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Stone JR, Avants BB, Tustison NJ, Gill J, Wilde EA, Neumann KD, Gladney LA, Kilgore MO, Bowling F, Wilson CM, Detro JF, Belanger HG, Deary K, Linsenbardt H, Ahlers ST. Neurological Effects of Repeated Blast Exposure in Special Operations Personnel. J Neurotrauma 2024; 41:942-956. [PMID: 37950709 PMCID: PMC11001960 DOI: 10.1089/neu.2023.0309] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2023] Open
Abstract
Exposure to blast overpressure has been a pervasive feature of combat-related injuries. Studies exploring the neurological correlates of repeated low-level blast exposure in career "breachers" demonstrated higher levels of tumor necrosis factor alpha (TNFα) and interleukin (IL)-6 and decreases in IL-10 within brain-derived extracellular vesicles (BDEVs). The current pilot study was initiated in partnership with the U.S. Special Operations Command (USSOCOM) to explore whether neuroinflammation is seen within special operators with prior blast exposure. Data were analyzed from 18 service members (SMs), inclusive of 9 blast-exposed special operators with an extensive career history of repeated blast exposures and 9 controls matched by age and duration of service. Neuroinflammation was assessed utilizing positron emission tomography (PET) imaging with [18F]DPA-714. Serum was acquired to assess inflammatory biomarkers within whole serum and BDEVs. The Blast Exposure Threshold Survey (BETS) was acquired to determine blast history. Both self-report and neurocognitive measures were acquired to assess cognition. Similarity-driven Multi-view Linear Reconstruction (SiMLR) was used for joint analysis of acquired data. Analysis of BDEVs indicated significant positive associations with a generalized blast exposure value (GBEV) derived from the BETS. SiMLR-based analyses of neuroimaging demonstrated exposure-related relationships between GBEV, PET-neuroinflammation, cortical thickness, and volume loss within special operators. Affected brain networks included regions associated with memory retrieval and executive functioning, as well as visual and heteromodal processing. Post hoc assessments of cognitive measures failed to demonstrate significant associations with GBEV. This emerging evidence suggests neuroinflammation may be a key feature of the brain response to blast exposure over a career in operational personnel. The common thread of neuroinflammation observed in blast-exposed populations requires further study.
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Affiliation(s)
- James R. Stone
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, USA
| | - Brian B. Avants
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, USA
| | - Nicholas J. Tustison
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, USA
| | - Jessica Gill
- School of Nursing, Johns Hopkins University, Baltimore, Maryland, USA
| | - Elisabeth A. Wilde
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
- George E. Wahlen VA, Salt Lake City Health Healthcare System, Salt Lake City, Utah, USA
| | - Kiel D. Neumann
- Molecular Imaging Research Hub, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Leslie A. Gladney
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, USA
| | - Madison O. Kilgore
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, USA
| | - F. Bowling
- U.S. Special Operations Command, Tampa, Florida, USA
| | | | - John F. Detro
- U.S. Special Operations Command, Tampa, Florida, USA
| | - Heather G. Belanger
- Departments of Psychiatry and Behavioral Neurosciences, and Psychology, University of South Florida, Tampa, Florida, USA
- Cognitive Research Corporation, St. Petersburg, Florida, USA
| | - Katryna Deary
- U.S. Special Operations Command, Tampa, Florida, USA
| | | | - Stephen T. Ahlers
- Operational and Undersea Medicine Directorate, Naval Medical Research Command, Silver Spring, Maryland, USA
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2
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Machado CA, Oliveira BDS, Dias TL, Barros JLVMD, Ferreira GMF, Cordeiro TM, Feracin V, Alexandre CH, Abreu LKS, Silva WND, Carvalho BC, Fernandes HDB, Vieira ÉLM, Castro PR, Ferreira RN, Kangussu LM, Franco GR, Guatimosim C, Barcelos LDS, Simões E Silva AC, Toscano ECDB, Rachid MA, Teixeira AL, Miranda ASD. Weight-drop model as a valuable tool to study potential neurobiological processes underlying behavioral and cognitive changes secondary to mild traumatic brain injury. J Neuroimmunol 2023; 385:578242. [PMID: 37951202 DOI: 10.1016/j.jneuroim.2023.578242] [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: 09/01/2023] [Revised: 10/27/2023] [Accepted: 11/05/2023] [Indexed: 11/13/2023]
Abstract
The pathophysiology of post-traumatic brain injury (TBI) behavioral and cognitive changes is not fully understood, especially in its mild presentation. We designed a weight drop TBI model in mice to investigate the role of neuroinflammation in behavioral and cognitive sequelae following mild TBI. C57BL/6 mice displayed depressive-like behavior at 72 h after mild TBI compared with controls, as indicated by a decrease in the latency to first immobility and climbing time in the forced swim test. Additionally, anxiety-like behavior and hippocampal-associated spatial learning and memory impairment were found in the elevated plus maze and in the Barnes maze, respectively. Levels of a set of inflammatory mediators and neurotrophic factors were analyzed at 6 h, 24 h, 72 h, and 30 days after injury in ipsilateral and contralateral hemispheres of the prefrontal cortex and hippocampus. Principal components analysis revealed two principal components (PC), which represented 59.1% of data variability. PC1 (cytokines and chemokines) expression varied between both hemispheres, while PC2 (neurotrophic factors) expression varied only across the investigated brain areas. Our model reproduces mild TBI-associated clinical signs and pathological features and might be a valuable tool to broaden the knowledge regarding mild TBI pathophysiology as well as to test potential therapeutic targets.
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Affiliation(s)
- Caroline Amaral Machado
- Department of Morphology, Institute of Biological Science, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Bruna da Silva Oliveira
- Department of Morphology, Institute of Biological Science, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Thomaz Lüscher Dias
- Department of Biochemistry and Immunology, Institute of Biological Science, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | | | | | - Thiago Macedo Cordeiro
- Interdisciplinary Laboratory of Medical Investigation, Faculty of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Victor Feracin
- Interdisciplinary Laboratory of Medical Investigation, Faculty of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Cristian Henrique Alexandre
- Department of Morphology, Institute of Biological Science, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Larissa Katharina Sabino Abreu
- Department of Morphology, Institute of Biological Science, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Walison Nunes da Silva
- Department of Physiology and Biophysics, Institute of Biological Science, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Brener Cunha Carvalho
- Department of Morphology, Institute of Biological Science, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Heliana de Barros Fernandes
- Department of Morphology, Institute of Biological Science, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Érica Leandro Marciano Vieira
- Interdisciplinary Laboratory of Medical Investigation, Faculty of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Pollyana Ribeiro Castro
- Department of Physiology and Biophysics, Institute of Biological Science, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Rodrigo Novaes Ferreira
- Department of Morphology, Institute of Biological Science, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Lucas Miranda Kangussu
- Department of Morphology, Institute of Biological Science, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Gloria Regina Franco
- Department of Biochemistry and Immunology, Institute of Biological Science, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Cristina Guatimosim
- Department of Morphology, Institute of Biological Science, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Lucíola da Silva Barcelos
- Department of Physiology and Biophysics, Institute of Biological Science, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Ana Cristina Simões E Silva
- Interdisciplinary Laboratory of Medical Investigation, Faculty of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | | | - Milene Alvarenga Rachid
- Department of Pathology, Faculty of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Antônio Lúcio Teixeira
- McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX.
| | - Aline Silva de Miranda
- Department of Morphology, Institute of Biological Science, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil; Interdisciplinary Laboratory of Medical Investigation, Faculty of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
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3
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Abou-El-Hassan H, Bernstock JD, Chalif JI, Yahya T, Rezende RM, Weiner HL, Izzy S. Elucidating the neuroimmunology of traumatic brain injury: methodological approaches to unravel intercellular communication and function. Front Cell Neurosci 2023; 17:1322325. [PMID: 38162004 PMCID: PMC10756680 DOI: 10.3389/fncel.2023.1322325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 11/15/2023] [Indexed: 01/03/2024] Open
Abstract
The neuroimmunology of traumatic brain injury (TBI) has recently gained recognition as a crucial element in the secondary pathophysiological consequences that occur following neurotrauma. Both immune cells residing within the central nervous system (CNS) and those migrating from the periphery play significant roles in the development of secondary brain injury. However, the precise mechanisms governing communication between innate and adaptive immune cells remain incompletely understood, partly due to a limited utilization of relevant experimental models and techniques. Therefore, in this discussion, we outline current methodologies that can aid in the exploration of TBI neuroimmunology, with a particular emphasis on the interactions between resident neuroglial cells and recruited lymphocytes. These techniques encompass adoptive cell transfer, intra-CNS injection(s), selective cellular depletion, genetic manipulation, molecular neuroimaging, as well as in vitro co-culture systems and the utilization of organoid models. By incorporating key elements of both innate and adaptive immunity, these methods facilitate the examination of clinically relevant interactions. In addition to these preclinical approaches, we also detail an emerging avenue of research that seeks to leverage human biofluids. This approach enables the investigation of how resident and infiltrating immune cells modulate neuroglial responses after TBI. Considering the growing significance of neuroinflammation in TBI, the introduction and application of advanced methodologies will be pivotal in advancing translational research in this field.
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Affiliation(s)
- Hadi Abou-El-Hassan
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Joshua D. Bernstock
- Department of Neurosurgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Joshua I. Chalif
- Department of Neurosurgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Taha Yahya
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Rafael M. Rezende
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Howard L. Weiner
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Saef Izzy
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
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4
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Rubin LH, Du Y, Sweeney SE, O’Toole R, Thomas CL, Zandi AG, Shinehouse LK, Brosnan MK, Nam H, Burke ME, Bureau SC, Kilgore JJ, Yoon M, Soule AR, Lesniak WG, Minn I, Rowe SP, Holt DP, Hall AW, Mathews WB, Smith GS, Nowinski CJ, Kassiou M, Dannals RF, Pomper MG, Coughlin JM. Imaging Brain Injury in Former National Football League Players. JAMA Netw Open 2023; 6:e2340580. [PMID: 37902750 PMCID: PMC10616723 DOI: 10.1001/jamanetworkopen.2023.40580] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 09/15/2023] [Indexed: 10/31/2023] Open
Abstract
Importance Pilot studies that involved early imaging of the 18 kDa translocator protein (TSPO) using positron emission tomography (PET) indicated high levels of TSPO in the brains of active or former National Football League (NFL) players. If validated further in larger studies, those findings may have implications for athletes involved in collision sport. Objective To test for higher TSPO that marks brain injury and repair in a relatively large, unique cohort of former NFL players compared with former elite, noncollision sport athletes. Design, Setting, and Participants This cross-sectional study used carbon 11-labeled N,N-diethyl-2-(4-methoxyphenyl)-5,7-dimethylpyrazolo[1,5-a]pyrimidine-3-acetamide positron emission tomography ([11C]DPA-713 PET) data from former NFL players within 12 years of last participation in the NFL and elite noncollision sport athletes from across the US. Participants were enrolled between April 2018 and February 2023. Main outcomes and measures Regional [11C]DPA-713 total distribution volume from [11C]DPA-713 PET that is a measure of regional brain TSPO; regional brain volumes on magnetic resonance imaging; neuropsychological performance, including attention, executive function, and memory domains. Results This study included 27 former NFL players and 27 former elite, noncollision sport athletes. Regional TSPO levels were higher in former NFL players compared with former elite, noncollision sport athletes (unstandardized β coefficient, 1.08; SE, 0.22; 95% CI, 0.65 to 1.52; P < .001). The magnitude of the group difference depended on region, with largest group differences in TSPO in cingulate and frontal cortices as well as hippocampus. Compared with noncollision sport athletes, former NFL players performed worse in learning (mean difference [MD], -0.70; 95% CI, -1.14 to -0.25; P = .003) and memory (MD, -0.77; 95% CI, -1.24 to -0.30; P = .002), with no correlation between total gray matter TSPO and these cognitive domains. Conclusions and relevance In this cross-sectional study using [11C]DPA-713 PET, higher brain TSPO was found in former NFL players compared with noncollision sport athletes. This finding is consistent with neuroimmune activation even after cessation of NFL play. Future longitudinal [11C]DPA-713 PET and neuropsychological testing promises to inform whether neuroimmune-modulating therapy may be warranted.
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Affiliation(s)
- Leah H. Rubin
- Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Epidemiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Molecular and Comparative Pathobiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Yong Du
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Shannon Eileen Sweeney
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Riley O’Toole
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Cykyra L. Thomas
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Adeline G. Zandi
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Laura K. Shinehouse
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Mary Katherine Brosnan
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Hwanhee Nam
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | | | | | - Jessica J. Kilgore
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Mark Yoon
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Ana R. Soule
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Wojciech G. Lesniak
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Il Minn
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Steven P. Rowe
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Daniel P. Holt
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Andrew W. Hall
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - William B. Mathews
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Gwenn S. Smith
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Christopher J. Nowinski
- Concussion Legacy Foundation, Boston, Massachusetts
- Alzheimer’s Disease and CTE Center, Boston University School of Medicine, Boston, Massachusetts
| | - Michael Kassiou
- School of Chemistry, University of Sydney, Sydney, New South Wales, Australia
| | - Robert F. Dannals
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Martin G. Pomper
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Molecular and Comparative Pathobiology, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Jennifer M. Coughlin
- Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, Maryland
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
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5
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Clark IA, Vissel B. Autocrine positive feedback of tumor necrosis factor from activated microglia proposed to be of widespread relevance in chronic neurological disease. Pharmacol Res Perspect 2023; 11:e01136. [PMID: 37750203 PMCID: PMC10520644 DOI: 10.1002/prp2.1136] [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: 06/29/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 09/27/2023] Open
Abstract
Over a decade's experience of post-stroke rehabilitation by administering the specific anti-TNF biological, etanercept, by the novel perispinal route, is consistent with a wide range of chronically diminished neurological function having been caused by persistent excessive cerebral levels of TNF. We propose that this TNF persistence, and cerebral disease chronicity, largely arises from a positive autocrine feedback loop of this cytokine, allowing the persistence of microglial activation caused by the excess TNF that these cells produce. It appears that many of these observations have never been exploited to construct a broad understanding and treatment of certain chronic, yet reversible, neurological illnesses. We propose that this treatment allows these chronically activated microglia to revert to their normal quiescent state, rather than simply neutralizing the direct harmful effects of this cytokine after its release from microglia. Logically, this also applies to the chronic cerebral aspects of various other neurological conditions characterized by activated microglia. These include long COVID, Lyme disease, post-stroke syndromes, traumatic brain injury, chronic traumatic encephalopathy, post-chemotherapy, post-irradiation cerebral dysfunction, cerebral palsy, fetal alcohol syndrome, hepatic encephalopathy, the antinociceptive state of morphine tolerance, and neurogenic pain. In addition, certain psychiatric states, in isolation or as sequelae of infectious diseases such as Lyme disease and long COVID, are candidates for being understood through this approach and treated accordingly. Perispinal etanercept provides the prospect of being able to treat various chronic central nervous system illnesses, whether they are of infectious or non-infectious origin, through reversing excess TNF generation by microglia.
