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Green TRF, Carey SD, Mannino G, Craig JA, Rowe RK, Zielinski MR. Sleep, inflammation, and hemodynamics in rodent models of traumatic brain injury. Front Neurosci 2024; 18:1361014. [PMID: 38426017 PMCID: PMC10903352 DOI: 10.3389/fnins.2024.1361014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Accepted: 01/29/2024] [Indexed: 03/02/2024] Open
Abstract
Traumatic brain injury (TBI) can induce dysregulation of sleep. Sleep disturbances include hypersomnia and hyposomnia, sleep fragmentation, difficulty falling asleep, and altered electroencephalograms. TBI results in inflammation and altered hemodynamics, such as changes in blood brain barrier permeability and cerebral blood flow. Both inflammation and altered hemodynamics, which are known sleep regulators, contribute to sleep impairments post-TBI. TBIs are heterogenous in cause and biomechanics, which leads to different molecular and symptomatic outcomes. Animal models of TBI have been developed to model the heterogeneity of TBIs observed in the clinic. This review discusses the intricate relationship between sleep, inflammation, and hemodynamics in pre-clinical rodent models of TBI.
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Affiliation(s)
- Tabitha R. F. Green
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, United States
| | - Sean D. Carey
- Veterans Affairs (VA) Boston Healthcare System, West Roxbury, MA, United States
- Department of Psychiatry, Harvard Medical School, West Roxbury, MA, United States
| | - Grant Mannino
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, United States
| | - John A. Craig
- Veterans Affairs (VA) Boston Healthcare System, West Roxbury, MA, United States
| | - Rachel K. Rowe
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, United States
| | - Mark R. Zielinski
- Veterans Affairs (VA) Boston Healthcare System, West Roxbury, MA, United States
- Department of Psychiatry, Harvard Medical School, West Roxbury, MA, United States
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2
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Green TR, Nguyen T, Dunker V, Ashton D, Ortiz JB, Murphy SM, Rowe RK. Blood-Brain Barrier Dysfunction Predicts Microglial Activation After Traumatic Brain Injury in Juvenile Rats. Neurotrauma Rep 2024; 5:95-116. [PMID: 38404523 PMCID: PMC10890961 DOI: 10.1089/neur.2023.0057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2024] Open
Abstract
Traumatic brain injury (TBI) disrupts the blood-brain barrier (BBB), which may exacerbate neuroinflammation post-injury. Few translational studies have examined BBB dysfunction and subsequent neuroinflammation post-TBI in juveniles. We hypothesized that BBB dysfunction positively predicts microglial activation and that vulnerability to BBB dysfunction and associated neuroinflammation are dependent on age at injury. Post-natal day (PND)17 and PND35 rats (n = 56) received midline fluid percussion injury or sham surgery, and immunoglobulin-G (IgG) stain was quantified as a marker of extravasated blood in the brain and BBB dysfunction. We investigated BBB dysfunction and the microglial response in the hippocampus, hypothalamus, and motor cortex relative to age at injury and days post-injury (DPI; 1, 7, and 25). We measured the morphologies of ionized calcium-binding adaptor molecule 1-labeled microglia using cell body area and perimeter, microglial branch number and length, end-points/microglial cell, and number of microglia. Data were analyzed using generalized hierarchical models. In PND17 rats, TBI increased levels of IgG compared to shams. Independent of age at injury, IgG in TBI rats was higher at 1 and 7 DPI, but resolved by 25 DPI. TBI activated microglia (more cells and fewer end-points) in PND35 rats compared to respective shams. Independent of age at injury, TBI induced morphological changes indicative of microglial activation, which resolved by 25 DPI. TBI rats had fewer cells and end-points per cell at 1 and 7 DPI than 25 DPI. Independent of TBI, PND17 rats had larger, more activated microglia than PND35 rats; PND17 TBI rats had larger cell body areas and perimeters than PND35 TBI rats. Importantly, we found support in both ages that IgG quantification predicted microglial activation after TBI. The number of microglia increased with increasing IgG, whereas branch length decreased with increasing IgG, which together indicate microglial activation. Our results suggest that stabilization of the BBB after pediatric TBI may be an important therapeutic strategy to limit neuroinflammation and promote recovery.
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Affiliation(s)
- Tabitha R.F. Green
- Department of Integrative Physiology, University of Colorado Boulder, Colorado, USA
| | - Tina Nguyen
- Department of Integrative Physiology, University of Colorado Boulder, Colorado, USA
| | - Veronika Dunker
- Department of Integrative Physiology, University of Colorado Boulder, Colorado, USA
| | - Danielle Ashton
- Department of Integrative Physiology, University of Colorado Boulder, Colorado, USA
| | - J. Bryce Ortiz
- Department of Child Health, University of Arizona College of Medicine–Phoenix, Arizona, USA
| | - Sean M. Murphy
- Cumberland Biological and Ecological Researchers, Longmont, Colorado, USA
| | - Rachel K. Rowe
- Department of Integrative Physiology, University of Colorado Boulder, Colorado, USA
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3
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Galindo EJ, Flores RR, Mejia-Alvarez R, Willis AM, Tartis MS. Simultaneous High-Frame-Rate Acoustic Plane-Wave and Optical Imaging of Intracranial Cavitation in Polyacrylamide Brain Phantoms during Blunt Force Impact. Bioengineering (Basel) 2024; 11:132. [PMID: 38391618 DOI: 10.3390/bioengineering11020132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/20/2024] [Accepted: 01/25/2024] [Indexed: 02/24/2024] Open
Abstract
Blunt and blast impacts occur in civilian and military personnel, resulting in traumatic brain injuries necessitating a complete understanding of damage mechanisms and protective equipment design. However, the inability to monitor in vivo brain deformation and potential harmful cavitation events during collisions limits the investigation of injury mechanisms. To study the cavitation potential, we developed a full-scale human head phantom with features that allow a direct optical and acoustic observation at high frame rates during blunt impacts. The phantom consists of a transparent polyacrylamide material sealed with fluid in a 3D-printed skull where windows are integrated for data acquisition. The model has similar mechanical properties to brain tissue and includes simplified yet key anatomical features. Optical imaging indicated reproducible cavitation events above a threshold impact energy and localized cavitation to the fluid of the central sulcus, which appeared as high-intensity regions in acoustic images. An acoustic spectral analysis detected cavitation as harmonic and broadband signals that were mapped onto a reconstructed acoustic frame. Small bubbles trapped during phantom fabrication resulted in cavitation artifacts, which remain the largest challenge of the study. Ultimately, acoustic imaging demonstrated the potential to be a stand-alone tool, allowing observations at depth, where optical techniques are limited.
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Affiliation(s)
- Eric J Galindo
- Department of Chemical Engineering, New Mexico Institute of Mining and Technology, Socorro, NM 87801, USA
| | - Riley R Flores
- Department of Chemical Engineering, New Mexico Institute of Mining and Technology, Socorro, NM 87801, USA
| | - Ricardo Mejia-Alvarez
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI 48824, USA
| | - Adam M Willis
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI 48824, USA
- 59th Medical Wing, Office of the Chief Scientist, Lackland AFB, San Antonio, TX 78236, USA
| | - Michaelann S Tartis
- Department of Chemical Engineering, New Mexico Institute of Mining and Technology, Socorro, NM 87801, USA
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4
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Buchholzer S, Aymon R, Becker M, Scolozzi P. Does the type of craniomaxillofacial fracture (CMF) differ between patients with intracranial hemorrhage (ICH) and those with blunt cerebrovascular injury (BCVI)? A retrospective study. J Craniomaxillofac Surg 2023; 51:740-745. [PMID: 37643933 DOI: 10.1016/j.jcms.2023.08.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/31/2023] [Accepted: 08/14/2023] [Indexed: 08/31/2023] Open
Abstract
The purpose of the present study was to investigate and compare craniomaxillofacial fracture (CMF) type in patients with intracranial hemorrhage (ICH) versus blunt cerebrovascular injury (BCVI). A retrospective cohort study was performed. The predictor variables were the types of CMF. The primary outcomes variables were ICH and BCVI. Secondary outcomes were death and survival with or without neurological sequelae. Descriptive, bivariate, and multiple logistic regression statistics were computed, and the significance level was set at P ≤ 0.05. The sample was composed of 1440 patients with a mean age of 46.6 years ±24 years, and 71% were men. Pure orbital wall (odds ratio [OR]), 3.62; 95% confidence interval [CI], 1.32-12.69; P < 0.022), Le Fort III (OR, 16.08; 95% CI, 5.89-43.50; P < 0.001), cranial vault (OR, 9.74; 95% CI, 3.83.24.32; P < 0.001), skull base (OR, 9.42; 95% CI, 3.86-24.02; P < 0.001) and cervical fractures (OR, 5.50; 95% CI, 1.65-15.97; P = 0.003) were significantly associated with BCVI. All of the CMFs (P < 0.001), except for Le Fort I (OR, 0.79; 95% CI, 0.18-2.63; P = 0.731), nasal (OR, 1.05; 95% CI, 0.77-1.42; P = 0.758), and mandibular (OR, 0.68; 95% CI, 0.45-1.01; P = 0.066) fractures, were significantly associated with ICH. Secondary outcomes were negatively influenced by ICH and BCVI (P < 0.001). Within the limitations of the study it seems that Le Fort I and nasal fractures could be protective of cerebrovascular injuries, by cushioning impact forces. On the other hand it seems that patients with pure orbital wall, Le Fort III and cranio-cervical fractures are more prone to having concomitant life-threatening cerebrovascular injuries. This category of patients should have an immediate and comprehensive neurological assessment and CT angiography to rule out BCVI and to determine its severity.
