IMPORTANCE: Head injury is associated with significant short-term morbidity and mortality. Research regarding the implications of head injury for long-term survival in community-dwelling adults ...remains limited. OBJECTIVE: To evaluate the association of head injury with long-term all-cause mortality risk among community-dwelling adults, with consideration of head injury frequency and severity. DESIGN, SETTING, AND PARTICIPANTS: This cohort study included participants with and without head injury in the Atherosclerosis Risk in Communities (ARIC) study, an ongoing prospective cohort study with follow-up from 1987 through 2019 in 4 US communities in Minnesota, Maryland, North Carolina, and Mississippi. Of 15 792 ARIC participants initially enrolled, 1957 were ineligible due to self-reported head injury at baseline; 103 participants not of Black or White race and Black participants at the Minnesota and Maryland field centers were excluded due to race-site aliasing; and an additional 695 participants with missing head injury date or covariate data were excluded, resulting in 13 037 eligible participants. EXPOSURES: Head injury frequency and severity, as defined via self-report in response to interview questions and via hospital-based International Classification of Diseases diagnostic codes (with head injury severity defined in the subset of head injury cases identified using these codes). Head injury was analyzed as a time-varying exposure. MAIN OUTCOMES AND MEASURES: All-cause mortality was ascertained via linkage to the National Death Index. Data were analyzed between August 5, 2021, and October 23, 2022. RESULTS: More than one-half of participants were female (57.7%; 42.3% men), 27.9% were Black (72.1% White), and the median age at baseline was 54 years (IQR, 49-59 years). Median follow-up time was 27.0 years (IQR, 17.6-30.5 years). Head injuries occurred among 2402 participants (18.4%), most of which were classified as mild. The hazard ratio (HR) for all-cause mortality among individuals with head injury was 1.99 (95% CI, 1.88-2.11) compared with those with no head injury, with evidence of a dose-dependent association with head injury frequency (1 head injury: HR, 1.66 95% CI, 1.56-1.77; 2 or more head injuries: HR, 2.11 95% CI, 1.89-2.37) and severity (mild: HR, 2.16 95% CI, 2.01-2.31; moderate, severe, or penetrating: HR, 2.87 95% CI, 2.55-3.22). Estimates were similar by sex and race, with attenuated associations among individuals aged 54 years or older at baseline. CONCLUSIONS AND RELEVANCE: In this community-based cohort with more than 3 decades of longitudinal follow-up, head injury was associated with decreased long-term survival time in a dose-dependent manner, underscoring the importance of measures aimed at prevention and clinical interventions to reduce morbidity and mortality due to head injury.
This prospective cohort study examined the relationship between a panel of four serum proteomic biomarkers (glial fibrillary acidic protein GFAP, ubiquitin C-terminal hydrolase-L1 UCH-L1, total Tau, ...and neurofilament light chain polypeptide NF-L) in 52 players from two different cohorts of male collegiate student football athletes from two different competitive seasons of Division I National Collegiate Athletic Association Football Bowl Subdivision. This study evaluated changes in biomarker concentrations (as indicators of brain injury) over the course of the playing season (pre- and post-season) and also assessed biomarker concentrations by player position using two different published classification systems. Player positions were divided into: 1) speed (quarterbacks, running backs, halfbacks, fullbacks, wide receivers, tight ends, defensive backs, safety, and linebackers) versus non-speed (offensive and defensive linemen), and 2) “Profile 1” (low frequency/high strain magnitudes positions including quarterbacks, wide receivers, and defensive backs), “Profile 2” (mid-range impact frequency and strain positions including linebackers, running backs, and tight ends), and “Profile 3” (high frequency/low strains positions including defensive and offensive linemen). There were significant increases in GFAP 39.3 to 45.6 pg/mL and NF-L 3.5 to 5.4 pg/mL over the course of the season (
p
< 0.001) despite only five players being diagnosed with concussion. UCH-L1 decreased significantly, and Tau was not significantly different. In both the pre- and post-season blood samples Tau and NF-L concentrations were significantly higher in speed versus non-speed positions. Concentrations of GFAP, Tau, and NF-L increased incrementally from “Profile 3,” to “Profile 2” to “Profile 1” in the post-season. UCH-L1 did not. GFAP increased (by Profiles 3, 2, 1) from 42.4 to 49.6 to 78.2, respectively (
p
= 0.051). Tau increased from 0.37 to 0.61 to 0.67, respectively (
p
= 0.024). NF-L increased from 3.5 to 4.9 to 8.2, respectively (
p
< 0.001). Although GFAP and Tau showed similar patterns of elevations by profile in the pre-season samples they were not statistically significant. Only NF-L showed significant differences between profiles 2.7 to 3.1 to 4.2 in the pre-season (
p
= 0.042). GFAP, Tau, and NF-L concentrations were significantly associated with different playing positions with the highest concentrations in speed and “Profile 1” positions and the lowest concentrations were in non-speed and “Profile 3” positions. Blood-based biomarkers (GFAP, Tau, NF-L) provide an additional layer of injury quantification that could contribute to a better understanding of the risks of playing different positions.
