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Taskina D, Zhu C, Schwab N, Hazrati LN. Brain pathology and symptoms linked to concussion history: beyond chronic traumatic encephalopathy. Brain Commun 2024; 6:fcad314. [PMID: 38560515 PMCID: PMC10977958 DOI: 10.1093/braincomms/fcad314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 10/13/2023] [Accepted: 02/23/2024] [Indexed: 04/04/2024] Open
Abstract
Repeated head trauma acquired through sports injuries has been associated with the development of long-term disabling symptoms that negatively impact the quality of life. In this retrospective case series, 52 male former professional athletes involved in contact sports and with a history of multiple concussions were evaluated for chronic clinical symptoms and post-mortem neuropathological diagnoses. The clinical symptoms of 19 cases were examined in greater detail for symptom type, severity and duration. Information on neurological, psychiatric and physical symptoms, substance use profiles and concussion histories was obtained from the athletes' next of kin and assessed in relation to post-mortem neuropathological diagnoses. Cases were categorized into three different neuropathological groups: no major neuropathological findings, the presence of only chronic traumatic encephalopathy (CTE) and the diagnosis(es) of other neurodegenerative diseases. Age at death and the presence of DNA damage in the post-mortem brains were analysed for correlation with the clinical symptoms. In this case series, 14/52 (26.9%) cases (mean age 48.2 ± 11.4) had neuropathological evidence of low-stage/low-burden CTE. A total of 11/52 (21.2%) cases (mean age 38.7 ± 12.7) presented a similar profile and severity of behavioural symptoms to those with CTE, despite the lack of significant post-mortem neuropathological findings. A total of 27/52 (51.9%) cases (mean age 75.5 ± 8.7) presented with complex post-mortem neurodegenerative diagnoses, including Alzheimer's disease and other mixed pathologies, and clinical symptoms associated with language, memory and sensory dysfunction. The presence of DNA damage in the brain was found in all neuropathological groups, predominantly in the ependymal lining of ventricles, and phosphorylated histone H2AX staining was correlated with higher age at death (r = 0.59) and symptoms of language dysfunction (r = 0.56). Findings from our case series suggest that post-concussive symptoms are not driven by CTE. Our findings show that proteinopathies alone may not account for the complexity of the clinical manifestations and suggest the possibility of other drivers, such as DNA damage, as potentially useful markers of brain trauma. Broadening the search for biological markers that reflect the effects of brain injury, even when proteinopathy is not observed, and taking a symptom-driven approach are therefore advised.
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Affiliation(s)
- Daria Taskina
- Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Cherrie Zhu
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Nicole Schwab
- Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Lili-Naz Hazrati
- Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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Eagle SR, Grashow R, DiGregorio H, Terry DP, Baggish A, Weisskopf MG, Okonkwo DO, Zafonte R. Interaction of Medical Conditions and Football Exposures Associated with Premortem Chronic Traumatic Encephalopathy Diagnosis in Former Professional American Football Players. Sports Med 2023:10.1007/s40279-023-01942-w. [PMID: 37798551 DOI: 10.1007/s40279-023-01942-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/19/2023] [Indexed: 10/07/2023]
Abstract
BACKGROUND AND OBJECTIVE Despite being a postmortem diagnosis, former professional American-style football players report receiving chronic traumatic encephalopathy (CTE) diagnoses from medical care providers. However, many players also report other health conditions that manifest with cognitive and psychological symptoms. The purpose of this study was to identify how medical conditions, psychological disorders, and football exposure combinations are associated with former athletes reporting a premortem CTE diagnosis. METHODS This study was a cross-sectional cohort survey from 2015 to 2019 of 4033 former professional American-style football players. Demographics (age, race, domestic status, primary care recipient), football-related factors (position, years of professional play, burden of symptoms following head impacts, performance-enhancing drug use), and comorbidities (sleep apnea, psychological disorder status [depression and anxiety; either depression or anxiety; neither depression nor anxiety], diabetes mellitus, attention-deficit/hyperactivity disorder, hypertension, heart conditions, high cholesterol, stroke, cancer, low testosterone, chronic pain, current and maximum body mass index) were recorded. A Chi-square automatic interaction detection (CHAID) decision tree model identified interactive effects between demographics, health conditions, and football exposures on the CTE diagnosis. RESULTS Depression showed the strongest univariate association with premortem CTE diagnoses (odds ratio [OR] = 9.5, 95% confidence interval [CI] 6.0-15.3). CHAID differentiated participants with premortem CTE diagnoses with 98.2% accuracy and area under the curve = 0.81. Participants reporting both depression and anxiety were more likely to have a CTE diagnosis compared with participants who reported no psychological disorders (OR = 12.2; 95% CI 7.3-21.1) or one psychological disorder (OR = 4.5; 95% CI 1.9-13.0). Sleep apnea was also associated with a CTE diagnosis amongst those with both depression and anxiety (OR = 2.7; 95% CI 1.4-5.2). CONCLUSIONS Clinical phenotypes including psychological disorders and sleep apnea were strongly associated with an increased likelihood of having received a pre-mortem CTE diagnosis in former professional football players. Depression, anxiety, and sleep apnea produce cognitive symptoms, are treatable conditions, and should be distinguished from neurodegenerative disease.
