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Sundaram V, Sundar V, Pearce AJ. Biomechanical characteristics of concussive and sub-concussive impacts in youth sports athletes: A systematic review and meta-analysis. J Sports Sci 2023:1-15. [PMID: 37393593 DOI: 10.1080/02640414.2023.2231317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 06/21/2023] [Indexed: 07/04/2023]
Abstract
This study aimed to quantitatively investigate and report the biomechanical characteristics of concussive and sub-concussive impacts in youth sports. A systematic search was conducted in September 2022 to identify biomechanical impact studies in athletes ≤18 years of age. Twenty-six studies met the inclusion criteria for quantitative synthesis and analysis. DerSimonian Laird random effects model was used to pool data across the included studies. The pooled estimate of mean peak linear and rotational acceleration of concussive impacts in male youth athletes was 85.56 g (95% CI 69.34-101.79) and 4505.58 rad/s2 (95% CI 2870.28-6140.98), respectively. The pooled estimate of mean peak linear and rotational acceleration of sub-concussive impacts in youth athletes was 22.89 g (95% CI 20.69-25.08) and 1290.13 rad/s2 (95% CI 1050.71-1529.55), respectively. A male vs female analysis in sub-concussive impacts revealed higher linear and rotational acceleration in males and females, respectively. This is the first study to report on impact data in both sexes of youth athletes. Disparity in kinematic impact values suggests future research should aim for standardised measures to reduce heterogeneity in data. Despite this, the data reveals notable impact data that youth athletes are exposed to, suggesting modifications may be required to reduce long-term neurological risks.
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Affiliation(s)
- Vasanth Sundaram
- Department of Sports Biomechanics and Kinesiology, Tamil Nadu Physical Education and Sports University, Chennai, India
| | - Viswanath Sundar
- Physical Education and Sports Science, Visva-Bharati University, West Bengal, India
| | - Alan J Pearce
- College of Science, Health, and Engineering, La Trobe University, Bundoora, Melbourne, Australia
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2
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Fesharaki-Zadeh A. A Case of Possible Chronic Traumatic Encephalopathy and Alzheimer's Disease in an Ex-Football Player. Neurologist 2022; 27:249-252. [PMID: 34879014 PMCID: PMC9439689 DOI: 10.1097/nrl.0000000000000391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Chronic traumatic encephalopathy (CTE) is a debilitating neurodegenerative disease, which is often the sequelae of repetitive head trauma. Although the definitive diagnosis of CTE is made postmortem, there are proposed clinical algorithms aimed at identifying characteristic features of CTE, based on a combination of clinical history, serum, cerebrospinal fluid and neuroimaging biomarkers. There are promising new advances in positron emission tomography neuroimaging, including tau specific ligands, which will potentially provide a robust assessment as well as an exploratory tool of the disease semiology and progression. CASE REPORT Here is a unique case of an ex-football player, who suffered multiple prior traumatic brain injuries throughout his career, and presented to our clinic with significant episodic memory, visuospatial and executive functioning deficits, as well as comorbid mood and behavioral changes in the absence of prior psychiatric history or substance use. His clinical presentation and biomarkers were consistent with a suspected diagnosis of CTE comorbid with Alzheimer disease, which comprises a significant portion of overall CTE cases. CONCLUSION This case report presents a patient with a subtle case of dementia, which could be easily mistaken for behavioral variant frontotemporal dementia or primary progressive aphasia. This in turn highlights the importance of detailed longitudinal history taking, as well as rigorous biomarker studies.