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Affiliation(s)
- Ian A. Clark
- Research School of Biology, Australian National UniversityCanberraAustralian Capital TerritoryAustralia
| | - Bryce Vissel
- St Vincent's Hospital Centre for Applied Medical ResearchSt Vincent's HospitalDarlinghurstAustralia
- UNSW Medicine & Health, St Vincent's Healthcare Clinical Campus, Faculty of Medicine and HealthSchool of Clinical Medicine, UNSW SydneySydneyNew South WalesAustralia
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6
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Neumann KD, Broshek DK, Newman BT, Druzgal TJ, Kundu BK, Resch JE. Concussion: Beyond the Cascade. Cells 2023; 12:2128. [PMID: 37681861 PMCID: PMC10487087 DOI: 10.3390/cells12172128] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 08/14/2023] [Accepted: 08/17/2023] [Indexed: 09/09/2023] Open
Abstract
Sport concussion affects millions of athletes each year at all levels of sport. Increasing evidence demonstrates clinical and physiological recovery are becoming more divergent definitions, as evidenced by several studies examining blood-based biomarkers of inflammation and imaging studies of the central nervous system (CNS). Recent studies have shown elevated microglial activation in the CNS in active and retired American football players, as well as in active collegiate athletes who were diagnosed with a concussion and returned to sport. These data are supportive of discordance in clinical symptomology and the inflammatory response in the CNS upon symptom resolution. In this review, we will summarize recent advances in the understanding of the inflammatory response associated with sport concussion and broader mild traumatic brain injury, as well as provide an outlook for important research questions to better align clinical and physiological recovery.
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Affiliation(s)
- Kiel D. Neumann
- Department of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA;
| | - Donna K. Broshek
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA 22903, USA;
| | - Benjamin T. Newman
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA 22903, USA; (B.T.N.); (T.J.D.); (B.K.K.)
| | - T. Jason Druzgal
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA 22903, USA; (B.T.N.); (T.J.D.); (B.K.K.)
| | - Bijoy K. Kundu
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA 22903, USA; (B.T.N.); (T.J.D.); (B.K.K.)
| | - Jacob E. Resch
- Department of Kinesiology, University of Virginia, Charlottesville, VA 22903, USA
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7
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Drieu A, Lanquetin A, Prunotto P, Gulhan Z, Pédron S, Vegliante G, Tolomeo D, Serrière S, Vercouillie J, Galineau L, Tauber C, Kuhnast B, Rubio M, Zanier ER, Levard D, Chalon S, Vivien D, Ali C. Persistent neuroinflammation and behavioural deficits after single mild traumatic brain injury. J Cereb Blood Flow Metab 2022; 42:2216-2229. [PMID: 35945692 PMCID: PMC9670002 DOI: 10.1177/0271678x221119288] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 06/17/2022] [Accepted: 06/20/2022] [Indexed: 12/14/2022]
Abstract
Despite an apparently silent imaging, some patients with mild traumatic brain injury (TBI) experience cognitive dysfunctions, which may persist chronically. Brain changes responsible for these dysfunctions are unclear and commonly overlooked. It is thus crucial to increase our understanding of the mechanisms linking the initial event to the functional deficits, and to provide objective evidence of brain tissue alterations underpinning these deficits. We first set up a murine model of closed-head controlled cortical impact, which provoked persistent cognitive and sensorimotor deficits, despite no evidence of brain contusion or bleeding on MRI, thus recapitulating features of mild TBI. Molecular MRI for P-selectin, a key adhesion molecule, detected no sign of cerebrovascular inflammation after mild TBI, as confirmed by immunostainings. By contrast, in vivo PET imaging with the TSPO ligand [18F]DPA-714 demonstrated persisting signs of neuroinflammation in the ipsilateral cortex and hippocampus after mild TBI. Interestingly, immunohistochemical analyses confirmed these spatio-temporal profiles, showing a robust parenchymal astrogliosis and microgliosis, at least up to 3 weeks post-injury in both the cortex and hippocampus. In conclusion, we show that even one single mild TBI induces long-term behavioural deficits, associated with a persistent neuro-inflammatory status that can be detected by PET imaging.
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Affiliation(s)
- Antoine Drieu
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237,
Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain
@ Caen-Normandie, Cyceron, France
| | - Anastasia Lanquetin
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237,
Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain
@ Caen-Normandie, Cyceron, France
| | - Paul Prunotto
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237,
Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain
@ Caen-Normandie, Cyceron, France
| | - Zuhal Gulhan
- UMR 1253, iBrain, Université de Tours, INSERM, Tours,
France
| | - Swannie Pédron
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237,
Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain
@ Caen-Normandie, Cyceron, France
| | - Gloria Vegliante
- Department of Neuroscience, Istituto di Ricerche Farmacologiche
Mario Negri, IRCCS, Milan, Italy
| | - Daniele Tolomeo
- Department of Neuroscience, Istituto di Ricerche Farmacologiche
Mario Negri, IRCCS, Milan, Italy
| | - Sophie Serrière
- UMR 1253, iBrain, Université de Tours, INSERM, Tours,
France
| | | | | | - Clovis Tauber
- UMR 1253, iBrain, Université de Tours, INSERM, Tours,
France
| | - Bertrand Kuhnast
- IMIV, Service Hospitalier Frédéric Joliot, CEA, Inserm,
Université Paris Sud, CNRS, Université Paris-Saclay, Orsay, France
| | - Marina Rubio
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237,
Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain
@ Caen-Normandie, Cyceron, France
| | - Elisa R Zanier
- Department of Neuroscience, Istituto di Ricerche Farmacologiche
Mario Negri, IRCCS, Milan, Italy
| | - Damien Levard
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237,
Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain
@ Caen-Normandie, Cyceron, France
| | - Sylvie Chalon
- UMR 1253, iBrain, Université de Tours, INSERM, Tours,
France
| | - Denis Vivien
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237,
Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain
@ Caen-Normandie, Cyceron, France
- Department of Clinical Research, Caen-Normandie Hospital (CHU),
Caen, France
| | - Carine Ali
- Normandie Univ, UNICAEN, INSERM, INSERM UMR-S U1237,
Physiopathology and Imaging of Neurological Disorders, Institut Blood and Brain
@ Caen-Normandie, Cyceron, France
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8
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Meier TB, Savitz J. The Kynurenine Pathway in Traumatic Brain Injury: Implications for Psychiatric Outcomes. Biol Psychiatry 2022; 91:449-458. [PMID: 34266671 PMCID: PMC8630076 DOI: 10.1016/j.biopsych.2021.05.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/05/2021] [Accepted: 05/21/2021] [Indexed: 12/18/2022]
Abstract
Traumatic brain injury (TBI) is an established risk factor for the development of psychiatric disorders, especially depression and anxiety. However, the mechanistic pathways underlying this risk remain unclear, limiting treatment options and hindering the identification of clinically useful biomarkers. One salient pathophysiological process implicated in both primary psychiatric disorders and TBI is inflammation. An important consequence of inflammation is the increased breakdown of tryptophan to kynurenine and, subsequently, the metabolism of kynurenine into several neuroactive metabolites, including the neurotoxic NMDA receptor agonist quinolinic acid and the neuroprotective NMDA receptor antagonist kynurenic acid. Here, we review studies of the kynurenine pathway (KP) in TBI and examine their potential clinical implications. The weight of the literature suggests that there is increased production of neurotoxic kynurenines such as quinolinic acid in TBI of all severities and that elevated quinolinic acid concentrations in both the cerebrospinal fluid and blood are a negative prognostic indicator, being associated with death, magnetic resonance imaging abnormalities, increased depressive and anxiety symptoms, and prolonged recovery. We hypothesize that an imbalance in KP metabolism is also one molecular pathway through which the TBI-induced neurometabolic cascade may predispose to the development of psychiatric sequelae. If this model is correct, KP metabolites could serve to predict who is likely to develop psychiatric illness while drugs that target the KP could help to prevent or treat depression and anxiety arising in the context of TBI.
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Affiliation(s)
- Timothy B. Meier
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin,Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, Wisconsin,Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin,Corresponding author: Timothy Meier, PhD, 414-955-7310, , Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226
| | - Jonathan Savitz
- Laureate Institute for Brain Research, Tulsa, Oklahoma,Oxley College of Health Sciences, The University of Tulsa, Tulsa, Oklahoma
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9
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Stormezand GN, Doorduin J, Rakers SE, Spikman JM, van der Naalt J, García DV, van der Hoorn A, van der Weijden CWJ, Kremer BPH, Renken RJ, Dierckx RAJO. Imaging of neuroinflammation due to repetitive head injury in currently active kickboxers. Eur J Nucl Med Mol Imaging 2022; 49:3162-3172. [PMID: 35165788 PMCID: PMC9250484 DOI: 10.1007/s00259-022-05715-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 01/28/2022] [Indexed: 12/02/2022]
Abstract
Purpose Chronic traumatic encephalopathy refers to a neurodegenerative disease resulting from repetitive head injury of participants in contact sports. Similar to other neurodegenerative diseases, neuroinflammation is thought to play a role in the onset and progression of the disease. Limited knowledge is available regarding the neuroinflammatory consequences of repetitive head injury in currently active contact sports athletes. PET imaging of the 18-kDa translocator protein (TSPO) allows quantification of microglial activation in vivo, a marker of neuroinflammation. Methods Eleven rank A kickboxers and 11 age-matched controls underwent TSPO PET using [11C]-PK11195, anatomical MRI, diffusion tensor imaging, and neuropsychological testing. Relevant imaging parameters were derived and correlated with the outcomes of the neuropsychological testing. Results On a group level, no statistically significant differences were detected in non-displaceable binding potential (BPND) using PET. Individually, 3 kickboxers showed increased BPNDs in widespread regions of the brain without a correlation with other modalities. Increased FA was observed in the superior corona radiata bilaterally. DTI parameters in other regions did not differ between groups. Conclusion Despite negative results on a group level, individual results suggest that neuroinflammation may be present as a consequence of repetitive head injury in active kickboxers. Future studies using a longitudinal design may determine whether the observed TSPO upregulation is related to the future development of neuropsychiatric symptoms. Supplementary Information The online version contains supplementary material available at 10.1007/s00259-022-05715-x.
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Affiliation(s)
- Gilles N Stormezand
- Department of Nuclear Medicine and Molecular Imaging, Medical Imaging Center, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands.
| | - Janine Doorduin
- Department of Nuclear Medicine and Molecular Imaging, Medical Imaging Center, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Sandra E Rakers
- Department of Clinical Neuropsychology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Jacoba M Spikman
- Department of Clinical Neuropsychology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Joukje van der Naalt
- Department of Neurology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - David Vállez García
- Department of Nuclear Medicine and Molecular Imaging, Medical Imaging Center, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Anouk van der Hoorn
- Department of Radiology, Medical Imaging Center, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Chris W J van der Weijden
- Department of Nuclear Medicine and Molecular Imaging, Medical Imaging Center, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
| | - Berry P H Kremer
- Department of Neurology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Remco J Renken
- Cognitive Neuroscience Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Rudi A J O Dierckx
- Department of Nuclear Medicine and Molecular Imaging, Medical Imaging Center, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands
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10
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Wilde EA, Wanner I, Kenney K, Gill J, Stone JR, Disner S, Schnakers C, Meyer R, Prager EM, Haas M, Jeromin A. A Framework to Advance Biomarker Development in the Diagnosis, Outcome Prediction, and Treatment of Traumatic Brain Injury. J Neurotrauma 2022; 39:436-457. [PMID: 35057637 PMCID: PMC8978568 DOI: 10.1089/neu.2021.0099] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Elisabeth A. Wilde
- University of Utah, Neurology, 383 Colorow, Salt Lake City, Utah, United States, 84108
- VA Salt Lake City Health Care System, 20122, 500 Foothill Dr., Salt Lake City, Utah, United States, 84148-0002
| | - Ina Wanner
- UCLA, Semel Institute, NRB 260J, 635 Charles E. Young Drive South, Los Angeles, United States, 90095-7332, ,
| | - Kimbra Kenney
- Uniformed Services University of the Health Sciences, Neurology, Center for Neuroscience and Regenerative Medicine, 4301 Jones Bridge Road, Bethesda, Maryland, United States, 20814
| | - Jessica Gill
- National Institutes of Health, National Institute of Nursing Research, 1 cloister, Bethesda, Maryland, United States, 20892
| | - James R. Stone
- University of Virginia, Radiology and Medical Imaging, Box 801339, 480 Ray C. Hunt Dr. Rm. 185, Charlottesville, Virginia, United States, 22903, ,
| | - Seth Disner
- Minneapolis VA Health Care System, 20040, Minneapolis, Minnesota, United States
- University of Minnesota Medical School Twin Cities, 12269, 10Department of Psychiatry and Behavioral Sciences, Minneapolis, Minnesota, United States
| | - Caroline Schnakers
- Casa Colina Hospital and Centers for Healthcare, 6643, Pomona, California, United States
- Ronald Reagan UCLA Medical Center, 21767, Los Angeles, California, United States
| | - Restina Meyer
- Cohen Veterans Bioscience, 476204, New York, New York, United States
| | - Eric M Prager
- Cohen Veterans Bioscience, 476204, External Affairs, 535 8th Ave, New York, New York, United States, 10018
| | - Magali Haas
- Cohen Veterans Bioscience, 476204, 535 8th Avenue, 12th Floor, New York City, New York, United States, 10018,
| | - Andreas Jeromin
- Cohen Veterans Bioscience, 476204, Translational Sciences, Cambridge, Massachusetts, United States
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11
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Delage C, Vignal N, Guerin C, Taib T, Barboteau C, Mamma C, Khacef K, Margaill I, Sarda-Mantel L, Rizzo-Padoin N, Hontonnou F, Marchand-Leroux C, Lerouet D, Hosten B, Besson V. From positron emission tomography to cell analysis of the 18-kDa Translocator Protein in mild traumatic brain injury. Sci Rep 2021; 11:24009. [PMID: 34907268 PMCID: PMC8671393 DOI: 10.1038/s41598-021-03416-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 11/17/2021] [Indexed: 11/24/2022] Open
Abstract
Traumatic brain injury (TBI) leads to a deleterious neuroinflammation, originating from microglial activation. Monitoring microglial activation is an indispensable step to develop therapeutic strategies for TBI. In this study, we evaluated the use of the 18-kDa translocator protein (TSPO) in positron emission tomography (PET) and cellular analysis to monitor microglial activation in a mild TBI mouse model. TBI was induced on male Swiss mice. PET imaging analysis with [18F]FEPPA, a TSPO radiotracer, was performed at 1, 3 and 7 days post-TBI and flow cytometry analysis on brain at 1 and 3 days post-TBI. PET analysis showed no difference in TSPO expression between non-operated, sham-operated and TBI mice. Flow cytometry analysis demonstrated an increase in TSPO expression in ipsilateral brain 3 days post-TBI, especially in microglia, macrophages, lymphocytes and neutrophils. Moreover, microglia represent only 58.3% of TSPO+ cells in the brain. Our results raise the question of the use of TSPO radiotracer to monitor microglial activation after TBI. More broadly, flow cytometry results point the lack of specificity of TSPO for microglia and imply that microglia contribute to the overall increase in TSPO in the brain after TBI, but is not its only contributor.