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Affiliation(s)
- Shawn R Eagle
- University of Pittsburgh, 3550 Terrace St, Pittsburgh, PA, 15261, USA.
| | | | | | | | | | | | - David O Okonkwo
- University of Pittsburgh, 3550 Terrace St, Pittsburgh, PA, 15261, USA
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Lee CD, Meehan WP, Bazarian J. Participation of Children in American Football. N Engl J Med 2023; 389:660-662. [PMID: 37585634 DOI: 10.1056/nejmclde2302021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/18/2023]
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LeClair J, Weuve J, Fox MP, Mez J, Alosco ML, Nowinski C, McKee A, Tripodis Y. Relationship Between Level of American Football Playing and Diagnosis of Chronic Traumatic Encephalopathy in a Selection Bias Analysis. Am J Epidemiol 2022; 191:1429-1443. [PMID: 35434739 PMCID: PMC9989358 DOI: 10.1093/aje/kwac075] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/15/2022] [Accepted: 04/12/2022] [Indexed: 01/28/2023] Open
Abstract
Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with exposure to repetitive head impacts such as those from American football. Our understanding of this association is based on research in autopsied brains, since CTE can only be diagnosed postmortem. Such studies are susceptible to selection bias, which needs to be accounted for to ensure a generalizable estimate of the association between repetitive head impacts and CTE. We evaluated the relationship between level of American football playing and CTE diagnosis after adjusting for selection bias. The sample included 290 deceased male former American football players who donated their brains to the Veterans Affairs-Boston University-Concussion Legacy Foundation (VA-BU-CLF) Brain Bank between 2008 and 2019. After adjustment for selection bias, college-level and professional football players had 2.38 (95% simulation interval (SI): 1.16, 5.94) and 2.47 (95% SI: 1.46, 4.79) times the risk of being diagnosed with CTE as high-school-level players, respectively; these estimates are larger than estimates with no selection bias adjustment. Since CTE is currently diagnosed only postmortem, we additionally provide plausible scenarios for CTE risk ratios for each level of play during the former players' lifetime. This study provides further evidence to support a dose-response relationship between American football playing and CTE.
