ligamentous flavum with resultant 
canal stenosis and segmental instability 1, 2. Progressive impingement on tracts, nerve roots, and neurons 
may be confined to the cervical spinal cord or may be co-occurring in many locations throughout the 
spinal column.  
 
In civilians, CSM reflects ‘wear and tear’ presenting generally in aging (> 50 year of age) and more often 
in males 3. Incidence is estimated at 4.1/100,000 person years in North America 4. Veterans are at greater 
risk for CSM owing to the rigors of military service (heavy axial loading, repeated vigorous activities, and 
direct trauma to the spine) 5, 6. Although there are no agreed upon rates, degenerative disc disease is 
highly incident in military personnel and is responsible for lost duty time and medical evacuation from 
forward deployment 6. Using Medical Research Surveillance Reports (MRSR) as a guide, incidence of 
cervical spondylosis is estimated at 150/100,000 person years for 2009 7. Although not specifically 
reported, incidence rates may be inferred to hold steady or slightly increase over the next surveillance 
period 8. Tracking incidence of CSM from military service to veterans is difficult given the lack of an 
agreed upon criteria and absence of distinct pathognomonic findings 9. However, it is reasonable to 
assume military experiences initiating degenerative processes would compound that of aging, which is the 
single most important risk factor in civilians 10.  
 
Three areas are critical for early identification and management of CSM: detection and diagnosis 5, 
differential diagnosis 11, and functional tracking of signs and symptoms.  

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Detection and Diagnosis. Given the progressive nature of the disorder, timely identification and treatment 
is paramount 3. Imaging of the cervical spine and notation of abnormalities alone is insufficient for 
diagnosis of CSM. Diagnosis of CSM involves a set of clinical findings which are confirmed by magnetic 
resonance imaging (MRI) and computerized tomography (CT) 12, 13. The most common symptoms of 
CSM are: numb or clumsy hands, impaired gait, neck and leg stiffness, sensory disturbances in the arms 
or legs, atrophy of the hand musculature, and sensory loss. Signs of CSM are hyperreflexia, atrophy of 
intrinsic hand muscles, motor deficits, a broad-based, unstable gait, and bowel and bladder dysfunction. 
Both sets have considerable variability in presentation depending on cervical level and the degree and 
severity of impingement. Current tools to assess severity of functional impairment in CSM are the Nurick 
Scale 14, 15 for mobility, Neck Disability Index (NDI)16 and the modified Japanese Orthopaedic Association 
(mJOA) scale 17, which provide a means for a standardized clinical scoring of dysfunction in broad 
strokes.  
 
Differential Diagnosis. Differential diagnosis is challenging because there is a lack of a definitive finding 
or biomarker, and signs and symptoms overlap with a number of pathological sensorimotor conditions 5, 
11. The most common are multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), vitamin B12 
deficiency and syringomyelia 11. Differential diagnosis requires a host of invasive and noninvasive tests 
adding time, expense, and discomfort.  
 
Treatment. Alleviation of impingement is typically surgical to decompress and stabilize the affected 
region 10. There is considerable debate concerning the efficacy of surgical and nonsurgical interventions, 
the best type of surgical intervention, as well as the efficacy of combination approaches 3, 18-21. With the 
available outcome measures (mJOA, NDI, Nurick), there is evidence of improvement after surgical 
intervention in moderate and severe cases of CSM, however, mild cases are less clear 10. In this regard, 
the clinical scales suffer from a lack of sensitivity.  
 
Critical Need. For all three areas – diagnosis, differential diagnosis, functional tracking in treatment – 
objective, empirical measures of dysfunction sensitive to severity of CSM have the potential to enhance 
rehabilitation of CSM in veterans.  
 
Static balance and CSM. One area with a high potential to advance sensitivity, selectivity and gradations 
of CSM is a measure of static balance. Balance is the ability to maintain stable postural sway that does not 
exceed the limits of stability. Balance arises through the integration of sensory (somatosensory, 
vestibular, and visual inputs) and motor components (flexors, extensors). Sway, measured through center 
of pressure (COP), is a necessary component of posture as well as a well-established metric of postural 
control. Excessive sway is a sign of instability which may arise through sensory disturbances, motor 
dysfunction, or environmental perturbations.  
 
