Thalamic Low Intensity Focused Ultrasound Stimulation in Disorders of Consciousness Following Severe Brain Injury
Phase: NA
Conditions: Consciousness Disorders, Brain Injuries
Sponsor: University of California, Los Angeles

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NCT02522429 
Thalamic Low Intensity Focused Ultrasound in Brain 
Injury 
 
10/30/2020 
 

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Background 
Few neurological conditions are as scientifically mysterious and clinically, legally, and ethically 
challenging as disorders of consciousness (DOC) 1. Typically developed after severe brain injury, this set 
of related conditions includes Coma, the Vegetative State (VS) and the Minimally Conscious State (MCS) 
2.  In the past 20 years, an increasing amount of research has broken many conventions about these disorders, 
including the once widespread belief that these patients are entirely apallic – that is, lack any kind of 
“higher” activity 3. Since then, it has been shown that a lot of brain activity, including relatively high-level 
cognitive processes, can remain in DOC patients. Nonetheless, to date there exists no standard intervention 
for patients suffering from these devastating conditions. Developing interventions for this population is 
extremely important first and foremost for the well-being of patients, who – today – remain completely 
dependent on assisted care, are often unable to participate in rehabilitative programs because of their lack 
of behavioral responsiveness, and thus find themselves prisoners of a condition characterized by uncertainty 
at the medical, legal and ethical decision-making levels 4. In addition, these conditions, which can last 
indefinitely, also place great emotional and monetary strain on families, large burdens on care-takers – often 
leading to increased rates of burn-out 5 – and large financial stress on medical structures and public finances 
due to the large costs imposed by prolonged intensive care.  
 
The present project is aimed at evaluating the potential of non-invasive Low Intensity Focused 
Ultrasound Pulsation (LIFUP) of thalamus as a neuro-restorative stimulation for patients with severe 
brain injury.  
 
The rationale for this proposal hinges upon four premises:  
(i) 
To date, there exists no standard intervention for severe brain injury patients who develop 
disorders of consciousness  
(ii) 
Recent advances in our understanding of the physiological mechanisms accompanying the loss 
and recovery of consciousness and cognitive function after severe brain injury suggest specific 
neural targets for therapeutic intervention 6-8  
(iii) 
Invasive surgical techniques based on permanently implanting neurostimulating electrodes in 
the brain (i.e., Deep Brain Stimulation – DBS) have shown that thalamic stimulation can lead 
to behavioral improvements in patients with severe brain injury 9-13 
(iv) 
Low-Intensity Focused Ultrasound Pulsation (LIFUP) stimulation 14 has been shown to be an 
effective and safe neuromodulation technique in humans 15, consistent with data from animal 
models, including rodents 16 and non-human primates 17. The empirical safety data is also well 
justified from a theoretical point of view considering that LIFUP delivers stimulation of 
intensities below those of commonly used ultrasound applications (e.g., pre-natal 
ultrasonography, doppler ultrasounds), as well other neuromodulatory techniques (e.g., 
Transcranial Magnetic Stimulation – TMS) 
  
In this project, we propose to assess, in a small number of patients with severe-TBI, the feasibility of 
LIFUP as a non-invasive alternative to stimulation via neuro-surgical insertion of brain electrodes (i.e., 
DBS). More specifically, we have three main aims: 
Aim 1: Assess the feasibility and preliminary efficacy of LIFUP thalamic stimulation, as measured by 
changes in clinical assessments measures of consciousness and behavioral responsiveness. 
Aim 2: Assess the brain effects of LIFUP stimulation, as measured by functional MRI and the degree to 
which they correlate with clinical/behavioral changes. 
 
 
The main hypotheses underlying the project are: 

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H1: As shown by previous literature 15-18, LIFUP stimulation is a safe and effective neuro-modulatory 
technique. 
H2: LIFUP thalamic stimulation is associated with an increase in clinical measures of patient arousal and/or 
awareness to an extent at least comparable to that demonstrated with neurosurgical thalamic stimulation 
procedures (i.e., DBS) 9-13. 
H3: The neuro-restorative effects of LIFUP stimulation are associated with detectable changes in brain 
function as detected with fMRI. 
 