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Affiliation(s)
| | | | | | | | | | | | | | - Yorghos Tripodis
- Correspondence to Dr. Yorghos Tripodis, Department of Biostatistics, School of Public Health, Boston University, 801 Massachusetts Avenue, Crosstown Center, 3rd Floor, Boston, MA 02118 (e-mail: )
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Schwab N, Wennberg R, Grenier K, Tartaglia C, Tator C, Hazrati LN. Association of Position Played and Career Duration and Chronic Traumatic Encephalopathy at Autopsy in Elite Football and Hockey Players. Neurology 2021; 96:e1835-e1843. [PMID: 33627496 PMCID: PMC8105967 DOI: 10.1212/wnl.0000000000011668] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 12/29/2020] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVE To determine whether an association exists between career duration or position played and the presence of chronic traumatic encephalopathy (CTE) at autopsy in a series of elite football and hockey players. METHODS This retrospective cohort study analyzed postmortem brains of 35 former football or hockey players (29 professional, 6 university varsity/major junior), with the presence of CTE at autopsy as the primary outcome. Position played (highest level), age at retirement (indicator of lifetime exposure to sport), and hockey fighting/penalization histories (surrogate marker for role/style of play) were collected. A blinded neuropathologic evaluation of each participant was performed, providing an assessment for neurodegenerative diseases including CTE, based on the 2015 National Institute of Neurological Disorders and Stroke/National Institute of Biomedical Imaging and Bioengineeringconsensus paper. RESULTS In total, 17 of 35 former players (48.6%) showed pathologic evidence of CTE. There was no correlation found between position played and CTE presence, nor between hockey fighting/penalization histories and CTE, in either the football or hockey groups (p > 0.75, Mann-Whitney-Wilcoxon). Similarly, there was no association between age at retirement and CTE presence (p > 0.5, Mann-Whitney-Wilcoxon). In 24 of 35 cases (68.6%), other neuropathologies were present, 13 of 24 (54.2%) of which were coexistent with CTE. CONCLUSION In this cohort of 35 former collision sports athletes, no significant associations were found between career duration, position or role played, and CTE presence at autopsy. Although limited by the small and nonrepresentative sample studied, these findings suggest that nonsport factors may be important to understand differing susceptibilities among athletes to CTE.
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Affiliation(s)
- Nicole Schwab
- From the Department of Laboratory Medicine and Pathobiology (N.S., K.G.), University of Toronto; Toronto Western Hospital Krembil Brain Institute (R.W., C. Tartaglia, C. Tator), Canadian Concussion Centre; Divisions of Neurology (R.W., C. Tartaglia) and Neurosurgery (C. Tator), University Health Network Toronto Western Hospital; The Hospital for Sick Children (L.-N.H.), Pathology; and Canadian Concussion Centre (L.-N.H.), Toronto, Ontario, Canada
| | - Richard Wennberg
- From the Department of Laboratory Medicine and Pathobiology (N.S., K.G.), University of Toronto; Toronto Western Hospital Krembil Brain Institute (R.W., C. Tartaglia, C. Tator), Canadian Concussion Centre; Divisions of Neurology (R.W., C. Tartaglia) and Neurosurgery (C. Tator), University Health Network Toronto Western Hospital; The Hospital for Sick Children (L.-N.H.), Pathology; and Canadian Concussion Centre (L.-N.H.), Toronto, Ontario, Canada
| | - Karl Grenier
- From the Department of Laboratory Medicine and Pathobiology (N.S., K.G.), University of Toronto; Toronto Western Hospital Krembil Brain Institute (R.W., C. Tartaglia, C. Tator), Canadian Concussion Centre; Divisions of Neurology (R.W., C. Tartaglia) and Neurosurgery (C. Tator), University Health Network Toronto Western Hospital; The Hospital for Sick Children (L.-N.H.), Pathology; and Canadian Concussion Centre (L.-N.H.), Toronto, Ontario, Canada
| | - Carmela Tartaglia
- From the Department of Laboratory Medicine and Pathobiology (N.S., K.G.), University of Toronto; Toronto Western Hospital Krembil Brain Institute (R.W., C. Tartaglia, C. Tator), Canadian Concussion Centre; Divisions of Neurology (R.W., C. Tartaglia) and Neurosurgery (C. Tator), University Health Network Toronto Western Hospital; The Hospital for Sick Children (L.-N.H.), Pathology; and Canadian Concussion Centre (L.-N.H.), Toronto, Ontario, Canada
| | - Charles Tator
- From the Department of Laboratory Medicine and Pathobiology (N.S., K.G.), University of Toronto; Toronto Western Hospital Krembil Brain Institute (R.W., C. Tartaglia, C. Tator), Canadian Concussion Centre; Divisions of Neurology (R.W., C. Tartaglia) and Neurosurgery (C. Tator), University Health Network Toronto Western Hospital; The Hospital for Sick Children (L.-N.H.), Pathology; and Canadian Concussion Centre (L.-N.H.), Toronto, Ontario, Canada
| | - Lili-Naz Hazrati
- From the Department of Laboratory Medicine and Pathobiology (N.S., K.G.), University of Toronto; Toronto Western Hospital Krembil Brain Institute (R.W., C. Tartaglia, C. Tator), Canadian Concussion Centre; Divisions of Neurology (R.W., C. Tartaglia) and Neurosurgery (C. Tator), University Health Network Toronto Western Hospital; The Hospital for Sick Children (L.-N.H.), Pathology; and Canadian Concussion Centre (L.-N.H.), Toronto, Ontario, Canada.
