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Kagialis A, Simos N, Manolitsi K, Vakis A, Simos P, Papadaki E. Functional connectivity-hemodynamic (un)coupling changes in chronic mild brain injury are associated with mental health and neurocognitive indices: a resting state fMRI study. Neuroradiology 2024; 66:985-998. [PMID: 38605104 PMCID: PMC11133187 DOI: 10.1007/s00234-024-03352-9] [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: 01/29/2024] [Accepted: 04/02/2024] [Indexed: 04/13/2024]
Abstract
PURPOSE To examine hemodynamic and functional connectivity alterations and their association with neurocognitive and mental health indices in patients with chronic mild traumatic brain injury (mTBI). METHODS Resting-state functional MRI (rs-fMRI) and neuropsychological assessment of 37 patients with chronic mTBI were performed. Intrinsic connectivity contrast (ICC) and time-shift analysis (TSA) of the rs-fMRI data allowed the assessment of regional hemodynamic and functional connectivity disturbances and their coupling (or uncoupling). Thirty-nine healthy age- and gender-matched participants were also examined. RESULTS Patients with chronic mTBI displayed hypoconnectivity in bilateral hippocampi and parahippocampal gyri and increased connectivity in parietal areas (right angular gyrus and left superior parietal lobule (SPL)). Slower perfusion (hemodynamic lag) in the left anterior hippocampus was associated with higher self-reported symptoms of depression (r = - 0.53, p = .0006) and anxiety (r = - 0.484, p = .002), while faster perfusion (hemodynamic lead) in the left SPL was associated with lower semantic fluency (r = - 0.474, p = .002). Finally, functional coupling (high connectivity and hemodynamic lead) in the right anterior cingulate cortex (ACC)) was associated with lower performance on attention and visuomotor coordination (r = - 0.50, p = .001), while dysfunctional coupling (low connectivity and hemodynamic lag) in the left ventral posterior cingulate cortex (PCC) and right SPL was associated with lower scores on immediate passage memory (r = - 0.52, p = .001; r = - 0.53, p = .0006, respectively). Uncoupling in the right extrastriate visual cortex and posterior middle temporal gyrus was negatively associated with cognitive flexibility (r = - 0.50, p = .001). CONCLUSION Hemodynamic and functional connectivity differences, indicating neurovascular (un)coupling, may be linked to mental health and neurocognitive indices in patients with chronic mTBI.
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Affiliation(s)
- Antonios Kagialis
- Department of Psychiatry, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece
- Department of Radiology, School of Medicine, University of Crete, University Hospital of Heraklion, 71003, Crete, Greece
| | - Nicholas Simos
- Institute of Computer Science, Foundation for Research and Technology - Hellas, Heraklion, Crete, Greece
| | - Katina Manolitsi
- Department of Neurosurgery, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece
| | - Antonios Vakis
- Department of Neurosurgery, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece
| | - Panagiotis Simos
- Department of Psychiatry, School of Medicine, University of Crete, University Hospital of Heraklion, Crete, Greece
- Institute of Computer Science, Foundation for Research and Technology - Hellas, Heraklion, Crete, Greece
| | - Efrosini Papadaki
- Department of Radiology, School of Medicine, University of Crete, University Hospital of Heraklion, 71003, Crete, Greece.
- Institute of Computer Science, Foundation for Research and Technology - Hellas, Heraklion, Crete, Greece.
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Peper CJ, Kilgore MD, Jiang Y, Xiu Y, Xia W, Wang Y, Shi M, Zhou D, Dumont AS, Wang X, Liu N. Tracing the path of disruption: 13C isotope applications in traumatic brain injury-induced metabolic dysfunction. CNS Neurosci Ther 2024; 30:e14693. [PMID: 38544365 PMCID: PMC10973562 DOI: 10.1111/cns.14693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 02/25/2024] [Accepted: 03/12/2024] [Indexed: 05/14/2024] Open
Abstract
Cerebral metabolic dysfunction is a critical pathological hallmark observed in the aftermath of traumatic brain injury (TBI), as extensively documented in clinical investigations and experimental models. An in-depth understanding of the bioenergetic disturbances that occur following TBI promises to reveal novel therapeutic targets, paving the way for the timely development of interventions to improve patient outcomes. The 13C isotope tracing technique represents a robust methodological advance, harnessing biochemical quantification to delineate the metabolic trajectories of isotopically labeled substrates. This nuanced approach enables real-time mapping of metabolic fluxes, providing a window into the cellular energetic state and elucidating the perturbations in key metabolic circuits. By applying this sophisticated tool, researchers can dissect the complexities of bioenergetic networks within the central nervous system, offering insights into the metabolic derangements specific to TBI pathology. Embraced by both animal studies and clinical research, 13C isotope tracing has bolstered our understanding of TBI-induced metabolic dysregulation. This review synthesizes current applications of isotope tracing and its transformative potential in evaluating and addressing the metabolic sequelae of TBI.
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Affiliation(s)
- Charles J. Peper
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Mitchell D. Kilgore
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Yinghua Jiang
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Yuwen Xiu
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Winna Xia
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Yingjie Wang
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Mengxuan Shi
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Di Zhou
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Aaron S. Dumont
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Xiaoying Wang
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
- Neuroscience Program, Tulane Brain InstituteTulane UniversityNew OrleansLouisianaUSA
| | - Ning Liu
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
- Neuroscience Program, Tulane Brain InstituteTulane UniversityNew OrleansLouisianaUSA
- Tulane University Translational Sciences InstituteNew OrleansLouisianaUSA
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Krieg JL, Leonard AV, Turner RJ, Corrigan F. Identifying the Phenotypes of Diffuse Axonal Injury Following Traumatic Brain Injury. Brain Sci 2023; 13:1607. [PMID: 38002566 PMCID: PMC10670443 DOI: 10.3390/brainsci13111607] [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: 11/01/2023] [Revised: 11/15/2023] [Accepted: 11/17/2023] [Indexed: 11/26/2023] Open
Abstract
Diffuse axonal injury (DAI) is a significant feature of traumatic brain injury (TBI) across all injury severities and is driven by the primary mechanical insult and secondary biochemical injury phases. Axons comprise an outer cell membrane, the axolemma which is anchored to the cytoskeletal network with spectrin tetramers and actin rings. Neurofilaments act as space-filling structural polymers that surround the central core of microtubules, which facilitate axonal transport. TBI has differential effects on these cytoskeletal components, with axons in the same white matter tract showing a range of different cytoskeletal and axolemma alterations with different patterns of temporal evolution. These require different antibodies for detection in post-mortem tissue. Here, a comprehensive discussion of the evolution of axonal injury within different cytoskeletal elements is provided, alongside the most appropriate methods of detection and their temporal profiles. Accumulation of amyloid precursor protein (APP) as a result of disruption of axonal transport due to microtubule failure remains the most sensitive marker of axonal injury, both acutely and chronically. However, a subset of injured axons demonstrate different pathology, which cannot be detected via APP immunoreactivity, including degradation of spectrin and alterations in neurofilaments. Furthermore, recent work has highlighted the node of Ranvier and the axon initial segment as particularly vulnerable sites to axonal injury, with loss of sodium channels persisting beyond the acute phase post-injury in axons without APP pathology. Given the heterogenous response of axons to TBI, further characterization is required in the chronic phase to understand how axonal injury evolves temporally, which may help inform pharmacological interventions.
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Affiliation(s)
- Justin L Krieg
- Translational Neuropathology Laboratory, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5000, Australia
| | - Anna V Leonard
- Translational Neuropathology Laboratory, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5000, Australia
| | - Renée J Turner
- Translational Neuropathology Laboratory, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5000, Australia
| | - Frances Corrigan
- Translational Neuropathology Laboratory, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5000, Australia
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Arya S, Bahuguna D, Bajad G, Loharkar S, Devangan P, Khatri DK, Singh SB, Madan J. Colloidal therapeutics in the management of traumatic brain injury: Portray of biomarkers and drug-targets, preclinical and clinical pieces of evidence and future prospects. Colloids Surf B Biointerfaces 2023; 230:113509. [PMID: 37595379 DOI: 10.1016/j.colsurfb.2023.113509] [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: 05/22/2023] [Revised: 07/28/2023] [Accepted: 08/05/2023] [Indexed: 08/20/2023]
Abstract
Complexity associated with the aberrant physiology of traumatic brain injury (TBI) makes its therapeutic targeting vulnerable. The underlying mechanisms of pathophysiology of TBI are yet to be completely illustrated. Primary injury in TBI is associated with contusions and axonal shearing whereas excitotoxicity, mitochondrial dysfunction, free radicals generation, and neuroinflammation are considered under secondary injury. MicroRNAs, proinflammatory cytokines, and Glial fibrillary acidic protein (GFAP) recently emerged as biomarkers in TBI. In addition, several approved therapeutic entities have been explored to target existing and newly identified drug-targets in TBI. However, drug delivery in TBI is hampered due to disruption of blood-brain barrier (BBB) in secondary TBI, as well as inadequate drug-targeting and retention effect. Colloidal therapeutics appeared helpful in providing enhanced drug availability to the brain owing to definite targeting strategies. Moreover, immense efforts have been put together to achieve increased bioavailability of therapeutics to TBI by devising effective targeting strategies. The potential of colloidal therapeutics to efficiently deliver drugs at the site of injury and down-regulate the mediators of TBI are serving as novel policies in the management of TBI. Therefore, in present manuscript, we have illuminated a myriad of molecular-targets currently identified and recognized in TBI. Moreover, particular emphasis is given to frame armamentarium of repurpose drugs which could be utilized to block molecular targets in TBI in addition to drug delivery barriers. The critical role of colloidal therapeutics such as liposomes, nanoparticles, dendrimers, and exosomes in drug delivery to TBI through invasive and non-invasive routes has also been highlighted.
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Affiliation(s)
- Shristi Arya
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Deepankar Bahuguna
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Gopal Bajad
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Soham Loharkar
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Pawan Devangan
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Dharmendra Kumar Khatri
- Department of Biological Sciences, National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Shashi Bala Singh
- Department of Biological Sciences, National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Jitender Madan
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India.