Protocol 
The research strategy is to recruit patients who have suffered a severe TBI and are in a Disorder of 
Consciousness (18 years or older and no contraindications to entering the MRI environment). Patients will 
be recruited either as Acute DOC patients or Chronic DOC patients. 
Inclusion Criteria: 
Acute patients 
    < 6 weeks since injury 
    A Glasgow Coma Score < 9 (at the time of injury) 
    Abnormal CT 
    Prolonged loss of consciousness (>24h) 
    Behavioral profile consistent with a VS or MCS as assessed with the Coma Recovery Scale 
Revised. 
Chronic patients 
    > 3 months post injury for non-traumatic injuries, >12 months post-injury for traumatic 
injuries 
    Behavioral profile consistent with a VS or MCS as assessed with the Coma Recovery Scale 
Revised. 
 
Exclusion Criteria (all patients): 
  deep sedation 
  history of neurological illness prior to injury 
  inability to safely enter the MR environment (e.g., ferromagnetic non MR safe implants) 
 
Neurobehavioral Assessment Procedure 
Neurobehavioral assessments will be conducted using the Coma Recovery Scale Revised (CRS-
R). 19 Baseline responsiveness will be assessed prior to LIFUP exposure. Responsiveness will also 
be assessed immediately following, as well as on the days following each LIFUP exposure. The 
Coma Recovery Scale – Revised, is a standard clinical protocol used to assess a patient’s level of 
consciousness. This test allows us to assess your level of response to sensory stimulation, ability 
to understand language and to communicate. This procedure is typically administered at bedside. 
This testing should take 25 minutes. 

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In addition, the Glasgow Outcome Scale extended score will be assessed to evaluate outcome at 
protocol end and follow-up 
. 
Paramedical Measurements 
(1) Clinical EEG: data from the clinical recordings will be collected.  
(2) MR acquisition (performed in MR suite):  
     (A) Structural MRI acquisition:  
          (i) T1-weighted (MPRAGE) 
          (ii) Diffusion Tensor Imaging (DTI) 
     (B) Functional MRI acquisition:  
          (ii) Resting state task (BOLD, during sonication) 
 
Electroencephalography (EEG) is a widely employed technique that measures electrical brain activity. In 
order to acquire EEG data we will fit you with a small elastic cap that you will wear on your head. This 
procedure (expected duration: 10 minutes + set-up time, up to 20 minutes) will allow us to measure 
electrical brain activity as you rest. This procedure is entirely non-invasive. 
 
Magnetic Resonance Imaging (MRI) is a widely used method to assess body tissues, including the brain, 
in a non-invasive manner. In the context of this study, MRI will be used to assess brain structure and 
function (in response to LIFU). MRI protocols include T1 MPRAGE, Diffusion Tensor Imaging (DTI), and 
T2* BOLD sequences.  
 
Procedure 
The temporal sequence of events, for each cycle, is as follows: 
- Clinical EEG (baseline): 10 min of EEG data, from the clinical recordings, will be collected for 
analysis 
- Baseline clinical measures collection (25 min) 
- Baseline f/MRI measures collection (in MRI suite; 30 min+20 min set-up) 
- Administration of LIFUP (in MRI suite; 10 min + 20 min set-up) 
- Post-LIFUP f/MRI measures collection (in MRI suite; 30 min) 
- Post-LIFUP clinical measures collection (25 min) 
- Clinical EEG (post-LIFUP): 10 min of EEG data, from the clinical recordings, will be collected 
for analysis 
 