Disturbances of postural control are hallmarks of CSM 22 and are a consequence of abnormalities in 
proprioception due to dorsal column or spinocerebellar tract damage of the spine 23 or postural commands 
to motor neurons 24, 25. Those presenting to the emergency room for head trauma from falling were more 
likely to have CSM 26. Similarly, those hospitalized for hip fracture were more likely to also have 
evidence of CSM than similarly aged individuals having elective hip arthroplasty 27. Further, CSM 
increases the risk of subsequent injury after hip replacement 28. Early detection could serve to decrease 
rates of injury and compound injury.  
 
Nardone et al. 24 studied body sway of patients with severe CSM and cervical spondylosis without 
myelopathy using a force platform under conditions of eyes open or closed on a level firm surface 
compared to healthy controls. COP sway area was greater in both clinical groups under both eyes open 
and eyes closed conditions, suggesting disturbances of ascending proprioceptive input and impaired 

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descending motor control. Further, they found substantially greater COP sway area in CSM patients in the 
eyes closed than eyes open conditions, demonstrating the dependency on visual input for balance in CSM. 
Yoshikawa et al. 29 also observed that individuals with CSM presented larger COP sway than the less 
severe CSM, however, there was not supporting MRI or CT abnormalities presented to confirm CSM or 
its severity. Freppel et al. 30 found COP sway differences between patients with herniated disc and CSM 
suggesting that while symptom reporting was similar, posturography is sensitive to etiology (acute vs 
chronic degenerative disease). Thus, the assessment of static balance has considerable promise in 
providing an objective measure of dysfunction in CSM and contributing to differential diagnosis. Further, 
evaluating proprioception using posturography may also help to predict surgical outcomes. Takayama et 
al. observed that early proprioceptive recovery was 
associated with better functional outcome 2 years after 
surgery for cervical myelopathy 22. Despite these promising 
findings, there has not been a study of posturography in 
veterans with CSM. 
 
The Virtual Environment TBI Screen (VETS) is a new 
construct that has been validated for evaluating postural 
control processes.  Building on established parameters, the 
VETS assesses posturography through easily accessible and 
relatively low cost technology.  Currently, a Wii Balance 
Board (WBB – Nintendo, Kyoto, Japan) 31, 32 provides a 
surface for testing and stabilometers for transducing COP 
sway area.  Virtual reality technology is used to simulate 
movement using a commercially available large screen 
television.  There are three conditions (eyes open, eyes 
closed, and watching a dynamic visual scene) repeated on a 
firm surface or a foam surface.  These 6 conditions allow 
for an assessment of generalized vs specific deficits in COP 
sway area considering proprioception (firm vs foam 
surface), dependence of visual input (eyes open vs eyes 
closed) and visuo-proprioceptive integration (static vs 
dynamic visual scene) (see Figure 1).  The VETS device 
was specifically designed to be low cost (all components 
are commercial off-the-shelf) and easily assembled.  The 
user interface was designed to be accessible to novice, but 
attentive providers.  Algorithms are included to provide 
easily understandable measures among the six conditions.  
As a clinical device, further development is necessary.   
 
Although we have yet to examine posturography in veterans 
with CSM, Servatius and Wright have active collaborations to study posturography in active duty military 
(Military Medicine in press) and veterans. We are currently conducting a study of posturography at the 
Syracuse Veterans Affairs Medical Center (SVAMC) in veterans as a function of lifetime mild traumatic 
brain injury (mTBI) and posttraumatic stress disorder (PTSD). In the interim between initial submission 
and revision, two veterans with MS volunteered for the study. Although the study has a different focus, 
the data illustrates the sensitivity of the VETS to subtle differences in balance. No veteran in the study to 
date has registered a self-reported problem with balance. Figure 2 depicts COP sway for otherwise 
HEALTHY (N = 10), lifetime mTBI (N = 7) and MS (N = 2) veterans under the six conditions. In 
observing the otherwise HEALTHY veterans (open bars), one can see that the foam condition places a 
substantial burden on balance compared to firm conditions. Further, eyes closed conditions exacerbate 
COP sway area, especially on foam. One can also see that the ranges of COP sway area in normal 

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HEALTHY veterans provide substantial room to detect 
abnormalities. It is against this background that we will be assessing 
balance disturbances in CSM.  
 
