More Than Skin Deep: Patient-Provider Racial and Ethnic Concordance and Discordance in Collegiate Athletics and Concussion Management.

CONTEXT: There is strong evidence that racial and ethnic disparities exist in multiple arenas of health and wellness. The causes of racial and ethnic differences in healthcare are multi- dimensional, one factor that may impact injury/illness communication, interactions, and outcomes is patient-provider racial and ethnic concordance. At present, it is unclear what role patient-provider racial and ethnic concordance and discordance plays in facilitating concussion care for collegiate athletes. OBJECTIVE: Investigate the presence of athlete-athletic trainer (AT) racial and ethnic concordance and discordance amongst diagnosed concussion cases, and examine if racial and ethnic concordance and discordance influences time (in days) until diagnosis, symptom resolution, or return-to-sport clinical milestones in collegiate athletes. DESIGN: Retrospective cohort study. SETTING: Collegiate athletics. PATIENTS OR OTHER PARTICIPANTS: A total of 694 concussion cases [38.6% (n=268) sustained by women, 61.4% (n=426) sustained by men] that occurred within the 2015-2016 through 2019- 2020 sport seasons at 9 institutions. MAIN OUTCOME MEASURE(S): The number of days from date of injury to diagnosis, symptom resolution, and return-to-sport; and from date of diagnosis to symptom resolution and return-to- sport. RESULTS: Overall, 68.4% (n=475) of concussion cases had patient-provider racial and ethnic concordance and 31.6% (n =219) were discordant. All concordant pairs included a White athlete and White AT. Time to diagnosis differed between the concordant and discordant groups (median[IQR]=1[0,2] versus 0[0,1], respectively) only in the model adjusted for sex, sport-type, and availability of an AT (OR[CI95]=1.46[1.07, 1.85]). There were no other group differences. CONCLUSIONS: One-third of concussion cases had athlete-AT racial and ethnic discordance. While this group was diagnosed with a concussion 1-day sooner than the concordant group, no differences were observed for any concussion recovery milestones. These findings suggest that patient-provider racial and ethnic concordance may play a minor role in concussion recognition or reporting, but not necessarily in the management and recovery thereafter.

The influence of ADHD on recovery from sport concussion among collegiate athletes in the United States: LIMBIC MATARS consortium investigation.

OBJECTIVE: The present study aimed to assess the potential influence of a diagnosis of ADHD on concussion recovery among collegiate athletes. DESIGN: Retrospective and cross-sectional. METHODS: Data were extracted retrospectively from medical records across LIMBIC MATARS member institutions (n = 11), representing 1,044 concussion cases among collegiate athletes. After exclusions, 406 concussions were included in our analysis (ADHD: n = 38, age = 20.2 ± 1.67 years, 18.4% female; No ADHD: n = 368, age = 19.8 ± 1.39 years, 40.1% female). Mann-Whitney U tests were used to compare days from injury to diagnosis, symptom resolution, and return to sport among athletes with and without ADHD. RESULTS: No differences were observed for days from concussion until diagnosis (z = -0.33, p = 0.74), until days to symptom resolution (z = -1.30, p = 0.19), or days until return to sport (z = -0.68, p = 0.49); among concussion cases with or without a previously reported diagnosis of ADHD. CONCLUSION: Our findings further expand the literature that suggests ADHD is not strongly associated with recovery trajectory following sport concussion in collegiate athletes. Future research should extend these findings to be inclusive of additional preexisting health conditions and moderating effects related to medication usage among diverse athlete levels.

Physical activity and recovery following concussion in collegiate athletes: a LIMBIC MATARS Consortium Investigation.

OBJECTIVE: To investigate whether routine daily activities (RDA), non-prescribed exercise (Non-ERx), or prescribed exercise (ERx) were associated with recovery from sport-related concussion (SRC) in collegiate athletes. MATERIALS AND METHODS: Data for this cross-sectional, retrospective chart review of collegiate athletes diagnosed with SRC (n = 285[39.6% female], age = 19.5 ± 1.4 years) were collected during the 2015-16 to 2019-20 athletic seasons. The independent variable was group (RDA, Non-ERx, ERx). Dependent variables included days from date of diagnosis to symptom resolution (Dx-SR) and SR to return to sport (SR-RTS). RESULTS: Those in the Non-ERx group took nearly 1.3 times longer to achieve SR (IRR = 1.28, 95% CI: 1.11, 1.46) and, 1.8 times longer for RTS (IRR = 1.82, 95% CI: 1.11, 2.71) when compared to those in the RDA group. No other comparisons were significant. CONCLUSION: Collegiate athletes in the Non-ERx group took approximately 1 week longer to achieve SR as compared to the RDA and ERx groups. Our findings suggest that if exercise is recommended following SRC, it must be clearly and specifically prescribed. If exercise parameters cannot be prescribed, or monitored, RDA appear to be similarly beneficial during recovery for collegiate athletes with concussion.