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Affiliation(s)
- Clément Delage
- Faculté de Pharmacie de Paris, Université Paris Descartes, EA4475 - Pharmacologie de la circulation cérébrale, Paris, France.
- Faculté de Pharmacie de Paris, Université de Paris, Inserm UMR-S 1144 - Optimisation Thérapeutique en Neuropsychopharmacologie, 4 avenue de l'Observatoire, 75006, Paris, France.
| | - Nicolas Vignal
- Faculté de Pharmacie de Paris, Université de Paris, Inserm UMR-S 1144 - Optimisation Thérapeutique en Neuropsychopharmacologie, 4 avenue de l'Observatoire, 75006, Paris, France
- Assistance Publique - Hôpitaux de Paris (AP-HP), Service de Médecine Nucléaire, Hôpital Lariboisière, Paris, France
- Université de Paris, Institut de Recherche Saint-Louis, Unité Claude Kellershohn, Paris, France
| | - Coralie Guerin
- Université de Paris, Innovative Therapies in Haemostasis, Inserm, 75006, Paris, France
- Institut Curie, Cytometry Core, 75005, Paris, France
- Université de Paris, Inserm UMS 3612 CNRS - US25 Inserm -Faculté de Pharmacie de Paris, Paris, France
| | - Toufik Taib
- Faculté de Pharmacie de Paris, Université Paris Descartes, EA4475 - Pharmacologie de la circulation cérébrale, Paris, France
| | - Clément Barboteau
- Faculté de Pharmacie de Paris, Université de Paris, Inserm UMR-S 1144 - Optimisation Thérapeutique en Neuropsychopharmacologie, 4 avenue de l'Observatoire, 75006, Paris, France
| | - Célia Mamma
- Faculté de Pharmacie de Paris, Université Paris Descartes, EA4475 - Pharmacologie de la circulation cérébrale, Paris, France
| | - Kahina Khacef
- Faculté de Pharmacie de Paris, Université Paris Descartes, EA4475 - Pharmacologie de la circulation cérébrale, Paris, France
| | - Isabelle Margaill
- Faculté de Pharmacie de Paris, Université Paris Descartes, EA4475 - Pharmacologie de la circulation cérébrale, Paris, France
- Faculté de Pharmacie de Paris, Université de Paris, Inserm UMR-S 1140, Paris, France
| | - Laure Sarda-Mantel
- Assistance Publique - Hôpitaux de Paris (AP-HP), Service de Médecine Nucléaire, Hôpital Lariboisière, Paris, France
- Université de Paris, Institut de Recherche Saint-Louis, Unité Claude Kellershohn, Paris, France
| | - Nathalie Rizzo-Padoin
- Université de Paris, Institut de Recherche Saint-Louis, Unité Claude Kellershohn, Paris, France
- CHU de Martinique, Service Pharmacie, Hôpital Pierre Zobda-Quitman, Fort-de-France, France
| | - Fortune Hontonnou
- Université de Paris, Institut de Recherche Saint-Louis, Unité Claude Kellershohn, Paris, France
- Université de Paris, Inserm UMR-S 942, Hôpital Lariboisière, Paris, France
| | - Catherine Marchand-Leroux
- Faculté de Pharmacie de Paris, Université Paris Descartes, EA4475 - Pharmacologie de la circulation cérébrale, Paris, France
- Faculté de Pharmacie de Paris, Université de Paris, Inserm UMR-S 1144 - Optimisation Thérapeutique en Neuropsychopharmacologie, 4 avenue de l'Observatoire, 75006, Paris, France
| | - Dominique Lerouet
- Faculté de Pharmacie de Paris, Université Paris Descartes, EA4475 - Pharmacologie de la circulation cérébrale, Paris, France
- Faculté de Pharmacie de Paris, Université de Paris, Inserm UMR-S 1144 - Optimisation Thérapeutique en Neuropsychopharmacologie, 4 avenue de l'Observatoire, 75006, Paris, France
| | - Benoit Hosten
- Faculté de Pharmacie de Paris, Université de Paris, Inserm UMR-S 1144 - Optimisation Thérapeutique en Neuropsychopharmacologie, 4 avenue de l'Observatoire, 75006, Paris, France
- Université de Paris, Institut de Recherche Saint-Louis, Unité Claude Kellershohn, Paris, France
- Assistance Publique - Hôpitaux de Paris (AP-HP), Service Pharmacie, Hôpital Saint-Louis, Paris, France
| | - Valérie Besson
- Faculté de Pharmacie de Paris, Université Paris Descartes, EA4475 - Pharmacologie de la circulation cérébrale, Paris, France
- Faculté de Pharmacie de Paris, Université de Paris, Inserm UMR-S 1144 - Optimisation Thérapeutique en Neuropsychopharmacologie, 4 avenue de l'Observatoire, 75006, Paris, France
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12
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Nikam RM, Yue X, Kandula VV, Paudyal B, Langhans SA, Averill LW, Choudhary AK. Unravelling neuroinflammation in abusive head trauma with radiotracer imaging. Pediatr Radiol 2021; 51:966-970. [PMID: 33999238 DOI: 10.1007/s00247-021-04995-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 12/07/2020] [Accepted: 01/27/2021] [Indexed: 01/07/2023]
Abstract
Abusive head trauma (AHT) is a leading cause of mortality and morbidity in child abuse, with a mortality rate of approximately 25%. In survivors, the prognosis remains dismal, with high prevalence of cerebral palsy, epilepsy and neuropsychiatric disorders. Early and accurate diagnosis of AHT is challenging, both clinically and radiologically, with up to one-third of cases missed on initial examination. Moreover, most of the management in AHT is supportive, reflective of the lack of clear understanding of specific pathogenic mechanisms underlying secondary insult, with approaches targeted toward decreasing intracranial hypertension and reducing cerebral metabolism, cell death and excitotoxicity. Multiple studies have elucidated the role of pro- and anti-inflammatory cytokines and chemokines with upregulation/recruitment of microglia/macrophages, oligodendrocytes and astrocytes in severe traumatic brain injury (TBI). In addition, recent studies in animal models of AHT have demonstrated significant upregulation of microglia, with a potential role of inflammatory cascade contributing to secondary insult. Despite the histological and biochemical evidence, there is a significant dearth of specific imaging approaches to identify this neuroinflammation in AHT. The primary motivation for development of such imaging approaches stems from the need to therapeutically target neuroinflammation and establish its utility in monitoring and prognostication. In the present paper, we discuss the available data suggesting the potential role of neuroinflammation in AHT and role of radiotracer imaging in aiding diagnosis and patient management.
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Affiliation(s)
- Rahul M Nikam
- Department of Medical Imaging, Nemours Alfred I. duPont Hospital for Children, 1600 Rockland Road, Wilmington, DE, 19803, USA. .,Katzin Diagnostic & Research PET/MR Center, Nemours Alfred I. duPont Hospital for Children, Wilmington, DE, USA.
| | - Xuyi Yue
- Katzin Diagnostic & Research PET/MR Center, Nemours Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Vinay V Kandula
- Department of Medical Imaging, Nemours Alfred I. duPont Hospital for Children, 1600 Rockland Road, Wilmington, DE, 19803, USA
| | - Bishnuhari Paudyal
- Katzin Diagnostic & Research PET/MR Center, Nemours Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Sigrid A Langhans
- Katzin Diagnostic & Research PET/MR Center, Nemours Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Lauren W Averill
- Department of Medical Imaging, Nemours Alfred I. duPont Hospital for Children, 1600 Rockland Road, Wilmington, DE, 19803, USA
| | - Arabinda K Choudhary
- Department of Radiology, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA
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13
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Solnes LB, Jacobs AH, Coughlin JM, Du Y, Goel R, Hammoud DA, Pomper MG. Central Nervous System Molecular Imaging. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00088-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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14
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Kreisl WC, Kim MJ, Coughlin JM, Henter ID, Owen DR, Innis RB. PET imaging of neuroinflammation in neurological disorders. Lancet Neurol 2020; 19:940-950. [PMID: 33098803 PMCID: PMC7912433 DOI: 10.1016/s1474-4422(20)30346-x] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 08/06/2020] [Accepted: 08/21/2020] [Indexed: 12/11/2022]
Abstract
A growing need exists for reliable in-vivo measurement of neuroinflammation to better characterise the inflammatory processes underlying various diseases and to inform the development of novel therapeutics that target deleterious glial activity. PET is well suited to quantify neuroinflammation and has the potential to discriminate components of the neuroimmune response. However, there are several obstacles to the reliable quantification of neuroinflammation by PET imaging. Despite these challenges, PET studies have consistently identified associations between neuroimmune responses and pathophysiology in brain disorders such as Alzheimer's disease. Tissue studies have also begun to clarify the meaning of changes in PET signal in some diseases. Furthermore, although PET imaging of neuroinflammation does not have an established clinical application, novel targets are under investigation and a small but growing number of studies have suggested that this imaging modality could have a role in drug development. Future studies are needed to further improve our knowledge of the cellular mechanisms that underlie changes in PET signal, how immune response contributes to neurological disease, and how it might be therapeutically modified.
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Affiliation(s)
- William C Kreisl
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - Min-Jeong Kim
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - Jennifer M Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Ioline D Henter
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - David R Owen
- Department of Brain Sciences, Imperial College London, London, UK
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA.
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15
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Zhou Y, Chen Q, Wang Y, Wu H, Xu W, Pan Y, Gao S, Dong X, Zhang JH, Shao A. Persistent Neurovascular Unit Dysfunction: Pathophysiological Substrate and Trigger for Late-Onset Neurodegeneration After Traumatic Brain Injury. Front Neurosci 2020; 14:581. [PMID: 32581697 PMCID: PMC7296179 DOI: 10.3389/fnins.2020.00581] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 05/12/2020] [Indexed: 12/14/2022] Open
Abstract
Traumatic brain injury (TBI) represents one of the major causes of death worldwide and leads to persisting neurological deficits in many of the survivors. One of the most significant long-term sequelae deriving from TBI is neurodegenerative disease, which is a group of incurable diseases that impose a heavy socio-economic burden. However, mechanisms underlying the increased susceptibility of TBI to neurodegenerative disease remain elusive. The neurovascular unit (NVU) is a functional unit composed of neurons, neuroglia, vascular cells, and the basal lamina matrix. The key role of NVU dysfunction in many central nervous system diseases has been revealed. Studies have proved the presence of prolonged structural and functional abnormalities of the NVU after TBI. Moreover, growing evidence suggests impaired NVU function is also implicated in neurodegenerative diseases. Therefore, we propose the Neurovascular Unit Dysfunction (NVUD) Hypothesis, in which the persistent NVU dysfunction is thought to underlie the development of post-TBI neurodegeneration. We deduce NVUD Hypothesis through relational inference and supporting evidence, and suggest continued NVU abnormalities following TBI serve as the pathophysiological substrate and trigger yielding chronic neuroinflammation, proteinopathies and oxidative stress, consequently leading to the progression of neurodegenerative diseases. The NVUD Hypothesis may provide potential treatment and prevention strategies for TBI and late-onset neurodegenerative diseases.
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Affiliation(s)
- Yunxiang Zhou
- Department of Surgical Oncology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Qiang Chen
- Department of Surgical Oncology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yali Wang
- Department of Surgical Oncology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Haijian Wu
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Weilin Xu
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yuanbo Pan
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shiqi Gao
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiao Dong
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - John H. Zhang
- Department of Physiology and Pharmacology, Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA, United States
- Department of Anesthesiology, Neurosurgery and Neurology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Anwen Shao
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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16
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Viscomi M. The plasticity of plasticity: lesson from remote microglia induced by focal central nervous system injury. Neural Regen Res 2020; 15:57-58. [PMID: 31535645 PMCID: PMC6862415 DOI: 10.4103/1673-5374.264448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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17
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Pace-Schott EF, Amole MC, Aue T, Balconi M, Bylsma LM, Critchley H, Demaree HA, Friedman BH, Gooding AEK, Gosseries O, Jovanovic T, Kirby LA, Kozlowska K, Laureys S, Lowe L, Magee K, Marin MF, Merner AR, Robinson JL, Smith RC, Spangler DP, Van Overveld M, VanElzakker MB. Physiological feelings. Neurosci Biobehav Rev 2019; 103:267-304. [DOI: 10.1016/j.neubiorev.2019.05.002] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/27/2019] [Accepted: 05/03/2019] [Indexed: 12/20/2022]
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18
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Kinetic modelling and quantification bias in small animal PET studies with [18F]AB5186, a novel 18 kDa translocator protein radiotracer. PLoS One 2019; 14:e0217515. [PMID: 31150436 PMCID: PMC6544349 DOI: 10.1371/journal.pone.0217515] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 05/13/2019] [Indexed: 11/19/2022] Open
Abstract
Introduction Positron Emission Tomography (PET) imaging with selective 18 kDa translocator protein (TSPO) radiotracers has contributed to our understanding on the role of inflammation in disease development and progression. With an increasing number of rodent models of human disease and expansion of the preclinical PET imaging base worldwide, accurate quantification of longitudinal rodent TSPO PET datasets is necessary. This is particularly relevant as TSPO PET quantification relies on invasive blood sampling due to lack of a suitable tissue reference region. Here we investigate the kinetics and quantification bias of a novel TSPO radiotracer [18F]AB5186 in rats using automatic, manual and image derived input functions. Methods [18F]AB5186 was administered intravenously and dynamic PET imaging was acquired over 2 hours. Arterial blood was collected manually to derive a population based input function or using an automatic blood sampler to derive a plasma input function. Manually sampled blood was also used to analyze the [18F]AB5186 radiometabolite profile in plasma and applied to all groups as a population based dataset. Kinetic models were used to estimate distribution volumes (VT) and [18F]AB5186 outcome measure bias was determined. Results [18F]AB5186 distribution in rats was consistent with TSPO expression and at 2 h post-injection 50% of parent compound was still present in plasma. Population based manual sampling methods and image derived input function (IDIF) underestimated VT by ~50% and 88% compared with automatic blood sampling, respectively. The VT variability was lower when using IDIF versus arterial blood sampling methods and analysis of the Bland-Altman plots showed a good agreement between methods of analysis. Conclusion Quantification of TSPO PET rodent data using image-derived methods, which are more amenable for longitudinal scanning of small animals, yields outcome measures with reduced variability and good agreement, albeit biased, compared with invasive blood sampling methods.