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Beri A, Pisulkar SG, Bansod AV, Dahihandekar C. Paradigm Shift in Materials for Skull Reconstruction Facilitated by Science and Technological Integration. Cureus 2022; 14:e28731. [PMID: 36204019 PMCID: PMC9528855 DOI: 10.7759/cureus.28731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 09/03/2022] [Indexed: 12/04/2022] Open
Abstract
The surgical repair of a bone deficiency in the skull caused by a prior procedure or accident is known as cranioplasty. There are various types of cranioplasties, but the majority entail raising the scalp and reshaping the skull using either the original piece of bone from the skull or a specially molded graft created from Titanium (plate or mesh), artificial bone in place of, a stable biomaterial (prefabricated customized implant to match the exact contour and shape of the skull). Cranioplasty, one of the oldest surgical treatments for cranial abnormalities, has undergone several changes throughout the years to discover the best material to improve patient outcomes. Various materials have been utilized in cranioplasty throughout history. As biomedical technology progresses, surgeons will have access to new materials. There is still no agreement on the optimum material, and research into biologic and nonbiologic alternatives is ongoing in the hopes of finding the finest reconstruction material. The materials and techniques used in cranioplasty are covered in this article.
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Secondary Mechanisms of Neurotrauma: A Closer Look at the Evidence. Diseases 2022; 10:diseases10020030. [PMID: 35645251 PMCID: PMC9149951 DOI: 10.3390/diseases10020030] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/18/2022] [Accepted: 05/19/2022] [Indexed: 11/16/2022] Open
Abstract
Traumatic central nervous system injury is a leading cause of neurological injury worldwide. While initial neuroresuscitative efforts are focused on ameliorating the effects of primary injury through patient stabilization, secondary injury in neurotrauma is a potential cause of cell death, oxidative stress, and neuroinflammation. These secondary injuries lack defined therapy. The major causes of secondary injury in neurotrauma include endoplasmic reticular stress, mitochondrial dysfunction, and the buildup of reactive oxygen or nitrogenous species. Stress to the endoplasmic reticulum in neurotrauma results in the overactivation of the unfolded protein response with subsequent cell apoptosis. Mitochondrial dysfunction can lead to the release of caspases and the buildup of reactive oxygen species; several characteristics make the central nervous system particularly susceptible to oxidative damage. Together, endoplasmic reticulum, mitochondrial, and oxidative stress can have detrimental consequences, beginning moments and lasting days to months after the primary injury. Understanding these causative pathways has led to the proposal of various potential treatment options.
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Nardone M, McCarthy M, Ardern CI, Nield LE, Toleva O, Cantor WJ, Miner SES. Concurrently Low Coronary Flow Reserve and Low Index of Microvascular Resistance Are Associated With Elevated Resting Coronary Flow in Patients With Chest Pain and Nonobstructive Coronary Arteries. Circ Cardiovasc Interv 2022; 15:e011323. [PMID: 35135301 DOI: 10.1161/circinterventions.121.011323] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Coronary microvascular function can be distinctly quantified using the coronary flow reserve (CFR) and index of microvascular resistance (IMR). Patients with low CFR can present with low or high IMR, although the prevalence and clinical characteristics of these patient groups remain unclear. METHODS One hundred ninety-nine patients underwent coronary microvascular assessments using coronary thermodilution techniques. A pressure-temperature sensor-tipped guidewire measured proximal and distal coronary pressure, whereas the inverse of the mean transit time to room temperature saline was used to measure coronary blood flow. The CFR and IMR were quantified during adenosine and acetylcholine hyperemia. RESULTS Low adenosine and acetylcholine CFR was observed in 70 and 49 patients, respectively, whereas low CFR/low IMR to adenosine and acetylcholine was observed in 39(56%) and 19(39%) patients, respectively. Despite similar adenosine CFR, patients with low CFR/low IMR had increased resting (2.8±1.2 versus 1.3±0.4s-1) and hyperemic coronary blood flow (4.8±1.5 versus 2.1±0.5s-1) compared with patients with low CFR/high IMR (both P<0.01). The same pattern was observed in response to acetylcholine. Patients with low CFR/low IMR to adenosine were younger (56±12 versus 63±10 years), women (84% versus 66%), had fewer coronary risk factors (1.1±1.0 versus 1.6±1.1), lower hemoglobin A1c (5.8±0.7 versus 6.1±0.9 mmol/L), and thinner septal thickness (8.5±2.5 versus 9.9±1.6 mm) compared with patients with low CFR/high IMR to adenosine (all P<0.05). CONCLUSIONS Low CFR/low IMR to adenosine and acetylcholine are associated with elevated resting coronary blood flow and preserved hyperemic coronary blood flow. These patients present with distinct phenotypic characteristics. Simultaneous CFR and IMR measures appear necessary to differentiate these endotypes.
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Affiliation(s)
- Massimo Nardone
- Division of Cardiology, Southlake Regional Health Centre, Newmarket, Ontario, Canada (M.M., W.J.C., S.E.S.M.)
| | - Mary McCarthy
- Department of Human Health and Nutritional Sciences, University of Guelph, Ontario, Canada (M.N.)
| | - Chris I Ardern
- School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada (C.I.A., S.E.S.M.)
| | - Lynne E Nield
- Department of Medicine, University of Toronto, Ontario, Canada (L.E.N., W.J.C., S.E.S.M.)
| | - Olga Toleva
- School of Medicine, Emory University, Atlanta, GA (O.T.)
| | - Warren J Cantor
- Division of Cardiology, Southlake Regional Health Centre, Newmarket, Ontario, Canada (M.M., W.J.C., S.E.S.M.).,Department of Medicine, University of Toronto, Ontario, Canada (L.E.N., W.J.C., S.E.S.M.)
| | - Steven E S Miner
- Division of Cardiology, Southlake Regional Health Centre, Newmarket, Ontario, Canada (M.M., W.J.C., S.E.S.M.).,School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada (C.I.A., S.E.S.M.).,Department of Medicine, University of Toronto, Ontario, Canada (L.E.N., W.J.C., S.E.S.M.)
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Irrera N, Russo M, Pallio G, Bitto A, Mannino F, Minutoli L, Altavilla D, Squadrito F. The Role of NLRP3 Inflammasome in the Pathogenesis of Traumatic Brain Injury. Int J Mol Sci 2020; 21:ijms21176204. [PMID: 32867310 PMCID: PMC7503761 DOI: 10.3390/ijms21176204] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 12/18/2022] Open
Abstract
Traumatic brain injury (TBI) represents an important problem of global health. The damage related to TBI is first due to the direct injury and then to a secondary phase in which neuroinflammation plays a key role. NLRP3 inflammasome is a component of the innate immune response and different diseases, such as neurodegenerative diseases, are characterized by NLRP3 activation. This review aims to describe NLRP3 inflammasome and the consequences related to its activation following TBI. NLRP3, caspase-1, IL-1β, and IL-18 are significantly upregulated after TBI, therefore, the use of nonspecific, but mostly specific NLRP3 inhibitors is useful to ameliorate the damage post-TBI characterized by neuroinflammation. Moreover, NLRP3 and the molecules associated with its activation may be considered as biomarkers and predictive factors for other neurodegenerative diseases consequent to TBI. Complications such as continuous stimuli or viral infections, such as the SARS-CoV-2 infection, may worsen the prognosis of TBI, altering the immune response and increasing the neuroinflammatory processes related to NLRP3, whose activation occurs both in TBI and in SARS-CoV-2 infection. This review points out the role of NLRP3 in TBI and highlights the hypothesis that NLRP3 may be considered as a potential therapeutic target for the management of neuroinflammation in TBI.
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Affiliation(s)
- Natasha Irrera
- Department of Clinical and Experimental Medicine, University of Messina, c/o AOU Policlinico G. Martino, Via C. Valeria Gazzi, 98,125 Messina, Italy; (N.I.); (M.R.); (G.P.); (A.B.); (F.M.); (L.M.)
| | - Massimo Russo
- Department of Clinical and Experimental Medicine, University of Messina, c/o AOU Policlinico G. Martino, Via C. Valeria Gazzi, 98,125 Messina, Italy; (N.I.); (M.R.); (G.P.); (A.B.); (F.M.); (L.M.)
| | - Giovanni Pallio
- Department of Clinical and Experimental Medicine, University of Messina, c/o AOU Policlinico G. Martino, Via C. Valeria Gazzi, 98,125 Messina, Italy; (N.I.); (M.R.); (G.P.); (A.B.); (F.M.); (L.M.)
| | - Alessandra Bitto
- Department of Clinical and Experimental Medicine, University of Messina, c/o AOU Policlinico G. Martino, Via C. Valeria Gazzi, 98,125 Messina, Italy; (N.I.); (M.R.); (G.P.); (A.B.); (F.M.); (L.M.)
| | - Federica Mannino
- Department of Clinical and Experimental Medicine, University of Messina, c/o AOU Policlinico G. Martino, Via C. Valeria Gazzi, 98,125 Messina, Italy; (N.I.); (M.R.); (G.P.); (A.B.); (F.M.); (L.M.)
| | - Letteria Minutoli
- Department of Clinical and Experimental Medicine, University of Messina, c/o AOU Policlinico G. Martino, Via C. Valeria Gazzi, 98,125 Messina, Italy; (N.I.); (M.R.); (G.P.); (A.B.); (F.M.); (L.M.)
| | - Domenica Altavilla
- Department of Biomedical, Dental, Morphologic and Functional Imaging Sciences, University of Messina, c/o AOU Policlinico G. Martino, Via C. Valeria Gazzi, 98,125 Messina, Italy;
| | - Francesco Squadrito
- Department of Clinical and Experimental Medicine, University of Messina, c/o AOU Policlinico G. Martino, Via C. Valeria Gazzi, 98,125 Messina, Italy; (N.I.); (M.R.); (G.P.); (A.B.); (F.M.); (L.M.)