LIFU Procedure. The area surrounding the planned LIFU entry point on the head will be shaved prior to 
positioning in order to minimize the impedance of ultrasound due to air bubbles. Ultrasound gel (aquasonic) 
will be first applied to this region and smoothed in order to remove air pockets. The ultrasound transducer 
will then positioned so that its center lay on the squamous portion of the temporal bone (the thinnest part 
of the human skull) in order to minimize ultrasound scatter and refraction through the bone. A thin layer of 
gel will be applied to the surface of the transducer, and bubbles will be similarly smoothed from this layer. 
The transducer will then be coupled to the head with gel filling any open space between the transducer 
membrane and the scalp with two straps—one horizontal and one vertical—securing the device to the 
patient. Conventional soft foam padding and pillows will be used to further secure the positioning of the 
device and decrease the potential for head motion during the procedure. Next, we will acquired a rapid (95 
s) T1-weighted MPRAGE anatomical image. Using a circular MR fiducial and the visible center of the 
transducer, reference lines will be drawn in the transverse and coronal planes, using the Siemens 3D display 
GUI available as part of the MRI device’s console software to visually locate the target of the LIFU beam 

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in three dimensions. Adjustments to the positioning of the transducer on the head will be made iteratively, 
re-acquiring a T1-weighted MPRAGE at each iteration, until the beam trajectory from the center of the 
transducer is assessed to be in-line with the intended target. 
Statistical Plan and Analysis 
- 
Change in CRS-R related to LIFUP. Maximum CRS-R score prior to LIFUP will be compared 
to the maximum CRS-R score following LIFUP. Behavioral responsiveness in patients was assessed 
using the total score on the CRS-R. Prior to analysis, the highest CRS-R prior-to and following 
LIFUP exposure will be calculated in order to best capture patients’ maximal performance. A 
matched samples T-test analysis will be performed. Where a violation of normality is detected 
(using a Shapiro-Wilk test) a non-parametric Wilcoxon signed rank test will be used to compare 
Pre-LIFUP and Post-LIFUP scores for all patients. 
- 
Change in BOLD signal during LIFUP. Brain BOLD signal during exposure to LIFUP will be 
compared to the brain BOLD signal during inter-stimulation intervals. MRI data preprocessing 
and analysis will be conducted using FSL (FMRIB Software Library v6.0.1) with in-house Bash 
shell scripts. Preprocessing will include brain extraction (using optiBET), spatial smoothing (using 
a Gaussian kernel of 5 mm full-width half-max), slice timing correction (Fourier-space time-series 
phase-shifting), highpass temporal filtering (Gaussian-weighted) at 0.01 Hz, and motion correction 
(MCFLIRT). With the exception of brain extraction, these procedures will be performed in fsl 
FEAT. Following recent data, in-scanner head motion will be mitigated by including in the 
statistical model a number of nuisance regressors, including individual time points with excessive 
motion (i.e., spike regression) derived from the output of fsl FLIRT, head-motion parameters, and 
regressors for white matter and CSF components. White matter and CSF regressors will be 
produced by segmenting T1 images for each patient using FSL Fast (visually inspected for 
accuracy). Tissue segmentations for white matter and CSF will be transformed into functional space 
and binarized (and again visually inspected for accuracy). Time series for white matter and CSF 
will then be extracted from functional images using fslmeants. Framewise displacements for each 
volume will be derived from FSL MCFLIRT and used to exclude unwanted volumes with a 
framewise displacement exceeding 0.5 mm (25% of voxel width). In order to register structural 
images to functional space, we will employ a combination of FSL epi_reg and conventional 12 dof 
linear coregistration (using FSL FLIRT). In order to register structural images to standard space, 
nonlinear registration (FSL FNIRT) will be used. BOLD data collected during LIFUP will first be 
analyzed employing a univariate general linear model (GLM) approach, including pre-whitening 
correction for autocorrelation (FILM). A univariate analysis will be conducted using a single “task” 
regressor, which represents the onset time of 30 s blocks of LIFUP administration. Thus, here the 
“baseline” conditions used will be the inter-sonication periods where no LIFUP is applied. For each 
BOLD sequence, we will compute the contrast LIFUP > Rest. For patients with two LIFU 
exposures, results from the two runs will be averaged at level two prior to third-level analysis. At 
the third level, data will be cluster corrected for multiple comparisons using a familywise cluster 
correction (p < 0.05).   
- 
Structural MRI – Diffusion Tensor Imaging (DTI). The aim of this analysis is to assess any 
changes, in terms of structural connectivity, and in particular thalamo-frontal connectivity, induced 