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19
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Ghadery C, Best LA, Pavese N, Tai YF, Strafella AP. PET Evaluation of Microglial Activation in Non-neurodegenerative Brain Diseases. Curr Neurol Neurosci Rep 2019; 19:38. [PMID: 31139952 PMCID: PMC6538572 DOI: 10.1007/s11910-019-0951-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE OF THE REVIEW Microglial cell activation is an important component of neuroinflammation, and it is generally well accepted that chronic microglial activation is indicative of accumulating tissue damage in neurodegenerative conditions, particularly in the earlier stages of disease. Until recently, there has been less focus on the role of neuroinflammation in other forms of neurological and neuropsychiatric conditions. Through this review, we hope to demonstrate the important role TSPO PET imaging has played in illuminating the pivotal role of neuroinflammation and microglial activation underpinning these conditions. RECENT FINDINGS TSPO is an 18 kDa protein found on the outer membrane of mitochondria and can act as a marker of microglial activation using nuclear imaging. Through the development of radiopharmaceuticals targeting TSPO, researchers have been able to better characterise the spatial-temporal evolution of chronic neurological conditions, ranging from the focal autoimmune reactions seen in multiple sclerosis to the Wallerian degeneration at remote parts of the brain months following acute cerebral infarction. Development of novel techniques to investigate neuroinflammation within the central nervous system, for the purposes of diagnosis and therapeutics, has flourished over the past few decades. TSPO has proven itself a robust and sensitive biomarker of microglial activation and neuroimaging affords a minimally invasive technique to characterise neuroinflammatory processes in vivo.
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Affiliation(s)
- Christine Ghadery
- The Edmond J. Safra Program in Parkinson's Disease & Movement Disorder Unit, Toronto Western Hospital & Krembil Research Institute, University Health Network; Research Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada
| | - Laura A Best
- Clinical Ageing Research Unit, Newcastle University, Campus for Ageing and Vitality, Westgate Road, Newcastle Upon Tyne, UK.
| | - Nicola Pavese
- Clinical Ageing Research Unit, Newcastle University, Campus for Ageing and Vitality, Westgate Road, Newcastle Upon Tyne, UK
- PET centre, University of Aarhus Denmark, Aarhus, Denmark
| | - Yen Foung Tai
- Imperial College London South Kensington Campus, London, UK
| | - Antonio P Strafella
- The Edmond J. Safra Program in Parkinson's Disease & Movement Disorder Unit, Toronto Western Hospital & Krembil Research Institute, University Health Network; Research Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada
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20
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Dissemination of brain inflammation in traumatic brain injury. Cell Mol Immunol 2019; 16:523-530. [PMID: 30846842 DOI: 10.1038/s41423-019-0213-5] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 01/28/2019] [Indexed: 12/13/2022] Open
Abstract
Traumatic brain injury (TBI) is recognized as a global health problem due to its increasing occurrence, challenging treatment, and persistent impacts on brain pathophysiology. Neural cell death in patients with TBI swiftly causes inflammation in the injured brain areas, which is recognized as focal brain inflammation. Focal brain inflammation causes secondary brain injury by exacerbating brain edema and neuronal death, while also exerting divergent beneficial effects, such as sealing the damaged limitans and removing cellular debris. Recent evidence from patients with TBI and studies on animal models suggest that brain inflammation after TBI is not only restricted to the focal lesion but also disseminates to remote areas of the brain. The dissemination of inflammation has been detected within days after the primary injury and persists chronically. This state of inflammation may be related to remote complications of TBI in patients, such as hyperthermia and hypopituitarism, and may lead to progressive neurodegeneration, such as chronic traumatic encephalopathy. Future studies should focus on understanding the mechanisms that govern the initiation and propagation of brain inflammation after TBI and its impacts on post-trauma brain pathology.
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21
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Plavén-Sigray P, Matheson GJ, Cselényi Z, Jucaite A, Farde L, Cervenka S. Test-retest reliability and convergent validity of (R)-[ 11C]PK11195 outcome measures without arterial input function. EJNMMI Res 2018; 8:102. [PMID: 30498919 PMCID: PMC6265355 DOI: 10.1186/s13550-018-0455-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 11/02/2018] [Indexed: 12/29/2022] Open
Abstract
Purpose The PET radioligand (R)-[11C]PK11195 is used to quantify the 18-kDa translocator protein (TSPO), a marker for glial activation. Since there is no brain region devoid of TSPO, an arterial input function (AIF) is ideally required for quantification of binding. However, obtaining an AIF is experimentally demanding, is sometimes uncomfortable for participants, and can introduce additional measurement error during quantification. The objective of this study was to perform an evaluation of the test-retest reliability and convergent validity of techniques used for quantifying (R)-[11C]PK11195 binding without an AIF in clinical studies. Methods Data from six healthy individuals who participated in two PET examinations, 6 weeks apart, were analyzed. Regional non-displaceable binding potential (BPND) values were calculated using the simplified reference tissue model, with either cerebellum as reference region or a reference input derived using supervised cluster analysis (SVCA). Standardized uptake values (SUVs) were estimated for the time interval of 40–60 min. Results Test-retest reliability for BPND estimates were poor (80% of ICCs < 0.5). BPND estimates derived without an AIF were not correlated with BPND, total or specific distribution volume from the 2TCM using an AIF (all R2 < 12%). SUVs showed moderate reliability but no correlation to any other outcome measure. Conclusions Caution is warranted when interpreting patient-control comparisons employing (R)-[11C]PK11195 outcome measures obtained without an AIF. Electronic supplementary material The online version of this article (10.1186/s13550-018-0455-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Pontus Plavén-Sigray
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76, Stockholm, Sweden.
| | - Granville James Matheson
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76, Stockholm, Sweden
| | - Zsolt Cselényi
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76, Stockholm, Sweden.,PET Imaging Centre, Precision Medicine and Genomics, IMED Biotech Unit, AstraZeneca, Karolinska Institutet, Stockholm, Sweden
| | - Aurelija Jucaite
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76, Stockholm, Sweden.,PET Imaging Centre, Precision Medicine and Genomics, IMED Biotech Unit, AstraZeneca, Karolinska Institutet, Stockholm, Sweden
| | - Lars Farde
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76, Stockholm, Sweden.,PET Imaging Centre, Precision Medicine and Genomics, IMED Biotech Unit, AstraZeneca, Karolinska Institutet, Stockholm, Sweden
| | - Simon Cervenka
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76, Stockholm, Sweden
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22
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Aldag M, Armstrong RC, Bandak F, Bellgowan PSF, Bentley T, Biggerstaff S, Caravelli K, Cmarik J, Crowder A, DeGraba TJ, Dittmer TA, Ellenbogen RG, Greene C, Gupta RK, Hicks R, Hoffman S, Latta RC, Leggieri MJ, Marion D, Mazzoli R, McCrea M, O'Donnell J, Packer M, Petro JB, Rasmussen TE, Sammons-Jackson W, Shoge R, Tepe V, Tremaine LA, Zheng J. The Biological Basis of Chronic Traumatic Encephalopathy following Blast Injury: A Literature Review. J Neurotrauma 2018; 34:S26-S43. [PMID: 28937953 DOI: 10.1089/neu.2017.5218] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The United States Department of Defense Blast Injury Research Program Coordinating Office organized the 2015 International State-of-the-Science meeting to explore links between blast-related head injury and the development of chronic traumatic encephalopathy (CTE). Before the meeting, the planning committee examined articles published between 2005 and October 2015 and prepared this literature review, which summarized broadly CTE research and addressed questions about the pathophysiological basis of CTE and its relationship to blast- and nonblast-related head injury. It served to inform participants objectively and help focus meeting discussion on identifying knowledge gaps and priority research areas. CTE is described generally as a progressive neurodegenerative disorder affecting persons exposed to head injury. Affected individuals have been participants primarily in contact sports and military personnel, some of whom were exposed to blast. The symptomatology of CTE overlaps with Alzheimer's disease and includes neurological and cognitive deficits, psychiatric and behavioral problems, and dementia. There are no validated diagnostic criteria, and neuropathological evidence of CTE has come exclusively from autopsy examination of subjects with histories of exposure to head injury. The perivascular accumulation of hyperphosphorylated tau (p-tau) at the depths of cortical sulci is thought to be unique to CTE and has been proposed as a diagnostic requirement, although the contribution of p-tau and other reported pathologies to the development of clinical symptoms of CTE are unknown. The literature on CTE is limited and is focused predominantly on head injuries unrelated to blast exposure (e.g., football players and boxers). In addition, comparative analyses of clinical case reports has been challenging because of small case numbers, selection biases, methodological differences, and lack of matched controls, particularly for blast-exposed individuals. Consequently, the existing literature is not sufficient to determine whether the development of CTE is associated with head injury frequency (e.g., single vs. multiple exposures) or head injury type (e.g., impact, nonimpact, blast-related). Moreover, the incidence and prevalence of CTE in at-risk populations is unknown. Future research priorities should include identifying additional risk factors, pursuing population-based longitudinal studies, and developing the ability to detect and diagnose CTE in living persons using validated criteria.
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Affiliation(s)
- Matt Aldag
- 1 Booz Allen Hamilton , McLean, Virginia
| | - Regina C Armstrong
- 2 Uniformed Services University of the Health Sciences , Bethesda, Maryland
| | - Faris Bandak
- 3 Defense Advanced Research Projects Agency , Arlington, Virginia
| | | | | | - Sean Biggerstaff
- 6 Office of the Assistant Secretary of Defense , Health Affairs, Falls Church, Virginia
| | | | - Joan Cmarik
- 7 Office of the Principal Assistant for Acquisition, United States Army Medical Research and Materiel Command , Frederick, Maryland
| | - Alicia Crowder
- 8 Combat Casualty Care Research Program , United States Army Medical Research and Materiel Command, Fort Detrick, Maryland
| | | | | | - Richard G Ellenbogen
- 10 Departments of Neurological Surgery and Global Health Medicine, University of Washington , Seattle, Washington
| | - Colin Greene
- 11 Joint Trauma Analysis and Prevention of Injuries in Combat Program, Frederick, Maryland
| | - Raj K Gupta
- 12 Department of Defense Blast Injury Research Program Coordinating Office, United States Army Medical Research and Materiel Command , Frederick, Maryland
| | | | | | | | - Michael J Leggieri
- 12 Department of Defense Blast Injury Research Program Coordinating Office, United States Army Medical Research and Materiel Command , Frederick, Maryland
| | - Donald Marion
- 16 Defense and Veterans Brain Injury Center , Silver Spring, Maryland
| | | | | | | | - Mark Packer
- 20 Hearing Center of Excellence , Lackland, Texas
| | - James B Petro
- 21 Office of the Assistant Secretary of Defense, Research and Engineering, Arlington, Virginia
| | - Todd E Rasmussen
- 8 Combat Casualty Care Research Program , United States Army Medical Research and Materiel Command, Fort Detrick, Maryland
| | - Wendy Sammons-Jackson
- 22 Office of the Principal Assistant for Research and Technology , United States Army Medical Research and Materiel Command, Fort Detrick, Maryland
| | - Richard Shoge
- 23 Military Operational Medicine Research Program, United States Army Medical Research and Materiel Command , Fort Detrick, Maryland
| | | | | | - James Zheng
- 25 Program Executive Office Soldier , Fort Belvoir, Virginia
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23
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Structural imaging of mild traumatic brain injury may not be enough: overview of functional and metabolic imaging of mild traumatic brain injury. Brain Imaging Behav 2018; 11:591-610. [PMID: 28194558 DOI: 10.1007/s11682-017-9684-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A majority of patients with traumatic brain injury (TBI) present as mild injury with no findings on conventional clinical imaging methods. Due to this difficulty of imaging assessment on mild TBI patients, there has been much emphasis on the development of diffusion imaging modalities such as diffusion tensor imaging (DTI). However, basic science research in TBI shows that many of the functional and metabolic abnormalities in TBI may be present even in the absence of structural damage. Moreover, structural damage may be present at a microscopic and molecular level that is not detectable by structural imaging modality. The use of functional and metabolic imaging modalities can provide information on pathological changes in mild TBI patients that may not be detected by structural imaging. Although there are various differences in protocols of positron emission tomography (PET), single photon emission computed tomography (SPECT), functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and magnetoencephalography (MEG) methods, these may be important modalities to be used in conjunction with structural imaging in the future in order to detect and understand the pathophysiology of mild TBI. In this review, studies of mild TBI patients using these modalities that detect functional and metabolic state of the brain are discussed. Each modality's advantages and disadvantages are compared, and potential future applications of using combined modalities are explored.
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24
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Guedes CES, Dias BRS, Petersen ALDOA, Cruz KP, Almeida NDJ, Andrade DR, Menezes JPBD, Borges VDM, Veras PST. In vitro evaluation of the anti-leishmanial activity and toxicity of PK11195. Mem Inst Oswaldo Cruz 2018; 113:e170345. [PMID: 29412342 PMCID: PMC5851033 DOI: 10.1590/0074-02760170345] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 11/30/2017] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Leishmaniasis, one of the most neglected diseases, is a serious public health problem in many countries, including Brazil. Currently available treatments require long-term use and have serious side effects, necessitating the development of new therapeutic interventions. Because translocator protein (TSPO) levels are reduced in Leishmania amazonensis-infected cells and because this protein participates in apoptosis and immunomodulation, TSPO represents a potential target for Leishmania chemotherapy. The present study evaluated PK11195, a ligand of this protein, as an anti-leishmanial agent. OBJECTIVE To evaluate the leishmanicidal activity of PK11195 against L. amazonensis in infected CBA mouse macrophages in vitro. METHODS The viability of axenic L. amazonensis, Leishmania major, and Leishmania braziliensis promastigotes was assessed after 48 h treatment with PK11195 (0.2-400 µM). Additionally, intracellular parasite viability was evaluated to determine IC50 values and the number of viable parasites in infected macrophages treated with PK11195 (50-100 µM). Infected macrophages were then treated with PK11195 (25-100 µM) to determine the percentage of L. amazonensis-infected cells and the number of parasites per infected cell. Electron microscopy was used to investigate morphological changes caused by PK11195. The production of free oxygen radicals, nitric oxide, and pro-inflammatory cytokines was also evaluated in infected macrophages treated with PK11195 and primed or not primed with IFN-γ. FINDINGS Median IC50 values for PK11195 were 14.2 µM for L. amazonensis, 8.2 µM for L. major, and 3.5 µM for L. braziliensis. The selective index value for L. amazonensis was 13.7, indicating the safety of PK11195 for future testing in mammals. Time- and dose-dependent reductions in the percentage of infected macrophages, the number of parasites per infected macrophage, and the number of viable intracellular parasites were observed. Electron microscopy revealed some morphological alterations suggestive of autophagy. Interestingly, MCP-1 and superoxide levels were reduced in L. amazonensis-infected macrophages treated with PK11195. MAIN CONCLUSIONS PK11195 causes the killing of amastigotes in vitro by mechanisms independent of inflammatory mediators and causes morphological alterations within Leishmania parasites, suggestive of autophagy, at doses that are non-toxic to macrophages. Thus, this molecule has demonstrated potential as an anti-leishmanial agent.