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3
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Orchard JW, Orchard JJ, Semsarian C, La Gerche A, Driscoll T. Reduced death rates of elite Australian Rules footballers compared to age-matched general population. J Sci Med Sport 2022; 25:710-714. [PMID: 35999145 DOI: 10.1016/j.jsams.2022.08.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 08/04/2022] [Accepted: 08/06/2022] [Indexed: 12/18/2022]
Abstract
OBJECTIVES To determine age-matched death rates of current and retired elite male Australian football players (Australian and/or Victorian Football League) with the general population. DESIGN Analysis of publicly-available birth, debut and death data for all Australian Victorian Football/Victorian Football League players who debuted prior to (and were still alive at) the start of 1971 or debuted 1971-2020. METHODS Wikipedia was used to source the dates of death (or record that the player was alive in 2021) for the cohort. New players became part of the cohort for analysis on debut and existing cohort members left it at death. Actual death rates (per year and per decade) were then compared to expected deaths, based on age-specific population death rates. RESULTS There were 5400 players and ex-players in the cohort at the start of 1971 (average age 47.3) and a further 4532 players debuted between 1971 and 2020 inclusive (a total of 9932 players). The expected deaths for the cohort in this 50-year period were 4955, but only 3914 deaths occurred (Standardized Mortality Ratio 0.79, 95 %CI 0.76-0.82). For younger members of the cohort (age <50) the discrepancy between expected (222) and actual (98) deaths was also significant (Standardized Mortality Ratio 0.44, 95 %CI 0.35-0.56). CONCLUSIONS We conclude that the death rates of elite male Australian footballers are lower than the reference general population, similar to other studies of elite athletes. Some of this may be explained by "healthy cohort" selection bias, a limitation which affects almost all studies in this genre.
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Affiliation(s)
- John W Orchard
- Faculty of Medicine and Health, The University of Sydney, Australia.
| | - Jessica J Orchard
- Faculty of Medicine and Health, The University of Sydney, Australia; Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, The University of Sydney, Australia
| | - Chris Semsarian
- Faculty of Medicine and Health, The University of Sydney, Australia; Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, The University of Sydney, Australia; Department of Cardiology, Royal Prince Alfred Hospital, Australia
| | - Andre La Gerche
- Sports Cardiology Lab, Baker Heart and Diabetes Institute, Melbourne, Australia; National Centre for Sports Cardiology, St Vincent's Hospital Melbourne, Fitzroy, Australia
| | - Timothy Driscoll
- Faculty of Medicine and Health, The University of Sydney, Australia
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4
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Nowinski CJ, Bureau SC, Buckland ME, Curtis MA, Daneshvar DH, Faull RLM, Grinberg LT, Hill-Yardin EL, Murray HC, Pearce AJ, Suter CM, White AJ, Finkel AM, Cantu RC. Applying the Bradford Hill Criteria for Causation to Repetitive Head Impacts and Chronic Traumatic Encephalopathy. Front Neurol 2022; 13:938163. [PMID: 35937061 PMCID: PMC9355594 DOI: 10.3389/fneur.2022.938163] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 06/22/2022] [Indexed: 02/05/2023] Open
Abstract
Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with a history of repetitive head impacts (RHI). CTE was described in boxers as early as the 1920s and by the 1950s it was widely accepted that hits to the head caused some boxers to become "punch drunk." However, the recent discovery of CTE in American and Australian-rules football, soccer, rugby, ice hockey, and other sports has resulted in renewed debate on whether the relationship between RHI and CTE is causal. Identifying the strength of the evidential relationship between CTE and RHI has implications for public health and medico-legal issues. From a public health perspective, environmentally caused diseases can be mitigated or prevented. Medico-legally, millions of children are exposed to RHI through sports participation; this demographic is too young to legally consent to any potential long-term risks associated with this exposure. To better understand the strength of evidence underlying the possible causal relationship between RHI and CTE, we examined the medical literature through the Bradford Hill criteria for causation. The Bradford Hill criteria, first proposed in 1965 by Sir Austin Bradford Hill, provide a framework to determine if one can justifiably move from an observed association to a verdict of causation. The Bradford Hill criteria include nine viewpoints by which to evaluate human epidemiologic evidence to determine if causation can be deduced: strength, consistency, specificity, temporality, biological gradient, plausibility, coherence, experiment, and analogy. We explored the question of causation by evaluating studies on CTE as it relates to RHI exposure. Through this lens, we found convincing evidence of a causal relationship between RHI and CTE, as well as an absence of evidence-based alternative explanations. By organizing the CTE literature through this framework, we hope to advance the global conversation on CTE mitigation efforts.