For the purposes of illustration we compared the two MS veterans to 
HEALTHY veterans with a 2 x 3 x 2 (Surface x Visual Condition x 
Clinical Group) mixed model analysis of variance (ANOVA) which 
yielded a significant triple interaction, F(2,16) = 5.49, p = .014. 
Specific comparisons between conditions showed the two eyes open 
conditions are similar to HEALTHY veterans (ps > .05) suggesting 
for these MS veterans postural control motor outputs are normal. 
Differences were apparent in the EC conditions suggesting visual 
input is necessary to maintain balance. Further, the DYN-FOAM 
condition was compromised in the two MS veterans (ps < .05), 
suggesting impaired ability to integrate visual, proprioceptive, and 
vestibular stimuli in MS. Comparison was also made between those 
with lifetime history of mTBI and HEALTHY veterans with a 
similar 2 x 3 x 2 (Surface x Visual Condition x Clinical Group) 
mixed model ANOVA. The triple interaction was significant, 
F(1.176, 17.645) = 5.385, p = .028 (Greenhouse-Geisser correction 
for violations of sphericity). Those with lifetime history of mTBI 
exhibit balance difficulties specifically on the DYN-FOAM 
condition (p < .05). For MS and lifetime mTBI, balance was 
compromised during the DYN-FOAM condition, which is designed 
to produce to roll vection 33, that is, perceived self-motion due to 
conflicting visual, proprioceptive and vestibular inputs.  
 
 
The ongoing research in veterans demonstrates the utility of the six conditions comprising VETS to 
expose motor, proprioceptive, vestibular, and integrative sensory deficits. The combination of conditions 
in VETS provide a means to advance research in CSM beyond that already conducted in civilians to date.  
 
Imposition of posturography is envisioned to aid in clinical assessment in CSM in three meaningful ways: 
a) assessment of CSM severity, especially in cases of ‘mild’ CSM, b) differentiating CSM from other 
entities, c) providing an objective target to assess treatments interventions and recovery. For differential 
diagnosis, the conditions potentially distinguished by posturography are trauma, ALS 34, MS (Figure 2), 
syringomyelia, myelitis, and vitamin B12 deficiency 35 (See Table 1).  
 
 
 
 
 
 
 
 

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3.0 
Objectives 
 
AIM 1A: Determine whether and to what degree balance is altered in CSM. The degree of COP sway will 
be compared between CSM and controls in the six conditions comprising VETS testing.  
Hypothesis 1: Impaired proprioceptive transmission in CSM will result in poorer balance (larger 
COP sway area) during EC conditions (eliminating the ability to compensate with visual 
feedback) and FOAM (reducing the reliability of somatosensory feedback) conditions compared 
to healthy veterans.  
 
AIM 1B: Determine whether VETS enhances sensitivity and selectivity in the diagnosis of CSM. 
Composite measures of balance will be related to clinical assessment tools and their relationship with 
MRI.  
Hypothesis 2: VETS will provide additional sensitivity and selectivity in identifying CSM 
compared to current clinical assessment tools.  
Hypothesis 3: The degree of COP sway area during EC and FOAM conditions is expected to 
directly relate to the degree of spinal cord compression quantified from MRI, leading to a more 
sensitive gradation in the severity of CSM.  
 
AIM 2: Evaluate the VETS scores after surgery for CSM. The degree of COP sway area under the 6 
conditions will be compared before surgery, 2 weeks, 6 weeks, and 6 months after surgery.  
Hypothesis 4: We expect surgery to reduce COP sway in EC conditions 
 
4.0 
Resources and Personnel 
All research activities will be conducted at the Syracuse VA Medical Center, using equipment 
already owned by the PI. All research activities and data storage will take place in the D-wing of 
the SVAMC. Potentially eligible CSM patients will be identified by Drs. Casella, Brose, and 
Marawar during CSM surgery scheduling and referred to the study coordinator. Interested 
patients will be screened additionally and scheduled for an appointment if they are eligible. The 
study coordinator will consent the participants and obtain HIPAA authorization before collecting 
study data. Collecting study data will involve administering questionnaires and VETS testing. 
Drs. Casella and Marawar will complete the clinical scales being used in the study. Dr. Wright 
will process VETS data and Dr. Servatius will run all statistical analyses.  
 
