Risk of Misdiagnosing Chronic Traumatic Encephalopathy in Men With Depression

Traumatic Brain Injury and Risk of Incident Dementia: Forensic Applications of Current Research

OBJECTIVE

Traumatic Brain Injury (TBI) has been identified as a risk factor for later developing neurodegenerative disorders, and there has been significant attention on this association in forensic settings. As a result, forensic neuropsychologists are frequently asked to comment on risk for dementia after an alleged TBI in litigation and criminal cases. This article provides an evidence-based foundation to aid forensic practice by synthesizing comprehensive information pertaining to: (i) the role of the neuropsychologist in TBI-related litigation, (ii) the complexities associated with identifying TBIs in forensic cases, (iii) the science of TBI in relation to incident dementia, and (iv) current scientific evidence for chronic traumatic encephalopathy.

RESULTS

Developing a neurodegenerative disorder after TBI is the exception rather than the rule. Prevalence rates suggest that only a small subset (< 5%) of individuals with moderate-to-severe TBI, and even fewer (< 1%) with mild TBI (mTBI), appear to develop certain neurodegenerative diseases, and the characteristics that place some at risk remain unclear. The literature is mixed in terms of identifying a relationship between mTBI and later-in-life dementia risk. Also, the quality of positive evidence for risk of dementia after mTBI is weak and mostly consists of observational studies characterized by methodological limitations.

CONCLUSIONS

Methods used to establish the likely occurrence of a TBI in a forensic context are typically more extensive than those used in a routine clinical evaluation. Research methodology to define TBI is often even more rudimentary and inconsistent. Applying clinical research results of TBI and dementia outcomes to forensic cases at an individual level carries significant limitations. Estimating the contribution of remote head hits or concussion in a causal manner to dementia is a challenge forensic experts sometimes face, yet at present, the task is impossible beyond correlations and speculation.

Single- versus two-test criteria for cognitive impairment: associations with CSF and imaging markers in former American football players

Objective: Cognitive impairment is a core feature of traumatic encephalopathy syndrome (TES), the putative clinical syndrome of chronic traumatic encephalopathy-a neuropathological disease associated with repetitive head impacts (RHI). Careful operationalization of cognitive impairment is essential to improving the diagnostic specificity and accuracy of TES criteria. We compared single- versus two-test criteria for cognitive impairment in their associations with CSF and imaging biomarkers in male former American football players. Method: 169 participants from the DIAGNOSE CTE Research Project completed neuropsychological tests of memory and executive functioning. Cognitive impairment was identified by single-test criteria (z≤-1.5 on one test) and two-test criteria (z<-1 on two tests within a domain). ANCOVAs adjusting for age, race, education, body mass index, word-reading score, and APOE ε4 status assessed whether single- or two-test criteria predicted CSF markers (Aβ1-42, p-tau181, p-tau181/Aβ1-42, total tau, neurofilament light [NfL], glial fibrillary acidic protein [GFAP]) and MRI markers (hippocampal volume, cortical thickness, white matter hyperintensities). Results: Ninety-nine participants met single-test criteria for cognitive impairment. Sixty-six met two-test criteria. Participants who met two-test criteria had greater exposure to RHI than those who did not (p=.04). Two-test criteria were -associated with higher CSF p-tau181/Aβ1-42 (q=.02) and CSF NfL (q=.02). The association between two-test criteria and CSF NfL remained after excluding amyloid-positive participants (q=.04). Single-test criteria were not associated with any biomarkers (q's>.05). Conclusions: Two-test but not single-test criteria for cognitive impairment were associated with markers of neurodegeneration. Future clinical research in TES may benefit from applying two-test criteria to operationalize cognitive impairment.

