History of Chronic Traumatic Encephalopathy

AbstractThe long-term effects of repetitive head impacts have been recognized for close to a century. What is now referred to as chronic traumatic encephalopathy (CTE) was first described by Martland in 1928 in a series of boxers. Over the years, several important articles were published, including Critchley's 1957 report where he introduced the term “chronic traumatic encephalopathy,” Robert's study in 1969 which provided evidence of the prevalence of neurological impairment in retired fighters, and Corsellis' initial description of the pathology of CTE. However, what brought public attention to the issue of CTE in sports were the postmortem findings of CTE pathology in professional American football players, initially reported by Omalu and subsequently in a large series by McKee. There is now standardization of pathological criteria for CTE and recognition that it can be seen across all activities that involve repetitive head impacts.

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Association Between Antemortem FLAIR White Matter Hyperintensities and Neuropathology in Brain Donors Exposed to Repetitive Head Impacts

Neurology ◽

10.1212/wnl.0000000000013012 ◽

2021 ◽

pp. 10.1212/WNL.0000000000013012

Author(s):

Madeline Uretsky ◽

Sylvain Bouix ◽

Ronald J. Killiany ◽

Yorghos Tripodis ◽

Brett Martin ◽

...

Keyword(s):

White Matter ◽

White Matter Hyperintensities ◽

Microvascular Disease ◽

Head Impact ◽

American Football ◽

Football Players ◽

Head Impacts ◽

Repetitive Head Impacts ◽

Pathological Correlation ◽

Daily Function

Background and Objectives:Late neuropathologies of repetitive head impacts from contact sports can include chronic traumatic encephalopathy (CTE) and white matter degeneration. White matter hyperintensities (WMH) on fluid attenuated inversion recovery (FLAIR) MRI scans are often viewed as microvascular disease from vascular risk, but might have unique underlying pathologies and risk factors in the setting of repetitive head impacts. We investigated the neuropathological correlates of antemortem WMH in brain donors exposed to repetitive head impacts. The association between WMH, and repetitive head impact exposure and informant-reported cognitive and daily function were tested.Methods:This imaging-pathological correlation study included symptomatic deceased men exposed to repetitive head impacts. Donors had antemortem FLAIR scans from medical records and were without evidence of CNS neoplasm, large vessel infarcts, hemorrhage, and/or encephalomalacia. WMH were quantified using log-transformed values for total lesion volume (TLV), calculated using the lesion prediction algorithm from the Lesion Segmentation Toolbox. Neuropathological assessments included semi-quantitative ratings of white matter rarefaction, cerebrovascular disease, p-tau severity (CTE stage, dorsolateral frontal cortex), and Aβ. Among football players, years of play was a proxy for repetitive head impact exposure. Retrospective informant-reported cognitive and daily function were assessed using the Cognitive Difficulties Scale (CDS) and Functional Activities Questionnaire (FAQ). Regression models controlled for demographics, diabetes, hypertension, and MRI resolution. Statistical significance was defined as p<0.05.Results:The sample included 75 donors: 67 football players and 8 non-football contact sport athletes and/or military veterans. Dementia was the most common MRI indication (64%). Fifty-three (70.7%) had CTE at autopsy. Log-TLV was associated with white matter rarefaction (OR=2.32, 95% CI=1.03,5.24, p=0.04), arteriolosclerosis (OR=2.38, 95% CI=1.02,5.52, p=0.04), CTE stage (OR=2.58, 95% CI=1.17,5.71, p=0.02), and dorsolateral frontal p-tau severity (OR=3.03, 95% CI=1.32,6.97, p=0.01). There was no association with Aβ. More years of football play was associated with log-TLV (b=0.04, 95% CI=0.01,0.06, p=0.01). Greater log-TLV correlated with higher FAQ (unstandardized beta=4.94, 95% CI=0.42,8.57, p=0.03) and CDS scores (unstandardized beta=15.35, 95% CI=-0.27,30.97, p=0.05).Discussion:WMH might capture long-term white matter pathologies from repetitive head impacts, including those from white matter rarefaction and p-tau, in addition to microvascular disease. Prospective imaging-pathological correlation studies are needed.Classification of Evidence:This study provides Class IV evidence of associations between FLAIR white matter hyperintensities, and neuropathological changes (white matter rarefaction, arteriolosclerosis, p-tau accumulation), years of American football play, and reported cognitive symptoms in symptomatic brain donors exposed to repetitive head impacts.