5.0 
Study Procedures 
5.1 Study Design 
For AIM 1, a cross-sectional design that includes within-subjects (VETS conditions) and between-
subjects (veteran groups) factors will be used to compare balance and posture in patients awaiting surgery 
for CSM (n = 20) to a cohort of age and gender-matched non-CSM controls (n = 20). The 20 veterans 
with CSM recruited for AIM 1 will also serve as the sample for AIM 2, which is a longitudinal 
assessment of balance following surgical intervention for CSM. The data generated from the proposed 
study will provide a base estimate of the variance in our veteran groups for use in the power calculation 
for a larger follow up study 

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Veteran volunteers (CSM and control) meeting eligibility criteria will complete one session of VETS 
balance testing. Those veterans awaiting surgery for CSM will be asked to return for three additional 
sessions of VETS at designated time points scheduled 2 weeks, 6 weeks, and 6 months post-surgery. For 
returning CSM veterans, self-report measures will be collected at each additional time point to compare 
objective (VETS) and subjective (scale measures) assessments of functional impairment related to CSM 
following surgery. None of the procedures involved in this research project will alter standard of care 
associated with CSM or the surgical treatment. “Each patient will be cleared by one of the study doctors 
(Dr. Marawar, Casella, or Brose) before participating in the post-surgery sessions. In the event that a 
patient is found to be physically incapable of safely participating in the first post-surgery session, they 
will not continue participation in the study until they are cleared by the study doctors. Thus, even if a 
patient is not cleared to participate in the two week post-surgery time point, they may be cleared to 
participate in the remaining two sessions (six weeks and six months post-surgery).” 
Risks/Benefits of Participation 
There are no risks associated with the questionnaires included in this study, as they ask only about 
physical symptoms and functioning associated with CSM. Although some emotional health questions will 
be included, they are not expected to be upsetting in any capacity. 
The risks associated with VETS testing are minimal and are as follows: 
• 
Discomfort from standing on the WBB or foam for a prolonged period of time 
• 
Dizziness or disorientation when viewing the dynamic condition 
These risks will be minimized by allowing participants to step off the WBB/foam between trials if the 
participant indicates any sign of discomfort. If a participant feels unable to continue with the testing, they 
will be allowed to cease participation at any time. All participants will be advised to step off the balance 
board if they feel too dizzy, to minimize fall risk. Additionally, the experimenter overseeing the VETS 
testing will be trained to spot participants to guard against falls.  
We do not expect the inclusion of patients with both CSM and an additional diagnosis (i.e. neuropathy or 
lumbar spine disease) to alter the risk profile for the study, as each patient will be screened by study 
clinicians before being allowed to participate in the study. Any patient who is not found physically 
capable of completing the study assessments will not be informed of the study.  
Participants will receive no direct benefit as a result of participating in this study. However, developing 
the VETS assessment as an objective marker of balance dysfunction in CSM will benefit veterans in the 
future who are being diagnosed, treated, and rehabilitated for CSM.   
5.2 Recruitment Methods 
Given the scope of the proposed study, a total sample size of 40 veterans is considered a realistic and 
achievable enrollment to generate pilot data. For AIM 1, a cross-sectional design that includes within-
subjects (VETS conditions) and between-subjects (veteran groups) factors will be used to compare 
balance and posture in patients awaiting surgery for CSM (n = 20) to a cohort of age and gender-matched 
non-CSM controls (n = 20). The 20 veterans with CSM recruited for AIM 1 will also serve as the sample 
for AIM 2, which is a longitudinal assessment of balance following surgical intervention for CSM. 