Chronic traumatic encephalopathy: State-of-the-science update and narrative review

OBJECTIVE

The long-recognized association of brain injury with increased risk of dementia has undergone significant refinement and more detailed study in recent decades. Chronic traumatic encephalopathy (CTE) is a specific neurodegenerative tauopathy related to prior exposure to repetitive head impacts (RHI). We aim to contextualize CTE within a historical perspective and among emerging data which highlights the scientific and conceptual evolution of CTE-related research in parallel with the broader field of neurodegenerative disease and dementia.

METHODS

We provide a narrative state-of-the-science update on CTE neuropathology, clinical manifestations, biomarkers, different types and patterns of head impact exposure relevant for CTE, and the complicated influence of neurodegenerative co-pathology on symptoms.

CONCLUSIONS

Now almost 20 years since the initial case report of CTE in a former American football player, the field of CTE continues evolving with increasing clarity but also several ongoing controversies. Our understanding of CTE neuropathology outpaces that of disease-specific clinical correlates or the development of in-vivo biomarkers. Diagnostic criteria for symptoms attributable to CTE are still being validated, but leveraging increasingly available biomarkers for other conditions like Alzheimer's disease may be helpful for informing the CTE differential diagnosis. As diagnostic refinement efforts advance, clinicians should provide care and/or referrals to providers best suited to treat an individual patient's clinical symptoms, many of which have evidence-based behavioral treatment options that are etiologically agnostic. Several ongoing research initiatives and the gradual accrual of gold standard clinico-pathological data will pay dividends for advancing the many existing gaps in the field of CTE.

Base rates of healthy community-dwelling adults meeting criteria for traumatic encephalopathy syndrome and levels of chronic traumatic encephalopathy certainty

Objective: The National Institute of Neurological Disorders and Stroke (NINDS) recently revised criteria for Traumatic Encephalopathy Syndrome (TES) (Katz et al.), aiming to improve the specificity of former TES criteria (Montenigro et al.) and adding methods to gauge certainty of underlying Chronic Traumatic Encephalopathy (CTE). This study examined base rates of Montenigro et al. and Katz et al. TES criteria in healthy community-dwelling adults. Method: Participants consisted of healthy adults (n = 835; M = 48.1 ± 18.2 years-old, range = 18-85; 37.1% male; 64.1% White) without known history of neurotrauma or psychiatric or neurological conditions. The former and current TES criteria were operationalized using the NIH Toolbox Cognition, Motor, and Emotion batteries and PROMIS-29. Results: Per Katz et al. criteria, 36.9% had symptoms Suggestive of CTE (i.e. either cognitive impairment or neurobehavioral dysregulation), 4.1% had Possible CTE (i.e. requiring cognitive impairment and two additional criteria), and 0.8% had Probable CTE (i.e. requiring cognitive impairment and three additional criteria). The requirement of cognitive impairment for Possible CTE certainty decreased the base rate of Possible CTE tenfold from Montenigro et al. criteria (40.1%). Conclusion: The Katz et al. criteria were met less frequently by healthy adults than the Montenigro et al. criteria. Requiring cognitive impairment and more supportive TES features when gauging CTE certainty may reduce false-positive diagnoses. This finding supports the role of neuropsychologists in the diagnosis and monitoring of patients in TES research studies. To assess specificity, future research should examine base rates of Katz et al. criteria in other psychiatric and neurological conditions.

Symptoms of Traumatic Encephalopathy Syndrome are Common in Community-Dwelling Adults

BACKGROUND AND OBJECTIVES

The consensus criteria for traumatic encephalopathy syndrome (TES), the possible in vivo clinical syndrome associated with significant repetitive head impacts, have only been minimally studied to date. This study examined the prevalence of the proposed core clinical features of TES in a sample of healthy adults.

METHODS

A cross-sectional survey study was conducted through ResearchMatch, a national health volunteer registry. Participants were assessed for symptoms of TES based on the 2021 consensus criteria, including prior repetitive head impacts and core clinical features. Additional health information (e.g., concussion history, psychological health, sleep, chronic pain) was also evaluated. The consensus proposed research criteria for TES (i.e., reporting at least one progressive core clinical feature of TES, as in progressive difficulties with episodic memory, executive functioning, or neurobehavioral dysregulation) were applied to the sample.