Objective
The present study explored the relationship between specific types of postconcussion symptoms and cognitive outcomes in student–athletes with chronic concussion symptoms.
Method
Forty ...student–athletes with chronic concussion symptoms were given a battery of neuropsychological tests and rated themselves on a variety of postconcussion symptoms, which included the following factors derived from prior work: Physical, Sleep, Cognitive, Affective, and Headache. Cognitive outcomes included performance on composites for the memory and attention/executive functioning speed tests, respectively. The following covariates were also explored: Sex, depression symptoms, number of previous concussions, and time since injury.
Results
Headache was the only individual symptom factor that significantly (p < .05) predicted worse attention/executive functioning performance. None of the symptom factors were significantly related to memory performance over and above the variable of time since injury, such that longer time since injury was related to worse memory performance.
Conclusion
Comparable to work examining symptom predictors of cognitive outcomes in acutely concussed samples, headache predicted worse attention/executive functioning performance. Additionally, we found that the longer athletes had been symptomatic since injury, the “worse” their memory functioning. Understanding how headache and the length of time an individual is symptomatic are related to cognitive outcomes can help inform treatment and recommendations for athletes with prolonged symptom recovery.
Introduction
Neurovascular decoupling is a common consequence after brain injuries like sports-related concussion. Failure to appropriately match cerebral blood flow (CBF) with increases in metabolic ...demands of the brain can lead to alterations in neurological function and symptom presentation. Therapeutic hypothermia has been used in medicine for neuroprotection and has been shown to improve outcome. This study aimed to examine the real time effect of selective head cooling on healthy controls and concussed athletes via magnetic resonance spectroscopy (MRS) and arterial spin labeling (ASL) measures.
Methods
24 participants (12 controls; 12 concussed) underwent study procedures including the Post-Concussion Symptom Severity (PCSS) Rating Form and an MRI cooling protocol (pre-cooling (T1 MPRAGE, ASL, single volume spectroscopy (SVS)); during cooling (ASL, SVS)).
Results
Results showed general decreases in brain temperature as a function of time for both groups. Repeated measures ANOVA showed a significant main effect of time (
F
= 7.94,
p
< 0.001) and group (
F
= 22.21,
p
< 0.001) on temperature, but no significant interaction of group and time (
F
= 1.36,
p
= 0.237). CBF assessed via ASL was non-significantly lower in concussed individuals at pre-cooling and generalized linear mixed model analyses demonstrated a significant main effect of time for the occipital left ROI (
F
= 11.29,
p
= 0.002) and occipital right ROI (
F
= 13.39,
p
= 0.001). There was no relationship between any MRI metric and PCSS symptom burden.
Discussion
These findings suggest the feasibility of MRS thermometry to monitor alterations of brain temperature in concussed athletes and that metabolic responses in response to cooling after concussion may differ from controls.
Falls are a leading cause of head injury among older adults, but the risk of fall occurring after a head injury is less well-characterized. We sought to examine the association between head injury ...and subsequent risk of falls requiring hospital care among community-dwelling older adults.
This analysis included 13,081 participants in the Atherosclerosis Risk in Communities Study enrolled in 1987-1989 and followed through 2019. The association of head injury (time-varying exposure, self-reported and/or ICD-9/10 code identified) with the risk of subsequent (occurring >1-month after head injury) falls requiring hospital care (ICD-9/10 code defined) was modeled using Cox proportional hazards regression. Secondary analyses included Fine and Gray proportional hazards regression to account for the competing risk of death, analysis of head injury frequency and severity, and formal testing for interaction by age, sex, and race. Models were adjusted for age, sex, race/center, education, military service, alcohol consumption, smoking, diabetes, hypertension, and psychotropic medication use.