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Drs. Casella, Brose and Marawar will identify potential participants for the CSM group by screening all 
CSM patients undergoing assessment and scheduling for surgical intervention. These potential 
participants will be referred to Dr. Servatius’ study team, where a staff member will provide background 
information, additional pre-screening, and scheduling (if eligible and interested). 
Healthy volunteers will be recruited using a poster/flyer within the SVAMC. Potentially interested 
participants will call the study staff, as prompted by the advertisement, and will undergo pre-screening 
and scheduling. A copy of this flyer may be found in the submission package. Healthy volunteers may 
also be recruited from the pool of participants who consented to future contact in the SMBI Data 
Repository. These individuals will be contacted by the research staff and will be asked if they are 
interested; the attached Telephone Script includes the language used for these participants.  
For the cross-sectional arm of the study, veteran volunteers in the CSM and control conditions will be 
compensated $40 for their participation. Veteran volunteers in the CSM group will have the opportunity 
to earn an additional $40 for attending each of the three post-operative assessments, resulting in a 
maximum remuneration of $160. Participants will be paid in full for all sessions attended, even if they 
cease participation before fully completing a session. Payment will be sent in the form of a VA check to 
the address specified by the participant.  
 
5.3 Informed Consent Procedures 
Before the start of the testing session, the experimenter (the PI or a designated member of the research 
staff) will review the consent form with the participant and any study-related questions will be answered. 
This will take place in a private office. Participants will be encouraged to take their time and read the 
form carefully and in its entirety before they sign. Should the participant wish to take the consent form to 
review and think over, they will be permitted to do so. The participant’s consent about his/her 
comprehension of the experiment and his/her willingness to participate will be obtained. The participant 
will also check a box indicating whether or not they consent to having their data stored in a research 
repository. Additionally, optional consent for recontacting will be requested. The participant will sign the 
form in front of the experimenter, indicating that they have read and understood all portions of the 
consent form, and the experimenter has answered any and all questions the participant had about the 
research of their participation. The same process will be followed for HIPAA authorization. The 
participant will be provided with a copy of the consent form and a copy of the signed HIPAA 
authorization form. 
5.4 Inclusion/Exclusion Criteria 
Inclusion criteria for the CSM group are:  
• 
Symptoms of myelopathy in upper and lower extremities and stenosis of the cervical spine 
demonstrated by MRI or myelography 
• 
Lower extremity muscle strength of 4 as quantified by manual muscle test (MMT) or above 
• 
Ability to stand without support with eyes closed for 30 seconds or more.  
Exclusion criteria for all study participants are:  

12 
 
• 
History of neurological disorder other than lumbar spine disease or peripheral neuropathy 
• 
Inability to stand in an upright position with both feet together and eyes closed.  
Veterans in the control group will be recruited via printed advertisement or through the SMBI Data 
Repository and age- and sex-matched with CSM veterans. Every effort will be made to ensure that the 
veteran participants enrolled in the proposed study are reflective of the VA population, with regard to sex 
and race/ethnicity. If any participant over the age of 89 happens to enroll, their exact age will be recorded 
as >89.  
5.5 Study Evaluations 
A. Materials 
Scale Measures. Measures to be used in the proposed study include the modified Japanese Orthopaedic 
Association (mJOA) scale, the Nurick Scale, Neck Disability Index (NDI), and Short Form-36 (SF-36). 
The mJOA and Nurick Scale will be completed by one of the study team doctors during clinical visits, 
and the NDI and SF-36 will be completed by the participant. Participants will also fill out a demographics 
questionnaire once. 
 
Modified Japanese Orthopaedic Association (mJOA) scale 17. The mJOA is an instrument used to assess 
motor dysfunction of the upper and lower extremities, sensory loss of the upper extremity, and sphincter 
dysfunction. Motor dysfunction of the upper extremities is assessed on a 6-point Likert scale, with values 
ranging from 0 (inability to move hands) to 5 (no dysfunction). Motor dysfunction of the lower extremity 
is assessed on an 8-point Likert scale, with values ranging from 0 (complete loss of motor and sensory 
function) to 7 (no dysfunction). Sensory dysfunction of the upper extremities is assessed on a 4-point 
Likert scale, with values ranging from 0 (complete loss of hand sensation) to 3 (no sensory loss). Finally, 
sphincter dysfunction is assessed on a 4-point Likert scale, with values ranging from 0 (inability to 
micturate voluntarily) to 3 (normal micturation).  
 