RESULTS

Out of 1100 participants (average age = 53.6 ± 17.7 years, 55% women), 34.6% endorsed one or more progressive core clinical features of TES. Participants with a significant history of contact sports (i.e., ≥ 5 years total, with ≥ 2 years in high school or beyond) had similar rates of endorsing a progressive core clinical feature of TES compared to those without significant histories of repetitive head impacts (36.4% vs 32.8%, respectively, χ2 = 0.52, p = 0.47). A significant history of repetitive head impacts in sports was not associated with endorsing a core clinical feature of TES in univariable or multivariable models (p > 0.47), whereas current depression/anxiety (odds ratio [OR] = 6.94), a history of psychiatric disorders (OR = 2.57), current sleep problems (OR = 1.56), and younger age (OR = 0.99) were significant predictors of TES status in a multivariable model. In a subsample of 541 participants who denied a lifetime history of contact sports, other forms of repetitive head impacts, and concussions, approximately 31.0% endorsed one or more progressive core clinical features of TES. Additionally, 73.5% of neurotrauma-naïve participants with current anxiety or depression reported at least one core progressive feature of TES, compared with 20.2% of those without clinically significant depression/anxiety symptoms.

CONCLUSIONS

A considerable proportion of adults without a significant history of repetitive head impacts from sports endorsed core TES features, particularly those experiencing mental health symptoms. Having a significant history of contact sports was not associated with endorsing a core progressive clinical feature of TES, whereas other health factors were. These findings underscore the need for validating and refining TES criteria in samples with and without substantial neurotrauma histories.

Applying the Consensus Criteria for Traumatic Encephalopathy Syndrome Retrospectively to Case Studies of Boxers from the 20th Century

There are no validated diagnostic criteria for traumatic encephalopathy syndrome (TES). During the early and middle 20th century, TES was described as a clinical condition that was experienced by some high-exposure boxers-and it was believed to reflect chronic traumatic brain injury. Consensus criteria for the diagnosis of TES were published in 2021. We applied the consensus criteria for TES retrospectively to cases of chronic brain damage in boxers described in articles published in the 20th century that were obtained from narrative and systematic reviews. The sample included 157 boxers identified in 21 articles published between 1929 and 1999. Two authors reviewed each case description and coded the criteria for TES. For the core clinical features, cognitive impairment was noted in 63.1%, and in 28.7% of cases the person's cognitive functioning appeared to be broadly normal. Neurobehavioral dysregulation was present in 25.5%. One third (34.4%) were identified as progressive, 30.6% were not progressive, and the course could not be clearly determined in 35.0%. In total, 29.9% met the TES consensus criteria, 28.0% did not, and 42.0% had insufficient information to make a diagnostic determination. TES, in the 20th century, was described as a neurological condition, not a psychiatric disorder-and this supports the decision of the 2021 consensus group to remove primary and secondary psychiatric diagnoses from being a core diagnostic feature. Future research is needed to determine whether, or the extent to which, cognitive impairment or neurobehavioral dysregulation described as characterizing TES are associated with chronic traumatic encephalopathy neuropathological change.

Examining the New Consensus Criteria for Traumatic Encephalopathy Syndrome in Community-Dwelling Older Adults