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Affiliation(s)
- Samanta Buchholzer
- Division of Oral and Maxillofacial Surgery, Department of Surgery, University of Geneva & University Hospitals of Geneva, Geneva, Switzerland
| | - Romain Aymon
- Division of Oral and Maxillofacial Surgery, Department of Surgery, Faculty of Medicine, University of Geneva & University Hospitals of Geneva, Geneva, Switzerland
| | - Minerva Becker
- Division of Radiology, Department of Imaging and Medical Informatics, University of Geneva & University Hospitals of Geneva, Geneva, Switzerland
| | - Paolo Scolozzi
- Division of Oral and Maxillofacial Surgery, Department of Surgery, Faculty of Medicine, University of Geneva & University Hospitals of Geneva, Geneva, Switzerland.
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Davidson CG, Woodford SJ, Mathur S, Valle DB, Foster D, Kioutchoukova I, Mahmood A, Lucke-Wold B. Investigation into the vascular contributors to dementia and the associated treatments. EXPLORATION OF NEUROSCIENCE 2023; 2:224-237. [PMID: 37981945 PMCID: PMC10655228 DOI: 10.37349/en.2023.00023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 09/20/2023] [Indexed: 11/21/2023]
Abstract
As the average lifespan has increased, memory disorders have become a more pressing public health concern. However, dementia in the elderly population is often neglected in light of other health priorities. Therefore, expanding the knowledge surrounding the pathology of dementia will allow more informed decision-making regarding treatment within elderly and older adult populations. An important emerging avenue in dementia research is understanding the vascular contributors to dementia. This review summarizes potential causes of vascular cognitive impairment like stroke, microinfarction, hypertension, atherosclerosis, blood-brain-barrier dysfunction, and cerebral amyloid angiopathy. Also, this review address treatments that target these vascular impairments that also show promising results in reducing patient's risk for and experience of dementia.
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Affiliation(s)
| | | | - Shreya Mathur
- College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | | | - Devon Foster
- University of Central Florida, Orlando, FL 32816, USA
| | | | - Arman Mahmood
- College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Brandon Lucke-Wold
- Department of Neurosurgery, University of Florida, Gainesville, FL 32610, USA
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6
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Rosen G, Kirsch D, Horowitz S, Cherry JD, Nicks R, Kelley H, Uretsky M, Dell'Aquila K, Mathias R, Cormier KA, Kubilus CA, Mez J, Tripodis Y, Stein TD, Alvarez VE, Alosco ML, McKee AC, Huber BR. Three dimensional evaluation of cerebrovascular density and branching in chronic traumatic encephalopathy. Acta Neuropathol Commun 2023; 11:123. [PMID: 37491342 PMCID: PMC10369801 DOI: 10.1186/s40478-023-01612-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 06/28/2023] [Indexed: 07/27/2023] Open
Abstract
Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with exposure to repetitive head impacts (RHI) and characterized by perivascular accumulations of hyperphosphorylated tau protein (p-tau) at the depths of the cortical sulci. Studies of living athletes exposed to RHI, including concussive and nonconcussive impacts, have shown increased blood-brain barrier permeability, reduced cerebral blood flow, and alterations in vasoreactivity. Blood-brain barrier abnormalities have also been reported in individuals neuropathologically diagnosed with CTE. To further investigate the three-dimensional microvascular changes in individuals diagnosed with CTE and controls, we used SHIELD tissue processing and passive delipidation to optically clear and label blocks of postmortem human dorsolateral frontal cortex. We used fluorescent confocal microscopy to quantitate vascular branch density and fraction volume. We compared the findings in 41 male brain donors, age at death 31-89 years, mean age 64 years, including 12 donors with low CTE (McKee stage I-II), 13 with high CTE (McKee stage III-IV) to 16 age- and sex-matched non-CTE controls (7 with RHI exposure and 9 with no RHI exposure). The density of vessel branches in the gray matter sulcus was significantly greater in CTE cases than in controls. The ratios of sulcus versus gyrus vessel branch density and fraction volume were also greater in CTE than in controls and significantly above one for the CTE group. Hyperphosphorylated tau pathology density correlated with gray matter sulcus fraction volume. These findings point towards increased vascular coverage and branching in the dorsolateral frontal cortex (DLF) sulci in CTE, that correlates with p-tau pathology.
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Affiliation(s)
- Grace Rosen
- VA Boston Healthcare System, US Department of Veterans Affairs, 150 S Huntington Avenue, Boston, MA, 02130, USA
- National Center for PTSD, US Department of Veterans Affairs, Boston, MA, USA
| | - Daniel Kirsch
- Department of Pathology and Laboratory Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
| | - Sarah Horowitz
- VA Boston Healthcare System, US Department of Veterans Affairs, 150 S Huntington Avenue, Boston, MA, 02130, USA
- National Center for PTSD, US Department of Veterans Affairs, Boston, MA, USA
| | - Jonathan D Cherry
- Department of Pathology and Laboratory Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Raymond Nicks
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Hunter Kelley
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Madeline Uretsky
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Kevin Dell'Aquila
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Rebecca Mathias
- VA Boston Healthcare System, US Department of Veterans Affairs, 150 S Huntington Avenue, Boston, MA, 02130, USA
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
| | - Kerry A Cormier
- VA Boston Healthcare System, US Department of Veterans Affairs, 150 S Huntington Avenue, Boston, MA, 02130, USA
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
- VA Bedford Healthcare System, US Department of Veterans Affairs, Bedford, MA, USA
| | - Caroline A Kubilus
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
- VA Bedford Healthcare System, US Department of Veterans Affairs, Bedford, MA, USA
| | - Jesse Mez
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Yorghos Tripodis
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
- Department of Biostatistics, Boston University School of Public Health, Boston, USA
| | - Thor D Stein
- VA Boston Healthcare System, US Department of Veterans Affairs, 150 S Huntington Avenue, Boston, MA, 02130, USA
- Department of Pathology and Laboratory Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Victor E Alvarez
- VA Boston Healthcare System, US Department of Veterans Affairs, 150 S Huntington Avenue, Boston, MA, 02130, USA
- Department of Pathology and Laboratory Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Michael L Alosco
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
| | - Ann C McKee
- VA Boston Healthcare System, US Department of Veterans Affairs, 150 S Huntington Avenue, Boston, MA, 02130, USA
- Department of Pathology and Laboratory Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA
- VA Bedford Healthcare System, US Department of Veterans Affairs, Bedford, MA, USA
| | - Bertrand R Huber
- VA Boston Healthcare System, US Department of Veterans Affairs, 150 S Huntington Avenue, Boston, MA, 02130, USA.
- Department of Neurology, Boston University Chobanian & Avedisian School of Medicine, Boston, USA.
- Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Boston, USA.
- National Center for PTSD, US Department of Veterans Affairs, Boston, MA, USA.
