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The purpose of this study was to determine changes in neurocognitive, psychosocial, and balance functioning in collegiate male and female soccer players across three consecutive years of baseline testing compared to a control group of non-contact athletes.Generalized estimating equations were used to compare changes in annual, pre-season baseline measures of neurocognitive function, neurobehavioral and psychological symptoms, and postural stability between collegiate soccer players (n = 75; 51 [68%] female soccer players) and non-contact athletes (n = 210; 133 [63%] female non-contact athletes) across three consecutive years.Among all participants, the group-by-time interaction was not significant for any outcome measures. Overall, soccer players reported lower (better) Brief Symptom Inventory 18 Depression (p = 0.004, Exp(B) = 0.36 [95% CI 0.18-0.73]), Global Severity Index (p = 0.006, Exp(B) = 0.53 [95% CI 0.33-0.84]), and Post-Concussion Symptom Scale (PCSS) Symptom Severity (p0.001, Exp(B) = 0.45 [95% CI 0.22-0.95]) scores than non-contact athletes. No other outcome measures were different between soccer players and non-contact athletes.Among collegiate athletes, soccer players report similar or better psychosocial functioning and symptom scores than non-contact athletes. Importantly, neurocognitive functioning, neurobehavioral and psychological symptoms, and postural stability does not worsen over time in collegiate soccer players relative to their non-contact counterparts. Our findings suggest that despite possible exposure to repetitive head impacts (RHIs), collegiate soccer players do not exhibit changes in observable function and symptoms across multiple seasons.

To determine whether cognitive and psychological symptom profiles differentiate clinical diagnostic classifications (eg, history of mild traumatic brain injury [mTBI] and posttraumatic stress disorder [PTSD]) in military personnel.US Active-Duty Service Members ( N = 209, 89% male) with a history of mTBI ( n = 56), current PTSD ( n = 23), combined mTBI + PTSD ( n = 70), or orthopedic injury controls ( n = 60) completed a neuropsychological battery assessing cognitive and psychological functioning. Latent profile analysis was performed to determine how neuropsychological outcomes of individuals clustered together. Diagnostic classifications (ie, mTBI, PTSD, mTBI + PTSD, and orthopedic injury controls) within each symptom profile were examined.A 5-profile model had the best fit. The profiles differentiated subgroups with high (34.0%) or normal (21.5%) cognitive and psychological functioning, cognitive symptoms (19.1%), psychological symptoms (15.3%), and combined cognitive and psychological symptoms (10.0%). The symptom profiles differentiated participants as would generally be expected. Participants with PTSD were mainly represented in the psychological symptom subgroup, while orthopedic injury controls were mainly represented in the high-functioning subgroup. Further, approximately 79% of participants with comorbid mTBI and PTSD were represented in a symptomatic group (∼24% = cognitive symptoms, ∼29% = psychological symptoms, and 26% = combined cognitive/psychological symptoms). Our results also showed that approximately 70% of military personnel with a history of mTBI were represented in the high- and normal-functioning groups.These results demonstrate both overlapping and heterogeneous symptom and performance profiles in military personnel with a history of mTBI, PTSD, and/or mTBI + PTSD. The overlapping profiles may underscore why these diagnoses are often difficult to diagnose and treat, but suggest that advanced statistical models may aid in identifying profiles representing symptom and cognitive performance impairments within patient groups and enable identification of more effective treatment targets.