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Affiliation(s)
- Christopher J. Nowinski
- Concussion Legacy Foundation, Boston, MA, United States,*Correspondence: Christopher J. Nowinski
| | | | - Michael E. Buckland
- Department of Neuropathology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia,School of Medical Sciences, University of Sydney, Camperdown, NSW, Australia
| | - Maurice A. Curtis
- Department of Anatomy and Medical Imaging and Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand
| | - Daniel H. Daneshvar
- Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, MA, United States,Department of Physical Medicine and Rehabilitation, Massachusetts General Hospital, Boston, MA, United States,Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Boston, MA, United States
| | - Richard L. M. Faull
- Department of Anatomy and Medical Imaging and Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand
| | - Lea T. Grinberg
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, United States,Global Brain Health Institute, University of California, San Francisco, San Francisco, CA, United States,Department of Pathology, University of Sao Paulo Medical School, São Paulo, Brazil,Department of Pathology, University of California, San Francisco, San Francisco, CA, United States
| | - Elisa L. Hill-Yardin
- School of Health and Biomedical Sciences, STEM College, RMIT University, Bundoora, VIC, Australia,Department of Anatomy & Physiology, The University of Melbourne, Parkville, VIC, Australia
| | - Helen C. Murray
- Department of Anatomy and Medical Imaging and Centre for Brain Research, Faculty of Medical and Health Science, University of Auckland, Auckland, New Zealand
| | - Alan J. Pearce
- College of Science, Health, and Engineering, La Trobe University, Melbourne, VIC, Australia
| | - Catherine M. Suter
- Department of Neuropathology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia,School of Medical Sciences, University of Sydney, Camperdown, NSW, Australia
| | - Adam J. White
- Department of Sport, Health Science, and Social Work, Oxford Brookes University, Oxford, United Kingdom,Concussion Legacy Foundation UK, Cheltenham, United Kingdom
| | - Adam M. Finkel
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI, United States
| | - Robert C. Cantu
- Concussion Legacy Foundation, Boston, MA, United States,Department of Neurology, Boston University School of Medicine, Boston, MA, United States,Department of Neurosurgery, Emerson Hospital, Concord, MA, United States
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McCann H, Bahar AY, Burkhardt K, Gardner AJ, Halliday GM, Iverson GL, Shepherd CE. Prevalence of chronic traumatic encephalopathy in the Sydney Brain Bank. Brain Commun 2022; 4:fcac189. [PMID: 35950093 PMCID: PMC9356727 DOI: 10.1093/braincomms/fcac189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 05/15/2022] [Accepted: 07/25/2022] [Indexed: 11/13/2022] Open
Abstract
Abstract
Chronic traumatic encephalopathy neuropathologic change can only be definitively diagnosed post-mortem. It has been associated with repetitive mild neurotrauma sustained in amateur and professional contact, collision and combat sports, although it has also been documented in people with a single severe traumatic brain injury and in some people with no known history of brain injury. The characteristic neuropathology is an accumulation of perivascular neuronal and astrocytic phosphorylated tau in the depths of the cortical sulci. The tau-immunopositive neurons and astrocytes that are considered pathognomonic for chronic traumatic encephalopathy are morphologically indistinguishable from Alzheimer-related neurofibrillary tangles and ageing-related tau astrogliopathy, respectively, although they are found in different spatial distributions throughout the cortex. The Sydney Brain Bank collection consists of neurodegenerative diseases and neurologically normal controls. We screened 636 of these cases for chronic traumatic encephalopathy neuropathologic change. A subset of 109 cases had a known history of traumatic brain injury. Three cortical regions were screened for the presence of neuronal and astrocytic phosphorylated tau according to the current 2021 National Institute on Neurological Disorders and Stroke/National Institute of Biomedical Imaging and Bioengineering consensus criteria for chronic traumatic encephalopathy. Five cases (0.79%) showed pathological evidence of chronic traumatic encephalopathy and three of these had a history of traumatic brain injury. Three cases had coexisting Alzheimer’s and/or Lewy body disease pathology meeting criteria for neurodegenerative disease. Another eight cases almost met criteria for chronic traumatic encephalopathy neuropathological change except for an absence of neuronal tau or a strict perivascular arrangement. Ageing-related tau astrogliopathy was found in all eight cases as a coexisting neuropathology. Traumatic brain injury was associated with increased odds ratio [1.79, confidence interval 1.18–2.72] of having a higher neurofibrillary tangle stage and phosphorylated TAR DNA binding protein 43 (OR 2.48, confidence interval 1.35–4.54). Our study shows a very low rate of chronic traumatic encephalopathy neuropathological change in brains with or without neurodegenerative disease from the Sydney Brain Bank. Our evidence suggests that isolated traumatic brain injury in the general population is unlikely to cause chronic traumatic encephalopathy neuropathologic change but may be associated with increased brain ageing.