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Anderl WJ, Pearson N, Converse MI, Yu SM, Monson KL. Strain-induced collagen denaturation is rate dependent in failure of cerebral arteries. Acta Biomater 2023; 164:282-292. [PMID: 37116635 DOI: 10.1016/j.actbio.2023.04.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 04/06/2023] [Accepted: 04/21/2023] [Indexed: 04/30/2023]
Abstract
While soft tissues are commonly damaged by mechanical loading, the manifestation of this damage at the microstructural level is not fully understood. Specifically, while rate-induced stiffening has been previously observed in cerebral arteries, associated changes in microstructural damage patterns following high-rate loading are largely undefined. In this study, we stretched porcine middle cerebral arteries to failure at 0.01 and >150 s-1, both axially and circumferentially, followed by probing for denatured tropocollagen using collagen hybridizing peptide (CHP). We found that collagen fibrils aligned with the loading direction experienced less denaturation following failure tests at high than low rates. Others have demonstrated similar rate dependence in tropocollagen denaturation during soft tissue failure, but this is the first study to quantify this behavior using CHP and to report it for cerebral arteries. These findings may have significant implications for traumatic brain injury and intracranial balloon angioplasty. We additionally observed possible tropocollagen denaturation in vessel layers primarily composed of fibrils transversely aligned to the loading axis. To our knowledge, this is the first observation of collagen denaturation due to transverse loading, but further research is needed to confirm this finding. STATEMENT OF SIGNIFICANCE: Previous work shows that collagen hybridizing peptide (CHP) can be used to identify collagen molecule unfolding and denaturation in mechanically overloaded soft tissues, including the cerebral arteries. But experiments have not explored collagen damage at rates relevant to traumatic brain injury. In this work, we quantified collagen damage in cerebral arteries stretched to failure at both high and low rates. We found that the collagen molecule is less damaged at high than at low rates, suggesting that damage mechanisms of either the collagen molecule or other elements of the collagen superstructure are rate dependent. This work implies that arteries failed at high rates, such as in traumatic brain injury, will have different molecular-level damage patterns than arteries failed at low rates. Consequently, improved understanding of damage characteristics may be expanded in the future to better inform clinically relevant cases of collagen damage such as angioplasty and injury healing.
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Affiliation(s)
| | - Noah Pearson
- DepSSSartment of Mechanical Engineering, University of Utah
| | | | - S Michael Yu
- Department of Biomedical Engineering, University of Utah; Department of Molecular Pharmaceutics, University of Utah
| | - Kenneth L Monson
- DepSSSartment of Mechanical Engineering, University of Utah; Department of Biomedical Engineering, University of Utah.
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Nguyen A, Nguyen A, Hsu TI, Lew HD, Gupta N, Nguyen B, Mandavalli A, Diaz MJ, Lucke-Wold B. Neutrophil to Lymphocyte Ratio as a Predictor of Postoperative Outcomes in Traumatic Brain Injury: A Systematic Review and Meta-Analysis. Diseases 2023; 11:diseases11010051. [PMID: 36975600 PMCID: PMC10047119 DOI: 10.3390/diseases11010051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 03/05/2023] [Accepted: 03/10/2023] [Indexed: 03/17/2023] Open
Abstract
(1) Introduction: Traumatic brain injury (TBI) is a leading cause of injury and mortality worldwide, carrying an estimated cost of $38 billion in the United States alone. Neutrophil to lymphocyte ratio (NLR) has been investigated as a standardized biomarker that can be used to predict outcomes of TBI. The aim of this review was to determine the prognostic utility of NLR among patients admitted for TBI. (2) Methods: A literature search was conducted in PubMed, Scopus, and Web of Science in November 2022 to retrieve articles regarding the use of neutrophil to lymphocyte ratio (NLR) as a prognostic measure in traumatic brain injury (TBI) patients. Inclusion criteria included studies reporting outcomes of TBI patients with associated NLR values. Exclusion criteria were studies reporting only non-primary data, those insufficiently disaggregated to extract NLR data, and non-English or cadaveric studies. The Newcastle-Ottawa Scale was utilized to assess for the presence of bias in included studies. (3) Results: Following the final study selection 19 articles were included for quantitative and qualitative analysis. The average age was 46.25 years. Of the 7750 patients, 73% were male. Average GCS at presentation was 10.51. There was no significant difference in the NLR between surgical vs. non-surgical cohorts (SMD 2.41 95% CI −1.82 to 6.63, p = 0.264). There was no significant difference in the NLR between bleeding vs. non-bleeding cohorts (SMD 4.84 95% CI −0.26 to 9.93, p = 0.0627). There was a significant increase in the NLR between favorable vs. non-favorable cohorts (SMD 1.31 95% CI 0.33 to 2.29, p = 0.0090). (4) Conclusions: Our study found that NLR was only significantly predictive for adverse outcomes in TBI patients and not surgical treatment or intracranial hemorrhage, making it nonetheless an affordable alternative for physicians to assess patient prognosis.
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Affiliation(s)
- Andrew Nguyen
- College of Medicine, University of Florida, Gainesville, FL 32601, USA
| | - Alexander Nguyen
- College of Medicine, University of Florida, Gainesville, FL 32601, USA
| | - Timothy I. Hsu
- School of Medicine, University of California, Irvine, CA 92617, USA
| | - Harrison D. Lew
- College of Medicine, University of Florida, Gainesville, FL 32601, USA
| | - Nithin Gupta
- School of Medicine, Campbell University, Lillington, NC 27546, USA
| | - Brandon Nguyen
- Alix School of Medicine, Mayo Clinic, Scottsdale, AZ 85054, USA
| | - Akhil Mandavalli
- College of Medicine, University of Florida, Gainesville, FL 32601, USA
| | - Michael J. Diaz
- College of Medicine, University of Florida, Gainesville, FL 32601, USA
- Correspondence:
| | - Brandon Lucke-Wold
- Department of Neurosurgery, University of Florida, Gainesville, FL 32608, USA
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9
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Johnstone DM, Mitrofanis J, Stone J. The brain's weakness in the face of trauma: How head trauma causes the destruction of the brain. Front Neurosci 2023; 17:1141568. [PMID: 36950132 PMCID: PMC10026135 DOI: 10.3389/fnins.2023.1141568] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 02/15/2023] [Indexed: 03/06/2023] Open
Abstract
Of all our organs, the brain is perhaps the best protected from trauma. The skull has evolved to enclose it and, within the skull, the brain floats in a protective bath of cerebrospinal fluid. It is becoming evident, however, that head trauma experienced in young adult life can cause a dementia that appears decades later. The level of trauma that induces such destruction is still being assessed but includes levels well below that which cracks the skull or causes unconsciousness or concussion. Clinically this damage appears as dementia, in people who played body-contact sports in their youth or have survived accidents or the blasts of combat; and appears also, we argue, in old age, without a history of head trauma. The dementias have been given different names, including dementia pugilistica (affecting boxers), chronic traumatic encephalopathy (following certain sports, particularly football), traumatic brain injury (following accidents, combat) and Alzheimer's (following decades of life). They share common features of clinical presentation and neuropathology, and this conceptual analysis seeks to identify features common to these forms of brain injury and to identify where in the brain the damage common to them occurs; and how it occurs, despite the protection provided by the skull and cerebrospinal fluid. The analysis suggests that the brain's weak point in the face of trauma is its capillary bed, which is torn by the shock of trauma. This identification in turn allows discussion of ways of delaying, avoiding and even treating these trauma-induced degenerations.
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Affiliation(s)
- Daniel M. Johnstone
- School of Biomedical Sciences and Pharmacy, University of Newcastle and School of Medical Sciences, The University of Sydney, Darlington, NSW, Australia
| | - John Mitrofanis
- Fonds de Dotation Clinatec, Université Grenoble Alpes, France and Institute of Ophthalmology, University College London, London, United Kingdom
| | - Jonathan Stone
- Honorary Associate, Centenary Institute and University of Sydney, Darlington, NSW, Australia
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10
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Whitehead B, Velazquez-Cruz R, Albowaidey A, Zhang N, Karelina K, Weil ZM. Mild Traumatic Brain Injury Induces Time- and Sex-Dependent Cerebrovascular Dysfunction and Stroke Vulnerability. J Neurotrauma 2023; 40:578-591. [PMID: 36322789 PMCID: PMC9986031 DOI: 10.1089/neu.2022.0335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mild traumatic brain injury (mTBI) produces subtle cerebrovascular impairments that persist over time and promote increased ischemic stroke vulnerability. We recently established a role for vascular impairments in exacerbating stroke outcomes 1 week after TBI, but there is a lack of research regarding long-term impacts of mTBI-induced vascular dysfunction, as well as a significant need to understand how mTBI promotes stroke vulnerability in both males and females. Here, we present data using a mild closed head TBI model and an experimental stroke occurring either 7 or 28 days later in both male and female mice. We report that mTBI induces larger stroke volumes 7 days after injury, however, this increased vulnerability to stroke persists out to 28 days in female but not male mice. Importantly, mTBI-induced changes in blood-brain barrier permeability, intravascular coagulation, angiogenic factors, total vascular area, and glial expression were differentially altered across time and by sex. Taken together, these data suggest that mTBI can result in persistent cerebrovascular dysfunction and increased susceptibility to worsened ischemic outcomes, although these dysfunctions occur differently in male and female mice.