Traumatic brain injury (TBI), a significant concern in military populations, is associated with alterations in brain structure and function, cognition, as well as physical and psychological dysfunction. Diffusion magnetic resonance imaging (dMRI) is particularly sensitive to changes in brain structure following TBI, as alterations in white matter (WM) microstructure are common. However, dMRI studies in mild TBI (mTBI) are conflicting, likely due to relatively small samples, sample heterogeneity (demographics, pre- and comorbidities) and injury characteristics (mechanism; chronicity). Furthermore, few studies account for brain asymmetry, which may impact cognitive functions subserved by WM tracts. Examining brain asymmetry in large samples may increase sensitivity to detect heterogeneous areas of subtle WM alteration in mTBI.Through the Enhancing Neuroimaging and Genetics through Meta-analysis (ENIGMA) Military-Relevant Brain Injury working group, we conducted a mega-analysis of neuroimaging and clinical data from 16 cohorts of Active Duty Service Members and Veterans (n=2,598; 2,321 males/277 females; age 19-85 years). 1,080 reported a deployment-related TBI, 480 had a history of only non-military-related TBI, 823 reported no history of TBI, and 215 did not differentiate between military and non-military TBI. dMRI data were processed in a harmonized manner along with harmonized demographic, injury, psychiatric, and cognitive measures. Hemispheric asymmetry of fractional anisotropy (FA, a common proxy for myelin organization) was calculated for 19 WM tracts and compared between those with and without TBI history.FA in the cingulum showed greater asymmetry in individuals with a history of deployment-related TBI; this effect was driven by greater left lateralization in the group with TBI. There was a trend towards lower FA of the right cingulum in the TBI group. These results remained significant after accounting for potentially confounding variables including posttraumatic stress disorder, depression, and handedness and were driven primarily by individuals who had sustained their worst TBI before age 40. We further found that alterations in the cingulum were associated with slower processing speed and poorer set shifting.The results indicate an enhancement of the previously reported natural left laterality, possibly due to vulnerability of the non-dominant hemisphere or compensatory mechanisms in the dominant hemisphere. The cingulum is one of the last WM tracts to mature, reaching peak FA around 42 years old. This effect was primarily detected in individuals whose worst injury occurred before age 40, suggesting that the protracted development of the cingulum may lead to increased vulnerability to insults, such as TBI.

Context Researchers have identified sex differences in sport-related concussion incidence and recovery time; however, few have examined sex differences in specific recovery trajectories: time to symptom resolution, return to academics, and return to athletic activity across collegiate sports. Objective To examine sex differences in sport-related concussion recovery trajectories across a number of club and varsity sports with different levels of contact. Design Descriptive epidemiology study. Setting Collegiate varsity and club sports. Patients or Other Participants Sport-related concussions sustained by student-athletes (n = 1974; women = 38.8%) participating in Ivy League sports were monitored between 2013–2014 and 2018–2019. Main Outcome Measure(s) Athletic trainers collected concussive injury and recovery characteristics as part of the Ivy League–Big Ten Epidemiology of Concussion Study's surveillance system. Time to symptom resolution, return to academics, and return to limited and full sport participation were collected. Survival analyses determined the time from injury to each recovery outcome for male and female athletes by sport. Peto tests were used to compare recovery outcomes between men's and women's sports and by sport. Results The median (interquartile range [IQR]) was 9 days (IQR = 4–18 days) for time to symptom resolution overall, 8 days (IQR = 3–15 days) for return to academics, 12 days (IQR = 8–23 days) for return to limited sport participation, and 16 days (IQR = 10–29 days) for return to full sport participation. We observed differences overall between sexes for median time to symptom resolution (men = 8 days [IQR = 4–17 days], women = 9 days [IQR = 5–20 days]; P = .03) and return to academics (men = 7 days [IQR = 3–14 days], women = 9 days [IQR = 4–17 days]; P < .001) but not for median time to return to athletics (limited sport participation: P = .12, full sport participation: P = .58). Within-sport comparisons showed that women's lacrosse athletes had longer symptom resolution (P = .03) and return to academics (P = .04) compared with men's lacrosse athletes, whereas men's volleyball athletes took longer to return to limited (P = .02) and full (P = .049) sport participation than women's volleyball athletes. Conclusions Recovery timelines between sexes were different. Athletes in women's sports experienced longer symptom durations and time to return to academics compared with men's sports, but athletes in men's and women's sports presented similar timelines for return to athletics.

Soccer athletes frequently experience repetitive head impacts (RHI) during games and practices, which may affect neural integrity over time and lead to altered brain structure. Neck strength is hypothesized to limit the transfer of force to the brain and decrease the effect of RHI on brain structure. The goal of our work was to examine whether greater neck strength is associated with more intact white matter organization (WMO) in collegiate athletes exposed to RHI. Collegiate soccer (n = 17) and limited/non-contact sport (n = 39) athletes were assessed prior to their athletic seasons. Participants completed neck strength assessments using handheld dynamometry in six test positions and diffusion tensor imaging. Fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) were calculated for 20 white matter (WM) regions. A multi-variate approach was used to examine the relationship between neck strength and diffusion measures in soccer and limited/non-contact athletes. Neck strength was positively associated with FA and negatively associated with RD across several WM regions in soccer players only. Neck strength was not significantly associated with MD or AD in either group. Greater neck strength was related to more intact WMO in athletes with high exposure to RHI, particularly in regions prone to damage from brain trauma such as the basal ganglia, superior longitudinal fasciculus, and frontoparietal WM. Future studies should examine neck strength as a factor to moderate neural outcomes in athletes with exposure to RHI.

