Please find a collection of peer-reviewed medical journal articles below supporting the concept of jugular compression for minimizing the risk of mild TBIs in various situations. The control numbers are the date of publication in the form YYMMDD, and the articles are presented in latest published to oldest…

Myer 2018 BJSM Altered brain microstructure in association with repetitive subconcussive head impacts and the potential protective effect of jugular vein compression (180903)

180903 | Myer 2018 BJSM Altered brain microstructure in association with repetitive subconcussive head impacts and the potential protective effect of jugular vein compression: a longitudinal study of female soccer athletes

ABSTRACT: Purpose To (1) quantify white matter (WM) alterations in female high school athletes during a soccer season and characterise the potential for normalisation during the off-season rest period, (2) determine the association between WM alterations and exposure to repetitive subconcussive head impacts, and (3) evaluate the efficacy of a jugular vein compression collar to prevent WM alterations associated with head impact exposure.

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Red Blood Cell Response to Blast Levels of Force Impartations Into Freely Moveable Fluid Surfaces Inside a Closed Container (180621)

180621 | Frontiers in Physics | David Smith, Robert Franco, Christopher A. DiCesare, Daniel K. Schneider, ChuckMcGill,QuintonD.Smith, and GregoryD.Myer

BACKGROUND: Blast waves have plagued mankind for centuries, yet their interaction with blood has been largely overlooked. Recent studies of ways to mitigate traumatic brain injury (TBI) in sport have utilized slosh-reducing techniques with varying success. However, hydrodynamic principles have not been used to assess the interaction of intense blast waves and the red blood cells themselves. | Conclusions: Damage to human blood resulting from the impartation of a force similar to an IED blast was mitigated by fully containing blood within a volume and thereby reducing fluid slosh.

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White Matter Alterations Over the Course of Two Consecutive High-School Football Seasons and the Effect of a Jugular Compression Collar: A Preliminary Longitudinal Diffusion Tensor Imaging Study (171016)

171016 | Human Brain Mapping 00:00–00 (2017) | Weihong Yuan , Kim D. Barber Foss, Staci Thomas, Christopher A. DiCesare, Jonathan A. Dudley, Katie Kitchen, Brooke Gadd, James L. Leach, David Smith, Mekibib Altaye, Paul Gubanich, Ryan T. Galloway, Paul McCrory, Julian E. Bailes, Rebekah Mannix, William P. Meehan III, and Gregory D. Myer

ABSTRACT: The cumulative effects of repetitive subclinical head impacts during sports may result in chronic white matter (WM) changes and possibly, neurodegenerative sequelae. In this pilot study, we investigated the longitudinal WM changes over the course of two consecutive high-school football sea- sons and explored the long-term effects of a jugular vein compression collar on these WM alterations. Diffusion tensor imaging data were prospectively collected both pre- and postseason in the two consecutive seasons. Participants were assigned into either collar or noncollar groups. Tract-based spatial statistics (TBSS) approach and region of interest-based approach were used to quantify changes in WM diffusion properties. Despite comparable exposure to repetitive head impacts, significant reductions in mean, axial, and/or radial diffusivity were identified in Season 1 in multiple WM regions in the noncollar group but not in the collar group. After an 8- to 9-month long off-season, these changes observed in the noncollar group partially and significantly reversed but also remained significantly different from the baseline. In Season 2, trend level WM alterations in the noncollar group were found but located in spatially different regions than Season 1. Last, the WM integrity in the collar group remained unchanged throughout the four time points. In conclusion, we quantitatively assessed the WM structural changes and partial reversal over the course of two consecutive high-school football seasons. In addition, the mitigated WM alterations in athletes in the collar group might indicate potential effect of the collar in ameliorating the changes against repetitive head impacts. Hum Brain Mapp 00:000–000, 2017. VC 2017 Wiley Periodicals, Inc.