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Affiliation(s)
- Bailey Whitehead
- Department of Neuroscience and Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, USA
| | - Ruth Velazquez-Cruz
- Department of Neuroscience and Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, USA
| | - Ali Albowaidey
- Department of Neuroscience and Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, USA
| | - Ning Zhang
- Department of Neuroscience and Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, USA
| | - Kate Karelina
- Department of Neuroscience and Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, USA
| | - Zachary M. Weil
- Department of Neuroscience and Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, USA
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Age effects on the mechanical behavior of human cerebral bridging veins. Clin Biomech (Bristol, Avon) 2022; 100:105792. [PMID: 36327547 DOI: 10.1016/j.clinbiomech.2022.105792] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 09/26/2022] [Accepted: 10/02/2022] [Indexed: 02/07/2023]
Abstract
BACKGROUND It is well established that the probability of occurrence of acute subdural hematomas in traumatic situations increases with age, since the main cause of such hematomas is the mechanical failure of cerebral blood vessels known as bridging veins. This research aims to determine whether there is an effect of age on the mechanical properties of these cerebral vessels, because previous reported studies were conflicting. METHODS This study used mechanical tests blue of cerebral bridging veins from post-mortem human subjects. In particular, a series of in vitro tensile tests were performed on a balanced sample of bridging veins from different human subjects. FINDINGS The mechanical parameters measured from the tests were analyzed by means of regression analysis looking for age related effects. The results show that there is a significant effect on both the ultimate strength, maximum stress and strain that the specimens can withstand. The quantitative analysis shows reductions of nearly 50% in ultimate stress, and almost 35% in ultimate strain. INTERPRETATION Mechanical deterioration of the mechanical strength of cerebral blood vessels seems to be a major factor involved in the increase of frequency of acute subdural hematoma in elderly people in a wide range of life-threatening traumatic situations.
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12
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Restoring After Central Nervous System Injuries: Neural Mechanisms and Translational Applications of Motor Recovery. Neurosci Bull 2022; 38:1569-1587. [DOI: 10.1007/s12264-022-00959-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/29/2022] [Indexed: 11/06/2022] Open
Abstract
AbstractCentral nervous system (CNS) injuries, including stroke, traumatic brain injury, and spinal cord injury, are leading causes of long-term disability. It is estimated that more than half of the survivors of severe unilateral injury are unable to use the denervated limb. Previous studies have focused on neuroprotective interventions in the affected hemisphere to limit brain lesions and neurorepair measures to promote recovery. However, the ability to increase plasticity in the injured brain is restricted and difficult to improve. Therefore, over several decades, researchers have been prompted to enhance the compensation by the unaffected hemisphere. Animal experiments have revealed that regrowth of ipsilateral descending fibers from the unaffected hemisphere to denervated motor neurons plays a significant role in the restoration of motor function. In addition, several clinical treatments have been designed to restore ipsilateral motor control, including brain stimulation, nerve transfer surgery, and brain–computer interface systems. Here, we comprehensively review the neural mechanisms as well as translational applications of ipsilateral motor control upon rehabilitation after CNS injuries.
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13
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Tomoto T, Le T, Tarumi T, Dieppa M, Bell K, Madden C, Zhang R, Ding K. Carotid Arterial Compliance and Aerobic Exercise Training in Chronic Traumatic Brain Injury: A Pilot Study. J Head Trauma Rehabil 2022; 37:263-271. [PMID: 34570024 DOI: 10.1097/htr.0000000000000722] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Decreased carotid arterial compliance (CAC) is associated with cerebral microvascular damage, cerebral blood flow (CBF) dysregulation, and increased risk for stroke and dementia, which are reported to be prevalent after traumatic brain injury (TBI). However, the effect of TBI on CAC has not been reported. The purposes of this pilot study were to (1) compare CAC between participants with chronic traumatic brain injury (cTBI) and age-matched healthy control (HC) subjects and (2) to examine whether CAC changed after 3 months of exercise training in those with cTBI. SETTING Community based. PARTICIPANTS Nineteen participants with cTBI (6-72 months postinjury) and 19 HC matched for age and sex were tested at baseline. The same cTBI cohort was enrolled in a proof-of-concept randomized controlled exercise training program to investigate the effects of 3 months of aerobic exercise training (AET) or nonaerobic stretching and toning (SAT) on cerebrovascular parameters. DESIGN Cross-sectional study and randomized controlled trial. MAIN MEASURES CAC was measured by tonometry and ultrasonography at the common carotid artery; CBF was measured by ultrasonography at the bilateral internal carotid and vertebral arteries, and pulsatile CBF was measured by transcranial Doppler ultrasonography at the middle cerebral arteries. Cerebrovascular resistance (CVR) was calculated as mean arterial pressure divided by total CBF. RESULTS Relative to HC, the participants with cTBI had lower CAC (0.10 ± 0.03 vs 0.12 ± 0.03 mm 2 /mm Hg, P = .046) and higher CVR (0.17 ± 0.03 vs 0.15 ± 0.03 mm Hg/mL/min, P = .028). CAC tended to increase after AET compared with SAT ( P = .080). Increases in CAC were associated with decreased pulsatile CBF ( r = -0.689, P = .003). CONCLUSION These findings suggest that the individuals with cTBI have decreased CAC, which may potentially be improved by AET.
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Affiliation(s)
- Tsubasa Tomoto
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (Drs Tomoto, Tarumi, and Zhang); Departments of Neurology (Drs Tomoto, Le, Tarumi, Dieppa, Zhang, and Ding), Physical Medicine and Rehabilitation (Dr Bell), Neurological Surgery (Dr Madden), and Internal Medicine (Dr Zhang), University of Texas Southwestern Medical Center, Dallas; and Human Informatics Interaction Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan (Dr Tarumi)
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14
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Duckworth H, Azor A, Wischmann N, Zimmerman KA, Tanini I, Sharp DJ, Ghajari M. A Finite Element Model of Cerebral Vascular Injury for Predicting Microbleeds Location. Front Bioeng Biotechnol 2022; 10:860112. [PMID: 35519616 PMCID: PMC9065595 DOI: 10.3389/fbioe.2022.860112] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 03/31/2022] [Indexed: 11/22/2022] Open
Abstract
Finite Element (FE) models of brain mechanics have improved our understanding of the brain response to rapid mechanical loads that produce traumatic brain injuries. However, these models have rarely incorporated vasculature, which limits their ability to predict the response of vessels to head impacts. To address this shortcoming, here we used high-resolution MRI scans to map the venous system anatomy at a submillimetre resolution. We then used this map to develop an FE model of veins and incorporated it in an anatomically detailed FE model of the brain. The model prediction of brain displacement at different locations was compared to controlled experiments on post-mortem human subject heads, yielding over 3,100 displacement curve comparisons, which showed fair to excellent correlation between them. We then used the model to predict the distribution of axial strains and strain rates in the veins of a rugby player who had small blood deposits in his white matter, known as microbleeds, after sustaining a head collision. We hypothesised that the distribution of axial strain and strain rate in veins can predict the pattern of microbleeds. We reconstructed the head collision using video footage and multi-body dynamics modelling and used the predicted head accelerations to load the FE model of vascular injury. The model predicted large axial strains in veins where microbleeds were detected. A region of interest analysis using white matter tracts showed that the tract group with microbleeds had 95th percentile peak axial strain and strain rate of 0.197 and 64.9 s−1 respectively, which were significantly larger than those of the group of tracts without microbleeds (0.163 and 57.0 s−1). This study does not derive a threshold for the onset of microbleeds as it investigated a single case, but it provides evidence for a link between strain and strain rate applied to veins during head impacts and structural damage and allows for future work to generate threshold values. Moreover, our results suggest that the FE model has the potential to be used to predict intracranial vascular injuries after TBI, providing a more objective tool for TBI assessment and improving protection against it.