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Affiliation(s)
- Carlos Eduardo Sampaio Guedes
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório de Patologia e Biointervenção, Salvador, BA, Brasil
| | - Beatriz Rocha Simões Dias
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório de Patologia e Biointervenção, Salvador, BA, Brasil
| | | | - Kercia Pinheiro Cruz
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório de Patologia e Biointervenção, Salvador, BA, Brasil
| | - Niara de Jesus Almeida
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório de Patologia e Biointervenção, Salvador, BA, Brasil
| | - Daniela Rodrigues Andrade
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório Integrado de Microbiologia e Imunoregulação, Salvador, BA, Brasil
| | | | - Valéria de Matos Borges
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório Integrado de Microbiologia e Imunoregulação, Salvador, BA, Brasil
| | - Patricia Sampaio Tavares Veras
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório de Patologia e Biointervenção, Salvador, BA, Brasil
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25
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Evidence of fatigue, disordered sleep and peripheral inflammation, but not increased brain TSPO expression, in seasonal allergy: A [ 11C]PBR28 PET study. Brain Behav Immun 2018; 68:146-157. [PMID: 29054675 DOI: 10.1016/j.bbi.2017.10.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 10/07/2017] [Accepted: 10/16/2017] [Indexed: 02/05/2023] Open
Abstract
Allergy is associated with non-specific symptoms such as fatigue, sleep problems and impaired cognition. One explanation could be that the allergic inflammatory state includes activation of immune cells in the brain, but this hypothesis has not been tested in humans. The aim of the present study was therefore to investigate seasonal changes in the glial cell marker translocator protein (TSPO), and to relate this to peripheral inflammation, fatigue and sleep, in allergy. We examined 18 patients with severe seasonal allergy, and 13 healthy subjects in and out-of pollen season using positron emission tomography (n = 15/13) and the TSPO radioligand [11C]PBR28. In addition, TNF-α, IL-5, IL-6, IL-8 and IFN-γ were measured in peripheral blood, and subjective ratings of fatigue and sleepiness as well as objective and subjective sleep were investigated. No difference in levels of TSPO was seen between patients and healthy subjects, nor in relation to pollen season. However, allergic subjects displayed both increased fatigue, sleepiness and increased percentage of deep sleep, as well as increased levels of IL-5 and TNF-α during pollen season, compared to healthy subjects. Allergic subjects also had shorter total sleep time, regardless of season. In conclusion, allergic subjects are indicated to respond to allergen exposure during pollen season with a clear pattern of behavioral disruption and peripheral inflammatory activation, but not with changes in brain TSPO levels. This underscores a need for development and use of more specific markers to understand brain consequences of peripheral inflammation that will be applicable in human subjects.
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26
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Hasturk AE, Gokce EC, Yilmaz ER, Horasanli B, Evirgen O, Hayirli N, Gokturk H, Erguder I, Can B. Therapeutic Evaluation of Tumor Necrosis Factor-alpha Antagonist Etanercept against Traumatic Brain Injury in Rats: Ultrastructural, Pathological, and Biochemical Analyses. Asian J Neurosurg 2018; 13:1018-1025. [PMID: 30459860 PMCID: PMC6208262 DOI: 10.4103/ajns.ajns_29_17] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Purpose The aim of the present study was to investigate the effect of etanercept (ETA) on histopathological and biochemical changes after traumatic brain injury (TBI) in rats. Materials and Methods Thirty-six male Wistar albino rats were distributed into three groups (n = 12 each). Control group rats were not subjected to trauma. Trauma group rats were subjected to TBI only. ETA group rats were subjected to TBI plus ETA (5 mg/kg intraperitoneal [i.p.]). The groups were further subdivided into those sacrificed in the hyperacute stage (1 h after TBI) (control-1, trauma-1, and ETA-1 groups) and the acute stage (6 h after TBI) (control-6, trauma-6, and ETA-6 groups). Tissue levels of tumour necrosis factor-alpha, interleukin-1 beta, malondialdehyde, catalase, glutathione peroxidase, and superoxide dismutase were analyzed. Histopathological and ultrastructural evaluations were also performed. Results i.p. administration of ETA at 1 and 6 h significantly reduced inflammatory cytokine expression, attenuated oxidative stress and lipid peroxidation, prevented apoptosis, and increased antioxidant defense mechanism activity in comparison to trauma group. Histopathological and ultrastructural abnormalities were significantly reduced in ETA-treated rats compared to closed head injury trauma groups. Conclusions ETA significantly improves neural function and prevents post-TBI histopathological damage in rats.
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Affiliation(s)
- Askin Esen Hasturk
- Department of Neurosurgery, Oncology Training and Research Hospital, Ankara, Turkey
| | - Emre Cemal Gokce
- Department of Neurosurgery, Oncology Training and Research Hospital, Ankara, Turkey
| | - Erdal Resit Yilmaz
- Department of Neurosurgery, Ministry of Health, Diskapi Yildirim Beyazit Education and Research Hospital, Ankara, Turkey
| | - Bahriye Horasanli
- Department of Neurology, Baskent University Faculty of Medicine, Konya, Turkey
| | - Oya Evirgen
- Department of Histology and Embryology, Ankara University Faculty of Medicine, Ankara, Turkey
| | - Nazli Hayirli
- Department of Histology and Embryology, Ankara University Faculty of Medicine, Ankara, Turkey
| | - Hilal Gokturk
- Department of Histology and Embryology, Yildirim Beyazit University Faculty of Medicine, Ankara, Turkey
| | - Imge Erguder
- Department of Biochemistry, Ankara University Faculty of Medicine, Ankara, Turkey
| | - Belgin Can
- Department of Histology and Embryology, Ankara University Faculty of Medicine, Ankara, Turkey
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27
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Tsitsopoulos PP, Abu Hamdeh S, Marklund N. Current Opportunities for Clinical Monitoring of Axonal Pathology in Traumatic Brain Injury. Front Neurol 2017; 8:599. [PMID: 29209266 PMCID: PMC5702013 DOI: 10.3389/fneur.2017.00599] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 10/25/2017] [Indexed: 01/14/2023] Open
Abstract
Traumatic brain injury (TBI) is a multidimensional and highly complex disease commonly resulting in widespread injury to axons, due to rapid inertial acceleration/deceleration forces transmitted to the brain during impact. Axonal injury leads to brain network dysfunction, significantly contributing to cognitive and functional impairments frequently observed in TBI survivors. Diffuse axonal injury (DAI) is a clinical entity suggested by impaired level of consciousness and coma on clinical examination and characterized by widespread injury to the hemispheric white matter tracts, the corpus callosum and the brain stem. The clinical course of DAI is commonly unpredictable and it remains a challenging entity with limited therapeutic options, to date. Although axonal integrity may be disrupted at impact, the majority of axonal pathology evolves over time, resulting from delayed activation of complex intracellular biochemical cascades. Activation of these secondary biochemical pathways may lead to axonal transection, named secondary axotomy, and be responsible for the clinical decline of DAI patients. Advances in the neurocritical care of TBI patients have been achieved by refinements in multimodality monitoring for prevention and early detection of secondary injury factors, which can be applied also to DAI. There is an emerging role for biomarkers in blood, cerebrospinal fluid, and interstitial fluid using microdialysis in the evaluation of axonal injury in TBI. These biomarker studies have assessed various axonal and neuroglial markers as well as inflammatory mediators, such as cytokines and chemokines. Moreover, modern neuroimaging can detect subtle or overt DAI/white matter changes in diffuse TBI patients across all injury severities using magnetic resonance spectroscopy, diffusion tensor imaging, and positron emission tomography. Importantly, serial neuroimaging studies provide evidence for evolving axonal injury. Since axonal injury may be a key risk factor for neurodegeneration and dementias at long-term following TBI, the secondary injury processes may require prolonged monitoring. The aim of the present review is to summarize the clinical short- and long-term monitoring possibilities of axonal injury in TBI. Increased knowledge of the underlying pathophysiology achieved by advanced clinical monitoring raises hope for the development of novel treatment strategies for axonal injury in TBI.
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Affiliation(s)
- Parmenion P Tsitsopoulos
- Section of Neurosurgery, Department of Neuroscience, Uppsala University, Uppsala, Sweden.,Hippokratio General Hospital, Aristotle University, Thessaloniki, Greece
| | - Sami Abu Hamdeh
- Section of Neurosurgery, Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Niklas Marklund
- Section of Neurosurgery, Department of Neuroscience, Uppsala University, Uppsala, Sweden.,Department of Clinical Sciences Lund, Neurosurgery, Skåne University Hospital, Lund University, Lund, Sweden
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28
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The chronic and evolving neurological consequences of traumatic brain injury. Lancet Neurol 2017; 16:813-825. [PMID: 28920887 DOI: 10.1016/s1474-4422(17)30279-x] [Citation(s) in RCA: 318] [Impact Index Per Article: 45.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 06/28/2017] [Accepted: 07/17/2017] [Indexed: 12/14/2022]
Abstract
Traumatic brain injury (TBI) can have lifelong and dynamic effects on health and wellbeing. Research on the long-term consequences emphasises that, for many patients, TBI should be conceptualised as a chronic health condition. Evidence suggests that functional outcomes after TBI can show improvement or deterioration up to two decades after injury, and rates of all-cause mortality remain elevated for many years. Furthermore, TBI represents a risk factor for a variety of neurological illnesses, including epilepsy, stroke, and neurodegenerative disease. With respect to neurodegeneration after TBI, post-mortem studies on the long-term neuropathology after injury have identified complex persisting and evolving abnormalities best described as polypathology, which includes chronic traumatic encephalopathy. Despite growing awareness of the lifelong consequences of TBI, substantial gaps in research exist. Improvements are therefore needed in understanding chronic pathologies and their implications for survivors of TBI, which could inform long-term health management in this sizeable patient population.
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29
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Thelin EP, Tajsic T, Zeiler FA, Menon DK, Hutchinson PJA, Carpenter KLH, Morganti-Kossmann MC, Helmy A. Monitoring the Neuroinflammatory Response Following Acute Brain Injury. Front Neurol 2017; 8:351. [PMID: 28775710 PMCID: PMC5517395 DOI: 10.3389/fneur.2017.00351] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/04/2017] [Indexed: 12/11/2022] Open
Abstract
Traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH) are major contributors to morbidity and mortality. Following the initial insult, patients may deteriorate due to secondary brain damage. The underlying molecular and cellular cascades incorporate components of the innate immune system. There are different approaches to assess and monitor cerebral inflammation in the neuro intensive care unit. The aim of this narrative review is to describe techniques to monitor inflammatory activity in patients with TBI and SAH in the acute setting. The analysis of pro- and anti-inflammatory cytokines in compartments of the central nervous system (CNS), including the cerebrospinal fluid and the extracellular fluid, represent the most common approaches to monitor surrogate markers of cerebral inflammatory activity. Each of these compartments has a distinct biology that reflects local processes and the cross-talk between systemic and CNS inflammation. Cytokines have been correlated to outcomes as well as ongoing, secondary injury progression. Alongside the dynamic, focal assay of humoral mediators, imaging, through positron emission tomography, can provide a global in vivo measurement of inflammatory cell activity, which reveals long-lasting processes following the initial injury. Compared to the innate immune system activated acutely after brain injury, the adaptive immune system is likely to play a greater role in the chronic phase as evidenced by T-cell-mediated autoreactivity toward brain-specific proteins. The most difficult aspect of assessing neuroinflammation is to determine whether the processes monitored are harmful or beneficial to the brain as accumulating data indicate a dual role for these inflammatory cascades following injury. In summary, the inflammatory component of the complex injury cascade following brain injury may be monitored using different modalities. Using a multimodal monitoring approach can potentially aid in the development of therapeutics targeting different aspects of the inflammatory cascade and improve the outcome following TBI and SAH.
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Affiliation(s)
- Eric Peter Thelin
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Tamara Tajsic
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Frederick Adam Zeiler
- Division of Anaesthesia, Department of Medicine, University of Cambridge, Cambridge, United Kingdom.,Rady Faculty of Health Sciences, Department of Surgery, University of Manitoba, Winnipeg, MB, Canada.,Clinician Investigator Program, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - David K Menon
- Division of Anaesthesia, Department of Medicine, University of Cambridge, Cambridge, United Kingdom.,Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Peter J A Hutchinson
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.,Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Keri L H Carpenter
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.,Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Maria Cristina Morganti-Kossmann
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, Australia.,Department of Child Health, Barrow Neurological Institute at Phoenix Children's Hospital, University of Arizona College of Medicine, Phoenix, Phoenix, AZ, United States
| | - Adel Helmy
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
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30
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Donat CK, Scott G, Gentleman SM, Sastre M. Microglial Activation in Traumatic Brain Injury. Front Aging Neurosci 2017; 9:208. [PMID: 28701948 PMCID: PMC5487478 DOI: 10.3389/fnagi.2017.00208] [Citation(s) in RCA: 271] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 06/12/2017] [Indexed: 12/15/2022] Open
Abstract
Microglia have a variety of functions in the brain, including synaptic pruning, CNS repair and mediating the immune response against peripheral infection. Microglia rapidly become activated in response to CNS damage. Depending on the nature of the stimulus, microglia can take a number of activation states, which correspond to altered microglia morphology, gene expression and function. It has been reported that early microglia activation following traumatic brain injury (TBI) may contribute to the restoration of homeostasis in the brain. On the other hand, if they remain chronically activated, such cells display a classically activated phenotype, releasing pro-inflammatory molecules, resulting in further tissue damage and contributing potentially to neurodegeneration. However, new evidence suggests that this classification is over-simplistic and the balance of activation states can vary at different points. In this article, we review the role of microglia in TBI, analyzing their distribution, morphology and functional phenotype over time in animal models and in humans. Animal studies have allowed genetic and pharmacological manipulations of microglia activation, in order to define their role. In addition, we describe investigations on the in vivo imaging of microglia using translocator protein (TSPO) PET and autoradiography, showing that microglial activation can occur in regions far remote from sites of focal injuries, in humans and animal models of TBI. Finally, we outline some novel potential therapeutic approaches that prime microglia/macrophages toward the beneficial restorative microglial phenotype after TBI.