CARE4Kids Study: Endophenotypes of Persistent Post-Concussive Symptoms in Adolescents: Study Rationale and Protocol.

Treatment of youth concussion during the acute phase continues to evolve, and this has led to the emergence of guidelines to direct care. While symptoms after concussion typically resolve in 14-28 days, a portion (∼20%) of adolescents endorse persistent post-concussive symptoms (PPCS) beyond normal resolution. This report outlines a study implemented in response to the National Institute of Neurological Diseases and Stroke call for the development and initial clinical validation of objective biological measures to predict risk of PPCS in adolescents. We describe our plans for recruitment of a Development cohort of 11- to 17-year-old youth with concussion, and collection of autonomic, neurocognitive, biofluid, and imaging biomarkers. The most promising of these measures will then be validated in a separate Validation cohort of youth with concussion, and a final, clinically useful algorithm will be developed and disseminated. Upon completion of this study, we will have generated a battery of measures predictive of high risk for PPCS, which will allow for identification and testing of interventions to prevent PPCS in the most high-risk youth.

Impact of Playing Surface on Concussion Symptoms in Young American Football Players.

OBJECTIVE: It has been suggested that sport-related concussion (SRC) occurs more commonly on natural grass compared with artificial turf in contact sports. As playing surface is a potentially modifiable risk factor, this study sought to identify differences in symptoms following SRC on these 2 surfaces in a sample of young American football players. DESIGN: Prospective. SETTING: Part of the multi-institutional North Texas Concussion Registry (ConTex) research project. PARTICIPANTS: Ten-year-old to 24-year-old male American football players (n = 62) who had sustained a helmet-to-ground SRC and presented to a specialty concussion clinic within 14 days of injury. INDEPENDENT VARIABLES: Helmeted impact with grass (n = 33) or artificial turf (n = 29). MAIN OUTCOME MEASURES: Severity and number of symptoms endorsed on the Sport Concussion Assessment Tool 5th Edition (SCAT5) Symptom Evaluation at the time of initial clinical evaluation. RESULTS: Both groups were similar in mean time since injury, concussion history, and history of headache, but the artificial turf group was slightly older, with a mean age of 14.6 versus 13.6 years (P = 0.039). Athletes who sustained a SRC on grass reported significantly higher mean total symptom severity scores (26.6 vs 11.6, P = 0.005) and total number of symptoms (10.3 vs 5.9, P = 0.006) compared with those who were injured on artificial turf. CONCLUSIONS: This may be the first study to examine postconcussive symptoms after SRC as they relate to playing surface. This small sample of young American football players reported higher symptom severity scores and higher total number of symptoms after SRC on natural grass compared with artificial turf.

Acute evaluation of sport-related concussion and implications for the Sport Concussion Assessment Tool (SCAT6) for adults, adolescents and children: a systematic review.