The mean age of participants at baseline was 54 years, 58% were female, 28% were Black, and 14% had at least one head injury occurring over the study period. Over a median 23 years of follow-up, 29% of participants had a fall requiring medical care. In adjusted Cox proportional hazards models, individuals with head injury had 2.01 (95% CI 1.85-2.18) times the risk of falls compared with individuals without head injury. Accounting for the competing risk of mortality, individuals with head injury had 1.69 (95% CI 1.57-1.82) times the risk of falls compared with individuals without head injury. We observed stronger associations among men compared with women (men: hazard ratio HR = 2.60, 95% CI 2.25-3.00; women: HR = 1.80, 95% CI 1.63-1.99,
-interaction <0.001). We observed evidence of a dose-response association for head injury number and severity with fall risk (1 injury: HR = 1.68, 95% CI 1.53-1.84; 2+ injuries: HR = 2.37, 95% CI 1.92-2.94 and mild: HR = 1.97, 95% CI 1.78-2.18; moderate/severe/penetrating: HR = 2.50, 95% CI 2.06-3.02).
Among community-dwelling older adults followed over 30 years, head injury was associated with subsequent falls requiring medical care. We observed stronger associations among men and with increasing number and severity of head injuries. Whether older individuals with head injury might benefit from fall prevention measures should be a focus of future research.
Older adults have the highest rates of head injury and are at the greatest risk for subsequent dysfunction, yet research on subsequent physical decline is limited. We sought to examine ...cross-sectional and prospective associations of head injury with physical functioning and frailty among older adults.
A total of 5 598 Atherosclerosis Risk in Communities Study participants from Visit 5 (2011-13) underwent assessments of physical functioning (Short Physical Performance Battery SPPB, comprised of gait speed, chair stands, and balance) and frailty (defined using established criteria) were followed through Visit 7 (2018-19). Head injury was self-reported or based on ICD-9 codes. Adjusted linear and multinomial logistic regression models were used to estimate associations. Prospective models incorporated inverse probability of attrition weights to account for death or attrition.
Participants were a mean age of 75 years, 58% were women, 22% were Black, and 27% had a prior head injury. Compared to individuals without head injury, individuals with head injury had worse physical functioning (SPPB total score, β-coefficient = -0.22, 95% CI: -0.35 to -0.09) and were more likely to be pre-frail (OR = 1.19, 95% CI: 1.04 to 1.35) or frail (OR = 1.40, 95% CI: 1.08 to 1.80) compared to robust. Prospectively, head injury was associated with a 0.02 m/s greater decline (95% CI: -0.04 to -0.01) in gait speed over a median of 5 years. Among baseline robust individuals (n = 1 847), head injury was associated with increased odds of becoming pre-frail (OR = 1.32, 95% CI: 1.04 to 1.67) or frail (OR = 1.92, 95% CI: 1.05 to 3.51) compared to robust.
Older adults with prior head injury had worse physical functioning and greater frailty at baseline and were more likely to become frail and walk slower over time, compared to individuals without head injury.
To investigate sleep disturbances and circadian timing changes on functional and physiological correlates specifically in collegiate athletes.
Scoping Review.
PubMed MEDLINE, SPORT-Discus, CINAHL, ...ERIC ProQuest, Web of Science.
Articles in English, studying college athletes 18–24 years old, employing a sleep measurement, and a comparison measure of cognitive, academic performance, athletic performance, injury rate, biomarkers and physiological measures, or imaging.
Thirty articles met inclusion criteria. There was wide range of study design, sport studied, modality used to measure sleep, frequency of sleep measurements, and functional and physiological outcomes across studies. Sleep measurements varied greatly in frequency of data collection and type of measurement tool, with the majority using a sleep questionnaire. While all variables of interest were represented within the review, most had a focus on cognitive performance, athletic performance, or injury rate as a function of sleep. Studies using biomarkers and physiological measures or imaging were largely underrepresented. Few studies used biomarkers and physiological measures, and one study used imaging measures. Most studies in this review reported negative cognitive and academic outcomes with worse sleep quality and quantity.