- Correspondence:
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Pavlova V, Filipova E, Uzunova K, Kalinov K, Vekov T. Pioglitazone Therapy and Fractures: Systematic Review and Meta- Analysis. Endocr Metab Immune Disord Drug Targets 2019; 18:502-507. [PMID: 29683100 DOI: 10.2174/1871530318666180423121833] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 03/22/2018] [Accepted: 04/03/2018] [Indexed: 01/01/2023]
Abstract
INTRODUCTION Thiazolidinediones are a group of synthetic medications used in type 2 diabetes treatment. Among available thiazolidinediones, pioglitazone is gaining increased attention due to its lower cardiovascular risk in type 2 diabetes mellitus sufferers and seems a promising future therapy. Accumulating evidence suggests that diabetic patients may exert bone fractures due to such treatments. Simultaneously, the female population is thought to be at greater risk. Still, the safety outcomes of pioglitazone treatment especially in terms of fractures are questionable and need to be clarified. METHODS We searched MEDLINE, Scopus, PsyInfo, eLIBRARY.ru electronic databases and clinical trial registries for studies reporting an association between pioglitazone and bone fractures in type 2 diabetes mellitus patients published before Feb 15, 2016. Among 1536 sources that were initially identified, six studies including 3172 patients proved relevant for further analysis. RESULT Pooled analysis of the included studies demonstrated that after treatment with pioglitazone patients with type 2 diabetes mellitus had no significant increase in fracture risk [odds ratio (OR): 1.18, 95% confidence interval (CI): 0.82 to 1.71, p=0.38] compared to other antidiabetic drugs or placebo. Additionally, no association was found between the risk of fractures and pioglitazone therapy duration. The gender of the patients involved was not relevant to the risk of fractures, too. CONCLUSION Pioglitazone treatment in diabetic patients does not increase the incidence of bone fractures. Moreover, there is no significant association between patients' fractures, their gender and the period of exposure to pioglitazone. Additional longitudinal studies need to be undertaken to obtain more detailed information on bone fragility and pioglitazone therapy.
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Affiliation(s)
- Velichka Pavlova
- Science Department, Tchaikapharma High-Quality Medicines, Inc., 1 G.M. Dimitrov Blvd, 1172 Sofia, Bulgaria
| | - Elena Filipova
- Science Department, Tchaikapharma High-Quality Medicines, Inc., 1 G.M. Dimitrov Blvd, 1172 Sofia, Bulgaria
| | - Katya Uzunova
- Science Department, Tchaikapharma High-Quality Medicines, Inc., 1 G.M. Dimitrov Blvd, 1172 Sofia, Bulgaria
| | - Krassimir Kalinov
- Department of Informatics, New Bulgarian University, 21 Montevideo Street, 1618 Sofia, Bulgaria
| | - Toni Vekov
- Medical University, Faculty of Pharmacy, Dean, Pleven, Bulgaria
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Abstract
Mild traumatic brain injury (mTBI) represents a significant public healthcare concern, accounting for the majority of all head injuries. While symptoms are generally transient, some patients go on to experience long-term cognitive impairments and additional mild impacts can result in exacerbated and persisting negative outcomes. To date, studies using a range of experimental models have reported chronic behavioral deficits in the presence of axonal injury and inflammation following repeated mTBI; assessments of oxidative stress and myelin pathology have thus far been limited. However, some models employed induced acute focal damage more suggestive of moderate–severe brain injury and are therefore not relevant to repeated mTBI. Given that the nature of mechanical loading in TBI is implicated in downstream pathophysiological changes, the mechanisms of damage and chronic consequences of single and repeated closed-head mTBI remain to be fully elucidated. This review covers literature on potential mechanisms of damage following repeated mTBI, integrating known mechanisms of pathology underlying moderate–severe TBIs, with recent studies on adult rodent models relevant to direct impact injuries rather than blast-induced damage. Pathology associated with excitotoxicity and cerebral blood flow-metabolism uncoupling, oxidative stress, cell death, blood-brain barrier dysfunction, astrocyte reactivity, microglial activation, diffuse axonal injury, and dysmyelination is discussed, followed by a summary of functional deficits and preclinical assessments of therapeutic strategies. Comprehensive characterization of the pathology underlying delayed and persisting deficits following repeated mTBI is likely to facilitate further development of therapeutic strategies to limit long-term sequelae.
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Affiliation(s)
- Brooke Fehily
- 1 Experimental and Regenerative Neurosciences, School of Biological sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Melinda Fitzgerald
- 1 Experimental and Regenerative Neurosciences, School of Biological sciences, The University of Western Australia, Perth, Western Australia, Australia.,2 Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia, Australia.,3 Perron Institute for Neurological and Translational Science, Sarich Neuroscience Research Institute, Nedlands, Western Australia, Australia
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Tu TW, Ibrahim WG, Jikaria N, Munasinghe JP, Witko JA, Hammoud DA, Frank JA. On the detection of cerebral metabolic depression in experimental traumatic brain injury using Chemical Exchange Saturation Transfer (CEST)-weighted MRI. Sci Rep 2018; 8:669. [PMID: 29330386 PMCID: PMC5766554 DOI: 10.1038/s41598-017-19094-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 12/21/2017] [Indexed: 12/13/2022] Open
Abstract
Metabolic abnormalities are commonly observed in traumatic brain injury (TBI) patients exhibiting long-term neurological deficits. This study investigated the feasibility and reproducibility of using chemical exchange saturation transfer (CEST) MRI to detect cerebral metabolic depression in experimental TBI. Phantom and in vivo CEST experiments were conducted at 9.4 Tesla to optimize the selective saturation for enhancing the endogenous contrast-weighting of the proton exchanges over the range of glucose proton chemical shifts (glucoCEST) in the resting rat brain. The optimized glucoCEST-weighted imaging was performed on a closed-head model of diffuse TBI in rats with 2-deoxy-D-[14C]-glucose (2DG) autoradiography validation. The results demonstrated that saturation duration of 1‒2 seconds at pulse powers 1.5‒2µT resulted in an improved contrast-to-noise ratio between the gray and white matter comparable to 2DG autoradiographs. The intrasubject (n = 4) and intersubject (n = 3) coefficient of variations for repeated glucoCEST acquisitions (n = 4) ranged between 8‒16%. Optimization for the TBI study revealed that glucoCEST-weighted images with 1.5μT power and 1 s saturation duration revealed the greatest changes in contrast before and after TBI, and positively correlated with 2DG autoradiograph (r = 0.78, p < 0.01, n = 6) observations. These results demonstrate that glucoCEST-weighted imaging may be useful in detecting metabolic abnormalities following TBI.
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Affiliation(s)
- Tsang-Wei Tu
- Frank Laboratory, Radiology & Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States. .,Center for Neuroscience and Regenerative Medicine, Henry Jackson Foundation, Bethesda, MD, United States. .,Molecular Imaging Laboratory, Department of Radiology, Howard University, Washington, DC, United States.
| | - Wael G Ibrahim
- Center for Infectious Disease Imaging, Radiology & Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Neekita Jikaria
- Frank Laboratory, Radiology & Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States.,Center for Neuroscience and Regenerative Medicine, Henry Jackson Foundation, Bethesda, MD, United States.,Acute Stroke Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Jeeva P Munasinghe
- Mouse Imaging Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Jaclyn A Witko
- Frank Laboratory, Radiology & Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States.,Center for Neuroscience and Regenerative Medicine, Henry Jackson Foundation, Bethesda, MD, United States
| | - Dima A Hammoud
- Center for Infectious Disease Imaging, Radiology & Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Joseph A Frank
- Frank Laboratory, Radiology & Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, United States.,National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, United States
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12
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Decreased susceptibility of major veins in mild traumatic brain injury is correlated with post-concussive symptoms: A quantitative susceptibility mapping study. NEUROIMAGE-CLINICAL 2017; 15:625-632. [PMID: 28664033 PMCID: PMC5479969 DOI: 10.1016/j.nicl.2017.06.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 06/04/2017] [Accepted: 06/07/2017] [Indexed: 01/28/2023]
Abstract
Cerebral venous oxygen saturation (SvO2) is an important biomarker of brain function. In this study, we aimed to explore the relative changes of regional cerebral SvO2 among axonal injury (AI) patients, non-AI patients and healthy controls (HCs) using quantitative susceptibility mapping (QSM). 48 patients and 32 HCs were enrolled. The patients were divided into two groups depending on the imaging based evidence of AI. QSM was used to measure the susceptibility of major cerebral veins. Nonparametric testing was performed for susceptibility differences among the non-AI patient group, AI patient group and healthy control group. Correlation was performed between the susceptibility of major cerebral veins, elapsed time post trauma (ETPT) and post-concussive symptom scores. The ROC analysis was performed for the diagnostic efficiency of susceptibility to discriminate mTBI patients from HCs. The susceptibility of the straight sinus in non-AI and AI patients was significantly lower than that in HCs (P < 0.001, P = 0.004, respectively, Bonferroni corrected), which may indicate an increased regional cerebral SvO2 in patients. The susceptibility of the straight sinus in non-AI patients positively correlated with ETPT (r = 0.573, P = 0.003, FDR corrected) while that in AI patients negatively correlated with the Rivermead Post Concussion Symptoms Questionnaire scores (r = − 0.582, P = 0.018, FDR corrected). The sensitivity, specificity and AUC values of susceptibility for the discrimination between mTBI patients and HCs were 88%, 69% and 0.84. In conclusion, the susceptibility of the straight sinus can be used as a biomarker to monitor the progress of mild TBI and to differentiate mTBI patients from healthy controls. Mild traumatic brain injury caused decreased venous susceptibility. The venous susceptibility can discriminate mTBI patients from healthy controls. Decreased susceptibility may indicate increased venous oxygen saturation (SvO2). Increased SvO2 of patients without axonal injury decreased with time post-injury. Increased SvO2 of axonal injury patients indicated severe post-concussive symptoms.