OBJECTIVES: To systematically review the scientific literature regarding the acute assessment of sport-related concussion (SRC) and provide recommendations for improving the Sport Concussion Assessment Tool (SCAT6). DATA SOURCES: Systematic searches of seven databases from 2001 to 2022 using key words and controlled vocabulary relevant to concussion, sports, SCAT, and acute evaluation. ELIGIBILITY CRITERIA: (1) Original research articles, cohort studies, case-control studies, and case series with a sample of >10; (2) ≥80% SRC; and (3) studies using a screening tool/technology to assess SRC acutely (<7 days), and/or studies containing psychometric/normative data for common tools used to assess SRC. DATA EXTRACTION: Separate reviews were conducted involving six subdomains: Cognition, Balance/Postural Stability, Oculomotor/Cervical/Vestibular, Emerging Technologies, and Neurological Examination/Autonomic Dysfunction. Paediatric/Child studies were included in each subdomain. Risk of Bias and study quality were rated by coauthors using a modified SIGN (Scottish Intercollegiate Guidelines Network) tool. RESULTS: Out of 12 192 articles screened, 612 were included (189 normative data and 423 SRC assessment studies). Of these, 183 focused on cognition, 126 balance/postural stability, 76 oculomotor/cervical/vestibular, 142 emerging technologies, 13 neurological examination/autonomic dysfunction, and 23 paediatric/child SCAT. The SCAT discriminates between concussed and non-concussed athletes within 72 hours of injury with diminishing utility up to 7 days post injury. Ceiling effects were apparent on the 5-word list learning and concentration subtests. More challenging tests, including the 10-word list, were recommended. Test-retest data revealed limitations in temporal stability. Studies primarily originated in North America with scant data on children. CONCLUSION: Support exists for using the SCAT within the acute phase of injury. Maximal utility occurs within the first 72 hours and then diminishes up to 7 days after injury. The SCAT has limited utility as a return to play tool beyond 7 days. Empirical data are limited in pre-adolescents, women, sport type, geographical and culturally diverse populations and para athletes. PROSPERO REGISTRATION NUMBER: CRD42020154787.

No association between age beginning tackle football, or years played and neurocognitive performance later-in-life among older National Football League retirees.

OBJECTIVE: In a retrospective cohort, we evaluated whether age beginning tackle football (ABTF) and more total years of playing football (TYPF) were associated with worse later-in-life neuropsychological change among older retired National Football League (NFL) players. METHOD: Participants were 19 older NFL retirees aged 54-79, including 12 who returned for follow-up evaluation 15-51 months later. Mixed-linear models evaluated the association between ABTF/TYFP and baseline neuropsychological composite scores (executive functioning/attention/speed, language, memory), and neuropsychological composites over time. RESULTS: ABTF and TYPF were not significantly associated with neuropsychological composites at baseline or over time (all p's > .05). There were no significant differences in neuropsychological performance between those ABTF <12 and ≥ 12 years old (all p's ≥ .475) or between those with TYPF <19 or ≥ 19 years played (median split; all p's ≥ .208). CONCLUSIONS: Preliminary findings suggest that ABTF and TYPF does not worsen neurocognitive decline later-in-life among older NFL retirees.

Early vs. delayed evaluation and persisting concussion symptoms during recovery in adults.

Objective: Persisting concussion symptoms may adversely affect return to work and functioning in daily activities. This study compared adults who were initially evaluated < 30 days versus those evaluated ≥ 30 days following a concussion at a specialty concussion clinic to determine if delayed initial evaluation is associated with persisting symptoms during recovery. Method: Participants (N = 205) 18 years of age and older who sustained a concussion and presented to a North Texas Concussion Registry (ConTex) clinic were evaluated at two time points: initial clinical visit and three-month follow-up. Participants provided medical history, injury related information, and completed the Sport Concussion Assessment Tool-5 Symptom Evaluation, Generalized Anxiety Disorder 7-item scale (GAD-7), and Patient Health Questionnaire (PHQ-8). Participants were divided into two groups: early and delayed evaluation (±30 days post injury). Results: Number and severity of concussion symptoms were similar between both groups at their initial clinical visit. However, linear regression models showed that a delayed clinical evaluation was associated with a greater number and severity of concussion symptoms along with greater aggravation of symptoms from physical and cognitive activity at three-month follow-up. Conclusions: Individuals who sought care at specialty concussion clinics regardless of previous care 30 or more days following their injury reported more serious persisting concussion symptoms at three month follow-up than those who sought care sooner. Education to improve adults' recognition of concussions when they occur and obtaining earlier clinical evaluation may represent important opportunities in promoting better recovery and reducing persisting concussion symptoms.

Recovery in children ages 5-10 years at three months post-concussion.