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Affiliation(s)
- Harry Duckworth
- HEAD Lab, Dyson School of Design Engineering, Imperial College London, London, United Kingdom
- The Computational, Cognitive and Clinical Neuroimaging Laboratory, Imperial College London, London, United Kingdom
| | - Adriana Azor
- HEAD Lab, Dyson School of Design Engineering, Imperial College London, London, United Kingdom
- The Computational, Cognitive and Clinical Neuroimaging Laboratory, Imperial College London, London, United Kingdom
| | - Nikolaus Wischmann
- HEAD Lab, Dyson School of Design Engineering, Imperial College London, London, United Kingdom
| | - Karl A. Zimmerman
- HEAD Lab, Dyson School of Design Engineering, Imperial College London, London, United Kingdom
- The Computational, Cognitive and Clinical Neuroimaging Laboratory, Imperial College London, London, United Kingdom
| | - Ilaria Tanini
- HEAD Lab, Dyson School of Design Engineering, Imperial College London, London, United Kingdom
- Industrial Engineering Department, University of Florence, Florence, Italy
| | - David J. Sharp
- The Computational, Cognitive and Clinical Neuroimaging Laboratory, Imperial College London, London, United Kingdom
- Care Research and Technology Centre, Dementia Research Institute, London, United Kingdom
| | - Mazdak Ghajari
- HEAD Lab, Dyson School of Design Engineering, Imperial College London, London, United Kingdom
- *Correspondence: Mazdak Ghajari,
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15
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Pearson N, Boiczyk GM, Kote VB, Sundaramurthy A, Subramaniam DR, Rubio JE, Unnikrishnan G, Reifman J, Monson K. A Strain-Rate Dependent Constitutive Model for Göttingen Minipig Cerebral Arteries. J Biomech Eng 2022; 144:1135617. [PMID: 35147172 DOI: 10.1115/1.4053796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Indexed: 11/08/2022]
Abstract
Computational simulations of traumatic brain injury (TBI) are commonly used to advance understanding of the injury-pathology relationship, tissue damage thresholds, and design of protective equipment such as helmets. Both human and animal TBI models have developed substantially over recent decades, partially due to the inclusion of more detailed brain geometry and representation of tissues like cerebral blood vessels. Explicit incorporation of vessels dramatically affects local strain and enables researchers to investigate TBI-induced damage to the vasculature. While some studies have indicated that cerebral arteries are rate-dependent, no published experimentally based, rate-sensitive constitutive models of cerebral arteries exist. In the present work, we characterize the mechanical properties of axially failed porcine arteries, both quasi-statically (0.01 s-1) and at high rate (<100 s-1), and propose a rate-sensitive model to fit the data. We find that the quasi-static and high-rate stress-stretch curves become significantly different (p>0.05) above a stretch of 1.23. We additionally find a significant change in both failure stretch and stress as a result of strain rate. The stress-stretch curve is then modeled as a Holzapfel-Gasser-Ogden material, with a Prony series added to capture the effects of viscoelasticity. Ultimately, this paper demonstrates that rate dependence should be considered in the material properties of cerebral arteries undergoing high strain-rate deformations and provides a ready-to-use model for finite element implementation.
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Affiliation(s)
- Noah Pearson
- Department of Mechanical Engineering, The University of Utah, 1495 E 100 S, Salt Lake City, UT 84112, USA
| | - Gregory M Boiczyk
- Department of Biomedical Engineering, The University of Utah, 36 S. Wasatch Drive, Salt Lake City, UT 84112, USA
| | - Vivek B Kote
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD 21702, USA; The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., 6720A Rockledge Drive, Bethesda, MD 20817, USA
| | - Aravind Sundaramurthy
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD 21702, USA; The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., 6720A Rockledge Drive, Bethesda, MD 20817, USA
| | - Dhananjay Radhakrishnan Subramaniam
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD 21702, USA; The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., 6720A Rockledge Drive, Bethesda, MD 20817, USA
| | - Jose E Rubio
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD 21702, USA; The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., 6720A Rockledge Drive, Bethesda, MD 20817, USA
| | - Ginu Unnikrishnan
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD 21702, USA; The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., 6720A Rockledge Drive, Bethesda, MD 20817, USA
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD 21702, USA; The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., 6720A Rockledge Drive, Bethesda, MD 20817, USA
| | - Ken Monson
- Department of Biomedical Engineering, The University of Utah, Department of Mechanical Engineering, The University of Utah, 1495 E 100 S, Salt Lake City, UT 84112, USA
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16
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Zhao W, Ji S. Cerebral vascular strains in dynamic head impact using an upgraded model with brain material property heterogeneity. J Mech Behav Biomed Mater 2022; 126:104967. [PMID: 34863650 PMCID: PMC8792345 DOI: 10.1016/j.jmbbm.2021.104967] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/27/2021] [Accepted: 11/06/2021] [Indexed: 02/03/2023]
Abstract
Cerebral vascular injury (CVI) is a frequent consequence of traumatic brain injury but has often been neglected. Substantial experimental work exists on vascular material properties and failure/subfailure thresholds. However, little is known about vascular in vivo loading conditions in dynamic head impact, which is necessary to investigate the risk, severity, and extent of CVI. In this study, we resort to the Worcester Head Injury Model (WHIM) V2.1 for investigation. The model embeds the cerebral vasculature network and is further upgraded to incorporate brain material property heterogeneity based on magnetic resonance elastography. The brain material property is calibrated to match with the previously validated anisotropic V1.0 version in terms of whole-brain strains against six experimental datasets of a wide range of blunt impact conditions. The upgraded WHIM is finally used to simulate five representative real-world head impacts drawn from contact sports and automotive crashes. We find that peak strains in veins are considerably higher than those in arteries and that peak circumferential strains are also higher than peak axial strains. For a typical concussive head impact, cerebral vascular axial strains reach the lowest reported yield strain of ∼7-8%. For severe automotive impacts, axial strains could reach ∼20%, which is on the order of the lowest reported ultimate failure strain of ∼24%. These results suggest in vivo mechanical loading conditions of the cerebral vasculature (excluding bridging veins not assessed here) due to rapid head rotation are at the lower end of failure/subfailure thresholds established from ex vivo experiments. This study provides some first insight into the risk, severity, and extent of CVI in real-world head impacts.
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Affiliation(s)
- Wei Zhao
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA
| | - Songbai Ji
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, Department of Mechanical Engineering, Worcester Polytechnic Institute, Worcester, MA,Corresponding author: Dr. Songbai Ji, 60 Prescott Street, Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA 01506, USA, ; (508) 831-4956
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17
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García-Vilana S, Sánchez-Molina D, Llumà J, Galtés I, Velázquez-Ameijide J, Rebollo-Soria MC, Arregui-Dalmases C. Viscoelastic Characterization of Parasagittal Bridging Veins and Implications for Traumatic Brain Injury: A Pilot Study. Bioengineering (Basel) 2021; 8:145. [PMID: 34677218 PMCID: PMC8533420 DOI: 10.3390/bioengineering8100145] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/05/2021] [Accepted: 10/12/2021] [Indexed: 01/29/2023] Open
Abstract
Many previous studies on the mechanical properties of Parasagittal Bridging Veins (PSBVs) found that strain rate had a significant effect on some mechanical properties, but did not extensively study the viscoelastic effects, which are difficult to detect with uniaxial simple tensile tests. In this study, relaxation tests and tests under cyclic loading were performed, and it was found that PSBVs do indeed exhibit clear viscoelastic effects. In addition, a complete viscoelastic model for the PSBVs is proposed and data from relaxation, cyclic load and load-unload tests for triangular loads are used to find reference values that characterize the viscoelastic behavior of the PSBVs. Although such models have been proposed for other types of blood vessels, this is the first study that clearly demonstrates the existence of viscoelastic effects from an experimental point of view and also proposes a specific model to explain the data obtained. Finally, this study provides reference values for the usual viscoelastic properties, which would allow more accurate numerical simulation of PSBVs by means of computational models.
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Affiliation(s)
- Silvia García-Vilana
- Escola d'Enginyeria de Barcelona Est, Universitat Politècnica de Catalunya, Av. Eduard Maristany, 16, 08019 Barcelona, Spain
| | - David Sánchez-Molina
- Escola d'Enginyeria de Barcelona Est, Universitat Politècnica de Catalunya, Av. Eduard Maristany, 16, 08019 Barcelona, Spain
| | - Jordi Llumà
- Escola d'Enginyeria de Barcelona Est, Universitat Politècnica de Catalunya, Av. Eduard Maristany, 16, 08019 Barcelona, Spain
| | - Ignasi Galtés
- Institut de Medicina Legal i Ciències Forenses de Catalunya, G.V. Corts Catalanes, 111, 08014 Barcelona, Spain
- Departament de Psiquiatria i de Medicina Legal, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain
| | - Juan Velázquez-Ameijide
- Escola d'Enginyeria de Barcelona Est, Universitat Politècnica de Catalunya, Av. Eduard Maristany, 16, 08019 Barcelona, Spain
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18
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Xie N, Hou Y, Wang S, Ai X, Bai J, Lai X, Zhang Y, Meng X, Wang X. Second near-infrared (NIR-II) imaging: a novel diagnostic technique for brain diseases. Rev Neurosci 2021; 33:467-490. [PMID: 34551223 DOI: 10.1515/revneuro-2021-0088] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/02/2021] [Indexed: 12/20/2022]
Abstract
Imaging in the second near-infrared II (NIR-II) window, a kind of biomedical imaging technology with characteristics of high sensitivity, high resolution, and real-time imaging, is commonly used in the diagnosis of brain diseases. Compared with the conventional visible light (400-750 nm) and NIR-I (750-900 nm) imaging, the NIR-II has a longer wavelength of 1000-1700 nm. Notably, the superiorities of NIR-II can minimize the light scattering and autofluorescence of biological tissue with the depth of brain tissue penetration up to 7.4 mm. Herein, we summarized the main principles of NIR-II in animal models of traumatic brain injury, cerebrovascular visualization, brain tumor, inflammation, and stroke. Simultaneously, we encapsulated the in vivo process of NIR-II probes and their in vivo and in vitro toxic effects. We further dissected its limitations and following optimization measures.