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Affiliation(s)
- Heather McCann
- Neuroscience Research Australia , Randwick, NSW 2031 , Australia
| | - Anita Y Bahar
- Neuroscience Research Australia , Randwick, NSW 2031 , Australia
| | - Karim Burkhardt
- School of Medical Sciences, University of New South Wales , Kensington, NSW 2052 , Australia
| | - Andrew J Gardner
- School of Medicine and Public Health, College of Health, Medicine and Wellbeing, The University of Newcastle , Callaghan, NSW 2308 , Australia
| | - Glenda M Halliday
- Neuroscience Research Australia , Randwick, NSW 2031 , Australia
- Faculty of Medicine and Health School of Medical Sciences, University of Sydney Brain and Mind Centre , Camperdown, NSW 2050 , Australia
| | - Grant L Iverson
- Department of Physical Medicine and Rehabilitation, Harvard Medical School , Boston, MA 02114 , USA
- Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital , Charlestown, MA 02114 , USA
- Home Base, A Red Sox Foundation and Massachusetts General Hospital Program , Charlestown, MA 02114 , USA
- MassGeneral Hospital for Children Sports Concussion Program , Boston, MA 02114 , USA
| | - Claire E Shepherd
- Neuroscience Research Australia , Randwick, NSW 2031 , Australia
- School of Medical Sciences, University of New South Wales , Kensington, NSW 2052 , Australia
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6
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Buckland ME, Affleck AJ, Pearce AJ, Suter CM. Chronic Traumatic Encephalopathy as a Preventable Environmental Disease. Front Neurol 2022; 13:880905. [PMID: 35769361 PMCID: PMC9234108 DOI: 10.3389/fneur.2022.880905] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 05/06/2022] [Indexed: 11/29/2022] Open
Abstract
In this Perspective we explore the evolution of our understanding of chronic traumatic encephalopathy (CTE) and its relationship with repetitive head injury. As with many neurodegenerative conditions, there is an imperfect correspondence between neuropathology and clinical phenotype, but unlike other neurodegenerative diseases, CTE has a discrete and easily modifiable risk factor: exposure to repetitive head injury. Consequently, evaluation of the evidence regarding exposure to repetitive head injury and CTE risk should be undertaken using public or occupational health frameworks of medical knowledge. The current debate over the existence of CTE as a disease of concern is fuelled in part by immediate medico-legal considerations, and the involvement of high-profile athletes, with inevitable media interest. Moving beyond this debate has significant potential to address and reduce disease impact in the near future, and provide novel insights into mechanisms underlying abnormal protein accumulation in CTE and other neurodegenerative diseases.
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Affiliation(s)
- Michael E. Buckland
- Department of Neuropathology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
- School of Medical Sciences, University of Sydney, Camperdown, NSW, Australia
- *Correspondence: Michael E. Buckland
| | - Andrew J. Affleck
- Department of Neuropathology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
| | - Alan J. Pearce
- College of Science, Health and Engineering, La Trobe University, Bundoora, VIC, Australia
| | - Catherine M. Suter
- Department of Neuropathology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
- School of Medical Sciences, University of Sydney, Camperdown, NSW, Australia
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7
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Suter CM, Affleck AJ, Lee M, Pearce AJ, Iles LE, Buckland ME. Chronic traumatic encephalopathy in Australia: the first three years of the Australian Sports Brain Bank. Med J Aust 2022; 216:530-531. [PMID: 35144312 PMCID: PMC9305557 DOI: 10.5694/mja2.51420] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 12/13/2021] [Accepted: 12/21/2021] [Indexed: 11/17/2022]
Affiliation(s)
| | | | - Maggie Lee
- Royal Prince Alfred Hospital, Sydney, NSW
| | | | - Linda E Iles
- Victorian Institute of Forensic Medicine, Melbourne, VIC
| | - Michael E Buckland
- Royal Prince Alfred Hospital, Sydney, NSW.,The University of Sydney, Sydney, NSW
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8
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Hellewell SC, Welton T, Pearce AJ, Maller JJ, Grieve SM. Diffusion MRI as a complementary assessment to cognition, emotion, and motor dysfunction after sports-related concussion: a systematic review and critical appraisal of the literature. Brain Imaging Behav 2021; 15:1685-1704. [PMID: 32720180 DOI: 10.1007/s11682-020-00336-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Sports-related concussion (SRC) is a complex and heterogeneous injury with psychological, cognitive and functional consequences. Advances in diffusion magnetic resonance imaging (dMRI) allow sensitive measurement of white matter pathology post-SRC and may provide insight into injury and recovery. We systematically reviewed and meta-analyzed the literature examining dMRI alongside cognitive, emotional or motor assessments to determine relationships between these analyses. Sixteen studies examining young athletes (n = 6) or retired professionals (n = 10) met the inclusion criteria, with 12 emotional, 10 cognitive and four motor assessments. Studies had heterogeneous methodology, moderate quality and modest sample sizes. Fractional anisotropy (FA) was the most frequent dMRI metric, with SRC-induced changes described most commonly in the frontal lobe and least in the cerebellum and brainstem. There is an emerging complementary role for dMRI as part of a comprehensive assessment battery for SRC. However, larger-scale studies with broader subject populations (specifically, in females and in the 30-45 year age range) are needed to corroborate findings and determine the true diagnostic utility of dMRI post-SRC.
