Chronic traumatic encephalopathy research viewed in the public domain: What makes headlines?

The bibliometric and altmetric analysis of chronic traumatic encephalopathy research: how great is the impact?

Background

The study of chronic traumatic encephalopathy (CTE) has received great attention from academia and the general public. This study aims to analyze the research productivity on CTE and investigate the most discussed articles in academia and the general public by conducting bibliometric and altmetric analyses.

Methods

Data of articles were obtained from the Web of Science Core Databases and Altmetric Explore. VOSviewer and CiteSpace software were used to analyze and visualize the articles. The correlation between Altmetric attention scores (AAS) and citation counts were assessed by Spearman correlation coefficient.

Results

788 publications of CTE were eventually gathered and analyzed, and 100 articles with highest citation counts (Top-cited) and 100 articles with highest AASs (Top-AAS) were then identified. The keywords density map showed both the general public and the scientists were particularly interested in the risk factors and pathology of CTE, and scientists were interested in the causes and characteristics of neurodegenerative diseases while the public became increasingly concerned about the detection and prevention of CTE. By examining the shared characteristics of the 44 articles (High-High articles) that overlapped between Top-cited and Top-AAS articles, we identified certain traits that may potentially contribute to their high citation rates and high AASs. Besides, significant positive correlations with varied strength between AAS and citation were observed in the 788 articles, Top-cited, Top-AAS and High-High datasets.

Conclusion

This study is the first to link bibliometric and altmetric analyses for CTE publications, which may provide deeper understanding of the attention of the scientists and the general public pay to the study of CTE, and offer some guidance and inspiration for future CTE in the selection of research topics and directions.

Interaction of Medical Conditions and Football Exposures Associated with Premortem Chronic Traumatic Encephalopathy Diagnosis in Former Professional American Football Players

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.

Examining later-in-life health risks associated with sport-related concussion and repetitive head impacts: a systematic review of case-control and cohort studies

OBJECTIVE

Concern exists about possible problems with later-in-life brain health, such as cognitive impairment, mental health problems and neurological diseases, in former athletes. We examined the future risk for adverse health effects associated with sport-related concussion, or exposure to repetitive head impacts, in former athletes.

DESIGN

Systematic review.

DATA SOURCES

Search of MEDLINE, Embase, Cochrane, CINAHL Plus and SPORTDiscus in October 2019 and updated in March 2022.

ELIGIBILITY CRITERIA

Studies measuring future risk (cohort studies) or approximating that risk (case-control studies).

RESULTS

Ten studies of former amateur athletes and 18 studies of former professional athletes were included. No postmortem neuropathology studies or neuroimaging studies met criteria for inclusion. Depression was examined in five studies in former amateur athletes, none identifying an increased risk. Nine studies examined suicidality or suicide as a manner of death, and none found an association with increased risk. Some studies comparing professional athletes with the general population reported associations between sports participation and dementia or amyotrophic lateral sclerosis (ALS) as a cause of death. Most did not control for potential confounding factors (eg, genetic, demographic, health-related or environmental), were ecological in design and had high risk of bias.

CONCLUSION

Evidence does not support an increased risk of mental health or neurological diseases in former amateur athletes with exposure to repetitive head impacts. Some studies in former professional athletes suggest an increased risk of neurological disorders such as ALS and dementia; these findings need to be confirmed in higher quality studies with better control of confounding factors.

PROSPERO REGISTRATION NUMBER

CRD42022159486.

Telling the Whole Story: Bibliometric Network Analysis to Evaluate Impact of Media Attention on Chronic Traumatic Encephalopathy Research