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Alyenbaawi H, Allison WT, Mok SA. Prion-Like Propagation Mechanisms in Tauopathies and Traumatic Brain Injury: Challenges and Prospects. Biomolecules 2020; 10:E1487. [PMID: 33121065 PMCID: PMC7692808 DOI: 10.3390/biom10111487] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 12/23/2022] Open
Abstract
The accumulation of tau protein in the form of filamentous aggregates is a hallmark of many neurodegenerative diseases such as Alzheimer's disease (AD) and chronic traumatic encephalopathy (CTE). These dementias share traumatic brain injury (TBI) as a prominent risk factor. Tau aggregates can transfer between cells and tissues in a "prion-like" manner, where they initiate the templated misfolding of normal tau molecules. This enables the spread of tau pathology to distinct parts of the brain. The evidence that tauopathies spread via prion-like mechanisms is considerable, but work detailing the mechanisms of spread has mostly used in vitro platforms that cannot fully reveal the tissue-level vectors or etiology of progression. We review these issues and then briefly use TBI and CTE as a case study to illustrate aspects of tauopathy that warrant further attention in vivo. These include seizures and sleep/wake disturbances, emphasizing the urgent need for improved animal models. Dissecting these mechanisms of tauopathy progression continues to provide fresh inspiration for the design of diagnostic and therapeutic approaches.
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Affiliation(s)
- Hadeel Alyenbaawi
- Centre for Prions & Protein Folding Disease, University of Alberta, Edmonton, AB T6G 2M8, Canada; (H.A.); (W.T.A.)
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Department of Medical Laboratories, Majmaah University, Majmaah 11952, Saudi Arabia
| | - W. Ted Allison
- Centre for Prions & Protein Folding Disease, University of Alberta, Edmonton, AB T6G 2M8, Canada; (H.A.); (W.T.A.)
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Sue-Ann Mok
- Centre for Prions & Protein Folding Disease, University of Alberta, Edmonton, AB T6G 2M8, Canada; (H.A.); (W.T.A.)
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
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Iverson GL, Luoto TM, Karhunen PJ, Castellani RJ. Mild Chronic Traumatic Encephalopathy Neuropathology in People With No Known Participation in Contact Sports or History of Repetitive Neurotrauma. J Neuropathol Exp Neurol 2020; 78:615-625. [PMID: 31169877 DOI: 10.1093/jnen/nlz045] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
It has been asserted that chronic traumatic encephalopathy (CTE) pathology is only present in former athletes and others who have been exposed to repetitive concussions, subconcussive blows, or both. We hypothesized that CTE pathology would be present in men who had no known history of repetitive neurotrauma. Comprehensive medical record reviews and health surveys completed by a family member were available for the 8 men in this case series, none of whom had known exposure to repetitive neurotrauma but 2 of whom had a history of traumatic brain injury (TBI). Postmortem tissue was immunostained for hyperphosphorylated tau (p-tau) to assess for CTE pathology, Braak stage, and aging-related p-tau. The neuropathologist was blind to age, personal history, and clinical history. Six of the 8 cases (75%) showed p-tau in neurons, astrocytes, and cell processes around small blood vessels in an irregular pattern at the depths of the cortical sulci. The changes were focal and limited in terms of overall extent, and some of the cases had a clearer pattern of pathology and some could be considered equivocal. Two of the 8 cases had a history of TBI and one of them showed CTE pathology. Five of the 6 cases with no known history of neurotrauma appeared to meet consensus criteria for CTE. This study adds to the emerging literature indicating that CTE pathology is present in people not known to have experienced multiple concussions or subconcussive blows to the head.