Sport-related brain injury is very common, and the potential long-term effects include a wide range of neurological and psychiatric symptoms, and potentially neurodegeneration. Around the globe, researchers are conducting neuroimaging studies on primarily homogenous samples of athletes. However, neuroimaging studies are expensive and time consuming, and thus current findings from studies of sport-related brain injury are often limited by small sample sizes. Further, current studies apply a variety of neuroimaging techniques and analysis tools which limit comparability among studies. The ENIGMA Sports Injury working group aims to provide a platform for data sharing and collaborative data analysis thereby leveraging existing data and expertise. By harmonizing data from a large number of studies from around the globe, we will work towards reproducibility of previously published findings and towards addressing important research questions with regard to diagnosis, prognosis, and efficacy of treatment for sport-related brain injury. Moreover, the ENIGMA Sports Injury working group is committed to providing recommendations for future prospective data acquisition to enhance data quality and scientific rigor.

Digital neuropsychological test batteries are popular in college athletics; however, well-validated digital tests that are short and portable are needed to expand the feasibility of performing cognitive testing quickly, reliably, and outside standard clinical settings. This study assessed performance on digital versions of Trail Making Test (dTMT) and a modified Symbol Digit Modalities Test (dSDMT) in uninjured collegiate athletes (n = 537; 47% female) using the C3Logix baseline assessment module. Time to complete (dTMT) and the number of correct responses (dSDMT) were computed, transformed into z scores, and compared to age-matched normative data from analogous paper-and-pencil tests. Overall sample performance was compared to normative sample performance using Cohen's d. Sample averages on the dTMT, Part A, and dSDMT were similar to published norms; 97 and 92% of z scores fell within 2 standard deviations of normative means, respectively. The sample averaged faster completion times on dTMT, Part B than published norms, although 98% of z scores were within 2 standard deviations of the normative means. Brief, digitized tests may be useful in populations and testing environments when longer cognitive test batteries are impractical. Future studies should assess the ability of these tests to detect clinically relevant changes following a suspected head injury.

INTRODUCTION: Impairments in cognitive performance after sports-related concussion (SRC) typically resolve within weeks of the injury, whereas alterations to white matter (WM) organization have been found to persist longer into the chronic injury stage. However, longer-term associations between cognition and WM organisation following SRC have not been studied. The objective of this study was to compare WM organisation and cognitive performance in collegiate athletes an average of almost 4 years post-SRC to athletes with no history of SRC. METHOD: National Collegiate Athletic Association Division III athletes (n = 71, age = 19.3 +/− 1.2; 14 with self-reported SRC) completed a neurocognitive assessment and diffusion tensor imaging (DTI). WM organisation was assessed by extracting measures of fractional anisotropy (FA), mean diffusivity (MD), and radial diffusivity (RD) from 20 WM regions of interest (ROIs). Multivariate partial least squares analyses were used to compare athletes with and without a history of SRC and assess relationships between DTI-derived metrics of WM organisation and cognitive measures. RESULTS: Cognitive performance and ROI metrics did not differ between athletes with and without prior SRC. However, among athletes with a history of SRC, better executive function, processing speed, and memory but worse choice reaction time were associated with higher FA and lower MD and RD in several WM tracts. CONCLUSION: Athletes with a history of SRC demonstrated greater associations between cognitive performance and WM organization, but also variability in the domains showing associations. Taken together, the findings demonstrate the importance of examining brain-behaviour relationships several years after SRC to better gauge how WM organisation supports cognition.