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Internal jugular vein blood flow in the upright position during external compression and increased central venous pressure: an ultrasound study in healthy volunteers (170515)

170515 | Canadian Journal of Anesthesiologists | Tze Yeng Yeoh, MBChB, MMed (Anaes) . Lashmi Venkatraghavan, MD, FRCA, FRCPC . Joseph A. Fisher, MD . Massimiliano Meineri, MD

ABSTRACT | BACKGROUND: External compression of the jugular veins is an effective method to increase intracranial blood volume and brain stiffness in rats and healthy volunteers. It has been reported that, on assuming an upright posture, cerebral venous drainage is distributed away from the internal jugular veins (IJVs) to the cervical venous plexus, causing complete collapse of the IJV. If so, it is not clear why external IJV compression would increase intracranial blood volume, but the latter is frequently observed in neurosurgery in the sitting position. The aim of this study was to observe the effect of external IJV compression and the Valsalva maneuver on the change in IJV cross- sectional area and IJV flow in volunteers in the upright posture. | Conclusions Compression of the internal jugular veins or an increase in intrathoracic pressure does not reduce venous drainage but actually may increase intracranial venous volume.

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Effect of Internal Jugular Vein Compression on Intracranial Hemorrhage in a Porcine Controlled Cortical Impact Model (170415)

170415 | JOURNAL OF NEUROTRAUMA | Brian Sindelar, Julian Bailes, Sydney Sherman, John Finan, James Stone, John Lee, Saman Ahmadian, Ying Zhou, Vimal Patel, and David Smith

ABSTRACT: Internal jugular vein (IJV) compression has been shown to reduce axonal injury in pre-clinical traumatic brain injury (TBI) models and clinical concussion studies. However, this novel approach to prophylactically mitigating TBI through venous congestion raises concerns of increasing the propensity for hemorrhage and hemorrhagic propagation. This study aims to test the safety of IJV compression in a large animal controlled cortical impact (CCI) injury model and the resultant effects on hemorrhage. Twelve swine were randomized to placement of a bilateral IJV compression collar (CCI+collar) or control/no collar (CCI) prior to CCI injury. A histological grading of the extent of hemorrhage, both subarachnoid (SAH) and intraparenchymal (IPH), was conducted in a blinded manner by two neuropathologists. Other various measures of TBI histology were also analyzed including: b-amyloid precursor protein (b-APP) expression, presence of degenerating neurons, extent of cerebral edema, and inflammatory infiltrates. Euthanized 5h after injury, the CCI+collar animals exhibited a significant reduction in total SAH ( p = 0.024–0.026) and IPH scores ( p = 0.03-0.05) compared with the CCI animals. There was no statistically significant difference in scoring for the other markers of TBI (b-APP, neuronal degeneration, cerebral edema, or inflammatory infiltration). In conclusion, IJV compression was shown to reduce hemorrhage (SAH and IPH) in the porcine CCI model when applied prior to injury. These results suggest the role of IJV compression for mitigation of not only axonal, but also hemorrhagic injury following TBI.

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Protection against Blast-Induced Traumatic Brain Injury by Increase in Brain Volume (170410)

170410 | Protection against Blast-Induced Traumatic Brain Injury by Increase in Brain Volume | BioMed Research International | Ming Gu, Usmah Kawoos, Richard McCarron, and Mikulas Chavk

Blast-induced traumatic brain injury (bTBI) is a leading cause of injuries in recent military conflicts and it is responsible for an increased number of civilian casualties by terrorist attacks. bTBI includes a variety of neuropathological changes depending on the intensity of blast overpressure (BOP) such as brain edema, neuronal degeneration, diffuse axonal damage, and vascular dysfunction with neurological manifestations of psychological and cognitive abnormalities. Internal jugular vein (IJV) compression is known to reduce intracranial compliance by causing an increase in brain volume and was shown to reduce brain damage during closed impact-induced TBI. We investigated whether IJV compression can attenuate signs of TBI in rats after exposure to BOP. Animals were exposed to three 110 ± 5 kPa BOPs separated by 30 min intervals. Exposure to BOP resulted in a significant decrease of neuronal nuclei (NeuN) together with upregulation of aquaporin-4 (AQP-4), 3-nitrotyrosine (3-NT), and endothelin 1 receptor A (ETRA) expression in frontal cortex and hippocampus one day following exposures. IJV compression attenuated this BOP-induced increase in 3-NT in cortex and ameliorated the upregulation of AQP-4 in hippocampus. These results suggest that elevated intracranial pressure and intracerebral volume have neuroprotective potential in blast-induced TBI.