There is a national debate regarding the existence of a relationship between contact sport participation and future risk of neurodegenerative disease. We employed bibliometrics and altmetrics to quantify the academic, popular, and social media impact of published scientific articles that report an association between contact sports or military service with chronic traumatic encephalopathy (CTE+), and compare with those scientific articles that report null or no association of contact sports or military service with CTE (CTE-). In this cross-sectional study, we extracted number of citations, total link strength, altmetric score, number of news stories, media outlets, and Twitter interaction from published CTE articles. The top 10 most cited articles were statistically compared on these outcomes using Mann-Whitney U tests. CTE+ publications had an average of 101 citations per article, Altmetric score of 272, 36 news stories in 26 media outlets, and upper-bound of Twitter users of 402,159. CTE- publications had an average of 29 citations per article, Altmetric score of 39, two news stories and media outlets, and upper-bound of Twitter users of 91,070. Top 10 CTE+ publications had, on average, 94% more citations (p < 0.001), 95% higher altmetric scores (p = 0.01), 99% higher number of news stories (p = 0.01), 98% higher number of media outlets (p = 0.01), and reached 95% more Twitter users than top 10 CTE- publications (p = 0.11). The bibliometric analysis indicates a significant inequality in media dissemination and popular consumption of scientific findings that do not support a relationship between contact sports or military service and future neurodegeneration.

Child participation in collision sports and football: what influences parental decisions?

OBJECTIVE

Sport participation promotes health benefits for children. Current media and scientific coverage of sport-related head injury may influence a parent's decision on sports participation. Physicians must understand what influences these decisions to effectively counsel patients and families. This study sought to better understand and quantify the parental decisions to allow/disallow collision sports, including football participation.

METHODS

A 31-question survey related to child/parent demographics, sports history, and influences to allow/disallow sport participation was available to parents in the United States through a national volunteer registry, between November 2016 and September 2019. Pearson's chi-squared and Wilcoxon's signed-rank test were used to analyze categorical and continuous variables, respectively. Multivariate logistic regression was performed to identify the most powerful factors associated with the decision.

RESULTS

Of the 884 responses, 430 (49%) parents would disallow collision sport participation and 334 (38%) would disallow football. Parents who would allow collision sports more commonly cited child desire, while those parents who would disallow cited safety concern as the greatest influence to generally disallow a sport. Those who would disallow reported doctors (35.1% vs 25.3%; P = 0.002), media (12.8% vs 7.3%; P = 0.006) and other parents (11.2% vs 7.3%; P = 0.045) as influences. A child's age (OR 1.039, 95%CI 1.007-1.073; P = 0.018) was independently associated with their parent responding that they would allow collision sports. Parent educational status showed that those with higher than a bachelor's degree would be less likely to allow football participation (OR 0.635, 95%CI 0.443-0.910; P = 0.013).

CONCLUSIONS

Parents incorporate many sources of information into the decision to allow or disallow their child to participate in collision sports. A child's desire to play a sport and child safety are driving factors for parents faced with the decision of whether to allow participation in collision sports. Physician input is more frequently influential to parents than the media, underscoring the responsibility of physicians to engage families on the risks, benefits, and resources available for sport participation.

Mild Cognitive Impairment and Dementia Reported by Former Professional Football Players over 50 Years of Age: An NFL-LONG Study

PURPOSE

To estimate prevalences of MCI and dementia diagnoses in former National Football League (NFL) players ≥50 years old and examine the relationships among these diagnoses and an array of predictors of long-term brain health.

METHODS

A cross-section of former NFL players (n = 922; aged [mean ± SD] 64.8 ± 8.9 years) completed a questionnaire. Prevalences of self-reported medical diagnoses of MCI and dementia were reported alongside U.S. population estimates across 5-year age intervals (e.g., 60-64 years). Prevalence ratios (PRs) were calculated for multiple predictors of long-term brain health.

RESULTS

Overall, MCI and dementia prevalences were n = 219(23.8%) and n = 82(8.9%), respectively. Each diagnosis was more prevalent in former NFL players across age groups than U.S. norms, with greater disparities at relatively younger ages (e.g., 65-69) compared with older ages. Greater prevalences of MCI and dementia were associated with: self-reported concussion history (10+ vs. 0; PRadjusted[95%CI] = 1.66[1.02-2.71] and 2.61[1.01-6.71], respectively); recent pain intensity (PRadjusted[95%CI] = 1.13[1.07-1.20] and 1.15[1.03-1.28]); and diagnoses of depression (PRadjusted[95%CI] = 2.70[1.92-3.81] and 3.22[1.69-6.14]), anxiety (PRadjusted[95%CI] = 1.96[1.26-3.07] and 3.14[1.47-6.74]), or both (PRadjusted[95%CI] = 3.11[2.38-4.08] and 4.43[2.71-7.25]). Higher MCI prevalence was related to sleep apnea (PRadjusted[95%CI] = 1.30[1.06-1.60]); higher dementia prevalence was associated with age (5-year interval, PRadjusted[95%CI] = 1.42[1.26-1.60]) and race (non-White vs. White, PRadjusted[95%CI] = 1.64[1.07-2.53]).