BACKGROUND Individualized baseline testing is resource and time intensive. The use of normative data to approximate changes after a suspected concussion is thus an appealing alternative. Yet, few peer-reviewed, large-sample studies are available from which to develop accurate normative averages of balance using force-plate technology. PURPOSE This study sought to validate a normative dataset from the force-plate manufacturer and examine the magnitude and nature of sample variability. STUDY DESIGN Cross-sectional. METHODS Baseline balance and self-reported sex, sport, and concussion history were assessed in 533 prospective collegiate athletes (45% female) during pre-participation physical examinations. Balance was measured using four stances from the modified Clinical Test of Sensory Interaction and Balance and quantified as Sway Index Scores with the Biodex Biosway Portable Balance System. Group averages are contrasted to data from the force-plate manufacturer. Individual variability around these averages was visualized and analyzed by sex and sport. RESULTS Male student athletes showed significantly more sway in the eyes open, soft stance condition than female athletes. These differences were maintained when concussion history was included as a covariate. Athletes, particularly male athletes, in the high versus low contact sport group showed significantly more sway in the eyes open, soft surface and the eyes closed, hard and soft surface stances. CONCLUSION There was substantial individual variability that was partially explained by sex differences and sport differences. The development of normative averages for sway may benefit from consideration of sex and sport. Further studies should characterize other factors that influence baseline balance in collegiate athletes. LEVEL OF EVIDENCE 2b, This study sought to validate a normative dataset from the force-plate manufacturer and examine the magnitude and nature of sample variability.

BACKGROUND Menstrual irregularity (MI) is common in female athletes and is a component of the Female Athlete Triad (Triad). Many athletes with the Triad are started on hormonal contraceptives (HC) for MI, but this interferes with the ability to monitor menstrual cycle regularity and can mask other causes of MI. There are limited studies investigating the relationship between MI, HC use, and injury in female collegiate athletes. OBJECTIVE To examine the prevalence of and relationship between HC use, MI, and bone stress injuries in female collegiate athletes in the United States. DESIGN Cross-sectional study. SETTING Online survey. PARTICIPANTS 1020 U.S. female collegiate athletes (age ≥ 18 years). METHODS OR INTERVENTIONS Assessment of risk factors for menstrual irregularity and bone stress injuries was conducted via a one-time survey. MAIN OUTCOME MEASURES HC use, MI, history of stress fractures. RESULTS Current HC use prevalence was 65% (95% confidence interval [CI], 61.9%, 67.8%). Of all athletes, 47% reported past MI. Of the athletes who were not currently using HCs, 32% had current MI. Compared with athletes without past MI, more athletes with past MI reported current HC use (73% vs. 57%) and indicated menstrual cycle consistency as the primary reason for use (24% vs. 4%) (P

This review summarizes the last decade of work by the ENIGMA (Enhancing NeuroImaging Genetics through Meta Analysis) Consortium, a global alliance of over 1400 scientists across 43 countries, studying the human brain in health and disease. Building on large-scale genetic studies that discovered the first robustly replicated genetic loci associated with brain metrics, ENIGMA has diversified into over 50 working groups (WGs), pooling worldwide data and expertise to answer fundamental questions in neuroscience, psychiatry, neurology, and genetics. Most ENIGMA WGs focus on specific psychiatric and neurological conditions, other WGs study normal variation due to sex and gender differences, or development and aging; still other WGs develop methodological pipelines and tools to facilitate harmonized analyses of “big data” (i.e., genetic and epigenetic data, multimodal MRI, and electroencephalography data). These international efforts have yielded the largest neuroimaging studies to date in schizophrenia, bipolar disorder, major depressive disorder, post-traumatic stress disorder, substance use disorders, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, autism spectrum disorders, epilepsy, and 22q11.2 deletion syndrome. More recent ENIGMA WGs have formed to study anxiety disorders, suicidal thoughts and behavior, sleep and insomnia, eating disorders, irritability, brain injury, antisocial personality and conduct disorder, and dissociative identity disorder. Here, we summarize the first decade of ENIGMA’s activities and ongoing projects, and describe the successes and challenges encountered along the way. We highlight the advantages of collaborative large-scale coordinated data analyses for testing reproducibility and robustness of findings, offering the opportunity to identify brain systems involved in clinical syndromes across diverse samples and associated genetic, environmental, demographic, cognitive, and psychosocial factors. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material.

Participation in sport is associated with numerous physical and psychological health benefits, but also can have negative consequences, such as career ending injuries, which may have long-term effects on mental health. Recent research suggests that involuntary retirement, due to injury, illness, or being cut from a sport, can be particularly detrimental. As such, this review focuses on the impact athletic retirement has on the psychological well-being of collegiate athletes. We provide an algorithm to inform clinical decision making regarding involuntary retirement, as well as recommendations for the development of support programs and educational resources for athletes struggling with career transition. Our aim is that in developing retirement algorithms, support programs, and educational resources for athletes who are retired from sport, we can intervene early thus reducing the potential long-term psychological burden they may experience.