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Internal Jugular Vein Compression: A Novel Approach to Mitigate Blast Induced Hearing Injury (170400)

170400 | Otology & Neurotology: April 2017 – Volume 38 – Issue 4 – p 591–598 | Sindelar, Brian; Shinners, Michael; Sherman, Sydney; Novak, Kevin; Erickson, Kristine; Patel, Vimal; Kubilis, Paul; Smith, David; Finan, John; Bailes, Julian E.

HYPOTHESIS: Internal jugular vein (IJV) compression before blast injury will lead to reduced risk of traumatic hearing injury following exposure to a blast injury.
BACKGROUND: IJV compression and its effects on not only intracranial, but also intracochlear pressure may potentiate blast induced hearing injury, therefore, precluding its use as a prophylactic therapy for blast induced traumatic brain injury. Conclusion: This study supports the use of IJV compression in a pre-clinical model as a new prophylactic mechanism to combat blast induced hearing injury.

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The Effects of External Jugular Compression Applied during High Intensity Power, Strength and Postural Control Tasks (170131)

170131 | Current Research Concussion 2017; 04(01): e23-e31 DOI: 10.1055/s-0037-1606580 | Christopher A. DiCesare, MS Kim D. Barber Foss, MS, ATC Staci Thomas, MS Daniel K. Schneider, BS Nicholas M. Edwards, MD, MPH Gregory D. Myer, PhD

ABSTRACT: Current strategies focused on mitigating concussion in sport have demonstrated limited effectiveness. There is a paucity of research on the optimization of intracranial brain dynamics to mitigate concussion; in the present study, we investigate a novel device that provides mild jugular vein compression and may provide adjunctive protection to protect the brain internally from concussive and sub-concussive impacts. The purpose of this study was to assess the tolerance and acceptance of this device in a population of normal, healthy adults undergoing exertion similar to that is experienced while participating in sports-related competition, while monitoring changes in their biomechanical, strength, power, and postural stability capabilities.

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Neck Collar with Mild Jugular Vein Compression Ameliorates Brain Activation Changes during a Working Memory Task after a Season of High School Football (170000)

170000 | Journal of Neurotrauma | Yuan W; Leach J; Maloney T; Altaye M; Smith D; Gubanich PJ; Barber Foss KD; Thomas S; DiCesare CA; Kiefer AW; Myer GD

Emerging evidence indicates that repetitive head impacts, even at a sub-concussive level, may result in exacerbated or prolonged neurological deficits in athletes. This study aimed to: 1) quantify the effect of repetitive head impacts on the alteration of neuronal activity based on functional magnetic resonance imaging (fMRI) of working memory after a high school football season; and 2) determine whether a neck collar that applies mild jugular vein compression designed to reduce brain energy absorption in head impact through “slosh” mitigation can ameliorate the altered fMRI activation during a working memory task. Participants were recruited from local high school football teams with 27 and 25 athletes assigned to the non-collar and collar group, respectively. A standard N-Back task was used to engage working memory in the fMRI at both pre- and post-season. The two study groups experienced similar head impact frequency and magnitude during the season (all p > 0.05). fMRI blood oxygen level dependent (BOLD) signal response (a reflection of the neuronal activity level) during the working memory task increased significantly from pre- to post-season in the non-collar group (corrected p < 0.05), but not in the collar group. Areas displaying less activation change in the collar group (corrected p < 0.05) included the precuneus, inferior parietal cortex, and dorsal lateral prefrontal cortex. Additionally, BOLD response in the non-collar group increased significantly in direct association with the total number of impacts and total g-force (p < 0.05). Our data provide initial neuroimaging evidence for the effect of repetitive head impacts on the working memory related brain activity, as well as a potential protective effect that resulted from the use of the purported brain slosh reducing neck collar in contact sports.