In 2021, an expert panel of clinician-scientists published the first consensus research diagnostic criteria for traumatic encephalopathy syndrome (TES), a clinical condition thought to be associated with chronic traumatic encephalopathy neuropathological change. This study evaluated the TES criteria in older adults and assessed associations between TES criteria and a history of repetitive head impacts. This cross-sectional, survey-based study examined the symptoms of TES, previous repetitive head impacts, and a variety of current health difficulties. To meet symptom criteria for TES, participants had to report progressive changes with memory, executive functioning, and/or neurobehavioral dysregulation. To meet the criterion for substantial exposure to repetitive head impacts via contact sports, participants reported at least 5 years of contact sport exposure (with 2+ years in high school or beyond). A sample of 507 older adults (mean age = 70.0 years, 65% women) completed the survey and 26.2% endorsed having one or more of the progressive core clinical features of TES. Those who had a significant history of contact sport exposure were not significantly more likely to meet TES criteria compared with those who did not (31.3% vs. 25.3%, p = 0.46). In a binary logistic regression predicting TES status, current depression or anxiety (odds ratio [OR] = 12.55; 95% confidence interval [CI] = 4.43-35.51), history of psychiatric disorders (OR = 2.07, 95% CI = 1.22-3.49), male sex (OR = 1.87), and sleep problems (OR = 1.71, 95% CI = 1.01-2.91) were associated with meeting TES criteria. The sport exposure criterion, age, and current pain were not significantly associated with TES status (ps > 0.05). A significant minority of participants with no history of neurotrauma endorsed symptoms consistent with TES (22.0% of men and 19.8% of women). Nearly 80% of neurotrauma naïve participants with clinically significant anxiety/depression met criteria for TES. In summary, approximately one in four older adults met the symptom criteria for TES, many of whom had no history of repetitive neurotrauma. Mental health problems and sleep issues were associated with TES, whereas having a history of repetitive head impacts in contact sports was not. These data suggest that the new consensus diagnostic criteria for TES may have low specificity and may carry a higher risk of misdiagnosing those with other physical and mental health conditions as having TES.

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.

A narrative review of psychiatric features of traumatic encephalopathy syndrome as conceptualized in the 20th century

Introduction

Some ultra-high exposure boxers from the 20th century suffered from neurological problems characterized by slurred speech, personality changes (e.g., childishness or aggressiveness), and frank gait and coordination problems, with some noted to have progressive Parkinsonian-like signs. Varying degrees of cognitive impairment were also described, with some experiencing moderate to severe dementia. The onset of the neurological problems often began while they were young men and still actively fighting. More recently, traumatic encephalopathy syndrome (TES) has been proposed to be present in athletes who have a history of contact (e.g., soccer) and collision sport participation (e.g., American-style football). The characterization of TES has incorporated a much broader description than the neurological problems described in boxers from the 20th century. Some have considered TES to include depression, suicidality, anxiety, and substance abuse.

Purpose

We carefully re-examined the published clinical literature of boxing cases from the 20th century to determine whether there is evidence to support conceptualizing psychiatric problems as being diagnostic clinical features of TES.

Methods

We reviewed clinical descriptions from 155 current and former boxers described in 21 articles published between 1928 and 1999.

Results

More than one third of cases (34.8%) had a psychiatric, neuropsychiatric, or neurobehavioral problem described in their case histories. However, only 6.5% of the cases were described as primarily psychiatric or neuropsychiatric in nature. The percentages documented as having specific psychiatric problems were as follows: depression = 11.0%, suicidality = 0.6%, anxiety = 3.9%, anger control problems = 20.0%, paranoia/suspiciousness = 11.6%, and personality change = 25.2%.

Discussion

We conclude that depression, suicidality (i.e., suicidal ideation, intent, or planning), and anxiety were not considered to be clinical features of TES during the 20th century. The present review supports the decision of the consensus group to remove mood and anxiety disorders, and suicidality, from the new 2021 consensus core diagnostic criteria for TES. More research is needed to determine if anger dyscontrol is a core feature of TES with a clear clinicopathological association. The present findings, combined with a recently published large clinicopathological association study, suggest that mood and anxiety disorders are not characteristic of TES and they are not associated with chronic traumatic encephalopathy neuropathologic change.