Some children and adolescents have persistent concussion symptoms that extend beyond the typical 3-4 week recovery window. Our understanding about what to expect when recovery is atypical, particularly in elementary-age children, is incomplete because there are very few targeted studies of this age group in the published literature. Aims were to identify lingering symptoms that present at three months post-concussion and to determine what factors are associated with prolonged recovery in an elementary-age group. Participants were 123 children aged 5-10 years who were seen at specialized concussion clinics, divided into expected and late recovery groups. Parents rated concussion symptoms on a scale from the Sideline Concussion Assessment Tool-5 (SCAT-5). The most frequent symptoms were headache, irritability, feeling more emotional, and sensitivity to noise. Stepwise logistic regression determined that female sex and total symptom burden at initial visit, but not any specific symptom, predicted prolonged recovery. Clinicians are advised to carefully monitor children who report numerous symptoms after concussion, particularly when the concussed children are girls.

Neurocognitive outcomes of older National Football League retirees.

OBJECTIVE: Determine if head-injury exposure relates to later-in-life cognitive decline in older National Football League (NFL) retirees. METHOD: NFL retirees (aged 50+) with or without cognitive impairment underwent baseline (n = 53) and follow-up (n = 29; 13-59 months later) neuropsychological evaluations. Cognitively normal (CN) retirees (n = 26) were age- and education-matched to healthy controls (n = 26). Cognitively impaired (CI) retirees with mild cognitive impairment or dementia (n = 27) were matched to a clinical sample (CS) by age, sex, education, and diagnosis (n = 83). ANOVAs compared neuropsychological composites at baseline and over time between retirees and their matched groups. Regression models evaluated whether concussions, concussions with loss of consciousness (LOC), or games played predicted neuropsychological functioning. RESULTS: At baseline, CN retirees had slightly worse memory than controls (MCN retirees = 50.69, SECN retirees = 1.320; MHealthy controls = 57.08, SEHealthy controls = 1.345; p = 0.005). No other group diferences were observed, and head-injury exposure did not predict neurocognitive performance at baseline or over time. CONCLUSIONS: Head-injury exposure was not associated with later-in-life cognition, regardless of cognitive diagnosis. Some retirees may exhibit lower memory scores compared to age-matched peers, though this is of unclear clinical significance.

Early psychological symptoms predict concussion recovery time in middle and high school athletes.

INTRODUCTION: Lingering concussion symptoms can negatively impact a child's well-being, yet variability in recovery is poorly understood. To aid detection of those at risk for prolonged symptom duration, we explored postconcussion mood and sleep symptoms as predictors of recovery time in adolescent athletes. METHOD: We utilized analyses designed to control for potentially confounding variables, such as concussion severity indicators and premorbid psychiatric history. Participants included 393 adolescent athletes (aged 12-18 years) evaluated in outpatient concussion clinics within 2 weeks after injury. Provider-documented date of symptom resolution was obtained via medical record review. Survival analysis for recovery time was conducted in the total sample, and separately for males and females using prior medical history (psychiatric disorder, prior concussion), injury-related factors (loss of consciousness, post-traumatic amnesia [PTA], concussion symptom severity), and psychological symptoms (General Anxiety Disorder-7 Item Scale, Patient Health Questionnaire-8 Item Depression Scale, Pittsburgh Sleep Quality Index) collected at initial clinic visit. RESULTS: PTA, concussion symptoms, and sleep quality were associated with recovery in the total sample (HRs = 0.64-0.99, ps < .05). When analyzed by sex, only concussion symptoms were associated with recovery for females (with females reporting greater symptom severity than males), while for males PTA and greater depression symptoms were significant predictors of recovery (HRs = 0.54-0.98, ps < .05). CONCLUSIONS: These findings identified differences in symptom presentation between sexes, particularly for mood symptoms, and suggest that assessment of postconcussive symptoms is useful in helping to identify individuals at risk for longer recovery. Continued exploration of post-injury psychological difficulties in athletes is warranted for better concussion management.

Sex differences in reporting of concussion symptoms in adults.