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Affiliation(s)
| | | | | | - Magdalena Sastre
- Division of Brain Sciences, Department of Medicine, Imperial College LondonLondon, United Kingdom
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Coughlin JM, Wang Y, Minn I, Bienko N, Ambinder EB, Xu X, Peters ME, Dougherty JW, Vranesic M, Koo SM, Ahn HH, Lee M, Cottrell C, Sair HI, Sawa A, Munro CA, Nowinski CJ, Dannals RF, Lyketsos CG, Kassiou M, Smith G, Caffo B, Mori S, Guilarte TR, Pomper MG. Imaging of Glial Cell Activation and White Matter Integrity in Brains of Active and Recently Retired National Football League Players. JAMA Neurol 2017; 74:67-74. [PMID: 27893897 DOI: 10.1001/jamaneurol.2016.3764] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Importance Microglia, the resident immune cells of the central nervous system, play an important role in the brain's response to injury and neurodegenerative processes. It has been proposed that prolonged microglial activation occurs after single and repeated traumatic brain injury, possibly through sports-related concussive and subconcussive injuries. Limited in vivo brain imaging studies months to years after individuals experience a single moderate to severe traumatic brain injury suggest widespread persistent microglial activation, but there has been little study of persistent glial cell activity in brains of athletes with sports-related traumatic brain injury. Objective To measure translocator protein 18 kDa (TSPO), a marker of activated glial cell response, in a cohort of National Football League (NFL) players and control participants, and to report measures of white matter integrity. Design, Setting, and Participants This cross-sectional, case-control study included young active (n = 4) or former (n = 10) NFL players recruited from across the United States, and 16 age-, sex-, highest educational level-, and body mass index-matched control participants. This study was conducted at an academic research institution in Baltimore, Maryland, from January 29, 2015, to February 18, 2016. Main Outcomes and Measures Positron emission tomography-based regional measures of TSPO using [11C]DPA-713, diffusion tensor imaging measures of regional white matter integrity, regional volumes on structural magnetic resonance imaging, and neuropsychological performance. Results The mean (SD) ages of the 14 NFL participants and 16 control participants were 31.3 (6.1) years and 27.6 (4.9) years, respectively. Players reported a mean (SD) of 7.0 (6.4) years (range, 1-21 years) since the last self-reported concussion. Using [11C]DPA-713 positron emission tomographic data from 12 active or former NFL players and 11 matched control participants, the NFL players showed higher total distribution volume in 8 of the 12 brain regions examined (P < .004). We also observed limited change in white matter fractional anisotropy and mean diffusivity in 13 players compared with 15 control participants. In contrast, these young players did not differ from control participants in regional brain volumes or in neuropsychological performance. Conclusions and Relevance The results suggest that localized brain injury and repair, indicated by higher TSPO signal and white matter changes, may be associated with NFL play. Further study is needed to confirm these findings and to determine whether TSPO signal and white matter changes in young NFL athletes are related to later onset of neuropsychiatric symptoms.
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Affiliation(s)
- Jennifer M Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland2Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Yuchuan Wang
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Il Minn
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Nicholas Bienko
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Emily B Ambinder
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Xin Xu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Matthew E Peters
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - John W Dougherty
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Melin Vranesic
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Soo Min Koo
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Hye-Hyun Ahn
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Merton Lee
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Chris Cottrell
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Haris I Sair
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Akira Sawa
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Cynthia A Munro
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland3Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Christopher J Nowinski
- Concussion Legacy Foundation, Waltham, Massachusetts5Alzheimer's Disease and CTE Center, Boston University School of Medicine, Boston, Massachusetts
| | - Robert F Dannals
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Constantine G Lyketsos
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Michael Kassiou
- School of Chemistry, University of Sydney, New South Wales, Australia7Discipline of Medical Radiation Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Gwenn Smith
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Brian Caffo
- Department of Biostatistics, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Susumu Mori
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Tomas R Guilarte
- Department of Environmental and Occupational Health, Florida International University, Miami10Program in Cognitive Neuroscience and Imaging, Florida International University, Miami
| | - Martin G Pomper
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland2Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
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Haarman BCM'B, Burger H, Doorduin J, Renken RJ, Sibeijn-Kuiper AJ, Marsman JBC, de Vries EFJ, de Groot JC, Drexhage HA, Mendes R, Nolen WA, Riemersma-Van der Lek RF. Volume, metabolites and neuroinflammation of the hippocampus in bipolar disorder - A combined magnetic resonance imaging and positron emission tomography study. Brain Behav Immun 2016; 56:21-33. [PMID: 26348581 DOI: 10.1016/j.bbi.2015.09.004] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 08/11/2015] [Accepted: 09/04/2015] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND The hippocampus is one of the brain regions that is involved in several pathophysiological theories about bipolar disorder (BD), such as the neuroinflammation theory and the corticolimbic metabolic dysregulation theory. We compared hippocampal volume and hippocampal metabolites in bipolar I disorder (BD-I) patients versus healthy controls (HCs) with magnetic resonance imaging (MRI) and spectroscopy (MRS). We post hoc investigated whether hippocampal volume and hippocampal metabolites were associated with microglial activation and explored if potential illness modifying factors affected these hippocampal measurements and whether these were associated with experienced mood and functioning. MATERIALS AND METHODS Twenty-two BD-I patients and twenty-four HCs were included in the analyses. All subjects underwent psychiatric interviews as well as an MRI scan, including a T1 scan and PRESS magnetic resonance spectroscopy (MRS). Volumetric analysis was performed with Freesurfer. MRS quantification was performed with LC Model. A subgroup of 14 patients and 11 HCs also underwent a successful [(11)C]-(R)-PK11195 neuroinflammation positron emission tomography scan. RESULTS In contrast to our hypothesis, hippocampal volumes were not decreased in patients compared to HC after correcting for individual whole-brain volume variations. We demonstrated decreased N-acetylaspartate (NAA)+N-acetyl-aspartyl-glutamate (NAAG) and creatine (Cr)+phosphocreatine (PCr) concentrations in the left hippocampus. In the explorative analyses in the left hippocampus we identified positive associations between microglial activation and the NAA+NAAG concentration, between alcohol use and NAA+NAAG concentration, between microglial activation and the depression score and a negative relation between Cr+PCr concentration and experienced occupational disability. Duration of illness associated positively with volume bilaterally. CONCLUSION Compared to HCs, the decreased NAA+NAAG concentration in the left hippocampus of BD-I patients suggests a decreased neuronal integrity in this region. In addition we found a positive relation between microglial activation and neuronal integrity in vivo, corresponding to a differentiated microglial function where some microglia induce apoptosis while others stimulate neurogenesis.
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Affiliation(s)
- Bartholomeus C M 'Benno' Haarman
- University of Groningen, University Medical Center Groningen, Department of Psychiatry, Groningen, The Netherlands; Radiology Morphological Solutions, Berkel en Rodenrijs, The Netherlands.
| | - Huibert Burger
- University of Groningen, University Medical Center Groningen, Department of Psychiatry, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Department of General Practice, Groningen, The Netherlands
| | - Janine Doorduin
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen, The Netherlands
| | - Remco J Renken
- University of Groningen, Neuroimaging Center, Groningen, The Netherlands
| | | | | | - Erik F J de Vries
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen, The Netherlands
| | - Jan Cees de Groot
- University of Groningen, University Medical Center Groningen, Department of Radiology, Groningen, The Netherlands
| | - Hemmo A Drexhage
- Erasmus MC, Department of Immunology, Rotterdam, The Netherlands
| | - Richard Mendes
- Radiology Morphological Solutions, Berkel en Rodenrijs, The Netherlands
| | - Willem A Nolen
- University of Groningen, University Medical Center Groningen, Department of Psychiatry, Groningen, The Netherlands
| | - Rixt F Riemersma-Van der Lek
- University of Groningen, University Medical Center Groningen, Department of Psychiatry, Groningen, The Netherlands
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Advanced neuroimaging applied to veterans and service personnel with traumatic brain injury: state of the art and potential benefits. Brain Imaging Behav 2016; 9:367-402. [PMID: 26350144 DOI: 10.1007/s11682-015-9444-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Traumatic brain injury (TBI) remains one of the most prevalent forms of morbidity among Veterans and Service Members, particularly for those engaged in the conflicts in Iraq and Afghanistan. Neuroimaging has been considered a potentially useful diagnostic and prognostic tool across the spectrum of TBI generally, but may have particular importance in military populations where the diagnosis of mild TBI is particularly challenging, given the frequent lack of documentation on the nature of the injuries and mixed etiologies, and highly comorbid with other disorders such as post-traumatic stress disorder, depression, and substance misuse. Imaging has also been employed in attempts to understand better the potential late effects of trauma and to evaluate the effects of promising therapeutic interventions. This review surveys the use of structural and functional neuroimaging techniques utilized in military studies published to date, including the utilization of quantitative fluid attenuated inversion recovery (FLAIR), susceptibility weighted imaging (SWI), volumetric analysis, diffusion tensor imaging (DTI), magnetization transfer imaging (MTI), positron emission tomography (PET), magnetoencephalography (MEG), task-based and resting state functional MRI (fMRI), arterial spin labeling (ASL), and magnetic resonance spectroscopy (MRS). The importance of quality assurance testing in current and future research is also highlighted. Current challenges and limitations of each technique are outlined, and future directions are discussed.
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Lafrenaye AD. Physical interactions between activated microglia and injured axons: do all contacts lead to phagocytosis? Neural Regen Res 2016; 11:538-40. [PMID: 27212901 PMCID: PMC4870897 DOI: 10.4103/1673-5374.180726] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Indexed: 12/22/2022] Open
Affiliation(s)
- Audrey D. Lafrenaye
- Department of Anatomy and Neurobiology, Virginia Commonwealth University Medical Center, Richmond, VA, USA
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Vállez García D, Otte A, Dierckx RAJO, Doorduin J. Three Month Follow-Up of Rat Mild Traumatic Brain Injury: A Combined [ 18F]FDG and [ 11C]PK11195 Positron Emission Study. J Neurotrauma 2016; 33:1855-1865. [PMID: 26756169 DOI: 10.1089/neu.2015.4230] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Mild traumatic brain injury (mTBI) is the most common cause of head trauma. The time course of functional pathology is not well defined, however. The purpose of this study was to evaluate the consequences of mTBI in rats over a period of 3 months by determining the presence of neuroinflammation ([11C]PK11195) and changes in brain metabolism ([18F]FDG) with positron emission tomography (PET) imaging. Male Sprague-Dawley rats were divided in mTBI (n = 8) and sham (n = 8) groups. In vivo PET imaging and behavioral tests (open field, object recognition, and Y-maze) were performed at different time points after induction of the trauma. Differences between groups in PET images were explored using volume-of-interest and voxel-based analysis. mTBI did not result in death, skull fracture, or suppression of reflexes. Weight gain was reduced (p = 0.003) in the mTBI group compared with the sham-treated group. No statistical differences were found in the behavioral tests at any time point. Volume-of-interest analysis showed neuroinflammation limited to the subacute phase (day 12) involving amygdala, globus pallidus, hypothalamus, pons, septum, striatum, and thalamus (p < 0.03, d > 1.2). Alterations in glucose metabolism were detected over the 3 month period, with increased uptake in the medulla (p < 0.04, d ≥ 1.2), and decreased uptake in the globus pallidus, striatum, and thalamus (p < 0.04, d ≤ 1.2). Similar findings were observed in the voxel-based analysis (p < 0.05 at corrected cluster level). As a consequence of the mTBI, and in the absence of apparent behavioral alterations, relative brain glucose metabolism was found altered in several brain regions, which mostly correspond with those presenting neuroinflammation in the subacute stage.
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Affiliation(s)
- David Vállez García
- 1 Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen , Groningen, The Netherlands
| | - Andreas Otte
- 2 Division of Biomedical Engineering, Department of Electrical Engineering and Information Technology, Offenburg University , Offenburg, Germany
| | - Rudi A J O Dierckx
- 1 Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen , Groningen, The Netherlands
| | - Janine Doorduin
- 1 Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen , Groningen, The Netherlands
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Changes in Binding of [(123)I]CLINDE, a High-Affinity Translocator Protein 18 kDa (TSPO) Selective Radioligand in a Rat Model of Traumatic Brain Injury. Neuromolecular Med 2016; 18:158-69. [PMID: 26969181 DOI: 10.1007/s12017-016-8385-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 02/02/2016] [Indexed: 01/01/2023]
Abstract
After traumatic brain injury (TBI), secondary injuries develop, including neuroinflammatory processes that contribute to long-lasting impairments. These secondary injuries represent potential targets for treatment and diagnostics. The translocator protein 18 kDa (TSPO) is expressed in activated microglia cells and upregulated in response to brain injury and therefore a potential biomarker of the neuroinflammatory processes. Second-generation radioligands of TSPO, such as [(123)I]CLINDE, have a higher signal-to-noise ratio as the prototype ligand PK11195. [(123)I]CLINDE has been employed in human studies using single-photon emission computed tomography to image the neuroinflammatory response after stroke. In this study, we used the same tracer in a rat model of TBI to determine changes in TSPO expression. Adult Sprague-Dawley rats were subjected to moderate controlled cortical impact injury and sacrificed at 6, 24, 72 h and 28 days post surgery. TSPO expression was assessed in brain sections employing [(123)I]CLINDE in vitro autoradiography. From 24 h to 28 days post surgery, injured animals exhibited a marked and time-dependent increase in [(123)I]CLINDE binding in the ipsilateral motor, somatosensory and parietal cortex, as well as in the hippocampus and thalamus. Interestingly, binding was also significantly elevated in the contralateral M1 motor cortex following TBI. Craniotomy without TBI caused a less marked increase in [(123)I]CLINDE binding, restricted to the ipsilateral hemisphere. Radioligand binding was consistent with an increase in TSPO mRNA expression and CD11b immunoreactivity at the contusion site. This study demonstrates the applicability of [(123)I]CLINDE for detailed regional and quantitative assessment of glial activity in experimental models of TBI.