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13
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Harris NG, Verley DR, Gutman BA, Sutton RL. Bi-directional changes in fractional anisotropy after experiment TBI: Disorganization and reorganization? Neuroimage 2016; 133:129-143. [PMID: 26975556 PMCID: PMC4889542 DOI: 10.1016/j.neuroimage.2016.03.012] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 03/02/2016] [Accepted: 03/03/2016] [Indexed: 11/26/2022] Open
Abstract
The current dogma to explain the extent of injury-related changes following rodent controlled cortical impact (CCI) injury is a focal injury with limited axonal pathology. However, there is in fact good, published histologic evidence to suggest that axonal injury is far more widespread in this model than generally thought. One possibility that might help to explain this is the often-used region-of-interest data analysis approach taken by experimental traumatic brain injury (TBI) diffusion tensor imaging (DTI) or histologic studies that might miss more widespread damage, when compared to the whole brain, statistically robust method of tract-based analysis used more routinely in clinical research. To determine the extent of DTI changes in this model, we acquired in vivo DTI data before and at 1 and 4weeks after CCI injury in 17 adult male rats and analyzed parametric maps of fractional anisotropy (FA), axial, radial, and mean diffusivity (AD, RD, MD), tensor mode (MO), and fiber tract density (FTD) using tract-based spatial statistics. Contusion volume was used as a surrogate marker of injury severity and as a covariate for investigating severity dependence of the data. Mean fiber tract length was also computed from seeds in the cortical spinal tract regions. In parallel experiments (n=3-5/group), we investigated corpus callosum neurofilaments and demyelination using immunohistochemistry (IHC) at 3days and 6weeks, callosal tract patency using dual-label retrograde tract tracing at 5weeks, and the contribution of gliosis to DTI parameter maps using GFAP IHC at 4weeks post-injury. The data show widespread ipsilateral regions of significantly reduced FA at 1week post-injury, driven by temporally changing values of AD, RD, and MD that persist to 4weeks. Demyelination, retrograde label tract loss, and reductions in MO (tract degeneration) and FTD were shown to underpin these data. Significant FA increases occurred in subcortical and corticospinal tract regions that were spatially distinct from regions of FA decrease, grossly affected gliotic areas, and MO changes. However, there was good spatial correspondence between regions of increased FA and areas of increased FTD and mean fiber length. We discuss these widespread changes in DTI parameters in terms of axonal degeneration and potential reorganization, with reference to a resting state fMRI companion paper (Harris et al., 2016, Exp. Neurol. 227:124-138) that demonstrated altered functional connectivity data acquired from the same rats used in this study.
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Affiliation(s)
- N G Harris
- UCLA Brain injury Research Center, Department of Neurosurgery, University of California, Los Angeles, Los Angeles, USA.
| | - D R Verley
- UCLA Brain injury Research Center, Department of Neurosurgery, University of California, Los Angeles, Los Angeles, USA
| | - B A Gutman
- Department of Neurology, Imaging Genetics Center, Keck/USC School of Medicine, Institute for Neuroimaging and Informatics, University of Southern California, Los Angeles, CA, USA
| | - R L Sutton
- UCLA Brain injury Research Center, Department of Neurosurgery, University of California, Los Angeles, Los Angeles, USA
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14
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Harris NG, Verley DR, Gutman BA, Thompson PM, Yeh HJ, Brown JA. Disconnection and hyper-connectivity underlie reorganization after TBI: A rodent functional connectomic analysis. Exp Neurol 2016; 277:124-138. [PMID: 26730520 PMCID: PMC4761291 DOI: 10.1016/j.expneurol.2015.12.020] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 12/01/2015] [Accepted: 12/22/2015] [Indexed: 10/22/2022]
Abstract
While past neuroimaging methods have contributed greatly to our understanding of brain function after traumatic brain injury (TBI), resting state functional MRI (rsfMRI) connectivity methods have more recently provided a far more unbiased approach with which to monitor brain circuitry compared to task-based approaches. However, current knowledge on the physiologic underpinnings of the correlated blood oxygen level dependent signal, and how changes in functional connectivity relate to reorganizational processes that occur following injury is limited. The degree and extent of this relationship remain to be determined in order that rsfMRI methods can be fully adapted for determining the optimal timing and type of rehabilitative interventions that can be used post-TBI to achieve the best outcome. Very few rsfMRI studies exist after experimental TBI and therefore we chose to acquire rsfMRI data before and at 7, 14 and 28 days after experimental TBI using a well-known, clinically-relevant, unilateral controlled cortical impact injury (CCI) adult rat model of TBI. This model was chosen since it has widespread axonal injury, a well-defined time-course of reorganization including spine, dendrite, axonal and cortical map changes, as well as spontaneous recovery of sensorimotor function by 28 d post-injury from which to interpret alterations in functional connectivity. Data were co-registered to a parcellated rat template to generate adjacency matrices for network analysis by graph theory. Making no assumptions about direction of change, we used two-tailed statistical analysis over multiple brain regions in a data-driven approach to access global and regional changes in network topology in order to assess brain connectivity in an unbiased way. Our main hypothesis was that deficits in functional connectivity would become apparent in regions known to be structurally altered or deficient in axonal connectivity in this model. The data show the loss of functional connectivity predicted by the structural deficits, not only within the primary sensorimotor injury site and pericontused regions, but the normally connected homotopic cortex, as well as subcortical regions, all of which persisted chronically. Especially novel in this study is the unanticipated finding of widespread increases in connection strength that dwarf both the degree and extent of the functional disconnections, and which persist chronically in some sensorimotor and subcortically connected regions. Exploratory global network analysis showed changes in network parameters indicative of possible acutely increased random connectivity and temporary reductions in modularity that were matched by local increases in connectedness and increased efficiency among more weakly connected regions. The global network parameters: shortest path-length, clustering coefficient and modularity that were most affected by trauma also scaled with the severity of injury, so that the corresponding regional measures were correlated to the injury severity most notably at 7 and 14 days and especially within, but not limited to, the contralateral cortex. These changes in functional network parameters are discussed in relation to the known time-course of physiologic and anatomic data that underlie structural and functional reorganization in this experiment model of TBI.
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Affiliation(s)
- N G Harris
- UCLA Brain Research Center, Department of Neurosurgery, University of California, Los Angeles, USA.
| | - D R Verley
- UCLA Brain Research Center, Department of Neurosurgery, University of California, Los Angeles, USA
| | - B A Gutman
- Imaging Genetics Center, Institute for Neuroimaging and Informatics, Department of Neurology, Keck/USC School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - P M Thompson
- Departments of Psychiatry, Engineering, Radiology, & Ophthalmology, Keck/USC School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - H J Yeh
- Department of Neurology, University of California, Los Angeles, USA
| | - J A Brown
- Department of Neurology, University of California at San Francisco School of Medicine, San Francisco, CA, USA
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15
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Prins ML, Matsumoto J. Metabolic Response of Pediatric Traumatic Brain Injury. J Child Neurol 2016; 31:28-34. [PMID: 25336427 PMCID: PMC4405388 DOI: 10.1177/0883073814549244] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 07/21/2014] [Indexed: 12/26/2022]
Abstract
Traumatic brain injury (TBI) in the pediatric brain presents unique challenges as the complex cascades of metabolic and biochemical responses to TBI are further complicated ongoing maturational changes of the developing brain. TBIs of all severities have been shown to significantly alter metabolism and hormones which impair the ability of the brain to process glucose for cellular energy. Under these conditions, the brain's primary fuel (glucose) becomes a less favorable fuel and the ability of the younger brain to revert to ketone metabolism can an advantage. This review addresses the potential of alternative substrate metabolic intervention as a logical pediatric TBI neuroprotective strategy.
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Affiliation(s)
- Mayumi L Prins
- Department of Neurosurgery, University of California Los Angeles, Los Angeles, CA, USA Brain Injury Research Center, University of California Los Angeles, Los Angeles, CA, USA
| | - Joyce Matsumoto
- Department of Pediatrics, Division of Pediatric Neurology, University of California Los Angeles, Los Angeles, CA, USA
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16
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Osier ND, Carlson SW, DeSana A, Dixon CE. Chronic Histopathological and Behavioral Outcomes of Experimental Traumatic Brain Injury in Adult Male Animals. J Neurotrauma 2015; 32:1861-82. [PMID: 25490251 PMCID: PMC4677114 DOI: 10.1089/neu.2014.3680] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The purpose of this review is to survey the use of experimental animal models for studying the chronic histopathological and behavioral consequences of traumatic brain injury (TBI). The strategies employed to study the long-term consequences of TBI are described, along with a summary of the evidence available to date from common experimental TBI models: fluid percussion injury; controlled cortical impact; blast TBI; and closed-head injury. For each model, evidence is organized according to outcome. Histopathological outcomes included are gross changes in morphology/histology, ventricular enlargement, gray/white matter shrinkage, axonal injury, cerebrovascular histopathology, inflammation, and neurogenesis. Behavioral outcomes included are overall neurological function, motor function, cognitive function, frontal lobe function, and stress-related outcomes. A brief discussion is provided comparing the most common experimental models of TBI and highlighting the utility of each model in understanding specific aspects of TBI pathology. The majority of experimental TBI studies collect data in the acute postinjury period, but few continue into the chronic period. Available evidence from long-term studies suggests that many of the experimental TBI models can lead to progressive changes in histopathology and behavior. The studies described in this review contribute to our understanding of chronic TBI pathology.
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Affiliation(s)
- Nicole D. Osier
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania
- School of Nursing, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Shaun W. Carlson
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Neurological Surgery, Brain Trauma Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Anthony DeSana
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania
- Seton Hill University, Greensburg, Pennsylvania
| | - C. Edward Dixon
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Neurological Surgery, Brain Trauma Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
- V.A. Pittsburgh Healthcare System, Pittsburgh, Pennsylvania
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17
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Acute Management of Children With Traumatic Brain Injury. CLINICAL PEDIATRIC EMERGENCY MEDICINE 2015. [DOI: 10.1016/j.cpem.2015.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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18
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Doshi H, Wiseman N, Liu J, Wang W, Welch RD, O’Neil BJ, Zuk C, Wang X, Mika V, Szaflarski JP, Haacke EM, Kou Z. Cerebral hemodynamic changes of mild traumatic brain injury at the acute stage. PLoS One 2015; 10:e0118061. [PMID: 25659079 PMCID: PMC4320047 DOI: 10.1371/journal.pone.0118061] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 01/05/2015] [Indexed: 12/03/2022] Open
Abstract
Mild traumatic brain injury (mTBI) is a significant public health care burden in the United States. However, we lack a detailed understanding of the pathophysiology following mTBI and its relation to symptoms and recovery. With advanced magnetic resonance imaging (MRI), we can investigate brain perfusion and oxygenation in regions known to be implicated in symptoms, including cortical gray matter and subcortical structures. In this study, we assessed 14 mTBI patients and 18 controls with susceptibility weighted imaging and mapping (SWIM) for blood oxygenation quantification. In addition to SWIM, 7 patients and 12 controls had cerebral perfusion measured with arterial spin labeling (ASL). We found increases in regional cerebral blood flow (CBF) in the left striatum, and in frontal and occipital lobes in patients as compared to controls (p = 0.01, 0.03, 0.03 respectively). We also found decreases in venous susceptibility, indicating increases in venous oxygenation, in the left thalamostriate vein and right basal vein of Rosenthal (p = 0.04 in both). mTBI patients had significantly lower delayed recall scores on the standardized assessment of concussion, but neither susceptibility nor CBF measures were found to correlate with symptoms as assessed by neuropsychological testing. The increased CBF combined with increased venous oxygenation suggests an increase in cerebral blood flow that exceeds the oxygen demand of the tissue, in contrast to the regional hypoxia seen in more severe TBI. This may represent a neuroprotective response following mTBI, which warrants further investigation.