Nurick Scale 15. The Nurick scale is a 6-grade ordinal scale assessing gait impairment, with grades 
ranging from 0 (signs and symptoms of root involvement but no evidence of spinal cord disease) to 5 
(chair bound or bedridden).  
 
Neck Disability Index (NDI) 16. The NDI is a 10-item self-report questionnaire addressing function 
activities (personal care, lifting, reading, work, driving, sleeping, and recreation), pain intensity, 
concentration, and headache. For each item, patients make their ratings on a 6-point Likert scale with 
values 0 = no disability and 5 = complete disability. Summed scores for each category are multiplied by 2 
to give a total NDI score ranging from 0-100.  
 
Short Form-36 (SF-36) 37. The SF-36 is a self-report general health survey that includes mental and 
physical component scores to measure functional status and overall quality of life. The instrument 
includes 8 scales: physical functioning, role limitations physical pain, bodily pain, general health 
perceptions, vitality, social functioning, role limitations, emotional health, and mental health.  
 
Demographics: The demographics form will ask about basic information, including: age, sex, history of 
head injury, and current medications. 
 
VETS. Postural stability will be assessed with the VETS system devised by Wright 31, 38-40. All postural 
conditions are performed in a darkened room. The physical set-up has the front edge of the Wii balance 
board (WBB) placed at a distance of 40 cm from a 60” commercially-available flat screen television. This 
device employs a custom-designed software user interface that allows wireless Bluetooth collection of 

13 
 
center-of-pressure data at 100 Hz with high test-retest reliability and immediate display of results. 
Excellent concurrent validity was determined by comparing VETS with a research grade gold-standard 
NeuroCom, which revealed ICC > 0.90 (min: 0.901, max: 0.995, p<0.01).  
 
The postural stability task will involve six conditions during which veterans are instructed to look straight 
ahead and maintain an upright stance as stably as possible (see Figure 2). Veterans are barefooted with 
feet comfortably placed ~25 cm apart. The six conditions are (1) Eyes Open (EO) Firm – eyes open with 
stable support surface (i.e. WBB) and static visual scene, (2) Eyes Closed (EC) Firm – eyes closed with 
stable support surface and dark screen, (3) Dynamic Scene (DYN) Firm – eyes open with a stable support 
surface while viewing a scene dynamically rotating in the roll (fronto-parallel) plane at 60 deg/s, (4) EO 
Foam - eyes open with unstable support (Airex foam pad placed on top of the WBB) and stable visual 
scene, (5) EC Foam – eyes closed with unstable support and dark screen, and (6) DYN Foam – eyes open 
with unstable support and rotating scene. Each condition lasts 30 secs and is repeated 3 times before 
progressing to the next condition. The conditions are tested in order 1-6, in a manner that emulates the 
validated Sensory Organization Test (SOT) protocol (Natus/Neurocom). For safety, an experimenter 
guards the veteran to protect against falls. 
B. Procedure 
Initial Testing Session: For all participants, the first session will involve obtaining informed 
consent and HIPAA authorization, completing self-report questionnaires, and a session of VETS 
testing. This initial session will last approximately 60 minutes. The informed consent procedure 
will follow the description outlined in section 5.3 and is expected to take around 15 minutes. 
Subsequently, the participant will fill out all listed self-report questionnaires, which will take 
about 15 minutes. Lastly, the participant will undergo one session of VETS testing, which will 
take about 20 minutes. VETS testing will follow the protocol outlined above in the “Materials” 
section. For CSM patients, one of the study doctors will fill out the clinical assessments during 
standard of care appointments throughout the study that correspond in time with the participant’s 
research appointments.   
All subsequent sessions (2, 3, & 4) will include CSM participants only, and will be conducted 
after surgical treatment. 
Testing Session 2: Participants will be scheduled for the second testing session 2 weeks post-
surgery. This session will include all self-report questionnaires except demographics and a 
session of VETS testing. It will last approximately 30-45 minutes.  
Testing Session 3: Participants will be scheduled for the second testing session 6 weeks post-
surgery. This session will include all self-report questionnaires except demographics and a 
session of VETS testing. 
Testing Session 4: Participants will be scheduled for the second testing session 6 months post-
surgery. This session will include all self-report questionnaires except demographics and a 
session of VETS testing. 
5.6 Data Analysis 
VETS data processing 
The COP can analyzed by transforming of the time series into various traditional measures including 
sway area, sway velocity and AP and medio-lateral (ML) standard deviations. COP sway area is found 
using a principal component analysis, which approximates an ellipse around the x-y COP data using the 
first two eigenvectors. We will also assess COP velocity as a secondary dependent measure of balance 
dysfunction. COP velocity is calculated using the COP path length traveled in the x-y plane per time 