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Masdeu JC, Pascual B. Genetic and degenerative disorders primarily causing dementia. HANDBOOK OF CLINICAL NEUROLOGY 2016; 135:525-564. [PMID: 27432682 DOI: 10.1016/b978-0-444-53485-9.00026-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Neuroimaging comprises a powerful set of instruments to diagnose the different causes of dementia, clarify their neurobiology, and monitor their treatment. Magnetic resonance imaging (MRI) depicts volume changes with neurodegeneration and inflammation, as well as abnormalities in functional and structural connectivity. MRI arterial spin labeling allows for the quantification of regional cerebral blood flow, characteristically altered in Alzheimer's disease, diffuse Lewy-body disease, and the frontotemporal dementias. Positron emission tomography allows for the determination of regional metabolism, with similar abnormalities as flow, and for the measurement of β-amyloid and abnormal tau deposition in the brain, as well as regional inflammation. These instruments allow for the quantification in vivo of most of the pathologic features observed in disorders causing dementia. Importantly, they allow for the longitudinal study of these abnormalities, having revealed, for instance, that the deposition of β-amyloid in the brain can antecede by decades the onset of dementia. Thus, a therapeutic window has been opened and the efficacy of immunotherapies directed at removing β-amyloid from the brain of asymptomatic individuals is currently being tested. Tau and inflammation imaging, still in their infancy, combined with genomics, should provide powerful insights into these disorders and facilitate their treatment.
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Affiliation(s)
- Joseph C Masdeu
- Department of Neurology, Houston Methodist Hospital, Houston, TX, USA.
| | - Belen Pascual
- Department of Neurology, Houston Methodist Hospital, Houston, TX, USA
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Scott G, Hellyer PJ, Ramlackhansingh AF, Brooks DJ, Matthews PM, Sharp DJ. Thalamic inflammation after brain trauma is associated with thalamo-cortical white matter damage. J Neuroinflammation 2015; 12:224. [PMID: 26627199 PMCID: PMC4666189 DOI: 10.1186/s12974-015-0445-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 11/25/2015] [Indexed: 11/21/2022] Open
Abstract
Background Traumatic brain injury can trigger chronic neuroinflammation, which may predispose to neurodegeneration. Animal models and human pathological studies demonstrate persistent inflammation in the thalamus associated with axonal injury, but this relationship has never been shown in vivo. Findings Using [11C]-PK11195 positron emission tomography, a marker of microglial activation, we previously demonstrated thalamic inflammation up to 17 years after traumatic brain injury. Here, we use diffusion MRI to estimate axonal injury and show that thalamic inflammation is correlated with thalamo-cortical tract damage. Conclusions These findings support a link between axonal damage and persistent inflammation after brain injury.
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Affiliation(s)
- Gregory Scott
- Division of Brain Sciences, Department of Medicine, Hammersmith Hospital Campus, Imperial College London, London, UK
| | - Peter J Hellyer
- Division of Brain Sciences, Department of Medicine, Hammersmith Hospital Campus, Imperial College London, London, UK.,Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, London, UK
| | - Anil F Ramlackhansingh
- Division of Brain Sciences, Department of Medicine, Hammersmith Hospital Campus, Imperial College London, London, UK
| | - David J Brooks
- Division of Brain Sciences, Department of Medicine, Hammersmith Hospital Campus, Imperial College London, London, UK.,Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Paul M Matthews
- Division of Brain Sciences, Department of Medicine, Hammersmith Hospital Campus, Imperial College London, London, UK
| | - David J Sharp
- Division of Brain Sciences, Department of Medicine, Hammersmith Hospital Campus, Imperial College London, London, UK. .,Computational, Cognitive and Clinical Neuroimaging Laboratory, 3rd Floor, Burlington Danes Building, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK.
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Amyot F, Arciniegas DB, Brazaitis MP, Curley KC, Diaz-Arrastia R, Gandjbakhche A, Herscovitch P, Hinds SR, Manley GT, Pacifico A, Razumovsky A, Riley J, Salzer W, Shih R, Smirniotopoulos JG, Stocker D. A Review of the Effectiveness of Neuroimaging Modalities for the Detection of Traumatic Brain Injury. J Neurotrauma 2015; 32:1693-721. [PMID: 26176603 PMCID: PMC4651019 DOI: 10.1089/neu.2013.3306] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The incidence of traumatic brain injury (TBI) in the United States was 3.5 million cases in 2009, according to the Centers for Disease Control and Prevention. It is a contributing factor in 30.5% of injury-related deaths among civilians. Additionally, since 2000, more than 260,000 service members were diagnosed with TBI, with the vast majority classified as mild or concussive (76%). The objective assessment of TBI via imaging is a critical research gap, both in the military and civilian communities. In 2011, the Department of Defense (DoD) prepared a congressional report summarizing the effectiveness of seven neuroimaging modalities (computed tomography [CT], magnetic resonance imaging [MRI], transcranial Doppler [TCD], positron emission tomography, single photon emission computed tomography, electrophysiologic techniques [magnetoencephalography and electroencephalography], and functional near-infrared spectroscopy) to assess the spectrum of TBI from concussion to coma. For this report, neuroimaging experts identified the most relevant peer-reviewed publications and assessed the quality of the literature for each of these imaging technique in the clinical and research settings. Although CT, MRI, and TCD were determined to be the most useful modalities in the clinical setting, no single imaging modality proved sufficient for all patients due to the heterogeneity of TBI. All imaging modalities reviewed demonstrated the potential to emerge as part of future clinical care. This paper describes and updates the results of the DoD report and also expands on the use of angiography in patients with TBI.
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Affiliation(s)
- Franck Amyot
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland
- Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - David B. Arciniegas
- Beth K. and Stuart C. Yudofsky Division of Neuropsychiatry, Baylor College of Medicine, Houston, Texas
- Brain Injury Research, TIRR Memorial Hermann, Houston, Texas
| | | | - Kenneth C. Curley
- Combat Casualty Care Directorate (RAD2), U.S. Army Medical Research and Materiel Command, Fort Detrick, Maryland
| | - Ramon Diaz-Arrastia
- Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Amir Gandjbakhche
- The Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland
| | - Peter Herscovitch
- Positron Emission Tomography Department, National Institutes of Health Clinical Center, Bethesda, Maryland
| | - Sidney R. Hinds
- Defense and Veterans Brain Injury Center, Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury Silver Spring, Maryland
| | - Geoffrey T. Manley
- Brain and Spinal Injury Center, Department of Neurological Surgery, University of California, San Francisco, San Francisco, California
| | - Anthony Pacifico
- Congressionally Directed Medical Research Programs, Fort Detrick, Maryland
| | | | - Jason Riley
- Queens University, Kingston, Ontario, Canada
- ArcheOptix Inc., Picton, Ontario, Canada
| | - Wanda Salzer
- Congressionally Directed Medical Research Programs, Fort Detrick, Maryland
| | - Robert Shih
- Walter Reed National Military Medical Center, Bethesda, Maryland
| | - James G. Smirniotopoulos
- Department of Radiology, Neurology, and Biomedical Informatics, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Derek Stocker
- Walter Reed National Military Medical Center, Bethesda, Maryland
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van der Doef TF, Doorduin J, van Berckel BNM, Cervenka S. Assessing brain immune activation in psychiatric disorders: clinical and preclinical PET imaging studies of the 18-kDa translocator protein. Clin Transl Imaging 2015; 3:449-460. [PMID: 28781965 PMCID: PMC5496979 DOI: 10.1007/s40336-015-0140-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 08/26/2015] [Indexed: 01/24/2023]
Abstract
Accumulating evidence from different lines of research suggests an involvement of the immune system in the pathophysiology of several psychiatric disorders. During recent years, a series of positron emission tomography (PET) studies have been published using radioligands for the translocator protein (TSPO) to study microglia activation in schizophrenia, bipolar I disorder, major depression, autism spectrum disorder, and drug abuse. The results have been somewhat conflicting, which could be due to differences both in patient sample characteristics and in PET methods. In particular, further work is needed to address both methodological and biological sources of variability in TSPO levels, a process in which the use of animal models and small animal PET systems can be a valuable tool. Given this development, PET studies of immune activation have the potential to further increase our understanding of disease mechanisms in psychiatric disorders, which is a requisite in the search for new treatment approaches. Furthermore, molecular imaging could become an important clinical tool for identifying specific subgroups of patients or disease stages that would benefit from treatment targeting the immune system.
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Affiliation(s)
- Thalia F van der Doef
- Department of Psychiatry, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Janine Doorduin
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Bart N M van Berckel
- Department of Psychiatry, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Simon Cervenka
- Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet, Stockholm, Sweden
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Velázquez A, Ortega M, Rojas S, González-Oliván FJ, Rodríguez-Baeza A. Widespread microglial activation in patients deceased from traumatic brain injury. Brain Inj 2015; 29:1126-33. [PMID: 26067626 DOI: 10.3109/02699052.2015.1018325] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
PRIMARY OBJECTIVE The role of microglial activation in traumatic brain injury (TBI) has been extensively described in established animal models. In contrast, very few studies have analysed this process in human patients, the majority being focused on the local reaction in the contused parenchyma. In this work, the main objective was the analysis of microglial activation in brain regions distant from the primary lesion. RESEARCH DESIGN Morphological changes of microglia were evaluated in the cerebral cortex of patients deceased from TBI in comparison with control subjects. METHODS AND PROCEDURES Cortical samples from five cases with TBI and 10 controls were evaluated using Ricinus communis lectin histochemistry and conventional Hematoxylin-eosin staining. MAIN OUTCOMES AND RESULTS It was observed that microglial cells from patients with TBI presented shorter and thicker cellular projections compared with controls. Moreover, the percentage of histological area reactive to lectin was statistically higher in samples from subjects with TBI. These signs of microglial activation were observed in all of the analysed cortical areas, thus indicating a generalized effect on the whole cerebral cortex. The results are consistent with previous imaging PET studies performed in living patients with the 11C-PK11195 radiotracer. CONCLUSIONS The findings indicate that TBI induces a widespread activation of brain microglia which affects all cortical areas, including those distant from the contusion site.
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Affiliation(s)
- Antonio Velázquez
- Departamento de Ciencias Morfológicas, Facultad de Medicina, Universitat Autònoma de Barcelona , Barcelona , Spain and
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Tobinick E, Rodriguez-Romanacce H, Levine A, Ignatowski TA, Spengler RN. Immediate neurological recovery following perispinal etanercept years after brain injury. Clin Drug Investig 2015; 34:361-6. [PMID: 24647830 DOI: 10.1007/s40261-014-0186-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Positron emission tomographic brain imaging and pathological examination have revealed that a chronic, intracerebral neuroinflammatory response lasting for years after a single brain injury may occur in humans. Evidence suggests the immune signaling molecule, tumor necrosis factor (TNF), is centrally involved in this pathology through its modulation of microglial activation, role in synaptic dysfunction, and induction of depressive symptoms and neuropathic pain. Etanercept is a recombinant TNF receptor fusion protein and potent TNF inhibitor that has been found to reduce microglial activation and neuropathic pain in multiple experimental models. We report that a single dose of perispinal etanercept produced an immediate, profound, and sustained improvement in expressive aphasia, speech apraxia, and left hemiparesis in a patient with chronic, intractable, debilitating neurological dysfunction present for more than 3 years after acute brain injury. These results indicate that acute brain injury-induced pathologic levels of TNF may provide a therapeutic target that can be addressed years after injury. Perispinal administration of etanercept is capable of producing immediate relief from brain injury-mediated neurological dysfunction.
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Affiliation(s)
- Edward Tobinick
- Institute of Neurological Recovery, 2300 Glades Road Suite 305E, Boca Raton, FL, 33431, USA,
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43
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Carpenter KLH, Czosnyka M, Jalloh I, Newcombe VFJ, Helmy A, Shannon RJ, Budohoski KP, Kolias AG, Kirkpatrick PJ, Carpenter TA, Menon DK, Hutchinson PJ. Systemic, local, and imaging biomarkers of brain injury: more needed, and better use of those already established? Front Neurol 2015; 6:26. [PMID: 25741315 PMCID: PMC4332345 DOI: 10.3389/fneur.2015.00026] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 01/30/2015] [Indexed: 02/02/2023] Open
Abstract
Much progress has been made over the past two decades in the treatment of severe acute brain injury, including traumatic brain injury and subarachnoid hemorrhage, resulting in a higher proportion of patients surviving with better outcomes. This has arisen from a combination of factors. These include improvements in procedures at the scene (pre-hospital) and in the hospital emergency department, advances in neuromonitoring in the intensive care unit, both continuously at the bedside and intermittently in scans, evolution and refinement of protocol-driven therapy for better management of patients, and advances in surgical procedures and rehabilitation. Nevertheless, many patients still experience varying degrees of long-term disabilities post-injury with consequent demands on carers and resources, and there is room for improvement. Biomarkers are a key aspect of neuromonitoring. A broad definition of a biomarker is any observable feature that can be used to inform on the state of the patient, e.g., a molecular species, a feature on a scan, or a monitoring characteristic, e.g., cerebrovascular pressure reactivity index. Biomarkers are usually quantitative measures, which can be utilized in diagnosis and monitoring of response to treatment. They are thus crucial to the development of therapies and may be utilized as surrogate endpoints in Phase II clinical trials. To date, there is no specific drug treatment for acute brain injury, and many seemingly promising agents emerging from pre-clinical animal models have failed in clinical trials. Large Phase III studies of clinical outcomes are costly, consuming time and resources. It is therefore important that adequate Phase II clinical studies with informative surrogate endpoints are performed employing appropriate biomarkers. In this article, we review some of the available systemic, local, and imaging biomarkers and technologies relevant in acute brain injury patients, and highlight gaps in the current state of knowledge.
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Affiliation(s)
- Keri L. H. Carpenter
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK,Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK,*Correspondence: Keri L. H. Carpenter, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Box 167, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK e-mail:
| | - Marek Czosnyka
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Ibrahim Jalloh
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Virginia F. J. Newcombe
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK,Division of Anaesthesia, Department of Medicine, University of Cambridge, Cambridge, UK
| | - Adel Helmy
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Richard J. Shannon
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Karol P. Budohoski
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Angelos G. Kolias
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Peter J. Kirkpatrick
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Thomas Adrian Carpenter
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - David K. Menon
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK,Division of Anaesthesia, Department of Medicine, University of Cambridge, Cambridge, UK
| | - Peter J. Hutchinson
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK,Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
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Van Der Naalt J. Resting functional imaging tools (MRS, SPECT, PET and PCT). HANDBOOK OF CLINICAL NEUROLOGY 2015; 127:295-308. [PMID: 25702224 DOI: 10.1016/b978-0-444-52892-6.00019-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Functional imaging includes imaging techniques that provide information about the metabolic and hemodynamic status of the brain. Most commonly applied functional imaging techniques in patients with traumatic brain injury (TBI) include magnetic resonance spectroscopy (MRS), single photon emission computed tomography (SPECT), positron emission tomography (PET) and perfusion CT (PCT). These imaging modalities are used to determine the extent of injury, to provide information for the prediction of outcome, and to assess evidence of cerebral ischemia. In TBI, secondary brain damage mainly comprises ischemia and is present in more than 80% of fatal cases with traumatic brain injury (Graham et al., 1989; Bouma et al., 1991; Coles et al., 2004). In particular, while SPECT measures cerebral perfusion and MRS determines metabolism, PET is able to assess both perfusion and cerebral metabolism. This chapter will describe the application of these techniques in traumatic brain injury separately for the major groups of severity comprising the mild and moderate to severe group. The application in TBI and potential difficulties of each technique is described. The use of imaging techniques in children will be separately outlined.