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Affiliation(s)
- Hardik Doshi
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, United States of America
| | - Natalie Wiseman
- Department of Psychiatry and Behavioral Neurosciences Translational Neuroscience Program, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Jun Liu
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, United States of America
- Department of Radiology, Second Xiangya Hospital, School of Public Health, Central South University, Changsha, Hunan Province, China
| | - Wentao Wang
- College of Computer Science, South-Central University for Nationalities, Wuhan, China
| | - Robert D. Welch
- Department of Emergency Medicine, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Brian J. O’Neil
- Department of Emergency Medicine, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Conor Zuk
- Department of Radiology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Xiao Wang
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, United States of America
- Department of Radiology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- Zhengzhou University First Affiliated Hospital, Zhengzhou, Henan Province, China
| | - Valerie Mika
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, United States of America
- Department of Emergency Medicine, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Jerzy P. Szaflarski
- Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - E. Mark Haacke
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, United States of America
- Department of Radiology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Zhifeng Kou
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, United States of America
- Department of Psychiatry and Behavioral Neurosciences Translational Neuroscience Program, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- Department of Radiology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- * E-mail:
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19
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Bothe MK, Stover JF. Monitoring of acute traumatic brain injury in adults to prevent secondary brain damage. FUTURE NEUROLOGY 2014. [DOI: 10.2217/fnl.13.78] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
ABSTRACT: Traumatic brain injury is typically characterized by the primary injury initiating a cascade of pathologic changes that then lead to secondary brain injury. Secondary brain injury is amenable to different therapeutic options. Monitoring of otherwise occult pathologic changes involving oxygenation and metabolism is crucial for treatment decisions. Currently, decision-making is mainly based on measuring intracranial pressure and cerebral perfusion pressure. Importantly, extending neuromonitoring by including parameters reflecting cerebral perfusion, oxygenation and metabolism may improve treatment of traumatic brain injury patients by detecting neuronal damage despite optimal intracranial pressure or cerebral perfusion pressure and preventing unnecessarily aggressive treatment potentially causing local and systemic harm. In this review, the authors describe the advantages and disadvantages of contemporary, extended neuromonitoring methods in traumatic brain injury patients aimed at unmasking secondary brain damage as early as possible.
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Affiliation(s)
- Melanie K Bothe
- Fresenius Kabi Deutschland GmbH, Rathausplatz 3, 61348 Bad Homburg, Germany
| | - John F Stover
- Fresenius Kabi Deutschland GmbH, Rathausplatz 3, 61348 Bad Homburg, Germany
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20
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Prins M, Greco T, Alexander D, Giza CC. The pathophysiology of traumatic brain injury at a glance. Dis Model Mech 2013; 6:1307-15. [PMID: 24046353 PMCID: PMC3820255 DOI: 10.1242/dmm.011585] [Citation(s) in RCA: 241] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Traumatic brain injury (TBI) is defined as an impact, penetration or rapid movement of the brain within the skull that results in altered mental state. TBI occurs more than any other disease, including breast cancer, AIDS, Parkinson's disease and multiple sclerosis, and affects all age groups and both genders. In the US and Europe, the magnitude of this epidemic has drawn national attention owing to the publicity received by injured athletes and military personnel. This increased public awareness has uncovered a number of unanswered questions concerning TBI, and we are increasingly aware of the lack of treatment options for a crisis that affects millions. Although each case of TBI is unique and affected individuals display different degrees of injury, different regional patterns of injury and different recovery profiles, this review and accompanying poster aim to illustrate some of the common underlying neurochemical and metabolic responses to TBI. Recognition of these recurrent features could allow elucidation of potential therapeutic targets for early intervention.
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Affiliation(s)
- Mayumi Prins
- Department of Neurosurgery, UCLA, Los Angeles, CA 90095, USA
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21
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Harris NG, Nogueira MSM, Verley DR, Sutton RL. Chondroitinase enhances cortical map plasticity and increases functionally active sprouting axons after brain injury. J Neurotrauma 2013; 30:1257-69. [PMID: 23517225 DOI: 10.1089/neu.2012.2737] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The beneficial effect of interventions with chondroitinase ABC enzyme to reduce axon growth-inhibitory chondroitin sulphate side chains after central nervous system injuries has been mainly attributed to enhanced axonal sprouting. After traumatic brain injury (TBI), it is unknown whether newly sprouting axons that occur as a result of interventional strategies are able to functionally contribute to existing circuitry, and it is uncertain whether maladaptive sprouting occurs to increase the well-known risk for seizure activity after TBI. Here, we show that after a controlled cortical impact injury in rats, chondroitinase infusion into injured cortex at 30 min and 3 days reduced c-Fos⁺ cell staining resulting from the injury alone at 1 week postinjury, indicating that at baseline, abnormal spontaneous activity is likely to be reduced, not increased, with this type of intervention. c-Fos⁺ cell staining elicited by neural activity from stimulation of the affected forelimb 1 week after injury was significantly enhanced by chondroitinase, indicating a widespread effect on cortical map plasticity. Underlying this map plasticity was a larger contribution of neuronal, rather than glial cells and an absence of c-Fos⁺ cells surrounded by perineuronal nets that were normally present in stimulated naïve rats. After injury, chondroitin sulfate proteoglycan digestion produced the expected increase in growth-associated protein 43-positive axons and perikarya, of which a significantly greater number were double labeled for c-Fos after intervention with chondroitinase, compared to vehicle. These data indicate that chondroitinase produces significant gains in cortical map plasticity after TBI, and that either axonal sprouting and/or changes in perineuronal nets may underlie this effect. Chondroitinase dampens, rather than increases nonspecific c-Fos activity after brain injury, and induction of axonal sprouting is not maladaptive because greater numbers are functionally active and provide a significant contribution to forelimb circuitry after brain injury.
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Affiliation(s)
- Neil G Harris
- Department of Neurosurgery, David Geffen School of Medicine at UCLA, Box 957039, Los Angeles, CA 90095-7039, USA.
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22
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Bouzat P, Sala N, Payen JF, Oddo M. Beyond intracranial pressure: optimization of cerebral blood flow, oxygen, and substrate delivery after traumatic brain injury. Ann Intensive Care 2013; 3:23. [PMID: 23837598 PMCID: PMC3716965 DOI: 10.1186/2110-5820-3-23] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 06/25/2013] [Indexed: 02/17/2023] Open
Abstract
Monitoring and management of intracranial pressure (ICP) and cerebral perfusion pressure (CPP) is a standard of care after traumatic brain injury (TBI). However, the pathophysiology of so-called secondary brain injury, i.e., the cascade of potentially deleterious events that occur in the early phase following initial cerebral insult—after TBI, is complex, involving a subtle interplay between cerebral blood flow (CBF), oxygen delivery and utilization, and supply of main cerebral energy substrates (glucose) to the injured brain. Regulation of this interplay depends on the type of injury and may vary individually and over time. In this setting, patient management can be a challenging task, where standard ICP/CPP monitoring may become insufficient to prevent secondary brain injury. Growing clinical evidence demonstrates that so-called multimodal brain monitoring, including brain tissue oxygen (PbtO2), cerebral microdialysis and transcranial Doppler among others, might help to optimize CBF and the delivery of oxygen/energy substrate at the bedside, thereby improving the management of secondary brain injury. Looking beyond ICP and CPP, and applying a multimodal therapeutic approach for the optimization of CBF, oxygen delivery, and brain energy supply may eventually improve overall care of patients with head injury. This review summarizes some of the important pathophysiological determinants of secondary cerebral damage after TBI and discusses novel approaches to optimize CBF and provide adequate oxygen and energy supply to the injured brain using multimodal brain monitoring.
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Affiliation(s)
- Pierre Bouzat
- Department of Intensive Care Medicine, CHUV-University Hospital, Rue du Bugnon 46, BH 08,623, CH-1011 Lausanne, Switzerland.
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23
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Harris NG, Chen SF, Pickard JD. Cortical reorganization after experimental traumatic brain injury: a functional autoradiography study. J Neurotrauma 2013; 30:1137-46. [PMID: 23305562 PMCID: PMC3700473 DOI: 10.1089/neu.2012.2785] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Cortical sensorimotor (SM) maps are a useful readout for providing a global view of the underlying status of evoked brain function, as well as a gross overview of ongoing mechanisms of plasticity. Recent evidence in the rat controlled cortical impact (CCI) injury model shows that the ipsilesional (injured) hemisphere is temporarily permissive for axon sprouting. This would predict that size and spatial alterations in cortical maps may occur much earlier than previously tested and that they might be useful as potential markers of the postinjury plasticity period as well as indicators of outcome. We investigated the evolution of changes in brain activation evoked by affected hindlimb electrical stimulation at 4, 7, and 30 days following CCI or sham injury over the hindlimb cortical region of adult rats. [(14)C]-iodoantipyrine autoradiography was used to quantitatively examine the local cerebral blood flow changes in response to hindlimb stimulation as a marker for neuronal activity. The results show that although ipsilesional hindlimb SM activity was persistently depressed from 4 days, additional novel regions of ipsilesional activity appeared concurrently within SM barrel and S2 regions as well as posterior auditory cortex. Simultaneously with this was the appearance of evoked activity within the intact, contralesional cortex that was maximal at 4 and 7 days, compared to stimulated sham-injured rats, where activation was solely unilateral. By 30 days, however, contralesional activation had greatly subsided and existing ipsilesional activity was enhanced within the same novel cortical regions that were identified acutely. These data indicate that significant reorganization of the cortical SM maps occurs after injury that evolves with a particular postinjury time course. We discuss these data in terms of the known mechanisms of plasticity that are likely to underlie these map changes, with particular reference to the differences and similarities that exist between rodent models of stroke and traumatic brain injury.