Sleep is critical to maintaining optimal health and collegiate athletes represent a unique population given their unique time constraints, stresses, and sleep behaviors. Findings on athletic performance and injury rate as a function of sleep were mixed. Employing standardized objective methodologies in future work will allow for better understanding of the influence of sleep on the overall well-being and performance of college athletes.
•First systematic approach reviewing effect of sleep on outcomes in college athletes.•Healthy sleep is critical to optimal athlete health and performance.•Most studies examined cognitive performance, athletic performance, or injury rate.•Most studies reported negative cognitive and academic outcomes with poor sleep.•Measures of sleep acquisition and outcome varied greatly across studies.
The cumulative effect of repetitive subconcussive collisions on the structural and functional integrity of the brain remains largely unknown. Athletes in collision sports, like football, experience a ...large number of impacts across a single season of play. The majority of these impacts, however, are generally overlooked, and their long-term consequences remain poorly understood. This study sought to examine the effects of repetitive collisions across a single competitive season in NCAA Football Bowl Subdivision athletes using advanced neuroimaging approaches. Players were evaluated before and after the season using multiple MRI sequences, including T
-weighted imaging, diffusion tensor imaging (DTI), arterial spin labeling (ASL), resting-state functional MRI (rs-fMRI), and susceptibility weighted imaging (SWI). While no significant differences were found between pre- and post-season for DTI metrics or cortical volumes, seed-based analysis of rs-fMRI revealed significant (
< 0.05) changes in functional connections to right isthmus of the cingulate cortex (ICC), left ICC, and left hippocampus. ASL data revealed significant (
< 0.05) increases in global cerebral blood flow (CBF), with a specific regional increase in right postcentral gyrus. SWI data revealed that 44% of the players exhibited outlier rates (
< 0.05) of regional decreases in SWI signal. Of key interest, athletes in whom changes in rs-fMRI, CBF and SWI were observed were more likely to have experienced high G impacts on a daily basis. These findings are indicative of potential pathophysiological changes in brain integrity arising from only a single season of participation in the NCAA Football Bowl Subdivision, even in the absence of clinical symptoms or a diagnosis of concussion. Whether these changes reflect compensatory adaptation to cumulative head impacts or more lasting alteration of brain integrity remains to be further explored.
Traumatic brain injury (TBI) triggers progressive neurodegeneration resulting in brain atrophy that continues months‐to‐years following injury. However, a comprehensive characterization of the ...spatial and temporal evolution of TBI‐related brain atrophy remains incomplete. Utilizing a sensitive and unbiased morphometry analysis pipeline optimized for detecting longitudinal changes, we analyzed a sample consisting of 37 individuals with moderate‐severe TBI who had primarily high‐velocity and high‐impact injury mechanisms. They were scanned up to three times during the first year after injury (3 months, 6 months, and 12 months post‐injury) and compared with 33 demographically matched controls who were scanned once. Individuals with TBI already showed cortical thinning in frontal and temporal regions and reduced volume in the bilateral thalami at 3 months post‐injury. Longitudinally, only a subset of cortical regions in the parietal and occipital lobes showed continued atrophy from 3 to 12 months post‐injury. Additionally, cortical white matter volume and nearly all deep gray matter structures exhibited progressive atrophy over this period. Finally, we found that disproportionate atrophy of cortex along sulci relative to gyri, an emerging morphometric marker of chronic TBI, was present as early as 3 month post‐injury. In parallel, neurocognitive functioning largely recovered during this period despite this pervasive atrophy. Our findings demonstrate msTBI results in characteristic progressive neurodegeneration patterns that are divergent across regions and scale with the severity of injury. Future clinical research using atrophy during the first year of TBI as a biomarker of neurodegeneration should consider the spatiotemporal profile of atrophy described in this study.
Traumatic brain injury (TBI) triggers progressive neurodegeneration resulting in brain atrophy that continues months‐to‐years following injury. Our findings demonstrate msTBI results in characteristic progressive neurodegeneration patterns that are divergent across regions and scale with the severity of injury. Future clinical research using atrophy during the first year of TBI as a biomarker of neurodegeneration should consider the spatiotemporal profile of atrophy described in this study.
PDF