CONCLUSIONS

Self-reported MCI and dementia prevalences were higher in former NFL players than national estimates and were associated with numerous personal factors, including mood-related disorders and a high number of self-reported concussions. Predictors of higher MCI and dementia prevalence may be modifiable and warrant consideration by clinicians and researchers as potential targets to mitigate the onset of these conditions.

The behavioral, psychological, and social impacts of team sports: a systematic review and meta-analysis

Objectives: To assess the association between team sport participation and behavioral, psychological, and social health outcomes in young athletes.Methods: A systematic review and meta-analysis were undertaken to identify studies published between 01/01/1950-05/01/2020 investigating the association between team sport participation and health outcomes in young athletes (<25 years). Included studies compared team sport participants to controls or themselves, assessed health outcomes, and had a sample size >50. Prospective and retrospective studies were included; non-primary literature was excluded. Health outcomes were categorized as: 1) behavioral, 2) psychological, or 3) social. Data were extracted to form 2 × 2 tables for each study to calculate odds ratios (OR) and 95% confidence intervals (CI).Results: Of 371 queried articles, 34 studies from 10 countries across 4 continents were included, with 9 reporting homogenous outcomes for meta-analysis.Behavioral: Fifteen studies evaluated behavioral health outcomes of alcohol and/or drug use, fitness, and diet. Quantitatively, team sport participation was found to decrease rates of cigarette/tobacco use across 5 studies (OR 0.72, 95% CI 0.69-0.76) and alcohol/drug use across 7 studies (OR 0.73, 95% CI 0.69-0.77). Qualitatively, 12/15 (80%) of studies confirmed improved behavioral health outcomes with team sport participation.Psychological: Nineteen studies evaluated psychological health outcomes including anorexia, anxiety, depression, self-esteem, and suicidal ideation. Quantitatively, team sport participation was associated with decreased depression/anxiety rates across 5 studies (OR 0.59, 95%CI 0.54-0.64). Qualitatively, 14/19 (74%) of studies confirmed improved psychological health.Social: Ten studies evaluated social health outcomes including academic performance, commitment, psychosocial health, social behavior/identity, and delinquency/high-risk activity. Qualitatively, 7/10 (70%) of studies confirmed improved social health outcomes with team sport participation.Conclusion: Team sport participation was associated with decreased odds of smoking/tobacco use, alcohol/drug use, and depression/anxiety. Though few studies mentioned potential negative effects of team sport participation, the majority reported improved behavioral, psychological, and social health outcomes in youth athletes worldwide.

The burden of unsubstantiated messaging: collegiate athletes' chronic traumatic encephalopathy mechanism beliefs

OBJECTIVE

To investigate factors associated with collegiate athletes' beliefs regarding chronic traumatic encephalopathy (CTE) mechanism.

DESIGN

Cross-sectional study.

METHODS

A total of 838 collegiate athletes (61.9% men) from seven institutions completed a 10-minute survey that captured information relative to demographics, diagnosed concussion history, formal sport-related concussion education, additional sources of concussion information, and beliefs about multiple concussions and premature return-to-play following a head impact as mechanisms for CTE.

RESULTS

More than half of collegiate athletes believed that multiple concussions (58.2%) and premature return-to-play (59.1%) may cause CTE. Those who reported getting concussion information from sports news had higher odds of believing multiple concussions and premature return-to-play were CTE mechanisms compared to those who did not get information from sports news sources. Additionally, CTE mechanism beliefs were significantly greater in collegiate athletes who were male, had sustained a previous diagnosed concussion, or had acquired concussion information from the NCAA.

CONCLUSIONS

Sports news' reporting of CTE storylines, which highlight former male athletes with complex brain injury histories, may influence collegiate athletes' beliefs about concussion. Therefore, it is recommended that concussion awareness initiatives incorporate information related specifically to CTE to empower collegiate athletes with evidence-based, patient-oriented information and knowledge regarding this condition.