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Affiliation(s)
- Neil G Harris
- UCLA Brain Injury Research Center, Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, California 90095-7039, USA.
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Prins ML, Alexander D, Giza CC, Hovda DA. Repeated mild traumatic brain injury: mechanisms of cerebral vulnerability. J Neurotrauma 2013; 30:30-8. [PMID: 23025820 DOI: 10.1089/neu.2012.2399] [Citation(s) in RCA: 231] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Among the 3.5 million annual new head injury cases is a subpopulation of children and young adults who experience repeated traumatic brain injury (TBI). The duration of vulnerability after a single TBI remains unknown, and biomarkers have yet to be determined. Decreases in glucose metabolism (cerebral metabolic rate of glucose [CMRglc]) are consistently observed after experimental and human TBI. In the current study, it is hypothesized that the duration of vulnerability is related to the duration of decreased CMRglc and that a single mild TBI (mTBI) increases the brain's vulnerability to a second insult for a period, during which a subsequent mTBI will worsen the outcome. Postnatal day 35 rats were given sham, single mTBI, or two mTBI at 24-h or 120-h intervals. (14)C-2-deoxy-D-glucose autoradiography was conducted at 1 or 3 days post-injury to calculate CMRglc. At 24 h after a single mTBI, CMRglc is decreased by 19% in both the parietal cortex and hippocampus, but approached sham levels by 3 days post-injury. When a second mTBI is introduced during the CMRglc depression of the first injury, the consequent CMRglc is depressed (36.5%) at 24 h and remains depressed (25%) at 3 days. In contrast, when the second mTBI is introduced after the metabolic recovery of the first injury, the consequent CMRglc depression is similar to that seen with a single injury. Results suggest that the duration of metabolic depression reflects the time-course of vulnerability to second injury in the juvenile brain and could serve as a valuable biomarker in establishing window of vulnerability guidelines.
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Affiliation(s)
- Mayumi L Prins
- Department of Neurosurgery, University of California, School of Medicine, Los Angeles, CA 90095, USA.
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Harris NG, Mironova YA, Chen SF, Richards HK, Pickard JD. Preventing flow-metabolism uncoupling acutely reduces axonal injury after traumatic brain injury. J Neurotrauma 2012; 29:1469-82. [PMID: 22321027 PMCID: PMC3335110 DOI: 10.1089/neu.2011.2161] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We have previously presented evidence that the development of secondary traumatic axonal injury is related to the degree of local cerebral blood flow (LCBF) and flow-metabolism uncoupling. We have now tested the hypothesis that augmenting LCBF in the acute stages after brain injury prevents further axonal injury. Data were acquired from rats with or without acetazolamide (ACZ) that was administered immediately following controlled cortical impact injury to increase cortical LCBF. Local cerebral metabolic rate for glucose (LCMRglc) and LCBF measurements were obtained 3 h post-trauma in the same rat via ¹⁸F-fluorodeoxyglucose and ¹⁴C-iodoantipyrine co-registered autoradiographic images, and compared to the density of damaged axonal profiles in adjacent sections, and in additional groups at 24 h used to assess different populations of injured axons stereologically. ACZ treatment significantly and globally elevated LCBF twofold above untreated-injured rats at 3 h (p<0.05), but did not significantly affect LCMRglc. As a result, ipsilateral LCMRglc:LCBF ratios were reduced by twofold to sham-control levels, and the density of β-APP-stained axons at 24 h was significantly reduced in most brain regions compared to the untreated-injured group (p<0.01). Furthermore, early LCBF augmentation prevented the injury-associated increase in the number of stained axons from 3-24 h. Additional robust stereological analysis of impaired axonal transport and neurofilament compaction in the corpus callosum and cingulum underlying the injury core confirmed the amelioration of β-APP axon density, and showed a trend, but no significant effect, on RMO14-positive axons. These data underline the importance of maintaining flow-metabolism coupling immediately after injury in order to prevent further axonal injury, in at least one population of injured axons.
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Affiliation(s)
- Neil G Harris
- Department of Neurosurgery, David Geffen School of Medicine at UCLA, Box 957039, Los Angeles, CA 90095-7039, USA.
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Johnström P, Bird JL, Davenport AP. Quantitative phosphor imaging autoradiography of radioligands for positron emission tomography. Methods Mol Biol 2012; 897:205-220. [PMID: 22674167 DOI: 10.1007/978-1-61779-909-9_10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Imaging using phosphor screens have increasingly been employed for the analysis of radioactive samples in molecular biology, pharmacology, and receptor autoradiography. The major advantages of phosphor screens compared to radiation sensitive film are their greatly increased sensitivity, reducing exposure times with at least one order of magnitude, and their increased linear dynamic range. These features make phosphor screens ideal for imaging short-lived radionuclides, where exposure times are limited, such as (11)C and (18)F widely used to label radioligands for positron emission tomography (PET). Phosphor imaging can also considerably reduce exposure times for weak β-particle emitters such as (3)H. In this chapter, we present methods for the characterization and evaluation of novel PET radioligands using quantitative phosphor imaging autoradiography.
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Marklund N, Hillered L. Animal modelling of traumatic brain injury in preclinical drug development: where do we go from here? Br J Pharmacol 2011; 164:1207-29. [PMID: 21175576 PMCID: PMC3229758 DOI: 10.1111/j.1476-5381.2010.01163.x] [Citation(s) in RCA: 178] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 12/02/2010] [Accepted: 12/06/2010] [Indexed: 11/26/2022] Open
Abstract
Traumatic brain injury (TBI) is the leading cause of death and disability in young adults. Survivors of TBI frequently suffer from long-term personality changes and deficits in cognitive and motor performance, urgently calling for novel pharmacological treatment options. To date, all clinical trials evaluating neuroprotective compounds have failed in demonstrating clinical efficacy in cohorts of severely injured TBI patients. The purpose of the present review is to describe the utility of animal models of TBI for preclinical evaluation of pharmacological compounds. No single animal model can adequately mimic all aspects of human TBI owing to the heterogeneity of clinical TBI. To successfully develop compounds for clinical TBI, a thorough evaluation in several TBI models and injury severities is crucial. Additionally, brain pharmacokinetics and the time window must be carefully evaluated. Although the search for a single-compound, 'silver bullet' therapy is ongoing, a combination of drugs targeting various aspects of neuroprotection, neuroinflammation and regeneration may be needed. In summary, finding drugs and prove clinical efficacy in TBI is a major challenge ahead for the research community and the drug industry. For a successful translation of basic science knowledge to the clinic to occur we believe that a further refinement of animal models and functional outcome methods is important. In the clinical setting, improved patient classification, more homogenous patient cohorts in clinical trials, standardized treatment strategies, improved central nervous system drug delivery systems and monitoring of target drug levels and drug effects is warranted.
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Affiliation(s)
- Niklas Marklund
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala University Hospital, Uppsala, Sweden.
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Haacke EM, Duhaime AC, Gean AD, Riedy G, Wintermark M, Mukherjee P, Brody DL, DeGraba T, Duncan TD, Elovic E, Hurley R, Latour L, Smirniotopoulos JG, Smith DH. Common data elements in radiologic imaging of traumatic brain injury. J Magn Reson Imaging 2011; 32:516-43. [PMID: 20815050 DOI: 10.1002/jmri.22259] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Traumatic brain injury (TBI) has a poorly understood pathology. Patients suffer from a variety of physical and cognitive effects that worsen as the type of trauma worsens. Some noninvasive insights into the pathophysiology of TBI are possible using magnetic resonance imaging (MRI), computed tomography (CT), and many other forms of imaging as well. A recent workshop was convened to evaluate the common data elements (CDEs) that cut across the imaging field and given the charge to review the contributions of the various imaging modalities to TBI and to prepare an overview of the various clinical manifestations of TBI and their interpretation. Technical details regarding state-of-the-art protocols for both MRI and CT are also presented with the hope of guiding current and future research efforts as to what is possible in the field. Stress was also placed on the potential to create a database of CDEs as a means to best record information from a given patient from the reading of the images.
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Affiliation(s)
- E Mark Haacke
- Department of Radiology and Biomedical Engineering, Wayne State University, Detroit, Michigan 48201, USA.
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Prins ML, Hovda DA. The effects of age and ketogenic diet on local cerebral metabolic rates of glucose after controlled cortical impact injury in rats. J Neurotrauma 2010; 26:1083-93. [PMID: 19226210 DOI: 10.1089/neu.2008.0769] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Previous studies from our laboratory have shown the neuroprotective potential of ketones after TBI in the juvenile brain. It is our premise that acutely after TBI, glucose may not be the optimum fuel and decreasing metabolism of glucose in the presence of an alternative substrate will improve cellular metabolism and recovery. The current study addresses whether TBI will induce age-related differences in the cerebral metabolic rates for glucose (CMRglc) after cortical controlled impact (CCI) and whether ketone metabolism will further decrease CMRglc after injury. Postnatal day 35 (PND35; n = 48) and PND70 (n = 42) rats were given either sham or CCI injury and placed on either a standard or a ketogenic (KG) diet. CMRglc studies using (14)C-2 deoxy-D-glucose autoradiography were conducted on days 1, 3, or 7 post-injury. PND35 and PND70 standard-fed CCI-injured rats exhibited no significant neocortical differences in CMRglc magnitude or time course compared to controls. Measurement of contusion volume also indicated no age differences in response to TBI. However, PND35 subcortical structures showed earlier metabolic recovery compared to controls than PND70. Ketosis induced by the KG diet was shown to affect CMRglc in an age-dependent manner after TBI. The presence of ketones after injury further reduced CMRglc in PND35 and normalized CMRglc in PND70 rats at 7 days bilaterally after injury. The changes in CMRglc seen in PND35 TBI rats on the KG diet were associated with decreased contusion volume. These results suggest that conditions of reduced glucose utilization and increased alternative substrate metabolism may be preferable acutely after TBI in the younger rat.