14 
 
epoch (0.01 sec). An instantaneous COP velocity is calculated for each sample and the average 
instantaneous COP velocity per trial. Multiscale entropy (MSE) is a nonlinear complexity measure of a 
time series over different temporal scales, which uses coarse-graining to average data points to generate a 
new time series 41. Repeating structure within the point-to-point fluctuations of the postural signals over a 
range of time series can be sensitive to sensory reweighting during upright standing 42, 43. MSE quantifies 
the physiological noise due to the various integrating processes, such that control and coordination of 
muscular contractions patterns employed during balance control can be systematically evaluated 44. Our 
primary measure will be COP sway area, but all measures will be analyzed particularly to compare and 
identify the most sensitive and selective measure. 
 
Statistical Analyses  
All statistical analyses will be performed using IBM SPSS Statistics Version 24 and MedCalc. For 
descriptive purposes, continuous data will be summarized with the number of non-missing values, mean, 
and standard deviation, minimum, median, and maximum and categorical data will be summarized with 
the number of non-missing values and the numbers (frequencies) of values equal to each of the possible 
categories, unless stated otherwise. Univariate analyses will examine data distributions, potential outliers 
and missing data. All statistical tests will be two-sided with a significance level of alpha=0.05. Unless 
otherwise stated, no multiplicity adjustment will be applied and no missing values will be imputed.  
For analysis of posturography data, each of the six VETS postural conditions (see Figure 2) will be tested 
three times for each participant from which an average is calculated for each condition. These within-
subject, within-condition averages will be used in model building to assess between groups differences in 
balance (AIM 1a) and within-groups change in balance over time following surgical intervention (AIM 
2).  
 
For AIM 1a, mixed model ANOVA will be used to compare veteran group (CSM vs Control) and within-
subject visual (EO, EC, and DYN) and surface conditions (FIRM and FOAM). Average COP sway, COP 
velocity, and MSE of COP sway velocity for each of the six VETS conditions will serve as dependent 
measures in separate models. Using Mauchly’s tests, violations of sphericity will be detected, are 
corrected with Greenhouse-Geisser adjustments.  
 
For AIM 1b, receiver operating characteristic (ROC) analyses will be conducted as a preliminary 
determination of sensitivity and specificity of VETS conditions to detect CSM. We will assess areas 
under the curve (AUC) and corresponding 95% confidence intervals, which will serve as indices of 
accuracy for CSM diagnosis. Using known groups (CSM and control veteran volunteers), we will 
compare AUC curves corresponding to 1) traditional diagnostic scale measures (e.g., mJOA scale, Nurick 
Scale, NDI, and SF-36), 2) VETS conditions, and 3) scale measures combined with VETS conditions. 
These analyses will serve as indicators for the degree the posturography, alone or in combination with 
scale measures, are sensitive and selective to CSM. An AUC = 0.50 will be considered chance level for 
correct classification into CSM and control groups. Differences in AUC for each of the three ROC curves 
will be accomplished using methods described by Delong et al 45.  
 