Traumatic brain injury (TBI) is a major cause of disability worldwide, but the heterogeneous nature of TBI with respect to injury severity and health comorbidities make patient outcome difficult to predict. Injury severity accounts for only some of this variance, and a wide range of preinjury, injury‐related, and postinjury factors may influence outcome, such as sex, socioeconomic status, injury mechanism, and social support. Neuroimaging research in this area has generally been limited by insufficient sample sizes. Additionally, development of reliable biomarkers of mild TBI or repeated subconcussive impacts has been slow, likely due, in part, to subtle effects of injury and the aforementioned variability. The ENIGMA Consortium has established a framework for global collaboration that has resulted in the largest‐ever neuroimaging studies of multiple psychiatric and neurological disorders. Here we describe the organization, recent progress, and future goals of the Brain Injury working group., Graphical Abstract

Importance Myocarditis is a leading cause of sudden death in competitive athletes. Myocardial inflammation is known to occur with SARS-CoV-2. Different screening approaches for detection of myocarditis have been reported. The Big Ten Conference requires comprehensive cardiac testing including cardiac magnetic resonance (CMR) imaging for all athletes with COVID-19, allowing comparison of screening approaches. Objective To determine the prevalence of myocarditis in athletes with COVID-19 and compare screening strategies for safe return to play. Design, Setting, and Participants Big Ten COVID-19 Cardiac Registry principal investigators were surveyed for aggregate observational data from March 1, 2020, through December 15, 2020, on athletes with COVID-19. For athletes with myocarditis, presence of cardiac symptoms and details of cardiac testing were recorded. Myocarditis was categorized as clinical or subclinical based on the presence of cardiac symptoms and CMR findings. Subclinical myocarditis classified as probable or possible myocarditis based on other testing abnormalities. Myocarditis prevalence across universities was determined. The utility of different screening strategies was evaluated. Exposures SARS-CoV-2 by polymerase chain reaction testing. Main Outcome and Measure Myocarditis via cardiovascular diagnostic testing. Results Representing 13 universities, cardiovascular testing was performed in 1597 athletes (964 men [60.4%]). Thirty-seven (including 27 men) were diagnosed with COVID-19 myocarditis (overall 2.3%; range per program, 0%-7.6%); 9 had clinical myocarditis and 28 had subclinical myocarditis. If cardiac testing was based on cardiac symptoms alone, only 5 athletes would have been detected (detected prevalence, 0.31%). Cardiac magnetic resonance imaging for all athletes yielded a 7.4-fold increase in detection of myocarditis (clinical and subclinical). Follow-up CMR imaging performed in 27 (73.0%) demonstrated resolution of T2 elevation in all (100%) and late gadolinium enhancement in 11 (40.7%). Conclusions and Relevance In this cohort study of 1597 US competitive athletes with CMR screening after COVID-19 infection, 37 athletes (2.3%) were diagnosed with clinical and subclinical myocarditis. Variability was observed in prevalence across universities, and testing protocols were closely tied to the detection of myocarditis. Variable ascertainment and unknown implications of CMR findings underscore the need for standardized timing and interpretation of cardiac testing. These unique CMR imaging data provide a more complete understanding of the prevalence of clinical and subclinical myocarditis in college athletes after COVID-19 infection. The role of CMR in routine screening for athletes safe return to play should be explored further.

Alterations in resting-state functional connectivity (rsFC) occur in the acute and chronic phases following traumatic brain injury (TBI); however, few studies have assessed long-term (>1 year) changes in rsFC. Resting-state functional magnetic resonance imaging (rsfMRI) scans were obtained from the Federal Interagency Traumatic Brain Injury Research Informatics Systems. Patients with primarily mild TBI (n = 39) completed rsfMRI scans at the sub-acute (~10 days) and long-term (~18 months) phases. We examined changes in voxel-based rsFC from anterior medial prefrontal cortex (aMPFC) and posterior cingulate cortex (PCC) seeds in the default mode network (DMN) between both phases. The effect of age at the time of injury on long-term rsFC was also examined. Increased rsFC from the aMPFC and the PCC to frontal and temporal regions was shown at ~18-months post-injury. Widespread increases in rsFC from the aMPFC and between the PCC and frontal regions were shown for younger patients at time of injury, but limited increases of rsFC were noted at ~18 months in older patients. Long-term increases in rsFC were found following TBI, but age at the time of injury was associated with distinct rsFC profiles suggesting that younger patients show greater increases in rsFC over time.