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Affiliation(s)
- Mayumi L Prins
- Department of Neurosurgery, UCLA Brain Injury Research Center, Los Angeles, California 90095-7039, USA.
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Harris NG, Mironova YA, Hovda DA, Sutton RL. Pericontusion axon sprouting is spatially and temporally consistent with a growth-permissive environment after traumatic brain injury. J Neuropathol Exp Neurol 2010; 69:139-54. [PMID: 20084019 PMCID: PMC2821052 DOI: 10.1097/nen.0b013e3181cb5bee] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
We previously reported that pericontusional extracellular chondroitin sulfate proteoglycans (CSPGs) are profoundly reduced for 3 weeks after experimental traumatic brain injury, indicating a potential growth-permissive window for plasticity. Here, we investigate the extracellular environment of sprouting neurons after controlled cortical impact injury in adult rats to determine the spatial and temporal arrangement of inhibitory and growth-promoting molecules in relation to growth-associated protein 43-positive (GAP43+) neurons. Spontaneous cortical sprouting was maximal in pericontused regions at 7 and 14 days after injury but absent by 28 days. Perineuronal nets containing CSPGs were reduced at 7 days after injury in the pericontused region (p < 0.05), which was commensurate with a reduction in extracellular CSPGs. Sprouting was restricted to the perineuronal nets and CSPG-deficient regions at 7 days, indicating that the pericontused region is temporarily and spatially permissive to new growth. At this time point,GAP43+ neurons were associated with brain regions containing cells positive for polysialic acid neural cell adhesion molecule but not with fibronectin-positive cells. Brain-derived neurotrophic factor was reduced in the immediate pericontused region at 7 days. Along with prior Western blot evidence, these data suggest that a lowered intrinsic growth stimulus, together with a later return of growth-inhibitory CSPGs, may contribute to the ultimate disappearance of sprouting neurons after traumatic brain injury.
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Affiliation(s)
- Neil G Harris
- UCLA Brain Injury Research Center, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-7039, USA.
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Harris NG, Carmichael ST, Hovda DA, Sutton RL. Traumatic brain injury results in disparate regions of chondroitin sulfate proteoglycan expression that are temporally limited. J Neurosci Res 2010; 87:2937-50. [PMID: 19437549 DOI: 10.1002/jnr.22115] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Axonal injury is a major hallmark of traumatic brain injury (TBI), and it seems likely that therapies directed toward enhancing axon repair could potentially improve functional outcomes. One potential target is chondroitin sulfate proteoglycans (CSPGs), which are major axon growth inhibitory molecules that are generally, but not always, up-regulated after central nervous system injury. The current study was designed to determine temporal changes in cerebral cortical mRNA or protein expression levels of CSPGs and to determine their regional localization and cellular association by using immunohistochemistry in a controlled cortical impact model of TBI. The results showed significant increases in versican mRNA at 4 and 14 days after TBI but no change in neurocan, aggrecan, or phosphacan. Semiquantitative Western blot (WB) analysis of cortical CSPG protein expression revealed a significant ipsilateral decrease of all CSPGs at 1 day after TBI. Lower CSPG protein levels were sustained until at least 14 days, after which the levels began to normalize. Immunohistochemistry data confirm previous reports of regional increases in CSPG proteins after CNS injury, seen primarily within the developing glial scar after TBI, but also corroborate the WB data by revealing wide areas of pericontusional tissue that are deficient in both extracellular and perineuronal net-associated CSPGs. Given the evidence that CSPGs are largely inhibitory to axonal growth, we interpret these data to indicate a potential for regional spontaneous plasticity after TBI. If this were the case, the gradual normalization of CSPG proteins over time postinjury would suggest that this may be temporally as well as regionally limited.
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Affiliation(s)
- N G Harris
- The UCLA Brain Injury Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California 90095-7039, USA.
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Paulson OB, Hasselbalch SG, Rostrup E, Knudsen GM, Pelligrino D. Cerebral blood flow response to functional activation. J Cereb Blood Flow Metab 2010; 30:2-14. [PMID: 19738630 PMCID: PMC2872188 DOI: 10.1038/jcbfm.2009.188] [Citation(s) in RCA: 173] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Cerebral blood flow (CBF) and cerebral metabolic rate are normally coupled, that is an increase in metabolic demand will lead to an increase in flow. However, during functional activation, CBF and glucose metabolism remain coupled as they increase in proportion, whereas oxygen metabolism only increases to a minor degree-the so-called uncoupling of CBF and oxidative metabolism. Several studies have dealt with these issues, and theories have been forwarded regarding the underlying mechanisms. Some reports have speculated about the existence of a potentially deficient oxygen supply to the tissue most distant from the capillaries, whereas other studies point to a shift toward a higher degree of non-oxidative glucose consumption during activation. In this review, we argue that the key mechanism responsible for the regional CBF (rCBF) increase during functional activation is a tight coupling between rCBF and glucose metabolism. We assert that uncoupling of rCBF and oxidative metabolism is a consequence of a less pronounced increase in oxygen consumption. On the basis of earlier studies, we take into consideration the functional recruitment of capillaries and attempt to accommodate the cerebral tissue's increased demand for glucose supply during neural activation with recent evidence supporting a key function for astrocytes in rCBF regulation.
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Affiliation(s)
- Olaf B Paulson
- Neurobiology Research Unit 9201, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
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Marklund N, Sihver S, Hovda DA, Långström B, Watanabe Y, Ronquist G, Bergström M, Hillered L. Increased Cerebral Uptake of [18F]Fluoro-Deoxyglucose but not [1-14C]Glucose Early following Traumatic Brain Injury in Rats. J Neurotrauma 2009; 26:1281-93. [DOI: 10.1089/neu.2008.0827] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- Niklas Marklund
- Department of Neuroscience, Unit of Neurosurgery, Uppsala University CSO, Imanet, and Uppsala Applied Science Laboratory, Uppsala, Sweden
| | - Sven Sihver
- Department of Neuroscience, Unit of Pharmacology, Uppsala University CSO, Imanet, and Uppsala Applied Science Laboratory, Uppsala, Sweden
| | - David A. Hovda
- UCLA Brain Injury Research Center, Departments of Neurosurgery and Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, University of California–Los Angeles, Los Angeles, California
| | - Bengt Långström
- Department of Biochemistry and Organic Chemistry, Uppsala University CSO, Imanet, and Uppsala Applied Science Laboratory, Uppsala, Sweden
| | - Yasuyoshi Watanabe
- Department of Neuroscience, Osaka Bioscience Institute, Osaka, Japan
- Department of Physiology, Osaka City University, Osaka, Japan
| | - Gunnar Ronquist
- Department of Medical Sciences, Biochemical Structure And Function, Uppsala University CSO, Imanet, and Uppsala Applied Science Laboratory, Uppsala, Sweden
| | - Mats Bergström
- Department of Biochemistry and Organic Chemistry, Uppsala University CSO, Imanet, and Uppsala Applied Science Laboratory, Uppsala, Sweden
| | - Lars Hillered
- Department of Neuroscience, Unit of Neurosurgery, Uppsala University CSO, Imanet, and Uppsala Applied Science Laboratory, Uppsala, Sweden
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Marklund N, Blennow K, Zetterberg H, Ronne-Engström E, Enblad P, Hillered L. Monitoring of brain interstitial total tau and beta amyloid proteins by microdialysis in patients with traumatic brain injury. J Neurosurg 2009; 110:1227-37. [PMID: 19216653 DOI: 10.3171/2008.9.jns08584] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Damage to axons contributes to postinjury disabilities and is commonly observed following traumatic brain injury (TBI). Traumatic brain injury is an important environmental risk factor for the development of Alzheimer disease (AD). In the present feasibility study, the aim was to use intracerebral microdialysis catheters with a high molecular cutoff membrane (100 kD) to harvest interstitial total tau (T-tau) and amyloid beta 1-42 (Abeta42) proteins, which are important biomarkers for axonal injury and for AD, following moderate-to-severe TBI. METHODS Eight patients (5 men and 3 women) were included in the study; 5 of the patients had a focal/mixed TBI and 3 had a diffuse axonal injury (DAI). Following the bedside analysis of the routinely measured energy metabolic markers (that is, glucose, lactate/pyruvate ratio, glycerol, and glutamate), the remaining dialysate was pooled and two 12-hour samples per day were used to analyze T-tau and Abeta42 by enzyme-linked immunosorbent assay from Day 1 up to 8 days postinjury. RESULTS The results show high levels of interstitial T-tau and Abeta42 postinjury. Patients with a predominantly focal lesion had higher interstitial T-tau levels than in the DAI group from Days 1 to 3 postinjury (p < 0.05). In contrast, patients with DAI had consistently higher Abeta42 levels when compared with patients with focal injury. CONCLUSIONS These results suggest that monitoring of interstitial T-tau and Abeta42 by using microdialysis may be an important tool when evaluating the presence and role of axonal injury following TBI.
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Affiliation(s)
- Niklas Marklund
- Department of Neuroscience, Neurosurgery, Uppsala University Hospital, Uppsala, Gothenburg, Sweden.