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Current state of concussion prevention strategies: a systematic review and meta-analysis of prospective, controlled studies (161223)

161223 | British Journal of Sports Medicine | Schneider DK, et al. Br J Sports Med 2016;0:1–11. doi:10.1136/bjsports-2015-095645 | Daniel K Schneider, Ravi K Grandhi, Purnima Bansal, George E Kuntz IV, Kate E Webster, Kelsey Logan, Kim D Barber Foss, Gregory D Myer

ABSTRACT | OBJECTIVE: The aim of the current review was to systematically identify, evaluate and synthesise trials that examine concussion prevention via equipment, educational programmes and training programmes. | Conclusions | Prospective controlled studies indicate that certain protective equipment may prevent superficial head injury, but these items are suboptimal for concussion prevention in sport.

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The effects of external Jugular compression applied during head impact exposure on longitudinal changes in Brain neuroanatomical and neurophysiological Biomarkers: a Preliminary investigation (160606)

160606 | Frontiers in Neurology | June 2016 | Volume 7 | Article 74 | Gregory D. Myer, Weihong Yuan, Kim D. Barber Foss, David Smith, Mekibib Altaye, Amit Reches, James Leach, Adam W. Kiefer, Jane C. Khoury, Michal Weiss, Staci Thomas, Chris Dicesare, Janet Adams, Paul J. Gubanich, Amir Geva, Joseph F. Clark, William P. Meehan III, Jason P. Mihalik and Darcy Krueger

OBJECTIVES: Utilize a prospective in vivo clinical trial to evaluate the potential for mild neck compression applied during head impact exposure to reduce anatomical and physiological biomarkers of brain injury. Conclusion: Group differences in the longitudinal changes in both neuroanatomical and electrophysiological measures, as well as the correlation between the measures, provide initial evidence indicating that mild jugular vein compression may have reduced alterations in the WM response to head impacts during a competitive hockey season. The data indicate sport-related alterations in WM microstructure were ameliorated by application of jugular compression during head impact exposure. These results may lead to a novel line of research inquiry to evaluate the effects of protecting the brain from sports-related head impacts via optimized intracranial fluid dynamics.

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Analysis of head impact exposure and brain microstructure response in a season-long application of a jugular vein compression collar: a prospective, neuroimaging investigation in American football (160521)

160521 | British Journal of Sports Medicine | Myer GD, et al. Br J Sports Med 2016;0:1–11. doi:10.1136/bjsports-2016-096134 | Gregory D Myer, Weihong Yuan, Kim D Barber Foss, Staci Thomas, David Smith, James Leach, Adam W Kiefer, Chris Dicesare, Janet Adams, Paul J Gubanich, Katie Kitchen, Daniel K Schneider, Daniel Braswell, Darcy Krueger, Mekibib Altaye

ABSTRACT | BACKGROUND: Historical approaches to protect the brain from outside the skull (eg, helmets and mouthpieces) have been ineffective in reducing internal injury to the brain that arises from energy absorption during sports- related collisions. We aimed to evaluate the effects of a neck collar, which applies gentle bilateral jugular vein compression, resulting in cerebral venous engorgement to reduce head impact energy absorption during collision. Specifically, we investigated the effect of collar wearing during head impact exposure on brain microstructure integrity following a competitive high school American football season. Conclusions | The data evaluated in the current project indicate that the device is safe during high intensity and dynamic postural stabilization exercise and does not alter normal physical or neuromuscular capabilities during physical activity.