Concussion and Psychological Effects: A Review of Recent Literature

ABSTRACT

The aim of this article is to provide an up-to-date review of psychological changes in association with postconcussive athletes. In particular, this article focused on the symptomatology, risk factors, and treatment of psychiatric diagnoses in patients who suffered a sports-related concussion (SRC). After an extensive review of prior and current literature, there is significant evidence that demonstrates an association of changes in mood and behavior, including new or worsening symptoms of anxiety, depression, and difficulty with attention and concentration in those who are recovering from a concussion. The goal of care in these patients is to identify and treat these psychological symptoms early to have more favorable long-term outcomes. Primary treatment should focus on psychotherapy; however, other considerations may be warranted in certain cases, such as selective serotonin reuptake inhibitors for depression and tricyclic antidepressants and gabapentin for short-term cognitive symptom improvement.

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.

Identifying degenerative effects of repetitive head trauma with neuroimaging: a clinically-oriented review

BACKGROUND AND SCOPE OF REVIEW

Varying severities and frequencies of head trauma may result in dynamic acute and chronic pathophysiologic responses in the brain. Heightened attention to long-term effects of head trauma, particularly repetitive head trauma, has sparked recent efforts to identify neuroimaging biomarkers of underlying disease processes. Imaging modalities like structural magnetic resonance imaging (MRI) and positron emission tomography (PET) are the most clinically applicable given their use in neurodegenerative disease diagnosis and differentiation. In recent years, researchers have targeted repetitive head trauma cohorts in hopes of identifying in vivo biomarkers for underlying biologic changes that might ultimately improve diagnosis of chronic traumatic encephalopathy (CTE) in living persons. These populations most often include collision sport athletes (e.g., American football, boxing) and military veterans with repetitive low-level blast exposure. We provide a clinically-oriented review of neuroimaging data from repetitive head trauma cohorts based on structural MRI, FDG-PET, Aβ-PET, and tau-PET. We supplement the review with two patient reports of neuropathology-confirmed, clinically impaired adults with prior repetitive head trauma who underwent structural MRI, FDG-PET, Aβ-PET, and tau-PET in addition to comprehensive clinical examinations before death.

REVIEW CONCLUSIONS

Group-level comparisons to controls without known head trauma have revealed inconsistent regional volume differences, with possible propensity for medial temporal, limbic, and subcortical (thalamus, corpus callosum) structures. Greater frequency and severity (i.e., length) of cavum septum pellucidum (CSP) is observed in repetitive head trauma cohorts compared to unexposed controls. It remains unclear whether CSP predicts a particular neurodegenerative process, but CSP presence should increase suspicion that clinical impairment is at least partly attributable to the individual's head trauma exposure (regardless of underlying disease). PET imaging similarly has not revealed a prototypical metabolic or molecular pattern associated with repetitive head trauma or predictive of CTE based on the most widely studied radiotracers. Given the range of clinical syndromes and neurodegenerative pathologies observed in a subset of adults with prior repetitive head trauma, structural MRI and PET imaging may still be useful for differential diagnosis (e.g., assessing suspected Alzheimer's disease).

National Institute of Neurological Disorders and Stroke Consensus Diagnostic Criteria for Traumatic Encephalopathy Syndrome

OBJECTIVE

To develop evidence-informed, expert consensus research diagnostic criteria for traumatic encephalopathy syndrome (TES), the clinical disorder associated with neuropathologically diagnosed chronic traumatic encephalopathy (CTE).

METHODS

A panel of 20 expert clinician-scientists in neurology, neuropsychology, psychiatry, neurosurgery, and physical medicine and rehabilitation, from 11 academic institutions, participated in a modified Delphi procedure to achieve consensus, initiated at the First National Institute of Neurological Disorders and Stroke Consensus Workshop to Define the Diagnostic Criteria for TES, April, 2019. Before consensus, panelists reviewed evidence from all published cases of CTE with neuropathologic confirmation, and they examined the predictive validity data on clinical features in relation to CTE pathology from a large clinicopathologic study (n = 298).