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Affiliation(s)
- Sarah C Hellewell
- Imaging and Phenotyping Laboratory, Sydney School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, 2006, Australia
| | - Thomas Welton
- Imaging and Phenotyping Laboratory, Sydney School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, 2006, Australia
| | - Alan J Pearce
- School of Allied Health, La Trobe University, Bundoora, VIC, 3086, Australia
| | - Jerome J Maller
- Imaging and Phenotyping Laboratory, Sydney School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, 2006, Australia.,General Electric Healthcare, Richmond, VIC, 3181, Australia
| | - Stuart M Grieve
- Imaging and Phenotyping Laboratory, Sydney School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, 2006, Australia. .,Department of Radiology, Royal Prince Alfred Hospital, Camperdown, NSW, 2006, Australia.
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9
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Alosco ML, Culhane J, Mez J. Neuroimaging Biomarkers of Chronic Traumatic Encephalopathy: Targets for the Academic Memory Disorders Clinic. Neurotherapeutics 2021; 18:772-791. [PMID: 33847906 PMCID: PMC8423967 DOI: 10.1007/s13311-021-01028-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/15/2021] [Indexed: 12/14/2022] Open
Abstract
Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with exposure to repetitive head impacts, such as those from contact sports. The pathognomonic lesion for CTE is the perivascular accumulation of hyper-phosphorylated tau in neurons and other cell process at the depths of sulci. CTE cannot be diagnosed during life at this time, limiting research on risk factors, mechanisms, epidemiology, and treatment. There is an urgent need for in vivo biomarkers that can accurately detect CTE and differentiate it from other neurological disorders. Neuroimaging is an integral component of the clinical evaluation of neurodegenerative diseases and will likely aid in diagnosing CTE during life. In this qualitative review, we present the current evidence on neuroimaging biomarkers for CTE with a focus on molecular, structural, and functional modalities routinely used as part of a dementia evaluation. Supporting imaging-pathological correlation studies are also presented. We targeted neuroimaging studies of living participants at high risk for CTE (e.g., aging former elite American football players, fighters). We conclude that an optimal tau PET radiotracer with high affinity for the 3R/4R neurofibrillary tangles in CTE has not yet been identified. Amyloid PET scans have tended to be negative. Converging structural and functional imaging evidence together with neuropathological evidence show frontotemporal and medial temporal lobe neurodegeneration, and increased likelihood for a cavum septum pellucidum. The literature offers promising neuroimaging biomarker targets of CTE, but it is limited by cross-sectional studies of small samples where the presence of underlying CTE is unknown. Imaging-pathological correlation studies will be important for the development and validation of neuroimaging biomarkers of CTE.