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Affiliation(s)
- J Van Der Naalt
- Department of Neurology, University Medical Center Groningen, University of Groningen, The Netherlands.
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45
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Coughlin JM, Wang Y, Munro CA, Ma S, Yue C, Chen S, Airan R, Kim PK, Adams AV, Garcia C, Higgs C, Sair HI, Sawa A, Smith G, Lyketsos CG, Caffo B, Kassiou M, Guilarte TR, Pomper MG. Neuroinflammation and brain atrophy in former NFL players: An in vivo multimodal imaging pilot study. Neurobiol Dis 2014; 74:58-65. [PMID: 25447235 DOI: 10.1016/j.nbd.2014.10.019] [Citation(s) in RCA: 177] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 10/10/2014] [Accepted: 10/22/2014] [Indexed: 12/14/2022] Open
Abstract
There are growing concerns about potential delayed, neuropsychiatric consequences (e.g, cognitive decline, mood or anxiety disorders) of sports-related traumatic brain injury (TBI). Autopsy studies of brains from a limited number of former athletes have described characteristic, pathologic changes of chronic traumatic encephalopathy (CTE) leading to questions about the relationship between these pathologic and the neuropsychiatric disturbances seen in former athletes. Research in this area will depend on in vivo methods that characterize molecular changes in the brain, linking CTE and other sports-related pathologies with delayed emergence of neuropsychiatric symptoms. In this pilot project we studied former National Football League (NFL) players using new neuroimaging techniques and clinical measures of cognitive functioning. We hypothesized that former NFL players would show molecular and structural changes in medial temporal and parietal lobe structures as well as specific cognitive deficits, namely those of verbal learning and memory. We observed a significant increase in binding of [(11)C]DPA-713 to the translocator protein (TSPO), a marker of brain injury and repair, in several brain regions, such as the supramarginal gyrus and right amygdala, in 9 former NFL players compared to 9 age-matched, healthy controls. We also observed significant atrophy of the right hippocampus. Finally, we report that these same former players had varied performance on a test of verbal learning and memory, suggesting that these molecular and pathologic changes may play a role in cognitive decline. These results suggest that localized brain injury and repair, indicated by increased [(11)C]DPA-713 binding to TSPO, may be linked to history of NFL play. [(11)C]DPA-713 PET is a promising new tool that can be used in future study design to examine further the relationship between TSPO expression in brain injury and repair, selective regional brain atrophy, and the potential link to deficits in verbal learning and memory after NFL play.
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Affiliation(s)
- Jennifer M Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Yuchuan Wang
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Cynthia A Munro
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA.,Department of Neurology, Johns Hopkins Medical Institutions,Baltimore, MD, USA
| | - Shuangchao Ma
- Department of Health Sciences Informatics, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Chen Yue
- Department of Biostatistics, Johns Hopkins Medical Institutions,Baltimore, MD, USA
| | - Shaojie Chen
- Department of Biostatistics, Johns Hopkins Medical Institutions,Baltimore, MD, USA
| | - Raag Airan
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Pearl K Kim
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Ashley V Adams
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Cinthya Garcia
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Cecilia Higgs
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Haris I Sair
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Akira Sawa
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Gwenn Smith
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Constantine G Lyketsos
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Brian Caffo
- Department of Biostatistics, Johns Hopkins Medical Institutions,Baltimore, MD, USA
| | - Michael Kassiou
- School of Chemistry, The University of Sydney, NSW 2006, Sydney, Australia.,Discipline of Medical Radiation Sciences, The University of Sydney, NSW 2006, Sydney, Australia
| | - Tomas R Guilarte
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA
| | - Martin G Pomper
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA.,Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
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Haarman BCMB, Riemersma-Van der Lek RF, de Groot JC, Ruhé HGE, Klein HC, Zandstra TE, Burger H, Schoevers RA, de Vries EFJ, Drexhage HA, Nolen WA, Doorduin J. Neuroinflammation in bipolar disorder - A [(11)C]-(R)-PK11195 positron emission tomography study. Brain Behav Immun 2014; 40:219-25. [PMID: 24703991 DOI: 10.1016/j.bbi.2014.03.016] [Citation(s) in RCA: 144] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/11/2014] [Accepted: 03/23/2014] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND The "monocyte-T-cell theory of mood disorders" regards neuroinflammation, i.e. marked activation of microglia, as a driving force in bipolar disorder. Microglia activation can be visualized in vivo using [(11)C]-(R)-PK11195 PET. Indirect evidence suggests the hippocampus as a potential focus of neuroinflammation in bipolar disorder. We aim to determine if there is increased [(11)C]-(R)-PK11195 binding to activated microglia in the hippocampus of patients with bipolar I disorder when compared to healthy controls. MATERIAL AND METHODS Fourteen patients with bipolar I disorder and eleven healthy controls were included in the analyses. Dynamic 60-min PET scans were acquired after the injection of [(11)C]-(R)-PK11195. All subjects underwent psychiatric interviews as well as an MRI scan, which was used for anatomic co-registration in the data analysis. The data from the PET scans was analyzed with a two-tissue-compartment model to calculate the binding potential, using the metabolite-corrected plasma and blood curve as input. RESULTS A significantly increased [(11)C]-(R)-PK11195 binding potential, which is indicative of neuroinflammation, was found in the right hippocampus of the patients when compared to the healthy controls (1.66 (CI 1.45-1.91) versus 1.33 (CI 1.16-1.53); p=0.033, respectively). Although the same trend was observed in the left hippocampus, this difference was not statistically significant. CONCLUSION This study is the first to demonstrate the presence of focal neuroinflammation in the right hippocampus in bipolar I disorder.
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Affiliation(s)
| | - Rixt F Riemersma-Van der Lek
- University of Groningen, University Medical Center Groningen, Department of Psychiatry, Groningen, The Netherlands
| | - Jan Cees de Groot
- University of Groningen, University Medical Center Groningen, Department of Radiology, Groningen, The Netherlands
| | - Henricus G Eric Ruhé
- University of Groningen, University Medical Center Groningen, Department of Psychiatry, Groningen, The Netherlands
| | - Hans C Klein
- University of Groningen, University Medical Center Groningen, Department of Psychiatry, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen, The Netherlands
| | - Tjitske E Zandstra
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen, The Netherlands
| | - Huibert Burger
- University of Groningen, University Medical Center Groningen, Department of Psychiatry, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Department of General Practice, Groningen, The Netherlands
| | - Robert A Schoevers
- University of Groningen, University Medical Center Groningen, Department of Psychiatry, Groningen, The Netherlands
| | - Erik F J de Vries
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen, The Netherlands
| | - Hemmo A Drexhage
- Erasmus MC, Department of Immunology, Rotterdam, The Netherlands
| | - Willem A Nolen
- University of Groningen, University Medical Center Groningen, Department of Psychiatry, Groningen, The Netherlands
| | - Janine Doorduin
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen, The Netherlands
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47
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Kou Z, VandeVord PJ. Traumatic white matter injury and glial activation: from basic science to clinics. Glia 2014; 62:1831-55. [PMID: 24807544 DOI: 10.1002/glia.22690] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 03/27/2014] [Accepted: 04/23/2014] [Indexed: 12/15/2022]
Abstract
An improved understanding and characterization of glial activation and its relationship with white matter injury will likely serve as a novel treatment target to curb post injury inflammation and promote axonal remyelination after brain trauma. Traumatic brain injury (TBI) is a significant public healthcare burden and a leading cause of death and disability in the United States. Particularly, traumatic white matter (WM) injury or traumatic axonal injury has been reported as being associated with patients' poor outcomes. However, there is very limited data reporting the importance of glial activation after TBI and its interaction with WM injury. This article presents a systematic review of traumatic WM injury and the associated glial activation, from basic science to clinical diagnosis and prognosis, from advanced neuroimaging perspective. It concludes that there is a disconnection between WM injury research and the essential role of glia which serve to restore a healthy environment for axonal regeneration following WM injury. Particularly, there is a significant lack of non-invasive means to characterize the complex pathophysiology of WM injury and glial activation in both animal models and in humans. An improved understanding and characterization of the relationship between glia and WM injury will likely serve as a novel treatment target to curb post injury inflammation and promote axonal remyelination.
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Affiliation(s)
- Zhifeng Kou
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan; Department of Radiology, Wayne State University, Detroit, Michigan
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Ng TS, Lin AP, Koerte IK, Pasternak O, Liao H, Merugumala S, Bouix S, Shenton ME. Neuroimaging in repetitive brain trauma. ALZHEIMERS RESEARCH & THERAPY 2014; 6:10. [PMID: 25031630 PMCID: PMC3978843 DOI: 10.1186/alzrt239] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sports-related concussions are one of the major causes of mild traumatic brain injury. Although most patients recover completely within days to weeks, those who experience repetitive brain trauma (RBT) may be at risk for developing a condition known as chronic traumatic encephalopathy (CTE). While this condition is most commonly observed in athletes who experience repetitive concussive and/or subconcussive blows to the head, such as boxers, football players, or hockey players, CTE may also affect soldiers on active duty. Currently, the only means by which to diagnose CTE is by the presence of phosphorylated tau aggregations post-mortem. Non-invasive neuroimaging, however, may allow early diagnosis as well as improve our understanding of the underlying pathophysiology of RBT. The purpose of this article is to review advanced neuroimaging methods used to investigate RBT, including diffusion tensor imaging, magnetic resonance spectroscopy, functional magnetic resonance imaging, susceptibility weighted imaging, and positron emission tomography. While there is a considerable literature using these methods in brain injury in general, the focus of this review is on RBT and those subject populations currently known to be susceptible to RBT, namely athletes and soldiers. Further, while direct detection of CTE in vivo has not yet been achieved, all of the methods described in this review provide insight into RBT and will likely lead to a better characterization (diagnosis), in vivo, of CTE than measures of self-report.
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Affiliation(s)
- Thomas Sc Ng
- Center for Clinical Spectroscopy, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 4 Blackfan Circle, Boston, MA 02115, USA ; Keck School of Medicine of the University of Southern California, 1975 Zonal Ave, Los Angeles, CA 90033, USA
| | - Alexander P Lin
- Center for Clinical Spectroscopy, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 4 Blackfan Circle, Boston, MA 02115, USA ; Psychiatric Neuroimaging Laboratory, Departments of Psychiatry and Radiology, Brigham and Women's Hospital, Harvard Medical School, 1249 Boylston Street, Boston, MA 02215, USA
| | - Inga K Koerte
- Psychiatric Neuroimaging Laboratory, Departments of Psychiatry and Radiology, Brigham and Women's Hospital, Harvard Medical School, 1249 Boylston Street, Boston, MA 02215, USA ; Institute for Clinical Radiology, Ludwig-Maximilians-University, Marchioninistrasse 15, 81377 Munich, Germany
| | - Ofer Pasternak
- Psychiatric Neuroimaging Laboratory, Departments of Psychiatry and Radiology, Brigham and Women's Hospital, Harvard Medical School, 1249 Boylston Street, Boston, MA 02215, USA
| | - Huijun Liao
- Center for Clinical Spectroscopy, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 4 Blackfan Circle, Boston, MA 02115, USA
| | - Sai Merugumala
- Center for Clinical Spectroscopy, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 4 Blackfan Circle, Boston, MA 02115, USA
| | - Sylvain Bouix
- Psychiatric Neuroimaging Laboratory, Departments of Psychiatry and Radiology, Brigham and Women's Hospital, Harvard Medical School, 1249 Boylston Street, Boston, MA 02215, USA
| | - Martha E Shenton
- Psychiatric Neuroimaging Laboratory, Departments of Psychiatry and Radiology, Brigham and Women's Hospital, Harvard Medical School, 1249 Boylston Street, Boston, MA 02215, USA ; Research and Development, VA Boston Healthcare System, 850 Belmont Street, Brockton, MA 02130, USA
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D'Ambrosio R, Eastman CL, Fattore C, Perucca E. Novel frontiers in epilepsy treatments: preventing epileptogenesis by targeting inflammation. Expert Rev Neurother 2014; 13:615-25. [PMID: 23738999 DOI: 10.1586/ern.13.54] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Currently available epilepsy drugs only affect the symptoms (seizures), and there is a need for innovative treatments that target the underlying disease. Increasing evidence points to inflammation as a potentially important mechanism in epileptogenesis. In the last decade, a new generation of etiologically realistic syndrome-specific experimental models have been developed, which are expected to capture the epileptogenic mechanisms operating in corresponding patient populations, and to exhibit similar treatment responsiveness. Recently, an intervention known to have broad-ranging anti-inflammatory effects (selective brain cooling) has been found to prevent the development of spontaneously occurring seizures in an etiologically realistic rat model of post-traumatic epilepsy. Several drugs used clinically for other indications also have the potential for inhibiting inflammation, and should be investigated for antiepileptogenic activity in these models. If results of such studies are positive, these compounds could rapidly enter Phase III trials in patients at high risk of developing epilepsy.
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Affiliation(s)
- Raimondo D'Ambrosio
- Department of Neurological Surgery, University of Washington, Seattle, WA, USA
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Abstract
There is increasing recognition of the involvement of the immune signaling molecule, tumor necrosis factor (TNF), in the pathophysiology of stroke and chronic brain dysfunction. TNF plays an important role both in modulating synaptic function and in the pathogenesis of neuropathic pain. Etanercept is a recombinant therapeutic that neutralizes pathologic levels of TNF. Brain imaging has demonstrated chronic intracerebral microglial activation and neuroinflammation following stroke and other forms of acute brain injury. Activated microglia release TNF, which mediates neurotoxicity in the stroke penumbra. Recent observational studies have reported rapid and sustained improvement in chronic post-stroke neurological and cognitive dysfunction following perispinal administration of etanercept. The biological plausibility of these results is supported by independent evidence demonstrating reduction in cognitive dysfunction, neuropathic pain, and microglial activation following the use of etanercept, as well as multiple studies reporting improvement in stroke outcome and cognitive impairment following therapeutic strategies designed to inhibit TNF. The causal association between etanercept treatment and reduction in post-stroke disability satisfy all of the Bradford Hill Criteria: strength of the association; consistency; specificity; temporality; biological gradient; biological plausibility; coherence; experimental evidence; and analogy. Recognition that chronic microglial activation and pathologic TNF concentration are targets that may be therapeutically addressed for years following stroke and other forms of acute brain injury provides an exciting new direction for research and treatment.
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