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Affiliation(s)
- Na Xie
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu611137, China
| | - Ya Hou
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu611137, China
| | - Shaohui Wang
- Ethnic Medicine Academic Heritage Innovation Research Center, Chengdu University of Traditional Chinese Medicine, Chengdu611137, China
| | - Xiaopeng Ai
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu611137, China
| | - Jinrong Bai
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu611137, China
| | - Xianrong Lai
- Ethnic Medicine Academic Heritage Innovation Research Center, Chengdu University of Traditional Chinese Medicine, Chengdu611137, China
| | - Yi Zhang
- Ethnic Medicine Academic Heritage Innovation Research Center, Chengdu University of Traditional Chinese Medicine, Chengdu611137, China
| | - Xianli Meng
- State Key Laboratory of Southwestern Chinese Medicine Resources, Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu611137, China
| | - Xiaobo Wang
- State Key Laboratory of Southwestern Chinese Medicine Resources, Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu611137, China
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19
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Sánchez-Molina D, García-Vilana S, Llumà J, Galtés I, Velázquez-Ameijide J, Rebollo-Soria MC, Arregui-Dalmases C. Mechanical Behavior of Blood Vessels: Elastic and Viscoelastic Contributions. BIOLOGY 2021; 10:831. [PMID: 34571709 PMCID: PMC8472519 DOI: 10.3390/biology10090831] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/19/2021] [Accepted: 08/23/2021] [Indexed: 11/16/2022]
Abstract
The mechanical properties of the cerebral bridging veins (CBVs) were studied using advanced microtensile equipment. Detailed high-quality curves were obtained at different strain rates, showing a clearly nonlinear stress-strain response. In addition, the tissue of the CBVs exhibits stress relaxation and a preconditioning effect under cyclic loading, unequivocal indications of viscoelastic behavior. Interestingly, most previous literature that conducts uniaxial tensile tests had not found significant viscoelastic effects in CBVs, but the use of more sensitive tests allowed to observe the viscoelastic effects. For that reason, a careful mathematical analysis is presented, clarifying why in uniaxial tests with moderate strain rates, it is difficult to observe any viscoelastic effect. The analysis provides a theoretical explanation as to why many recent studies that investigated mechanical properties did not find a significant viscoelastic effect, even though in other circumstances, the CBV tissue would clearly exhibit viscoelastic behavior. Finally, this study provides reference values for the usual mechanical properties, as well as calculations of constitutive parameters for nonlinear elastic and viscoelastic models that would allow more accurate numerical simulation of CBVs in Finite Element-based computational models in future works.
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Affiliation(s)
- David Sánchez-Molina
- Escola d’Enginyeria de Barcelona Est, Universitat Politècnica de Catalunya, Av. Eduard Maristany, 16, 08019 Barcelona, Spain; (S.G.-V.); (J.L.); (J.V.-A.)
| | - Silvia García-Vilana
- Escola d’Enginyeria de Barcelona Est, Universitat Politècnica de Catalunya, Av. Eduard Maristany, 16, 08019 Barcelona, Spain; (S.G.-V.); (J.L.); (J.V.-A.)
| | - Jordi Llumà
- Escola d’Enginyeria de Barcelona Est, Universitat Politècnica de Catalunya, Av. Eduard Maristany, 16, 08019 Barcelona, Spain; (S.G.-V.); (J.L.); (J.V.-A.)
| | - Ignasi Galtés
- Institut de Medicina Legal i Ciències Forenses de Catalunya, G.V. Corts Catalanes, 111, 08014 Barcelona, Spain;
- Departament de Psiquiatria i de Medicina Legal, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain
| | - Juan Velázquez-Ameijide
- Escola d’Enginyeria de Barcelona Est, Universitat Politècnica de Catalunya, Av. Eduard Maristany, 16, 08019 Barcelona, Spain; (S.G.-V.); (J.L.); (J.V.-A.)
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20
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Gou K, Baek S, Lutnesky MMF, Han HC. Growth-profile configuration for specific deformations of tubular organs: A study of growth-induced thinning and dilation of the human cervix. PLoS One 2021; 16:e0255895. [PMID: 34379659 PMCID: PMC8357173 DOI: 10.1371/journal.pone.0255895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 07/26/2021] [Indexed: 12/02/2022] Open
Abstract
Growth is a significant factor that results in deformations of tubular organs, and particular deformations associated with growth enable tubular organs to perform certain physiological functions. Configuring growth profiles that achieve particular deformation patterns is critical for analyzing potential pathological conditions and for developing corresponding clinical treatments for tubular organ dysfunctions. However, deformation-targeted growth is rarely studied. In this article, the human cervix during pregnancy is studied as an example to show how cervical thinning and dilation are generated by growth. An advanced hyperelasticity theory called morphoelasticity is employed to model the deformations, and a growth tensor is used to represent growth in three principle directions. The computational results demonstrate that both negative radial growth and positive circumferential growth facilitate thinning and dilation. Modeling such mixed growth represents an advancement beyond commonly used uniform growth inside tissues to study tubular deformations. The results reveal that complex growth may occur inside tissues to achieve certain tubular deformations. Integration of further biochemical and cellular activities that initiate and mediate such complex growth remains to be explored.
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Affiliation(s)
- Kun Gou
- Department of Mathematical, Physical, and Engineering Sciences, Texas A&M University-San Antonio, San Antonio, Texas, United States of America
- * E-mail:
| | - Seungik Baek
- Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan, United States of America
| | - Marvin M. F. Lutnesky
- Department of Life Sciences, Texas A&M University-San Antonio, San Antonio, Texas, United States of America
| | - Hai-Chao Han
- Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, Texas, United States of America
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21
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Farajzadeh Khosroshahi S, Yin X, K Donat C, McGarry A, Yanez Lopez M, Baxan N, J Sharp D, Sastre M, Ghajari M. Multiscale modelling of cerebrovascular injury reveals the role of vascular anatomy and parenchymal shear stresses. Sci Rep 2021; 11:12927. [PMID: 34155289 PMCID: PMC8217506 DOI: 10.1038/s41598-021-92371-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 06/07/2021] [Indexed: 01/28/2023] Open
Abstract
Neurovascular injury is often observed in traumatic brain injury (TBI). However, the relationship between mechanical forces and vascular injury is still unclear. A key question is whether the complex anatomy of vasculature plays a role in increasing forces in cerebral vessels and producing damage. We developed a high-fidelity multiscale finite element model of the rat brain featuring a detailed definition of the angioarchitecture. Controlled cortical impacts were performed experimentally and in-silico. The model was able to predict the pattern of blood-brain barrier damage. We found strong correlation between the area of fibrinogen extravasation and the brain area where axial strain in vessels exceeds 0.14. Our results showed that adjacent vessels can sustain profoundly different axial stresses depending on their alignment with the principal direction of stress in parenchyma, with a better alignment leading to larger stresses in vessels. We also found a strong correlation between axial stress in vessels and the shearing component of the stress wave in parenchyma. Our multiscale computational approach explains the unrecognised role of the vascular anatomy and shear stresses in producing distinct distribution of large forces in vasculature. This new understanding can contribute to improving TBI diagnosis and prevention.
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Affiliation(s)
| | - Xianzhen Yin
- Shanghai Institute of Materia Medica, Shanghai, China
| | - Cornelius K Donat
- Department of Brain Sciences, Imperial College London, London, UK
- Centre for Blast Injury Studies, Imperial College London, London, UK
| | - Aisling McGarry
- Department of Brain Sciences, Imperial College London, London, UK
| | | | - Nicoleta Baxan
- Biological Imaging Centre, Imperial College London, London, UK
| | - David J Sharp
- Department of Brain Sciences, Imperial College London, London, UK
| | - Magdalena Sastre
- Department of Brain Sciences, Imperial College London, London, UK
| | - Mazdak Ghajari
- Dyson School of Design Engineering, Imperial College London, London, UK
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22
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Cao XY, Qian X, Liu GD, Wang YH. Bioinformatics-based Identification of Key Pathways and Hub Genes of Traumatic Brain Injury in a Rat Model. Curr Med Sci 2021; 41:610-617. [PMID: 34047944 DOI: 10.1007/s11596-021-2365-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 12/04/2020] [Indexed: 01/05/2023]
Abstract
Traumatic brain injury (TBI) is a common injury caused by external forces that lead to damaged brain function or pathological changes in the brain tissue. To explore the molecular mechanism and the hub genes of TBI, we downloaded gene expression profiles of the TBI model of rat and the sham control for the subsequent gene set enrichment analysis, pathway analysis and protein-protein interactions analysis. The results of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis indicated that multiple biological pathways, including immune response, inflammatory response and cellular response to interleukin-1, as well as signaling pathways, such as tumor necrosis factor signaling pathway, chemokine signaling pathway, cytokine-cytokine receptor interaction, Toll-like receptor signaling pathway and nuclear factor kappa B signaling pathway were implicated in the TBI. In conclusion, this study provides insights into the molecular mechanism of TBI by screening the differentially expressed genes and hub genes that can be used as biomarkers and therapeutic targets.