RESULTS

Consensus was achieved in 4 rounds of the Delphi procedure. Diagnosis of TES requires (1) substantial exposure to repetitive head impacts (RHIs) from contact sports, military service, or other causes; (2) core clinical features of cognitive impairment (in episodic memory and/or executive functioning) and/or neurobehavioral dysregulation; (3) a progressive course; and (4) that the clinical features are not fully accounted for by any other neurologic, psychiatric, or medical conditions. For those meeting criteria for TES, functional dependence is graded on 5 levels, ranging from independent to severe dementia. A provisional level of certainty for CTE pathology is determined based on specific RHI exposure thresholds, core clinical features, functional status, and additional supportive features, including delayed onset, motor signs, and psychiatric features.

CONCLUSIONS

New consensus diagnostic criteria for TES were developed with a primary goal of facilitating future CTE research. These criteria will be revised as updated clinical and pathologic information and in vivo biomarkers become available.

Examining the Research Criteria for Traumatic Encephalopathy Syndrome in Middle-Aged Men From the General Population Who Played Contact Sports in High School

Objective: There are no validated or agreed upon diagnostic clinical criteria for chronic traumatic encephalopathy or traumatic encephalopathy syndrome. This study examines the leading research criteria for traumatic encephalopathy syndrome (TES) in middle-aged men in the general population.

Method: Participants were 409 men between the ages of 35 and 55 recruited through an online crowdsourcing platform. Participants provided demographic information, medication history, concussion history, contact sport history, current medication use, and current symptoms. Research criteria for TES were applied to the sample.

Results: Over half of the total sample met TES symptom criteria (56.2%), without applying the neurotrauma exposure criteria. Those with 4+ prior concussions had higher rates of meeting TES criteria compared to those with 0–3 prior concussions, but the results were not statistically significant (69.8 vs. 54.6%; χ² = 3.58, p = 0.06). Exposure to contact sports was not related to higher rates of TES (ps ≥ 0.55). In a binary logistic regression predicting the presence of mild or greater TES, significant predictors were sleep difficulties [Odds ratio (OR) = 6.68], chronic pain (OR = 3.29), and age (OR = 1.04). Neurotrauma exposure was not a significant predictor (p = 0.66). When analyzing those with no prior concussions or contact sport histories (n = 126), 45.2% met symptom criteria for mild or greater TES; chronic pain and sleep difficulties were associated with a higher prevalence of meeting criteria for TES in this subgroup (ps < 0.001).

Conclusions: Men who participated in contact sports in high school or college were not more likely to meet criteria for TES than men who participated in non-contact sports or no sports. In a multivariable model, sleep problems and chronic pain were predictive of meeting the symptom criteria for TES, but the repetitive neurotrauma exposure criterion was not a significant predictor of meeting the TES symptom criteria.

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.

Symptoms of traumatic encephalopathy syndrome are common in the US general population

There are no validated criteria for diagnosing chronic traumatic encephalopathy, or traumatic encephalopathy syndrome, in a living person. The purpose of this study is to examine symptom reporting resembling the research criteria for traumatic encephalopathy syndrome in men and women from the US general population. This is a retrospective analysis of publicly available data from a cross-sectional epidemiological study. The National Comorbidity Survey Replication was designed to examine the prevalence and correlates of mental disorders in the USA. The study included a nationally representative sample of 9282 adults (4139 men and 5143 women). An in-person interview and survey were conducted in the homes of men and women from the general population. The study was conducted with participants residing in New York City, Los Angeles, Chicago, Philadelphia, Detroit, San Francisco, Washington DC, Dallas/Fort Worth, Houston, Boston, Nassau-Suffolk NY, St. Louis, Pittsburgh, Baltimore, Minneapolis and Atlanta. Symptoms from the research criteria for the diagnosis of traumatic encephalopathy syndrome were applied to men and women in the general population and in sub-groups of people with health problems and mental health problems. A small percentage of the US general population met symptom criteria for traumatic encephalopathy syndrome (6.6–11.9%, depending on the definition applied). People with chronic pain were much more likely to meet criteria (i.e. 14.8–30.5%), and two out of three people who have experienced suicidality in the past year met symptom criteria for traumatic encephalopathy syndrome (65.2–72.2%). The majority of women with a mood disorder and chronic pain met criteria (62.7–89.8%). This is the largest study, to date, examining the aspects of the research criteria for the diagnosis of traumatic encephalopathy syndrome in the general population, and the first study to examine these criteria in women. This study has important clinical and public health implications. The potential rate for misdiagnosing traumatic encephalopathy syndrome in adults who are experiencing chronic pain, idiopathic mental health problems or both is high.