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Detecting a History of Repetitive Head Impacts from a Short Voice Recording

10.1101/2021.09.20.21263753 ◽

2021 ◽

Author(s):

Michael G. Tauro ◽

Mirco Ravanelli ◽

Cristian A. Droppelmann

Keyword(s):

Chronic Traumatic Encephalopathy ◽

Control Group ◽

Head Impacts ◽

Repetitive Head Impacts ◽

Potential Biomarker ◽

Increased Risk ◽

Clinical Diagnoses ◽

History Of ◽

Brain Changes ◽

Fine Tune

Repetitive head impacts (RHI) are associated with an increased risk of developing various neurodegenerative disorders, such as Alzheimer's disease (AD), Parkinson's disease (PD), and most notably, chronic traumatic encephalopathy (CTE). While the clinical presentation of AD and PD is well established, CTE can only be diagnosed post-mortem. Therefore, a distinction can be made between the pathologically defined CTE and RHI-related functional or structural brain changes (RHI-BC) which may result in CTE. Unfortunately, there are currently no accepted biomarkers of CTE nor RHI-BC, a major hurdle to achieving clinical diagnoses. Interestingly, speech has shown promise as a potential biomarker of both AD and PD, being used to accurately classify individuals with AD and PD from those without. Given the overlapping symptoms between CTE, RHI-BC, PD and AD, we aimed to determine if speech could be used to identify individuals with a history of RHI from those without. We therefore created the Verus dataset, consisting of 13 second voice recordings from 605 professional fighters (RHI group) and 605 professional athletes in non-contact sports (control group) for a total of 1210 recordings. Using a deep learning approach, we achieved 85% accuracy in detecting individuals with a history of RHI from those without. We then used our model trained on the Verus dataset to fine-tune on publicly available AD and PD speech datasets and achieved new state-of-the-art accuracies of 84.99% on the AD dataset and 89% on the PD dataset. Finding a biomarker of CTE and RHI-BC that presents early in disease progression is critical to improve risk management and patient outcome. Our study is the first we are aware of to investigate speech as such a candidate biomarker of RHI-BC.

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Chronic Traumatic Encephalopathy: Advocacy and Communicating with the Public

Seminars in Neurology ◽

10.1055/s-0040-1713621 ◽

2020 ◽

Vol 40 (04) ◽

pp. 461-468

Author(s):

Madeline Uretsky ◽

Christopher J. Nowinski

Keyword(s):

Chronic Traumatic Encephalopathy ◽

American Football ◽

Football Players ◽

Advocacy Groups ◽

Contact Sport ◽

Head Impacts ◽

The Public ◽

The Past ◽

Raising Awareness ◽

Sports Concussions

AbstractOver the past 40 years, advocacy groups have been instrumental in raising awareness for neurodegenerative diseases such as Alzheimer's disease. More recently, advocates have emerged to educate about sports concussions and chronic traumatic encephalopathy (CTE), including the Concussion Legacy Foundation (CLF). CTE is a neurodegenerative disease caused in part by repetitive head impacts (RHI). While the majority of CTE research has focused on studying former American football players, CTE has also been found in military personnel, victims of domestic violence, and contact sport athletes from high school to professional levels of play. Advocates' many goals include creating a culture of brain donation and modifying youth contact sports to decrease RHI. Here, we provide the first review of CTE advocacy, summarize the accomplishments of the CLF, and consider the connections between CTE advocacy, research, and legislation over the last decade.

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Exposure to Repetitive Head Impacts Is Associated With Corpus Callosum Microstructure and Plasma Total Tau in Former Professional American Football Players

Journal of Magnetic Resonance Imaging ◽

10.1002/jmri.27774 ◽

2021 ◽

Author(s):

Janna Kochsiek ◽

Lauren J. O'Donnell ◽

Fan Zhang ◽

Elena M. Bonke ◽

Nico Sollmann ◽

...

Keyword(s):

Corpus Callosum ◽

American Football ◽

Football Players ◽

Head Impacts ◽

Repetitive Head Impacts ◽

Total Tau

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Age at First Exposure to Repetitive Head Impacts Is Associated with Smaller Thalamic Volumes in Former Professional American Football Players

Journal of Neurotrauma ◽

10.1089/neu.2017.5145 ◽

2018 ◽

Vol 35 (2) ◽

pp. 278-285 ◽

Cited By ~ 38

Author(s):

Vivian Schultz ◽

Robert A. Stern ◽

Yorghos Tripodis ◽

Julie Stamm ◽

Pawel Wrobel ◽

...

Keyword(s):

American Football ◽

Football Players ◽

Head Impacts ◽

Repetitive Head Impacts

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Concussion related deficits in the general population predict impairments in varsity footballers

10.31234/osf.io/b2gxv ◽

2019 ◽

Author(s):

Clara Alexandra Stafford ◽

Bobby Stojanoski ◽

Conor Wild ◽

Danielle Brewer-Deluce ◽

Timothy D. Wilson ◽

...