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Affiliation(s)
- Michael L Alosco
- Department of Neurology, Boston University Alzheimer's Disease Research Center, Boston University CTE Center, Boston University School of Medicine, 72 E Concord St, Suite B7800, MA, 02118, Boston, USA.
| | - Julia Culhane
- Department of Neurology, Boston University Alzheimer's Disease Research Center, Boston University CTE Center, Boston University School of Medicine, 72 E Concord St, Suite B7800, MA, 02118, Boston, USA
| | - Jesse Mez
- Department of Neurology, Boston University Alzheimer's Disease Research Center, Boston University CTE Center, Boston University School of Medicine, 72 E Concord St, Suite B7800, MA, 02118, Boston, USA
- Framingham Heart Study, Boston University School of Medicine, MA, Boston, USA
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10
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Pearce AJ, Kidgell DJ, Tommerdahl MA, Frazer AK, Rist B, Mobbs R, Batchelor J, Buckland ME. Chronic Neurophysiological Effects of Repeated Head Trauma in Retired Australian Male Sport Athletes. Front Neurol 2021; 12:633320. [PMID: 33767661 PMCID: PMC7985524 DOI: 10.3389/fneur.2021.633320] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 02/17/2021] [Indexed: 12/16/2022] Open
Abstract
Aim: This study investigated the somatosensory and corticomotor physiology of retired contact sport athletes with a history of repeated concussion/subconcussion head trauma. Methods: Retired male athletes with a history of playing contact sports and repeated head trauma (n = 122) were divided into two groups: those who expressed concerns regarding their mental and cognitive health (“symptomatic”: n = 83), and those who did not express any ongoing concerns (“asymptomatic”: n = 39). Both groups were compared to age-matched male controls (n = 50) with no history of concussions or participation in contact sports, an absence of self-reported cognitive, or mood impairments. Transcranial magnetic stimulation (TMS) and vibrotactile stimulation were used to assess corticomotor and somatosensory pathways respectively. TMS and vibrotactile stimulation were correlated to self-reported responses using the Fatigue and Related Symptom Survey. Linear regression was used to associate concussion history with TMS, somatosensory variables. Results: Significant differences were found in symptom survey scores between all groups (p < 0.001). TMS showed significant differences between the “symptomatic” and control groups for intracortical inhibition and paired pulse TMS measures. Somatosensory measures showed significant differences for reaction time (p < 0.01) and reaction time variability (p < 0.01) between the “symptomatic” group to the “asymptomatic” and control groups. For other somatosensory measures, the “symptomatic” measures showed differences to the “control” group. Correlations showed significant associations between severity of symptom reporting with TMS and somatosensory measure, and regression revealed the number of concussions reported was shown to have significant relationships to increased intracortical inhibition and poorer somatosensory performance. Conclusion: This study shows that retired contact sport athletes expressing chronic symptoms showed significant pathophysiology compared to those with no ongoing concerns and non-concussed controls. Further, there is a linear dose-response relationship between number of reported concussions and abnormal neurophysiology. Neurophysiological assessments such as TMS and somatosensory measures represent useful and objective biomarkers to assess cortical impairments and progression of neuropsychological impairment in individuals with a history of repeated head trauma.
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Affiliation(s)
- Alan J Pearce
- College of Science, Health and Engineering, La Trobe University, Melbourne, VIC, Australia
| | - Dawson J Kidgell
- Department of Physiotherapy, Faculty of Medicine Nursing and Health Science, Monash University, Melbourne, VIC, Australia
| | - Mark A Tommerdahl
- Department of Biomedical Engineering, University of North Carolina, Chappell Hill, NC, United States.,Cortical Metrics, Carrboro, NC, United States
| | - Ashlyn K Frazer
- Department of Physiotherapy, Faculty of Medicine Nursing and Health Science, Monash University, Melbourne, VIC, Australia
| | - Billymo Rist
- College of Science, Health and Engineering, La Trobe University, Melbourne, VIC, Australia
| | - Rowena Mobbs
- Department of Neurology, Macquarie University Hospital, Macquarie University, Sydney, NSW, Australia
| | | | - Michael E Buckland
- Department of Neuropathology, Royal Prince Alfred Hospital, Sydney, NSW, Australia.,Brain and Mind Centre, University Sydney, Camperdown, NSW, Australia
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Daly E, Pearce AJ, Ryan L. A Systematic Review of Strength and Conditioning Protocols for Improving Neck Strength and Reducing Concussion Incidence and Impact Injury Risk in Collision Sports; Is There Evidence? J Funct Morphol Kinesiol 2021; 6:jfmk6010008. [PMID: 33462169 PMCID: PMC7838928 DOI: 10.3390/jfmk6010008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 01/07/2021] [Accepted: 01/09/2021] [Indexed: 11/22/2022] Open
Abstract
The objective of this systematic literature review was to evaluate the evidence regarding the development of neck strength in reducing concussion and cervical spine injuries in adult amateur and professional sport populations. PubMed, CINAHL, Science Direct, and Web of Science databases were searched systematically. The criteria for inclusion in the review were as follows: (1) a human adult (≥18 or above); (2) involved in amateur, semi-professional, or professional sports; (3) sports included involved collisions with other humans, apparatus or the environment; (4) interventions included pre- and post-neck muscle strength measures or neck stability measures; (5) outcomes included effects on increasing neck strength in participants and/or injury incidence. Database searches identified 2462 articles. Following title, abstract, and full paper screening, three papers were eligible for inclusion. All of the papers reported information from male participants, two were focused on rugby union, and one on American football. Two of the included studies found a significant improvement in isometric neck strength following intervention. None of the studies reported any impact of neck strengthening exercises on cervical spine injuries. This review has shown that there is currently a lack of evidence to support the use of neck strengthening interventions in reducing impact injury risk in adult populations who participate in sport.