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by the LIFUP stimulation. Data will be first preprocessed following standard pipelines in the field 
(Behrens et al., 2003b); then, streamlines from thalamus to the whole brain will be calculated, for 
every subject individually, between thalamus and cortex (Behrens et al., 2003a). The streamlines 
will then be entered, the dependent variable, in the group analysis (i.e., the mixed-design 
ANCOVA). This analysis is a direct test of whether thalamo-cortical connectivity is affected (as 
the mesocircuit hypothesis predicts) by our intervention. 
- 
Electroencephalography. This analysis is aimed at assessing whether LIFUP session alters the 
spectral profile of electroencephalographic recordings (EEG). Indeed, it is known that patients at 
different levels of consciousness after severe brain injury exhibit different electrocortical patterns 
(e.g., patients with severe disorder of consciousness exhibit large "delta" -- that is: slow -- waves 
of activity, as compared to the more rapid "alpha" waves typically seen in healthy individuals). 
Data will be preprocessed following previous literature (Lechinger et al., 2013), then for each 
channel we will derive a characterization of each patient’s spectral profile. This information will 
then be entered in the group analysis. 
1. 
Monti MM. Ethics, Neuroimaging and Disorders of Consciousness: What Is the Question? AJOB 
Neuroscience. 2013;4(4):1-2. 
2. 
Monti MM, Laureys S, Owen AM. The vegetative state. BMJ. 2010;341:c3765. Epub 2010/08/04. doi: 
10.1136/bmj.c3765. PubMed PMID: 20679291. 
3. 
Monti MM. Cognition in the vegetative state. Annu Rev Clin Psychol. 2012;8:431-54. Epub 2012/01/10. doi: 
10.1146/annurev-clinpsy-032511-143050. PubMed PMID: 22224835. 
4. 
Jennett B. Thirty years of the vegetative state: clinical, ethical and legal problems. Prog Brain Res. 
2005;150:537-43. Epub 2005/09/28. doi: 10.1016/S0079-6123(05)50037-2. PubMed PMID: 16186047. 
5. 
Gosseries O, Demertzi A, Ledoux D, Bruno MA, Vanhaudenhuyse A, Thibaut A, Laureys S, Schnakers C. 
Burnout in healthcare workers managing chronic patients with disorders of consciousness. Brain Inj. 
2012;26(12):1493-9. Epub 2012/06/26. doi: 10.3109/02699052.2012.695426. PubMed PMID: 22725684. 
6. 
Lutkenhoff ES, McArthur DL, Hua X, Thompson PM, Vespa PM, Monti MM. Thalamic atrophy in antero-
medial and dorsal nuclei correlates with six-month outcome after severe brain injury. Neuroimage Clin. 2013;3:396-
404. Epub 2013/11/26. doi: 10.1016/j.nicl.2013.09.010. PubMed PMID: 24273723; PMCID: 3815017. 
7. 
Monti MM, Lutkenhoff ES, Rubinov M, Boveroux P, Vanhaudenhuyse A, Gosseries O, Bruno MA, 
Noirhomme Q, Boly M, Laureys S. Dynamic change of global and local information processing in propofol-induced 
loss and recovery of consciousness. PLoS Comput Biol. 2013;9(10):e1003271. Epub 2013/10/23. doi: 
10.1371/journal.pcbi.1003271. PubMed PMID: 24146606; PMCID: 3798283. 
8. 
Schiff ND. Recovery of consciousness after brain injury: a mesocircuit hypothesis. Trends Neurosci. 
2010;33(1):1-9. Epub 2009/12/04. doi: 10.1016/j.tins.2009.11.002. PubMed PMID: 19954851; PMCID: 2931585. 
9. 
Schiff ND, Giacino JT, Kalmar K, Victor JD, Baker K, Gerber M, Fritz B, Eisenberg B, Biondi T, O'Connor 
J, Kobylarz EJ, Farris S, Machado A, McCagg C, Plum F, Fins JJ, Rezai AR. Behavioural improvements with thalamic 
stimulation after severe traumatic brain injury. Nature. 2007;448(7153):600-3. Epub 2007/08/03. doi: 
10.1038/nature06041. PubMed PMID: 17671503. 
10. 
Yamamoto T, Katayama Y, Kobayashi K, Kasai M, Oshima H, Fukaya C. DBS therapy for a persistent 
vegetative state: ten years follow-up results. Acta Neurochir Suppl. 2003;87:15-8. Epub 2003/10/02. PubMed PMID: 
14518516. 
11. 
Yamamoto T, Katayama Y, Kobayashi K, Oshima H, Fukaya C, Tsubokawa T. Deep brain stimulation for 
the treatment of vegetative state. Eur J Neurosci. 2010;32(7):1145-51. Epub 2010/11/03. doi: 10.1111/j.1460-
9568.2010.07412.x. PubMed PMID: 21039954. 
12. 
Yamamoto T, Katayama Y, Oshima H, Fukaya C, Kawamata T, Tsubokawa T. Deep brain stimulation 
therapy for a persistent vegetative state. Acta Neurochir Suppl. 2002;79:79-82. Epub 2002/04/27. PubMed PMID: 
11974994. 
13. 
Yamamoto T, Kobayashi K, Kasai M, Oshima H, Fukaya C, Katayama Y. DBS therapy for the vegetative 
state and minimally conscious state. Acta Neurochir Suppl. 2005;93:101-4. Epub 2005/07/01. PubMed PMID: 
15986737. 