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Affiliation(s)
- Grant L Iverson
- Department of Physical Medicine and Rehabilitation, Harvard Medical School.,Spaulding Rehabilitation Hospital, Spaulding Research Institute.,MassGeneral Hospital for Children™ Sports Concussion Program.,Home Base, A Red Sox Foundation and Massachusetts General Hospital Program, Boston, Massachusetts
| | - Teemu M Luoto
- Department of Neurosurgery, Tampere University Hospital and University of Tampere, Tampere, Finland
| | - Pekka J Karhunen
- Department of Forensic Medicine, Faculty of Medicine and Life Sciences, University of Tampere.,Fimlab Laboratories and Finnish Cardiovascular Research Center Tampere, Tampere, Finland
| | - Rudolph J Castellani
- Department of Pathology, Anatomy and Laboratory Medicine.,Department of Neuroscience, Rockefeller Neuroscience Institute.,West Virginia University School of Medicine, Morgantown, West Virginia
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Schwab N, Grenier K, Hazrati LN. DNA repair deficiency and senescence in concussed professional athletes involved in contact sports. Acta Neuropathol Commun 2019; 7:182. [PMID: 31727161 PMCID: PMC6857343 DOI: 10.1186/s40478-019-0822-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 09/29/2019] [Indexed: 12/11/2022] Open
Abstract
Mild traumatic brain injury (mTBI) leads to diverse symptoms including mood disorders, cognitive decline, and behavioral changes. In some individuals, these symptoms become chronic and persist in the long-term and can confer an increased risk of neurodegenerative disease and dementia diagnosis later in life. Despite the severity of its consequences, the pathophysiological mechanism of mTBI remains unknown. In this post-mortem case series, we assessed DNA damage-induced cellular senescence pathways in 38 professional athletes with a history of repeated mTBI and ten controls with no mTBI history. We assessed clinical presentation, neuropathological changes, load of DNA damage, morphological markers of cellular senescence, and expression of genes involved in DNA damage signaling, DNA repair, and cellular senescence including the senescence-associated secretory phenotype (SASP). Twenty-eight brains with past history of repeated mTBI history had DNA damage within ependymal cells, astrocytes, and oligodendrocytes. DNA damage burden was increased in brains with proteinopathy compared to those without. Cases also showed hallmark features of cellular senescence in glial cells including astrocytic swelling, beading of glial cell processes, loss of H3K27Me3 (trimethylation at lysine 27 of histone H3) and lamin B1 expression, and increased expression of cellular senescence and SASP pathways. Neurons showed a spectrum of changes including loss of emerin nuclear membrane expression, loss of Brahma-related gene-1 (BRG1 or SMARCA4) expression, loss of myelin basic protein (MBP) axonal expression, and translocation of intranuclear tau to the cytoplasm. Expression of DNA repair proteins was decreased in mTBI brains. mTBI brains showed substantial evidence of DNA damage and cellular senescence. Decreased expression of DNA repair genes suggests inefficient DNA repair pathways in this cohort, conferring susceptibly to cellular senescence and subsequent brain dysfunction after mTBI. We therefore suggest that brains of contact-sports athletes are characterized by deficient DNA repair and DNA damage-induced cellular senescence and propose that this may affect neurons and be the driver of brain dysfunction in mTBI, predisposing the progression to neurodegenerative diseases. This study provides novel targets for diagnostic and prognostic biomarkers, and represents viable targets for future treatments.
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Abstract
Our clinical experience at a specialized brain injury clinic suggests that numerous patients with traumatic brain injury (TBI) are using cannabis to alleviate their symptoms. While this patient population often inquires about the evidence of using cannabis post-head injury for the neurosensory, neurocognitive, and neuropsychiatric sequelae, most health professionals have little to no knowledge of this evidence. Given the recent legalization of recreational cannabis in Canada, questions and guidance related to cannabis use following a TBI are likely to become more common. This article reviews the evidence for cannabis use in psychiatric disorders with or without TBI. Overall, we found that the evidence for the use of cannabis among TBI patients is sparse and that patients tend to have little knowledge of the proven benefits and diverse effects of cannabis use. We feel this paper can serve as a stepping stone for future studies that explore the impact of cannabis use in a TBI population and can guide clinicians in advising their patients.