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Hamberger A, Viano DC, Säljö A, Bolouri H. CONCUSSION IN PROFESSIONAL FOOTBALL. Neurosurgery 2009; 64:1174-82; discussion 1182. [DOI: 10.1227/01.neu.0000316855.40986.2a] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Anders Hamberger
- Institute of Biomedicine, Section of Anatomy and Cell Biology, University of Göteborg, Göteborg, Sweden
| | - David C. Viano
- Mild Traumatic Brain Injury Committee, National Football League, New York, New York; and ProBiomechanics LLC, Bloomfield Hills, Michigan
| | - Annette Säljö
- Institute of Biomedicine, Section of Anatomy and Cell Biology, University of Göteborg, Göteborg, Sweden
| | - Hayde Bolouri
- Institute of Biomedicine, Section of Anatomy and Cell Biology, University of Göteborg, Göteborg, Sweden
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Marklund N, Sihver S, Hovda D, Långström B, Watanabe Y, Ronquist G, Bergström M, Hillered L. INCREASED CEREBRAL UPTAKE OF [18F]FLUORO-DEOXYGLUCOSE BUT NOT [1-14C]GLUCOSE EARLY FOLLOWING TRAUMATIC BRAIN INJURY IN RATS. J Neurotrauma 2009. [DOI: 10.1089/neu.2008-0827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Branched-chain amino acids may improve recovery from a vegetative or minimally conscious state in patients with traumatic brain injury: a pilot study. Arch Phys Med Rehabil 2008; 89:1642-7. [PMID: 18760149 DOI: 10.1016/j.apmr.2008.02.023] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Accepted: 02/26/2008] [Indexed: 01/25/2023]
Abstract
OBJECTIVE To investigate whether supplementation with branched-chain amino acids (BCAAs) may improve recovery of patients with a posttraumatic vegetative or minimally conscious state. DESIGN Patients were randomly assigned to 15 days of intravenous BCAA supplementation (n=22; 19.6g/d) or an isonitrogenous placebo (n=19). SETTING Tertiary care rehabilitation setting. PARTICIPANTS Patients (N=41; 29 men, 12 women; mean age, 49.5+/-21 y) with a posttraumatic vegetative or minimally conscious state, 47+/-24 days after the index traumatic event. INTERVENTION Supplementation with BCAAs. MAIN OUTCOME MEASURE Disability Rating Scale (DRS) as log(10)DRS. RESULTS Fifteen days after admission to the rehabilitation department, the log(10)DRS score improved significantly only in patients who had received BCAAs (log(10)DRS score, 1.365+/-0.08 to 1.294+/-0.05; P<.001), while the log(10)DRS score in the placebo recipients remained virtually unchanged (log(10)DRS score, 1.373+/-0.03 to 1.37+/-0.03; P not significant). The difference in improvement of log(10)DRS score between the 2 groups was highly significant (P<.000). Moreover, 68.2% (n=15) of treated patients achieved a log(10)DRS point score of .477 or higher (3 as geometric mean) that allowed them to exit the vegetative or minimally conscious state. CONCLUSIONS Supplemented BCAAs may improve the recovery from a vegetative or minimally conscious state in patients with posttraumatic vegetative or minimally conscious state.
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Henninger N, Sicard KM, Li Z, Kulkarni P, Dützmann S, Urbanek C, Schwab S, Fisher M. Differential recovery of behavioral status and brain function assessed with functional magnetic resonance imaging after mild traumatic brain injury in the rat. Crit Care Med 2008; 35:2607-14. [PMID: 17828037 DOI: 10.1097/01.ccm.0000286395.79654.8d] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The relationship between cerebral integrity, recovery of brain function, and neurologic status after mild traumatic brain injury is incompletely characterized. DESIGN Prospective and randomized study in rodents. SETTING University laboratory. SUBJECTS Male Wistar rats (290-310 g). INTERVENTIONS In rats, quantitative diffusion weighted imaging (DWI), perfusion weighted imaging (PWI), T2-weighted imaging (T2WI), and functional magnetic resonance imaging (fMRI) were performed up to 21 days after weight-induced, closed-head, mild traumatic brain injury (MTBI, n = 6) or sham operation (n = 6). Pixel-by-pixel analysis and region of interest analysis were used to evaluate structural (apparent diffusion coefficient [ADC] and basal cerebral blood flow [bCBF]) and functional magnetic resonance signal changes within the brain, respectively. Quantitative fMRI signal changes were correlated with behavioral measures. MEASUREMENTS AND MAIN RESULTS Despite normal appearing DWI and T2WI findings following MTBI, persistent hypoperfusion developed that was not associated with cytotoxic edema. In contrast, the ADC was significantly increased by approximately 5% at 1 and 7 days post-MTBI. Post-MTBI fMRI responses to hypercapnia and forepaw stimulation were significantly impaired and showed a differential recovery rate between and within investigated region of interests. Significant dysfunction in forepaw placement test persisted up to day 1 and correlated significantly with fMRI signal changes in the primary somatosensory and motor cortices. CONCLUSIONS MTBI produced distinct changes on multimodal MRI and behavioral variables acutely and chronically. Following MTBI, fMRI and ADC-bCBF pixel-by-pixel analysis identified subtle structural and functional alterations in the brain that appeared completely normal on conventional DWI and T2WI after concussion injury. The former techniques may therefore provide great potential for understanding mild traumatic brain injury, identifying mechanisms underlying recovery, and investigating specific interventions to enhance functional outcome.
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Affiliation(s)
- Nils Henninger
- Department of Internal Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
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Abstract
The knowledge of the pathophysiology after traumatic head injury is necessary for adequate and patient-oriented treatment. As the primary insult, which represents the direct mechanical damage, cannot be therapeutically influenced, target of the treatment is the limitation of the secondary damage (delayed non-mechanical damage). It is influenced by changes in cerebral blood flow (hypo- and hyperperfusion), impairment of cerebrovascular autoregulation, cerebral metabolic dysfunction and inadequate cerebral oxygenation. Furthermore, excitotoxic cell damage and inflammation may lead to apoptotic and necrotic cell death. Understanding the multidimensional cascade of secondary brain injury offers differentiated therapeutic options.
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Affiliation(s)
- C Werner
- Klinik für Anästhesiologie, der Johannes Gutenberg-Universität Mainz, Langenbeckstrasse 1, D-55131 Mainz, Germany.
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Konsman JP, Drukarch B, Van Dam AM. (Peri)vascular production and action of pro-inflammatory cytokines in brain pathology. Clin Sci (Lond) 2006; 112:1-25. [PMID: 17132137 DOI: 10.1042/cs20060043] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In response to tissue injury or infection, the peripheral tissue macrophage induces an inflammatory response through the release of IL-1β (interleukin-1β) and TNFα (tumour necrosis factor α). These cytokines stimulate macrophages and endothelial cells to express chemokines and adhesion molecules that attract leucocytes into the peripheral site of injury or infection. The aims of the present review are to (i) discuss the relevance of brain (peri)vascular cells and compartments to bacterial meningitis, HIV-1-associated dementia, multiple sclerosis, ischaemic and traumatic brain injury, and Alzheimer's disease, and (ii) to provide an overview of the production and action of pro-inflammatory cytokines by (peri)vascular cells in these pathologies of the CNS (central nervous system). The brain (peri)vascular compartments are highly relevant to pathologies affecting the CNS, as infections are almost exclusively blood-borne. Insults disrupt blood and energy flow to neurons, and active brain-to-blood transport mechanisms, which are the bottleneck in the clearance of unwanted molecules from the brain. Perivascular macrophages are the most reactive cell type and produce IL-1β and TNFα after infection or injury to the CNS. The main cellular target for IL-1β and TNFα produced in the brain (peri)vascular compartment is the endothelium, where these cytokines induce the expression of adhesion molecules and promote leucocyte infiltration. Whether this and other effects of IL-1 and TNF in the brain (peri)vascular compartments are detrimental or beneficial in neuropathology remains to be shown and requires a clear understanding of the role of these cytokines in both damaging and repair processes in the CNS.
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Affiliation(s)
- Jan P Konsman
- Laboratory of Integrative Neurobiology, CNRS FRE 2723/INRA UR 1244/University Bordeaux2, Institut François Magendie, Bordeaux, France
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41
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Pickard JD, Hutchinson PJ, Coles JP, Steiner LA, Johnston AJ, Fryer TD, Coleman MR, Smielewski P, Chatfield DA, Aigbirhio F, Williams GB, Rice K, Clark JC, Salmond CH, Sahakian BJ, Bradley PG, Carpenter TA, Salvador R, Pena A, Gillard JH, Cunningham AS, Piechnik S, Czosnyka M, Menon DK. Imaging of cerebral blood flow and metabolism in brain injury in the ICU. ACTA NEUROCHIRURGICA. SUPPLEMENT 2006; 95:459-64. [PMID: 16463901 DOI: 10.1007/3-211-32318-x_94] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
Abstract
The heterogeneity of the initial insult and subsequent pathophysiology has made both the study of human head injury and design of randomised controlled trials exceptionally difficult. The combination of multimodality bedside monitoring and functional brain imaging positron emission tomography (PET) and magnetic resonance (MR), incorporated within a Neurosciences Critical Care Unit, provides the resource required to study critically ill patients after brain injury from initial ictus through recovery from coma and rehabilitation to final outcome. Methods to define cerebral ischemia in the context of altered cerebral oxidative metabolism have been developed, traditional therapies for intracranial hypertension re-evaluated and bedside monitors cross-validated. New modelling and analytical approaches have been developed.
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Affiliation(s)
- J D Pickard
- Wolfson Brain Imaging Centre, University of Cambridge, Addenbrookes Hospital, Cambridge, UK.
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42
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Abstract
PURPOSE OF REVIEW The focus of this review is outcome from mild traumatic brain injury. Recent literature relating to pathophysiology, neuropsychological outcome, and the persistent postconcussion syndrome will be integrated into the existing literature. RECENT FINDINGS The MTBI literature is enormous, complex, methodologically flawed, and controversial. There have been dozens of studies relating to pathophysiology, neuropsychological outcome, and the postconcussion syndrome during the past year. Two major reviews have been published. Some of the most interesting prospective research has been done with athletes. SUMMARY The cognitive and neurobehavioral sequelae are self-limiting and reasonably predictable. Mild traumatic brain injuries are characterized by immediate physiological changes conceptualized as a multilayered neurometabolic cascade in which affected cells typically recover, although under certain circumstances a small number might degenerate and die. The primary pathophysiologies include ionic shifts, abnormal energy metabolism, diminished cerebral blood flow, and impaired neurotransmission. During the first week after injury the brain undergoes a dynamic restorative process. Athletes typically return to pre-injury functioning (assessed using symptom ratings or brief neuropsychological measures) within 2-14 days. Trauma patients usually take longer to return to their pre-injury functioning. In these patients recovery can be incomplete and can be complicated by preexisting psychiatric or substance abuse problems, poor general health, concurrent orthopedic injuries, or comorbid problems (e.g. chronic pain, depression, substance abuse, life stress, unemployment, and protracted litigation).
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Affiliation(s)
- Grant L Iverson
- Department of Psychiatry, University of British Columbia, Neuropsychiatry Program, Riverview Hospital, Vancouver, British Columbia, Canada.
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