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Affiliation(s)
- Xin-Yi Cao
- Wuxi Clinical College of Anhui Medical University (904th Hospital of the Joint Logistic Support Force of the Chinese People's Liberation Army), Wuxi, 214000, China
| | - Xiao Qian
- Wuxi Clinical College of Anhui Medical University (904th Hospital of the Joint Logistic Support Force of the Chinese People's Liberation Army), Wuxi, 214000, China
| | - Guo-Dong Liu
- Wuxi Clinical College of Anhui Medical University (904th Hospital of the Joint Logistic Support Force of the Chinese People's Liberation Army), Wuxi, 214000, China
| | - Yu-Hai Wang
- Wuxi Clinical College of Anhui Medical University (904th Hospital of the Joint Logistic Support Force of the Chinese People's Liberation Army), Wuxi, 214000, China.
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Baird A, Oelsner L, Fisher C, Witte M, Huynh M. A multiscale computational model of angiogenesis after traumatic brain injury, investigating the role location plays in volumetric recovery. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2021; 18:3227-3257. [PMID: 34198383 DOI: 10.3934/mbe.2021161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Vascular endothelial growth factor (VEGF) is a key protein involved in the process of angiogenesis. VEGF is of particular interest after a traumatic brain injury (TBI), as it re-establishes the cerebral vascular network in effort to allow for proper cerebral blood flow and thereby oxygenation of damaged brain tissue. For this reason, angiogenesis is critical in the progression and recovery of TBI patients in the days and weeks post injury. Although well established experimental work has led to advances in our understanding of TBI and the progression of angiogenisis, many constraints still exist with existing methods, especially when considering patient progression in the days following injury. To better understand the healing process on the proposed time scales, we develop a computational model that quickly simulates vessel growth and recovery by coupling VEGF and its interactions with its associated receptors to a physiologically inspired fractal model of the microvascular re-growth. We use this model to clarify the role that diffusivity, receptor kinetics and location of the TBI play in overall blood volume restoration in the weeks post injury and show that proper therapeutic angiogenesis, or vasculogenic therapies, could speed recovery of the patient as a function of the location of injury.
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Affiliation(s)
- Austin Baird
- Applied Research Associates Inc., Advanced Modeling & Simulation Systems Directorate, 8537 Six Forks Rd, Raleigh, NC 27615, USA
| | - Laura Oelsner
- Varian Medical Systems, 3100 Hansen Way, Palo Alto, CA 94304, USA
| | - Charles Fisher
- Applied Research Associates Inc., Advanced Modeling & Simulation Systems Directorate, 8537 Six Forks Rd, Raleigh, NC 27615, USA
| | - Matt Witte
- Applied Research Associates Inc., Advanced Modeling & Simulation Systems Directorate, 8537 Six Forks Rd, Raleigh, NC 27615, USA
| | - My Huynh
- Applied Research Associates Inc., Advanced Modeling & Simulation Systems Directorate, 8537 Six Forks Rd, Raleigh, NC 27615, USA
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Keating CE, Cullen DK. Mechanosensation in traumatic brain injury. Neurobiol Dis 2020; 148:105210. [PMID: 33259894 DOI: 10.1016/j.nbd.2020.105210] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/10/2020] [Accepted: 11/24/2020] [Indexed: 12/14/2022] Open
Abstract
Traumatic brain injury (TBI) is distinct from other neurological disorders because it is induced by a discrete event that applies extreme mechanical forces to the brain. This review describes how the brain senses, integrates, and responds to forces under both normal conditions and during injury. The response to forces is influenced by the unique mechanical properties of brain tissue, which differ by region, cell type, and sub-cellular structure. Elements such as the extracellular matrix, plasma membrane, transmembrane receptors, and cytoskeleton influence its properties. These same components also act as force-sensors, allowing neurons and glia to respond to their physical environment and maintain homeostasis. However, when applied forces become too large, as in TBI, these components may respond in an aberrant manner or structurally fail, resulting in unique pathological sequelae. This so-called "pathological mechanosensation" represents a spectrum of cellular responses, which vary depending on the overall biomechanical parameters of the injury and may be compounded by repetitive injuries. Such aberrant physical responses and/or damage to cells along with the resulting secondary injury cascades can ultimately lead to long-term cellular dysfunction and degeneration, often resulting in persistent deficits. Indeed, pathological mechanosensation not only directly initiates secondary injury cascades, but this post-physical damage environment provides the context in which these cascades unfold. Collectively, these points underscore the need to use experimental models that accurately replicate the biomechanics of TBI in humans. Understanding cellular responses in context with injury biomechanics may uncover therapeutic targets addressing various facets of trauma-specific sequelae.
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Affiliation(s)
- Carolyn E Keating
- Department of Neurosurgery, Center for Brain Injury and Repair, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz VA Medical Center, USA
| | - D Kacy Cullen
- Department of Neurosurgery, Center for Brain Injury and Repair, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, USA; Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz VA Medical Center, USA.
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Age-Related Changes in the Association Between Traumatic Brain Injury and Dementia in Older Men and Women. J Head Trauma Rehabil 2020; 36:E139-E146. [PMID: 33201033 DOI: 10.1097/htr.0000000000000624] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To investigate age-related changes in the association between traumatic brain injury (TBI) and dementia in older men and women separately. SETTING A total of 243 general practices in the UK. PARTICIPANTS This study included 4760 patients who received a first TBI diagnosis between 1995 and 2010 (index date), and 4760 patients without TBI who were matched to those with TBI by age, sex, index year, Charlson Comorbidity Index, alcohol dependence, and physician (index date: a randomly selected visit date). DESIGN Retrospective cohort study. MAIN MEASURES Incidence of dementia in the decade following index date. RESULTS Within 10 years of index date, 8.8% of men with TBI and 4.8% of those without TBI were diagnosed with dementia, while the respective figures were 9.0% and 6.7% in women (P values < .01). There was a significant association between TBI and dementia in men (hazard ratio [HR] = 2.29, 95% confidence interval [CI]: 1.64-3.19) and in women (HR = 1.33, 95% CI: 1.07-1.64). Furthermore, the association between TBI and dementia was significant in men aged 60 to 70 (HR = 2.51, 95% CI: 1.27-4.96) and 71 to 80 years (HR = 3.00, 95% CI: 1.82-4.93), whereas the relationship was only significant and potentially unreliable in women aged 81 to 90 years (HR = 1.49, 95% CI: 1.03-2.14). CONCLUSIONS The age-related relationship between TBI and dementia differed between men and women. More research of a prospective nature and including behavioral data is needed to better understand these differences.
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A critical review of radiotracers in the positron emission tomography imaging of traumatic brain injury: FDG, tau, and amyloid imaging in mild traumatic brain injury and chronic traumatic encephalopathy. Eur J Nucl Med Mol Imaging 2020; 48:623-641. [DOI: 10.1007/s00259-020-04926-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 06/11/2020] [Indexed: 12/14/2022]
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Byrne MP, McMillan KR, Coats B. Morphological Analysis of Retinal Microvasculature to Improve Understanding of Retinal Hemorrhage Mechanics in Infants. Invest Ophthalmol Vis Sci 2020; 61:16. [PMID: 32176264 PMCID: PMC7401705 DOI: 10.1167/iovs.61.3.16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose In this experimental study, we quantify retinal microvasculature morphological features with depth, region, and age in immature and mature ovine eyes. These data identify morphological vulnerabilities in young eyes to inform the mechanics of retinal hemorrhage in children. Methods Retinal specimens from the equator and posterior pole of preterm (n = 4) and adult (n = 9) sheep were imaged using confocal microscopy. Vessel segment length, diameter, angular asymmetry, tortuosity, and branch points were quantified using a custom image segmentation code. Significant differences were identified through two-way ANOVAs and correlation analyses. Results Vessel segment lengths were significantly shorter in immature eyes compared to adults (P < 0.003) and were significantly shorter at increasing depths in the immature retina (P < 0.04). Tortuosity significantly increased with depth, regardless of age (P < 0.05). These data suggest a potential vulnerability of vasculature in the deeper retinal layers, particularly in immature eyes. Preterm retina had significantly more branch points than adult retina in both the posterior pole and equator, and the number increased significantly with depth (P < 0.001). Conclusions The increased branch points and decreased segment lengths in immature microvasculature suggest that infants will experience greater stress and strain during traumatic loading compared to adults. The increased morphological vulnerability of the immature microvasculature in the deeper layers of the retina suggest that intraretinal hemorrhages have a greater likelihood of occurring from trauma compared to preretinal hemorrhages. The morphological features captured in this study lay the foundation to explore the mechanics of retinal hemorrhage in infants and identify vulnerabilities that explain patterns of retinal hemorrhage in infants.