Objective: To examine differences in concussion symptom reporting between female and male adults considering current psychological symptoms such as anxiety and depression and pre-injury factors in order to identify sex differences which may guide treatment efforts. Method: This prospective study is part of the North Texas Concussion Registry (ConTex). Subjects (N = 132) age 19 to 78 years had sustained a concussion within 30 days of clinic visit. The independent variable was sex and covariates included age, ethnicity, current anxiety and depression ratings, history of attention deficit disorder, history of headache/migraine, and time to clinic. The dependent variables were 22 post-concussion symptoms as measured by the Sport Concussion Assessment Tool-5 Post-Concussion Symptom Scale. Results: Analysis of covariance and ordinal logistic regression results both revealed that females had a greater likelihood of reporting increased symptom severity for 15/22 concussion symptoms. The largest risk ratios (effect size) in symptom reporting between sexes (higher symptoms in females) included: feeling more emotional 4.05 (0.72), fatigue or low energy 4.05 (0.72), sensitivity to light 3.74 (0.69), headache 3.65 (0.57), balance problems 3.31 (0.53), pressure in head 3.06 (0.51), and neck pain 2.97 (0.60). Conclusions: Adult females in our sample reported higher levels of many concussion symptoms than males and showed an increased risk of developing these same symptoms following concussion. Examination of the magnitude of sex difference in concussion symptom reporting will better inform medical staff to anticipate and address symptoms that may present greater challenges for adult females.

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.

Sex Differences and Reporting of SCAT-5 Concussion Symptoms in Adolescent Athletes.

OBJECTIVE: To elucidate specific symptoms that may differ between adolescent female and male athletes after a sports-related concussion (SRC) and identify symptoms that may require greater clinical attention by medical and athletic staff. DESIGN: Prospective. SETTING: This study is part of a larger research project conducted at clinics in the North Texas Concussion Network (ConTex) Registry. PARTICIPANTS: Subjects (N = 491) aged 12 to 18 years who sustained a diagnosed SRC within 30 days of clinic visit. INDEPENDENT VARIABLES: Sex (female vs male). Covariates included age, race, current mood (anxiety and depression), learning disability/ADHD, and time to clinic. MAIN OUTCOME MEASURES: Twenty-two individual postconcussion symptoms as measured by the Post-Concussion Symptom Scale from the Sport Concussion Assessment Tool-5 (SCAT-5). RESULTS: Girls endorsed higher levels of anxiety and depression symptoms at initial clinic visit. analysis of covariance results revealed that girls had significantly greater symptom severity of headache, dizziness, sensitivity to light, sensitivity to noise, pressure in the head, feeling slowed down, fatigue, and drowsiness than boys. Ordinal logistic regression results also revealed that girls had significantly greater predicted odds of higher symptom severity on these 8 symptoms and in trouble concentrating than boys. CONCLUSIONS: Closer examination of specific symptoms with attention to patients' current levels of anxiety and depression symptoms may better inform medical and athletic staff to anticipate and address symptoms that may present greater challenges for adolescent girls than boys.

Utility of Brief Psychological Measures for Prediction of Prolonged Symptom Clearance in Concussed Student Athletes.

OBJECTIVE: Variability in recovery time following sport-related concussion (SRC) is poorly understood. We explored the utility of brief mood, anxiety, and sleep questionnaires as postinjury predictors of SRC symptom clearance in adolescents. METHOD: At initial visit 0-2 weeks postinjury, concussed athletes aged 12-18 years self-reported injury/medical factors (prior concussion, loss of consciousness, amnesia, and concussion symptom severity) and were administered psychological symptom measures. At 3 months, medical record review determined return-to-play (RTP) date. Subjects were divided into two datasets, with the first utilized for developing cutoff scores and then validated with the second dataset. RESULTS: A total of 64% of the 141 participants had early RTP (within 21 days postinjury), and 23% had late RTP (postinjury day 30 or later). The Generalized Anxiety Disorder Screener (GAD-7, M = 2.1, SD = 3.1) was the only significant predictor (p = .001), with a 1.4-fold [95% CI 1.2-1.8] increased risk for every point. No other factors in the full model discriminated recovery groups (ps > .05). Receiver operating characteristic curve analysis derived a GAD-7 cut score ≥3 (sensitivity= 56.7%, specificity = 74.2%, AUCs = 0.63-0.79, ps < .001). CONCLUSIONS: Postconcussion anxiety symptoms may help identify individuals at increased risk for prolonged recovery.

Differences in Adolescent Symptom Reporting Following Motor Vehicle Accident Versus Sport-Related Concussion.