Keyword(s):

General Population ◽

Inhibitory Control ◽

Population Level ◽

American Football ◽

Cognitive Tasks ◽

Football Players ◽

Head Impacts ◽

Demographic Questionnaire ◽

History Of

ObjectiveWe investigated the long-term cognitive effects of concussion in 19,261 members of the general population and a cohort of varsity American football players with a history of frequent head impacts, using tests that are known to be sensitive to small changes in performance. MethodsWe asked 19,261 participants to complete a demographic questionnaire and 12 cognitive tests measuring aspects of executive function, including inhibitory control. We compared the performance of those reporting a history of concussion (post-concussion) to those reporting no history of concussion (non-concussed) on the cognitive battery and four non-cognitive variables. We used the results of this population-level study to predict the profile of cognitive performance in varsity American football players, who completed the same cognitive tasks. ResultsPost-concussion and non-concussed participants did not differ on 11 of the 12 cognitive tasks employed. However, on a test of inhibitory control based on the classic Stroop paradigm, post-concussion participants showed accuracy-related impairments specific to the incongruent conditions of the task. Post-concussion participants reported higher levels of anxiety, depression, and trouble concentrating. An entirely independent sample of 74 varsity American football players demonstrated the same pattern of impairment: compared to healthy controls, they scored significantly lower on the test of inhibitory control but were indistinguishable from controls on the 11 other tasks.InterpretationSelf-reported concussion is not associated with long-term general effects on cognitive function. Nevertheless, those who report at least one concussion and those who expose themselves to long-term frequent sport-related head impacts, do have a modest, but statistically robust, deficit of inhibitory control.

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Repetitive head impacts in a collegiate football season: Exposure and effects

International Journal of Sports Science & Coaching ◽

10.1177/17479541211027277 ◽

2021 ◽

pp. 174795412110272

Author(s):

Laura D Wilson ◽

Rachel A Hildebrand ◽

Trang Le ◽

Brett A McKinney

Keyword(s):

Reaction Time ◽

American Football ◽

Division I ◽

Football Players ◽

Short Term ◽

Head Impacts ◽

Repetitive Head Impacts ◽

The Past ◽

Acute Increase ◽

Collegiate Football

This study describes exposure to repetitive head impacts (RHI) by player position and activity during a collegiate football season, and investigates the relationship between RHI and acute (i.e., daily and weekly) and short-term (i.e., pre- to post-season) changes in balance, reaction time, symptoms, and cognition. We recorded RHI exposure in twenty Division I collegiate American football players during a single season using the Riddell InSite system. Participants sustained 4,586 impacts (4.20% high impact, i.e., >63 g; 95.79% low impact, i.e., 20–63 g). Greatest exposure to RHI was observed in running backs and defensive ends during games, and tight ends and defensive ends during practices. Running plays and team drills placed players at greatest risk for exposure during practice. Cumulative RHI exposure across the season was associated with short-term declines in reaction time (p = 0.045), but not balance or cognition. Acute decline in balance was associated with the number of impacts sustained in the past week (p < 0.05), but not the past 24 hours (p > 0.05). Acute increase in total symptom score was also associated with the number of impacts sustained in the past week (p < 0.01), but not the past 24 hours (p > 0.05). Reaction time did not decline based on impact exposure in the past 24 hours or week. This study identifies activities and positions that may put players at risk for RHI exposure, and demonstrates that RHI sustained during the course of typical American football play by non-concussed individuals may result in small changes in balance, reaction time, and symptoms, but not cognition.

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Effect of Turf Toe on Foot Contact Pressures in Professional American Football Players

Foot & Ankle International ◽

10.3113/fai-2009-0405 ◽

2009 ◽

Vol 30 (5) ◽

pp. 405-409 ◽

Cited By ~ 17

Author(s):

Robert H. Brophy ◽

Seth C. Gamradt ◽

Scott J. Ellis ◽

Ronnie P. Barnes ◽

Scott A. Rodeo ◽

...

Keyword(s):

Body Mass Index ◽

National Football League ◽

Peak Pressure ◽

American Football ◽

Football Players ◽

Plantar Pressures ◽

History Of ◽

Turf Toe ◽

The Relationship ◽

Contact Pressures

Background: The relationship between turf toe and plantar foot pressures has not been extensively studied. Two hypotheses were tested in a cohort of professional American football players: first, that a history of turf toe is associated with increased peak hallucal and first metatarsophalangeal (MTP) plantar pressures; second, that decreased range of motion (ROM) of the first MTP correlates with increased peak hallucal and first MTP plantar pressures. Materials and Methods: Forty-four athletes from one National Football League (NFL) team were screened for a history of turf toe during preseason training. Dorsal passive MTP ROM and dynamic plantar pressures were measured in both feet of each player. Anatomical masking was used to assess peak pressure at the first MTP and hallux. Results: First MTP dorsiflexion was significantly lower in halluces with a history of turf toe (40.6 ± 15.1 degrees versus 48.4 ± 12.8 degrees, p = 0.04). Peak hallucal pressures were higher in athletes with turf toe (535 ± 288 kPa versus 414 ± 202 kPa, p = 0.05) even after normalizing for athlete body mass index ( p = 0.0003). Peak MTP pressure was not significantly different between the two groups tested. First MTP dorsiflexion did not correlate with peak hallucal or first MTP pressures. Conclusion: This study showed that turf toe is associated with decreased MTP motion. In addition, increased peak hallucal pressures were found. Further study is warranted to determine whether these pressures correlate with the severity of symptoms or progression of turf toe to first MTP arthritis.

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