7 | P a g e  
 
14. 
Bystritsky A, Korb AS, Douglas PK, Cohen MS, Melega WP, Mulgaonkar AP, DeSalles A, Min BK, Yoo 
SS. A review of low-intensity focused ultrasound pulsation. Brain Stimul. 2011;4(3):125-36. Epub 2011/07/23. doi: 
10.1016/j.brs.2011.03.007. PubMed PMID: 21777872. 
15. 
Legon W, Sato TF, Opitz A, Mueller J, Barbour A, Williams A, Tyler WJ. Transcranial focused ultrasound 
modulates the activity of primary somatosensory cortex in humans. Nat Neurosci. 2014;17(2):322-9. Epub 
2014/01/15. doi: 10.1038/nn.3620. PubMed PMID: 24413698. 
16. 
Tufail Y, Yoshihiro A, Pati S, Li MM, Tyler WJ. Ultrasonic neuromodulation by brain stimulation with 
transcranial ultrasound. Nat Protoc. 2011;6(9):1453-70. Epub 2011/09/03. doi: 10.1038/nprot.2011.371. PubMed 
PMID: 21886108. 
17. 
Deffieux T, Younan Y, Wattiez N, Tanter M, Pouget P, Aubry JF. Low-intensity focused ultrasound 
modulates 
monkey 
visuomotor 
behavior. 
Curr 
Biol. 
2013;23(23):2430-3. 
Epub 
2013/11/19. 
doi: 
10.1016/j.cub.2013.10.029. PubMed PMID: 24239121. 
18. 
Tufail Y, Matyushov A, Baldwin N, Tauchmann ML, Georges J, Yoshihiro A, Tillery SI, Tyler WJ. 
Transcranial pulsed ultrasound stimulates intact brain circuits. Neuron. 2010;66(5):681-94. Epub 2010/06/16. doi: 
10.1016/j.neuron.2010.05.008. PubMed PMID: 20547127. 
19. 
Giacino JT, Kalmar K, Whyte J. The JFK Coma Recovery Scale-Revised: measurement characteristics and 
diagnostic utility. Arch Phys Med Rehabil. 2004;85(12):2020-9. Epub 2004/12/18. doi: 10.1016/j.apmr.2004.02.033. 
PubMed PMID: 15605342.