Risk for Misdiagnosing Chronic Traumatic Encephalopathy in Men With Anger Control Problems

Background: There are no validated or agreed upon criteria for diagnosing chronic traumatic encephalopathy (CTE) in a living person. In recent years, it has been proposed that anger dyscontrol represents a behavioral clinical phenotype of CTE. This is the first study to examine the specificity of the diagnostic research criteria for traumatic encephalopathy syndrome (TES, the clinical condition proposed to be CTE) in men from the US general population who have anger dyscontrol problems. It was hypothesized that a substantial percentage of these men would meet the research criteria for TES. Methods: Data from 4,139 men who participated in the National Comorbidity Survey Replication, an in-person survey that examined the prevalence and correlates of mental disorders in the United States, were included in this study. Men who were diagnosed with intermittent explosive disorder in the past year were the clinical sample of interest (n = 206; 5.0% of all men in the database), and the remaining men were used as a comparison sample. They were classified as meeting the research criteria for TES if they presented with the purported supportive clinical features of CTE (e.g., impulsivity/substance abuse, anxiety, apathy, suicidality, headache). Results: In this sample of men from the general population with intermittent explosive disorder, 27.3% met a conservative definition of the proposed research criteria for CTE (i.e., traumatic encephalopathy syndrome). If one assumes the delayed-onset criterion is present, meaning that the men in the sample are compared to former athletes or military veterans presenting with mental health problems years after retirement, then 65.0% of this sample would meet the research criteria for TES. Conclusions: These results have important implications. Using conservative criteria, at least one in four men from the general population, who have serious anger control problems, will meet the symptom criteria for TES. If one considers former athletes and military veterans with anger control problems who present many years after retirement and who experienced a documented decline in their mental health, nearly two-thirds will meet these research criteria. More research is needed to examine risks for misdiagnosing TES and to determine whether anger dyscontrol is a clinical phenotype of CTE.

Chronic traumatic encephalopathy neuropathology might not be inexorably progressive or unique to repetitive neurotrauma

In the 20th century, chronic traumatic encephalopathy (CTE) was conceptualized as a neurological disorder affecting some active and retired boxers who had tremendous exposure to neurotrauma. In recent years, the two research groups in the USA who have led the field have asserted definitively that CTE is a delayed-onset and progressive neurodegenerative disease, with symptoms appearing in midlife or decades after exposure. Between 2005 and 2012 autopsy cases of former boxers and American football players described neuropathology attributed to CTE that was broad and diverse. This pathology, resulting from multiple causes, was aggregated and referred to, in toto, as the pathology ‘characteristic’ of CTE. Preliminary consensus criteria for defining the neuropathology of CTE were forged in 2015 and published in 2016. Most of the macroscopic and microscopic neuropathological findings described as characteristic of CTE, in studies published before 2016, were not included in the new criteria for defining the pathology. In the past few years, there has been steadily emerging evidence that the neuropathology described as unique to CTE may not be unique. CTE pathology has been described in individuals with no known participation in collision or contact sports and no known exposure to repetitive neurotrauma. This pathology has been reported in individuals with substance abuse, temporal lobe epilepsy, amyotrophic lateral sclerosis, multiple system atrophy, and other neurodegenerative diseases. Moreover, throughout history, some clinical cases have been described as not being progressive, and there is now evidence that CTE neuropathology might not be progressive in some individuals. Considering the current state of knowledge, including the absence of a series of validated sensitive and specific biomarkers, CTE pathology might not be inexorably progressive or specific to those who have experienced repetitive neurotrauma.