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MR Elastography Can Be Used to Measure Brain Stiffness Changes as a Result of Altered Cranial Venous Drainage During Jugular Compression (151000)

151000 | American Journal of Neurological Research | American Journal of Neuroradiology October 2015, 36 (10) 1971-1977; DOI: https://doi.org/10.3174/ajnr.A4361 | A. Hatt, S. Cheng, X K. Tan, R. Sinkus, and L.E. Bilston

ABSTRACT | BACKGROUND AND PURPOSE: Compressing the internal jugular veins can reverse ventriculo-megalyinthe syndrome of inappropriately low pressure acute hydrocephalus, and it has been suggested that this works by “stiffening” the brain tissue. Jugular compression may also alter blood and CSF flow in other conditions. We aimed to understand the effect of jugular compression on brain tissue stiffness and CSF flow. CONCLUSIONS: Jugular compression influences cerebral CSF hydrodynamics in healthy subjects and can increase brain tissue stiffness, but the magnitude of the stiffening depends on the percentage of cranial blood draining through the internal jugular veins during compression—that is, subjects who maintain venous drainage through the internal jugular veins during jugular compression have stiffer brains than those who divert venous blood through alternative pathways. These methods may be useful for studying this phenomenon in patients with the syndrome of inappropriately low-pressure acute hydrocephalus and other conditions.

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The effect of jugular vein compression on cerebral hemodynamics in healthy subjects (150700)

150700 |Joseph A. Fisher M.D., James Duffin PhD., David Mikulis M.D., Olivia Sobczyk MSc., PhD (candidate)

Introduction. As upright animals, the human brain is high above the level of the heart resulting in low intracranial venous pressures. Indeed, air can be sucked into the venous sinuses during neurosurgery. This low pressure also indicates that there is room for the vessels to expand, or the presence of a capacitance for volume. It has been recently proposed that intracranial volume being less than skull volume allows the brain to be to be mobile inside the skull. In the presence of head trauma the brain may move relative to, and collide with, the skull (“rattle”) or be internally deformed by pressure waves (“slosh”), resulting in traumatic brain injury. Both mechanisms can be mitigated, or eliminated by increasing the intra-cranial compartment volume, forcing all parts of the brain and skull to move as a unit. In addition, if the intracranial volume fills the skull, the brain will conduct blast energy waves through with minimal energy absorption by the brain, avoiding tissue displacement and shear. It has been proposed that a way to expand the intracranial volume is to fill it with venous blood. Since the brain blood flow is large, a small degree of resistance to drainage will quickly fill the cerebrovascular compliance. The major route of venous drainage in humans is via the internal jugular veins (IJV). In contrast, most quadrupeds have their head at near heart level and the vertebral venous plexi are the main venous outflow conduits (Lavoie et al., 2008). Therefore, studies of the effects of jugular venous compression on brain blood flow and intracranial blood distribution must be performed in humans. Summary of findings: Compression of the internal jugular veins in supine healthy volunteers… | 1) …increases in blood volume in the skull with venous blood distributed particularly to the large venous sinuses. A small increase in BOLD signal seen in the middle cerebral artery and cerebellum indicate the possibility of a slightly increased cerebral blood flow or the accumulation of arterial blood diffusely as well. | 2) …does not change the level or distribution of the resting blood flow in the brain. | 3) …does not affect the response of the brain blood flow to hypercapnia. This implies that it would not affect the brain blood flow in response to an increase in metabolic demand. | 4) …does not reduce the CBF if applied during an increase in demand, as occurs in this study during hypercapnia. This finding provides confidence that the brain would be able to maintain CBF if the collar is applied under other high flow demand states such as exercise.