Factors Influencing College Football Players' Beliefs About Incurring Football-Related Dementia

Background:

Football participation is associated with risks to acute and long-term health, including the possibility of incurring football-related dementia. Concerns have been raised regarding media coverage of these risks, which may have influenced athletes’ beliefs. However, little is known about football players’ views on football-related dementia. The risk-perception literature suggests that related risk perceptions and features of individual cognition, such as the ability to switch to reasoned, deliberative thinking, may influence individual perception of a long-term risk.

Purpose:

To evaluate factors influencing college football players’ belief that they are likely to incur football-related dementia in the future.

Study Design:

Cross-sectional study.

Methods:

Members of 4 National Collegiate Athletic Association Division I Power 5 Football teams participated in this survey-based study, providing responses to demographic, athletic, and risk-posture questions, and completed the cognitive reflection test. Logistic regressions were used to evaluate relationships between beliefs about football-related dementia and factors including athletic and demographic characteristics, football risk posture, health-risk posture, and cognitive reflection test score.

Results:

About 10% of the 296 participating athletes thought football-related dementia was likely to occur in their future. Skill players had lower odds than linemen of believing that football-related dementia was likely (odds ratio [OR], 0.35; 95% CI, 0.14-0.89). For each additional suspected concussion in an athlete’s career, his odds of believing football-related dementia was likely increased by 24% (OR, 1.24; 95% CI, 1.07-1.45). Acute and chronic football-related risk perceptions, as well as non–football-related health-risk perceptions, were positively associated with athletes’ belief that football-related dementia was likely. Higher cognitive reflection test scores, a measure of ability to switch to slow, deliberative thinking, was positively associated with odds of believing football-related dementia was likely (OR, 1.57; 95% CI, 1.12-2.21).

Conclusion:

Some athletes view football as generally riskier, while others view football as generally lessri sky. These risk postures are informed by athletes’ concussion history, primary playing position, and ability to switch from fast, reactive thinking to slow, deliberative thinking. Ensuring that athletes are appropriately informed of the risks of participation is an ethical obligation of universities; sports medicine clinicians are appropriate facilitators of conversations about athletes’ health risks.

Frequency and Predictors of Traumatic Encephalopathy Syndrome in a Prospective Cohort of Retired Professional Athletes

Traumatic encephalopathy syndrome (TES) is proposed to represent the long-term impact of repetitive head-injury exposure and the clinical manifestation of chronic traumatic encephalopathy (CTE). This study aimed to evaluate the frequency of TES in a cohort of retired professional contact sport athletes, compare the frequency of TES to clinical consensus diagnoses, and identify predictors that increase the likelihood of TES diagnosis. Participants were 85 retired professional contact sport athletes from a prospective cohort at the University of Texas Southwestern Medical Center and the University of Texas at Dallas. Participants ranged in age from 23 to 79 (M = 55.95, SD = 13.82) and obtained 7 to 19 years of education (M = 16.08, SD = 1.03). Retirees were either non-Hispanic white (n = 62) or African-American (n = 23). Retired athletes underwent a standard clinical evaluation, which included a clinical interview, neurological exam, neuroimaging, neuropsychological testing, and consensus diagnosis of normal, mild cognitive impairment, or dementia. TES criteria were applied to all 85 athletes, and frequencies of diagnoses were compared. Fourteen predictors of TES diagnosis were evaluated using binary logistic regressions, and included demographic, neuropsychological, depression symptoms, and head-injury exposure variables. A high frequency (56%) of TES was observed among this cohort of retired athletes, but 54% of those meeting criteria for TES were diagnosed as cognitively normal via consensus diagnosis. Games played in the National Football League (OR = 0.993, p = 0.087), number of concussions (OR = 1.020, p = 0.532), number of concussions with loss of consciousness (OR = 1.141 p = 0.188), and years playing professionally (OR = 0.976, p = 0.627) were not associated with TES diagnosis. Degree of depressive symptomatology, as measured by the total score on the Beck Depression Inventory-II, was the only predictor of TES diagnosis (OR = 1.297, p < 0.001). Our results add to previous findings underscoring the risk for false positive diagnosis, highlight the limitations of the TES criteria in clinical and research settings, and question the relationship between TES and head-injury exposure. Future research is needed to examine depression in retired professional athletes.