OBJECTIVE: To characterize potential differences in youth concussion sustained in motor vehicle accident (MVA) versus sport-related concussion (SRC), hypothesizing that youth who sustain concussion in a MVA would endorse higher initial and persistent symptom scores compared to those with SRC, despite similar injury severity levels. METHODS: Participants age 12-18 who sustained a concussion (i.e., Glasgow Coma Scale = 13-15) in a MVA (n = 35) were matched with SRC participants (n = 35) by sex, age, and days since injury. ANCOVA comparing initial postconcussion total symptom scores between the MVA and SRC groups were performed. Chi-square analysis with injury group by recovery time was used to determine whether youth who sustained concussion from MVA were more likely to endorse symptoms persisting >30 days at 3 months postinjury, and ANCOVA compared 3-month total symptom scores. RESULTS: On average, the MVA group reported significantly higher initial postconcussion and more frequent persistent symptom scores compared to the SRC group. CONCLUSIONS: This is the first known study to examine context of injury in youth concussion while matching for injury severity, age, sex, and days since injury. Findings suggest the context of injury is an important clinical variable related to initial reporting of symptoms and endorsement of symptoms lasting more than 30 days. Tailored interventions that consider the context of injury may facilitate symptom resolution.

Mild Cognitive Impairment in Retired Professional Football Players With a History of Mild Traumatic Brain Injury: A Pilot Investigation.

BACKGROUND: Traumatic brain injury (TBI) is a known risk factor for neurodegenerative dementias such as Alzheimer disease (AD); however, the potential risk of mild cases of TBI, such as concussions, remains unclear. OBJECTIVE: To explore whether a small sample of retired professional athletes with a diagnosis of mild cognitive impairment (MCI)-the prodromal stage of AD-and a history of multiple mild TBIs exhibit greater neuropsychological impairment than age-matched nonathletes with MCI and no history of TBI. METHOD: Ten retired National Football League players diagnosed with MCI and reporting multiple mild TBIs, and 10 nonathletes, also diagnosed with MCI but with no history of TBI, completed a standard neurologic examination and neuropsychological testing. Independent samples t tests were conducted to examine differences in neuropsychological performance between the two groups. RESULTS: The retired athletes with a history of mild TBI obtained generally similar scores to the nonathlete controls on measures of verbal learning and memory, verbal fluency, and processing speed. However, the retired athletes scored lower than the controls on tests of confrontation naming and speeded visual attention. CONCLUSION: Retired athletes with MCI and a history of mild TBI demonstrated similar neuropsychological profiles as nonathlete controls despite lower scores on measures of confrontation naming and speeded visual attention. These findings suggest that a history of multiple mild TBIs does not significantly alter the overall neuropsychological profile of individuals with MCI; confirmation of this will require longitudinal research with larger sample sizes.

Clinical and neuropsychological profile of patients with dementia and chronic traumatic encephalopathy.

OBJECTIVE: To determine whether subjects with chronic traumatic encephalopathy (CTE) and dementia have distinct clinical features compared to subjects with pathologically confirmed Alzheimer's disease (AD). METHODS: Among 339 subjects assessed for CTE in the National Alzheimer's Coordinating Center dataset, 6 subjects with CTE and 25 subjects with AD neuropathologic change matched for age (±5 years) and sex were identified. All subjects had a clinical diagnosis of dementia. Neurological examination, neuropsychological testing and emotional/behavioural data were compared between CTE and AD subjects at the time of dementia diagnosis and last clinical visit near death. RESULTS: A history of traumatic brain injury with loss of consciousness (LOC) was reported in one CTE and one AD subject; information about injuries without LOC or multiple injuries was unavailable. CTE and AD subjects did not differ significantly at the time of diagnosis or last visit on the Unified Parkinson's Disease Rating Scale-Motor Exam, global measures of cognitive functioning (Mini-Mental State Exam and Clinical Dementia Rating Scale), emotional/behaviour symptoms as assessed with the Neuropsychiatric Inventory questionnaire or across neuropsychological measures. All CTE participants had co-occurring neuropathologic processes, including AD and most had TAR DNA-binding protein 43 (TDP-43) neuropathology. CONCLUSIONS: CTE pathology was rare in a large multicentre national dataset, and when present, was accompanied by AD and TDP-43 pathologies. CTE was not associated with a different clinical presentation from AD or with greater cognitive impairment or neurobehavioral symptoms. These findings suggest that CTE may not have a distinct clinical profile when other neuropathologic processes are coexistent with CTE pathology.