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Altitude Modulates Concussion Incidence: Implications for Optimizing Brain Compliance to Prevent Brain Injury in Athletes (140509)

140509 | The Orthopaedic Journal of Sports Medicine | David W. Smith, MD, Gregory D. Myer, Dustin W. Currie, MPH, R. Dawn Comstock, PhD, Joseph F. Clark, PhD, and Julian E. Bailes, MD

BACKGROUND: Recent research indicates that the volume and/or pressure of intracranial fluid, a physiology affected by one’s altitude (ie, elevation above sea level), may be associated with the likelihood and/or severity of a concussion. The objective was to employ an epidemiological field investigation to evaluate the relationship between altitude and concussion rate in high school sports. | Conclusion: The results of this epidemiological investigation indicate increased physiological responses to altitude may be associated with a reduction in sports-related concussion rates, especially in collision sports. Future research that focuses on the potential prophy- lactic effect of optimizing outflow impedance and thus reduction of intracranial compliance (a ‘‘tighter fit’’) in humans is warranted to determine the most effective approaches to mitigate sport-related concussion, especially in football players.

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Rates of concussion are lower in National Football League games played at higher altitudes (140100)

140100 | Journal of Orthopaedic and Sports Physical Therapy 2014, 44 (3): 164-72 | GREGORY D. MYER, PhD, FACSM, CSCS*D • DAVID SMITH, MD • KIM D. BARBER FOSS, MS, ATC, LAT CHRISTOPHER A. DICESARE, MS, CSCS • ADAM W. KIEFER, PhD • ADAM M. KUSHNER, BS, CSCS STACI M. THOMAS, MS • HEIDI SUCHAREW, PhD • JANE C. KHOURY, PhD

OBJECTIVE: To investigate the relationship between altitude and concussion rate in the National Football League (NFL). Because of the physiologic responses that occur during acclimatization to altitude, it was hypothesized that games played on fields at a higher altitude would have reduced concussion rates compared to games played on fields at a lower altitude. CONCLUSION: The results of this epidemiological investigation indicate that increased altitude was associated with a reduction in the odds of a sport-related concussion in NFL athletes. The reported relationship of concussion incidence and field elevation should be further investigated, and, if verified, further work will be needed to understand why that relationship exists.

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Effect of slosh mitigation on histologic markers of traumatic brain injury (121200)

121200 | Journal of Neurosurgery / Volume 117 / December 2012 | RYAN C. TURNER, B.S., ZACHARY J. NASER, B.A., JULIAN E. BAILES, M.D., DAVID W. SMITH, M.D., JOSEPH A. FISHER, M.D., AND CHARLES L. ROSEN, M.D., PH.D.

Object. Helmets successfully prevent most cranial fractures and skull traumas, but traumatic brain injury (TBI) and concussions continue to occur with frightening frequency despite the widespread use of helmets on the athletic field and battlefield. Protection against such injury is needed. The object of this study was to determine if slosh mitigation reduces neural degeneration, gliosis, and neuroinflammation.

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Internal Jugular Vein Compression Mitigates Traumatic Axonal Injury in a Rat Model by Reducing the Intracranial Slosh Effect (110905)

110905 | Neurosurgery, Volume 70, Issue 3, 1 March 2012, Pages 740–746 | David W. Smith, MD Julian E. Bailes, MD Joseph A. Fisher, MD Javier Robles, MD Ryan C. Turner, BS James D. Mills, MD

ABSTRACT | BACKGROUND: Traumatic brain injury (TBI) remains a devastating condition for which extracranial protection traditionally has been in the form of helmets, which largely fail to protect against intracranial injury. Objective: To determine whether the pathological outcome after traumatic brain injury can be improved via slosh mitigation by internal jugular vein (IJV) compression. Conclusion: Using a standard acceleration-deceleration laboratory model of mild traumatic brain injury, we have shown successful prevention of axonal injury after IJV compression as indicated by immunohistochemical staining of amyloid precursor protein. We argue that IJV compression reduces slosh-mediated brain injury by increasing intracranial blood volume, which can be indirectly measured by intracranial and intraocular pressures.

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