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28
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The effectiveness of hyperbaric oxygen modalities against vascular component of traumatic brain injury. BRAIN HEMORRHAGES 2020. [DOI: 10.1016/j.hest.2020.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
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Razaghi R, Biglari H, Karimi A. A patient-specific fluid–structure interaction model of the cerebrovascular damage in relation to traumatic brain injury. TRAUMA-ENGLAND 2020. [DOI: 10.1177/1460408620921729] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Background There is a lack of knowledge on the magnitudes of the biomechanical stresses and deformations occurring in the cerebral arterial wall after traumatic brain injury (TBI). Experimental techniques are unable to calculate the stresses and deformations in the cerebral arterial wall after TBI; therefore, the application of numerical simulations, such as finite element modeling, is preferred. Methods This study was aimed to calculate the stresses and deformations as well as the alteration in the pressure and velocity of the blood in the cerebrovascular artery using a fluid–structure interaction model. Results The results revealed considerable increase in the pressure and velocity of the blood which might lead to cerebrovascular damage followed by hemorrhage. The arterial wall showed the highest deformation of 0.047 mm in the X direction which was higher than that in the Y (0.035–0.050 mm) and Z (0.019–0.030 mm) directions. Conclusions These results have implications not only for the understanding of the stresses and deformations in the cerebral artery because of TBI, but also for providing a comprehensive knowledge for biomechanical and medical experts in regard to thresholds of cerebrovascular damage for use in establishing preventive and/or treatment methods.
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Affiliation(s)
- Reza Razaghi
- Department of Mechanical Engineering, University of Tabriz, Tabriz, Iran
| | - Hasan Biglari
- Department of Mechanical Engineering, University of Tabriz, Tabriz, Iran
| | - Alireza Karimi
- Department of Mechanical Engineering, Kyushu University, Fukuoka, Japan
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Zhao W, Ji S. Incorporation of vasculature in a head injury model lowers local mechanical strains in dynamic impact. J Biomech 2020; 104:109732. [PMID: 32151380 DOI: 10.1016/j.jbiomech.2020.109732] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 02/25/2020] [Accepted: 02/27/2020] [Indexed: 01/28/2023]
Abstract
Cerebral vasculature is several orders of magnitude stiffer than the brain tissue. However, only a handful of studies have investigated its potential stiffening effect on dynamic brain strains; yet, they report contradictory findings. Here, we reanalyze the cerebrovascular stiffening effect by incorporating vasculature derived from the latest neuroimaging atlases into a re-meshed Worcester Head Injury Model using an embedded element method. Regional brain strains with and without vasculature were simulated using a reconstructed, predominantly sagittal head impact. Using the two previously adopted linear or non-linear vessel material models, we reproduced the earlier conflicting results (~40% vs. ~1-6% in regional strain reductions). Nevertheless, with refitted non-linear material models chosen to represent the average dynamic tension behaviors of arteries and veins, respectively, inclusion of vasculature reduced regional brain strains by ~13-36% relative to the baselines without vasculature. Compared to the whole brain baseline response, inclusion of vasculature led to an element-wise linear regression slope of 0.8 and a Pearson correlation coefficient of 0.8. The vascular stiffening effect appears mild for the whole brain but more significant locally, which should not be ignored in head injury models. Nevertheless, more work is necessary to investigate the cerebrovascular mechanical behaviors and loading environment to allow for more biofidelic modeling of the brain in the future.
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Affiliation(s)
- Wei Zhao
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA 01605, United States
| | - Songbai Ji
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA 01605, United States; Department of Mechanical Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, United States.
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Szepesi Z, Manouchehrian O, Bachiller S, Deierborg T. Bidirectional Microglia-Neuron Communication in Health and Disease. Front Cell Neurosci 2018; 12:323. [PMID: 30319362 PMCID: PMC6170615 DOI: 10.3389/fncel.2018.00323] [Citation(s) in RCA: 290] [Impact Index Per Article: 48.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/06/2018] [Indexed: 12/12/2022] Open
Abstract
Microglia are ramified cells that exhibit highly motile processes, which continuously survey the brain parenchyma and react to any insult to the CNS homeostasis. Although microglia have long been recognized as a crucial player in generating and maintaining inflammatory responses in the CNS, now it has become clear, that their function are much more diverse, particularly in the healthy brain. The innate immune response and phagocytosis represent only a little segment of microglia functional repertoire that also includes maintenance of biochemical homeostasis, neuronal circuit maturation during development and experience-dependent remodeling of neuronal circuits in the adult brain. Being equipped by numerous receptors and cell surface molecules microglia can perform bidirectional interactions with other cell types in the CNS. There is accumulating evidence showing that neurons inform microglia about their status and thus are capable of controlling microglial activation and motility while microglia also modulate neuronal activities. This review addresses the topic: how microglia communicate with other cell types in the brain, including fractalkine signaling, secreted soluble factors and extracellular vesicles. We summarize the current state of knowledge of physiological role and function of microglia during brain development and in the mature brain and further highlight microglial contribution to brain pathologies such as Alzheimer’s and Parkinson’s disease, brain ischemia, traumatic brain injury, brain tumor as well as neuropsychiatric diseases (depression, bipolar disorder, and schizophrenia).
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Affiliation(s)
- Zsuzsanna Szepesi
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Oscar Manouchehrian
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Sara Bachiller
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Tomas Deierborg
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Science, Lund University, Lund, Sweden
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Shi H, Hua X, Kong D, Stein D, Hua F. Role of Toll-like receptor mediated signaling in traumatic brain injury. Neuropharmacology 2018; 145:259-267. [PMID: 30075158 DOI: 10.1016/j.neuropharm.2018.07.022] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 07/04/2018] [Accepted: 07/18/2018] [Indexed: 12/13/2022]
Abstract
The mechanisms underlying secondary brain damage following traumatic brain injury (TBI) remain unclear. A great many studies have demonstrated that inflammatory cascades contribute to brain damage through the activation of immune/inflammatory responses, including the increased release of cytokines and chemokines, and the recruitment of leukocytes. The cells and tissues damaged by primary mechanical injury release a number of endogenous factors acting as damage-associated molecular patterns (DAMPs), which initiate and perpetuate noninfectious inflammatory responses through transduction signaling pathways. Toll-like receptors (TLRs) are a transmembrane receptor family that can recognize the specific DAMPs released from damaged cells and recruit a set of adaptors leading to the activation of downstream kinases and nuclear factors which regulate the expression of inflammatory genes. The activation of inflammatory responses mediated by TLR signaling is closely associated with brain tissue damage and neurological dysfunction following TBI. TLRs and their downstream protein kinases may be potential targets for the treatment of TBI. Modulation of TLR-mediated signaling may attenuate brain damage and improve TBI outcome. In this review, we briefly discuss the role of TLR-mediated signaling in TBI and the new treatments targeting TLR signaling. This article is part of the Special Issue entitled "Novel Treatments for Traumatic Brain Injury".
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Affiliation(s)
- Hongjuan Shi
- Department of Neurology, The Affiliated Hospital, Xuzhou Medical University, Xuzhou, Jiangsu, 221002, China
| | - Xiaodong Hua
- Augusta University/University of Georgia Medical Partnership, Athens, GA, 30606, USA; Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Delian Kong
- Department of Neurology, The Affiliated Hospital, Xuzhou Medical University, Xuzhou, Jiangsu, 221002, China
| | - Donald Stein
- Brain Research Laboratory, Department of Emergency Medicine, Emory University School of Medicine, Atlanta, GA, 30032, USA
| | - Fang Hua
- Department of Neurology, The Affiliated Hospital, Xuzhou Medical University, Xuzhou, Jiangsu, 221002, China; Key Laboratory of Anesthesiology of Jiangsu Province, Xuzhou, 221002, China.
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