For AIM 2, VETS data for CSM veterans will be assessed for changes in balance following surgical 
intervention. VETS dependent measures outlined above will be entered into repeated-measures ANOVA 
with time point (pre-surgery, 2 weeks, 6 weeks, and 6 months post-surgery) entered as an additional 
repeated measure. Using Mauchly’s tests, violations of sphericity will be detected, are corrected with 
Greenhouse-Geisser adjustments. 
5.7 Withdrawal of Subjects 

15 
 
Subjects will be told that they may withdraw from the study at any time. As soon as the subject notifies 
the PI or researcher that they wish to cease their participation in the study, any appointments will be 
canceled and the participant will be paid for any sessions partially or fully completed.  
Participants may be withdrawn without their consent if the study is suspended during their participation or 
they suffer a health-related event within the time frame of their participation that precludes them from 
participating further, including complications from surgery.  
6.0 
Reporting 
Adverse Event (AE): If a research participant exhibits acute discomfort as noted by the researcher during 
a testing session (e.g., expressing discomfort or overwhelming disorientation while standing on the VETS 
apparatus), they will be asked if they feel they are able to carry on with the session and offered a break. If 
they are unable to carry on, the PI will be informed immediately and the testing session will be terminated 
for the day.  
Serious Adverse Event (SAE): An example of a SAE would be a participant suffering severe 
complications associated with the CSM surgical treatment. It is likely that such complications will occur 
only unrelatedly to any study activities—especially if a participant is prohibited from active participation 
while experiencing such complications. In the event that a participant has a strongly negative response to 
the surgery, the participant will not be scheduled for any post-surgical appointments.  
An AE temporally related to participation in the study will be documented whether or not considered 
related to the test article or procedure. This definition includes current illnesses and injuries and 
exacerbations of preexisting conditions including changes to psychological state. AE will be kept in the 
subject tracking log and reported as a summary at continuing review. Expected adverse events which are 
not serious are reported on the Continuing Review Progress Report (CR).  Any unanticipated adverse 
event related to application of tDCS will be reported to the IRB within 10 days, as per Federal 
Regulations Title 21 812.150 (1).  
SAE, such as hospitalization for more than 24 hours, will be reported to the IRB within 5 days per SOP 
151-17. This will be accomplished by submitting an adverse event report to the IRB. 
7.0 
Privacy and Confidentiality 
Data Storage  
All research data (physical and electronic) will be anonymized using identifiers supplied by the 
experimenter. In this study, each participant will be assigned a subject number (e.g., Subject 001), which 
will be used to link all data provided by the participant. There will be no direct correspondence between 
the participant’s subject number and other personally identifying information, such as names or contact 
information, which could link them to the study or their data. Signed consent forms will be stored in a 
locked filing cabinet in room D311, which is located in a secured access research wing of the SVAMC. 
Only authorized study personnel will have access to these files.  
De-identified electronic data will uploaded to a VAMC network computer for storage and data analysis 
purposes. Data will be stored in a secure, encrypted network subfolder (G:\SYR-MS\MS-SMBI). No 
study data will be stored on a computer hard drive. Only approved study personnel will have access to 

16 
 
electronic data. Raw numerical data from the VETS assessment containing no identifying information 
whatsoever will be shared offsite with Dr. Wright using VA Remote Access. This data is the output from 
our balance assessment, and contains nothing except numeric information reflecting the participant’s 
standing balance pressure. No other information about the participant is contained in these files, although 
the files are named using the participant’s unique study code. The paper study key will be maintained 
onsite and will never leave its locked file cabinet at the SVAMC. When study personnel are removed 
from the protocol, their access to the data will be terminated.  
In the event that the security of VA research-related information (physical or electronic data) is 
compromised, either by unauthorized use, disclosure, transmission, removal, theft, loss, or destruction, 
the PI and authorized research staff will report to ACOS for Research, Privacy Officer, and Information 
Security Officer within 1 hour, as specified in Research & Development Policy 151-17.  
Data Repository 
During the consent process, the researcher will also obtain the participant’s optional consent for storing 
data in a data repository. If the participant consents to data storage, their data will enter a data repository 
maintained at the Syracuse VA Medical Center by the PI and will not expire or be destroyed at the end of 
the current study. For all participants who do not consent to having their data entered into the data 
repository, their study records will be destroyed within 6 years of the end of the study, as per RCS 10-1.  
Participants will agree to the data repository both in the consent form and in the HIPAA authorization 
form. Data entered into the data repository will be maintained in the manner detailed in the IRB protocol 
submitted for the data repository itself. Only authorized study personnel will have access to the data 
repository, and access will be terminated immediately upon an individual’s removal from the protocol. 
 
8.0 
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