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Affiliation(s)
- Ed Daly
- School of Science and Computing, Galway-Mayo Institute of Technology (GMIT), H91 T8NW Galway, Ireland;
| | - Alan J. Pearce
- College of Science Health and Engineering, La Trobe University, Melbourne, VIC 3086, Australia;
| | - Lisa Ryan
- School of Science and Computing, Galway-Mayo Institute of Technology (GMIT), H91 T8NW Galway, Ireland;
- Correspondence:
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12
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Krishnadas N, Doré V, Lamb F, Groot C, McCrory P, Guzman R, Mulligan R, Huang K, O'Donnell M, Ponsford J, Hopwood M, Villemagne VL, Rowe CC. Case Report: 18F-MK6240 Tau Positron Emission Tomography Pattern Resembling Chronic Traumatic Encephalopathy in a Retired Australian Rules Football Player. Front Neurol 2020; 11:598980. [PMID: 33414760 PMCID: PMC7783156 DOI: 10.3389/fneur.2020.598980] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 11/24/2020] [Indexed: 12/14/2022] Open
Abstract
Introduction: It remains unclear if tau imaging may assist diagnosis of chronic traumatic encephalopathy (CTE). Flortaucipir PET has shown superior frontal with medial temporal tau binding consistent with the provisional neuropathological criteria for mid-stage CTE in group-level analyses of retired symptomatic NFL players and in one individual with pathologically confirmed CTE. 18F-MK6240 is a new PET ligand that has high affinity for tau. We present the case of a 63-year-old cognitively impaired, former Australian rules football player with distinct superior frontal and medial temporal 18F-MK6240 binding and show it to be significantly different to the pattern seen in prodromal Alzheimer's disease (AD). Findings: The participant was recruited for a study of amyloid-β and tau several decades after traumatic brain injury. He had multiple concussions during his football career but no cognitive complaints at retirement. A thalamic stroke in his mid 50s left stable mild cognitive deficits but family members reported further short-term memory, behavioral, and personality decline preceding the study. Imaging showed extensive small vessel disease on MRI, a moderate burden of amyloid-β plaques, and 18F-MK6240 binding in bilateral superior frontal and medial temporal cortices. Voxel-wise analysis demonstrated that the frontally predominant pattern of the participant was significantly different to the posterior temporo-parietal predominant pattern of prodromal AD. Conclusion: Although lacking neuropathological examination to distinguish CTE from a variant of AD, the clear demonstration of a CTE-like tau pattern in a single at-risk individual suggests further research on the potential of 18F-MK6240 PET for identifying CTE is warranted.