Premortem Chronic Traumatic Encephalopathy Diagnoses in Professional Football

OBJECTIVE

American-style football (ASF) has gained attention because of possible links between repetitive head injury and neurodegenerative diseases. Although postmortem pathologic changes consistent with chronic traumatic encephalopathy (CTE) have been reported in ASF players, there are currently no established premortem diagnostic criteria for CTE. Nevertheless, presented with symptoms of cognitive impairment, clinicians treating former players may be inclined to suggest CTE without a thorough exploration of comorbid factors that demonstrate similar clinical phenotypes to putative CTE.

METHODS

A survey of 3,913 former ASF players aged 24 to 89 was conducted for those who responded by March 2019.

RESULTS

Despite being a postmortem diagnosis, 108 players (2.8%) self-reported clinician-diagnosed CTE. The percentage of players under age 60 years reporting a CTE diagnosis was 2.3% versus 3.7% in participants age 60 or older. Comorbidities in participants self-reporting CTE were significantly more common, including sleep apnea, hypercholesterolemia, obesity, indicators of past or current depression, hypertension, prescription pain medication use, heart conditions, and low testosterone when compared to non-CTE respondents. Patterns of reporting for obesity, hypertension, heart conditions, or hypercholesterolemia differed between older and younger participants. Cognitive impairment symptoms were significantly higher in participants self-reporting CTE.

INTERPRETATION

Some former professional football players have been clinically diagnosed with CTE, a postmortem condition. Comorbidities that can affect cognition were associated with CTE diagnoses in both older and younger players. Although underlying neuropathology cannot be ruled out, treatable conditions should be explored in former athletes demonstrating CTE-linked clinical phenotypes or symptoms as a means of improving cognitive health in these patients. ANN NEUROL 2020 ANN NEUROL 2020;88:106-112.

Neurobehavioral Symptoms in Community-Dwelling Adults With and Without Chronic Traumatic Brain Injury: Differences by Age, Gender, Education, and Health Condition

Neurobehavioral symptoms after Traumatic Brain Injury (TBI) are prevalent, persist for many years, and negatively affect long-term health, function, and quality of life. Symptoms may differ based on age, gender, education, race, ethnicity, and injury severity. To better understand neurobehavioral functioning after TBI, we need a comprehensive picture of emotional, cognitive, and behavioral symptoms in the context of personal factors that may affect these symptoms. We also need to understand the extent to which these symptoms are specific to TBI, shared across other neurological conditions, or attributable to factors outside of the injury itself. We collected neurobehavioral symptoms via the self-reported Behavioral Assessment Screening Tool (BAST) in a National Cohort of English (n = 2,511) and Spanish speaking (n = 350) community-dwelling adults with and without chronic TBI and other neurological and mental health conditions. The primary focus of the present study was to comprehensively describe neurobehavioral symptoms in adults with and without TBI, broken down by gender and health conditions and then further by age group or educational attainment. As expected, participants with TBI reported more symptoms than Healthy Controls. Regardless of condition, women reported more fatigue, while men reported more substance abuse and impulsivity. Hispanic participants reported more neurobehavioral symptoms than non-Hispanic participants did across health conditions, though primarily Spanish-speakers reported fewer symptoms than English-speakers, suggesting that level of acculturation may contribute to symptom reporting. These data provide a comprehensive characterization of neurobehavioral symptoms in adults with TBI and adults without TBI (healthy controls, adults with other neurological conditions, and adults with mental health conditions).