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Castellani RJ, Smith M, Bailey K, Perry G, deJong JL. Neuropathology in Consecutive Forensic Consultation Cases with a History of Remote Traumatic Brain Injury. J Alzheimers Dis 2019; 72:683-691. [PMID: 31609691 DOI: 10.3233/jad-190782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Traumatic brain injury (TBI) is widely assumed to be causal in neurodegenerative disease, based on epidemiological surveys demonstrating an increased risk of Alzheimer disease (AD) following TBI, and on recent theories surrounding repetitive head movement. We tested this assumption by evaluating 30 consecutive forensic examinations in which neuropathology consultation was sought, and in which a history of remote TBI was uncovered during the course of the investigation. In this series, there was a high frequency of psychiatric co-morbidities (100%), remote contusion (90%), and seizures (63%). Extent of proteinopathy showed no differences with age-matched controls. A subset of the cases showed focal geographic tauopathy that correlated with older age at autopsy, but had no correlation with clinical signs, and was minimal in comparison with the encephalomalacia secondary to trauma. The results suggest that cerebral contusion and post-traumatic epilepsy may be over-represented in civilian TBI, while structural brain damage from trauma is the predominant cause of morbidity following TBI. We found no evidence that TBI initiates a progressive proteinopathy.
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Affiliation(s)
- Rudy J Castellani
- Department of Pathology, Anatomy, and Laboratory Medicine, Rockefeller Neuroscience Institute, West Virginia University, Morgantown, WV, USA.,Department of Pathology, Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, MI, USA
| | - Margaret Smith
- Department of Pathology, Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, MI, USA
| | - Kristi Bailey
- Department of Pathology, Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, MI, USA
| | - George Perry
- College of Sciences, University of Texas, San Antonio, San Antonio, TX, USA
| | - Joyce L deJong
- Department of Pathology, Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, MI, USA
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Schwab N, Tator C, Hazrati LN. DNA damage as a marker of brain damage in individuals with history of concussions. J Transl Med 2019; 99:1008-1018. [PMID: 30760862 DOI: 10.1038/s41374-019-0199-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 11/27/2018] [Accepted: 11/28/2018] [Indexed: 12/13/2022] Open
Abstract
Mild traumatic brain injury (mTBI) is common in many populations, including athletes, veterans, and domestic abuse victims. mTBI can cause chronic symptoms, including depression, irritability, memory problems, and attention deficits. A history of repetitive mTBI has been epidemiologically associated with developing early-onset dementia and neurodegenerative diseases and, in particular, is thought to be the underlying cause of chronic traumatic encephalopathy (CTE)-a progressive tauopathy diagnosed by the presence of perivascular hyperphosphorylated tau protein (p-tau) in the depths of cortical sulci. However, the scarce and focal pathology often seen in CTE does not correlate with the severity of symptoms experienced by patients. This paper proposes accumulation of γH2AX, a marker of double-stranded DNA damage, as a novel pathological marker to identify brain damage post-mTBI. We present two cases of men with history of mTBI. Immunohistochemistry revealed extensive DNA damage throughout the frontal cortex, hippocampus, and brainstem areas. Furthermore, gene expression profiling showed increases of ataxia telangiectasia mutated (ATM) and checkpoint kinase 2 (CHEK2), two serine/threonine kinases recruited in response to double-strand breaks in the DNA damage response pathway. These cases highlight the complex pathophysiology of head trauma, and suggest DNA damage as the molecular mechanism behind mTBI-induced pathology and symptoms.
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Affiliation(s)
- Nicole Schwab
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.,The Hospital for Sick Children, Toronto, ON, Canada.,Canadian Concussion Centre, Toronto Western Hospital, Toronto, ON, Canada
| | - Charles Tator
- Canadian Concussion Centre, Toronto Western Hospital, Toronto, ON, Canada.,Division of Neurosurgery, University Health Network, Toronto Western Hospital, University of Toronto, Toronto, ON, Canada
| | - Lili-Naz Hazrati
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada. .,The Hospital for Sick Children, Toronto, ON, Canada. .,Canadian Concussion Centre, Toronto Western Hospital, Toronto, ON, Canada.
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