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Affiliation(s)
- Natasha Krishnadas
- Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia.,Department of Molecular Imaging & Therapy, Austin Health, Heidelberg, VIC, Australia
| | - Vincent Doré
- Department of Molecular Imaging & Therapy, Austin Health, Heidelberg, VIC, Australia.,The Australian e-Health Research Centre, CSIRO Health & Biosecurity, Parkville, VIC, Australia
| | - Fiona Lamb
- Department of Molecular Imaging & Therapy, Austin Health, Heidelberg, VIC, Australia
| | - Colin Groot
- Department of Neurology, Alzheimer Center Amsterdam, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Paul McCrory
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
| | - Rodney Guzman
- Department of Molecular Imaging & Therapy, Austin Health, Heidelberg, VIC, Australia
| | - Rachel Mulligan
- Department of Molecular Imaging & Therapy, Austin Health, Heidelberg, VIC, Australia
| | - Kun Huang
- Department of Molecular Imaging & Therapy, Austin Health, Heidelberg, VIC, Australia
| | - Meaghan O'Donnell
- Phoenix Australia, Parkville, VIC, Australia.,The Department of Psychiatry, The University of Melbourne, Parkville, VIC, Australia
| | - Jennie Ponsford
- Monash-Epworth Rehabilitation Centre, Turner Institute for Brain and Mental Health, Monash University, Clayton, VIC, Australia
| | - Malcolm Hopwood
- The Department of Psychiatry, The University of Melbourne, Parkville, VIC, Australia
| | - Victor L Villemagne
- Department of Molecular Imaging & Therapy, Austin Health, Heidelberg, VIC, Australia
| | - Christopher C Rowe
- Department of Molecular Imaging & Therapy, Austin Health, Heidelberg, VIC, Australia.,The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
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13
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Scott E, Kidgell DJ, Frazer AK, Pearce AJ. The Neurophysiological Responses of Concussive Impacts: A Systematic Review and Meta-Analysis of Transcranial Magnetic Stimulation Studies. Front Hum Neurosci 2020; 14:306. [PMID: 33192374 PMCID: PMC7481389 DOI: 10.3389/fnhum.2020.00306] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 07/08/2020] [Indexed: 01/20/2023] Open
Abstract
Aim: This systematic review and meta-analysis investigated neurophysiological responses using transcranial magnetic stimulation (TMS) following a concussion or sub-concussion. Methods: A systematic searching of relevant databases for peer-reviewed literature quantifying motor evoked potentials from TMS between 1999 and 2019 was performed. A meta-analysis quantified pooled data for measures including motor threshold, motor latency, and motor evoked potential amplitude and for inhibitory measures such as cortical silent period duration, short-interval intracortical inhibition (SICI), and long-interval intracortical inhibition (LICI) ratios. Results: Fifteen articles met the inclusion criteria. The studies were arbitrarily classified into the groups, based on time post-concussion, “acute” (subjects 0–3 months post-injury, n = 8) and “post-acute” (3 months−2 years post-concussion, n = 7). A TMS quality of study checklist rated studies from moderate to high in methodological quality; however, the risk of bias analysis found that the included studies were categorised as high risk of bias, particularly for a lack of allocation concealment and blinding of participants in the methodologies. A meta-analysis showed no differences in excitability measures, apart from a decreased motor threshold that was observed in the concussed group (SMD −0.28, 95% CI −0.51 to −0.04; P = 0.02) for the post-acute time frame. Conversely, all inhibitory measures showed differences between groups. Cortical silent period duration was found to be significantly increased in the acute (SMD 1.19, 95% CI 0.58–1.81; P < 0.001) and post-acute (SMD 0.55, 95% CI 0.12–0.98; P = 0.01) time frames. The SICI (SMD −1.15, 95% CI −1.95 to −0.34; P = 0.005) and LICI (SMD −1.95, 95% CI −3.04 to −0.85; P = 0.005) ratios were reduced, inferring increased inhibition, for the post-acute time frame. Conclusion: This systematic review and meta-analysis demonstrates that inhibitory pathways are affected in the acute period post-concussion. However, persistent alterations in cortical excitability remain, with increased intracortical inhibition. While TMS should be considered as a reliable technique to measure the functional integrity of the central nervous system, the high risk of bias and heterogeneity in data suggest that future studies should aim to incorporate standardised methodological techniques, particularly with threshold determination and stimulus intervals for paired-pulse measures.
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Affiliation(s)
- Emily Scott
- College of Science, Health and Engineering, La Trobe University, Melbourne, VIC, Australia
| | - Dawson J Kidgell
- Department of Physiotherapy, Faculty of Medicine, Nursing and Health Science, School of Primary and Allied Health Care, Monash University, Melbourne, VIC, Australia
| | - Ashlyn K Frazer
- Department of Physiotherapy, Faculty of Medicine, Nursing and Health Science, School of Primary and Allied Health Care, Monash University, Melbourne, VIC, Australia
| | - Alan J Pearce
- College of Science, Health and Engineering, La Trobe University, Melbourne, VIC, Australia
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