Intimate partner violence includes psychological aggression, physical violence, sexual violence, and stalking from a current or former intimate partner. Past research suggests that exposure to intimate partner violence can impact cognitive and psychological functioning, as well as neurological outcomes. These seem to be compounded in those who suffer a brain injury as a result of trauma to the head, neck or body due to physical and/or sexual violence. However, our understanding of the neurobehavioral and neurobiological effects of head trauma in this population is limited due to factors including difficulty in accessing/recruiting participants, heterogeneity of samples, and premorbid and comorbid factors that impact outcomes. Thus, the goal of the Enhancing Neuroimaging and Genetics through Meta-Analysis (ENIGMA) Consortium Intimate Partner Violence Working Group is to develop a global collaboration that includes researchers, clinicians, and other key community stakeholders. Participation in the working group can include collecting harmonized data, providing data for meta- and mega-analysis across sites, or stakeholder insight on key clinical research questions, promoting safety, participant recruitment and referral to support services. Further, to facilitate the mega-analysis of data across sites within the working group, we provide suggestions for behavioral surveys, cognitive tests, neuroimaging parameters, and genetics that could be used by investigators in the early stages of study design. We anticipate that the harmonization of measures across sites within the working group prior to data collection could increase the statistical power in characterizing how intimate partner violence-related head trauma impacts long-term physical, cognitive, and psychological health.

ObjectiveTo identify CSF biomarkers that are related to decreased white matter (WM) integrity and poor cognitive performance in former professional athletes with a history of multiple concussions.MethodsConcentrations of phosphorylated tau181, total tau (t-tau), and β-amyloid in the CSF were measured in 3 groups: 22 former professional athletes with multiple concussions (mean ± SD age 55.9 ± 12.2 years), 5 healthy controls (age 57.4 ± 5.2 years), and 12 participants (age 60.0 ± 6.6 years) diagnosed with Alzheimer disease (AD). All participants in the former athletes group underwent diffusion tensor imaging to determine WM tract integrity and completed neuropsychological testing. We divided the former athletes group into those with normal (300 pg/mL) CSF t-tau.ResultsCSF t-tau in the former athletes group was significantly higher than in the healthy control group (349.3 ± 182.6 vs 188.8 ± 39.9 pg/mL, p = 0.003) and significantly lower than in the patients with AD (349.3 ± 182.6 vs 857.0 ± 449.3 pg/mL, p = 0.007). Fractional anisotropy values across all the tracts were significantly lower in the high CSF t-tau group compared to the normal CSF t-tau group (p = 0.036). Participants in the high CSF t-tau group scored significantly lower on the Trail Making Test (TMT) Part B compared to the normal CSF t-tau group (t scores 45.6 ± 18.8 vs 62.3 ± 10.1, p = 0.017).ConclusionOur findings indicate that former athletes with multiple concussions are at increased risk of elevated levels of CSF t-tau and that high CSF t-tau is associated with reduced WM integrity and worse scores on the TMT Part B.

Traumatic brain injury (TBI) is a highly prevalent condition with significant effects on cognition and behavior. While the acute and sub-acute effects of TBI recover over time, relatively little is known about the long-term effects of TBI in relation to neurodegenerative disease. This issue has recently garnered a great deal of attention due to publicity surrounding chronic traumatic encephalopathy (CTE) in professional athletes, although CTE is but one of several neurodegenerative disorders associated with a history of TBI. Here, we review the literative on neurodegenerative disorders linked to remote TBI. We also review the evidence for neuroimaging changes associated with unhealthy brain aging in the context of remote TBI. We conclude that neuroimaging biomarkers have significant potential to increase understanding of the mechanisms of unhealthy brain aging and neurodegeneration following TBI, with potential for identifying those at risk for unhealthy brain aging prior to the clinical manifestation of neurodegenerative disease.

The theory of embodied cognition postulates that the brain represents semantic knowledge as a function of the interaction between the body and the environment. The goal of our research was to provide a neuroanatomical examination of embodied cognition using action-related pictures and words. We used functional magnetic resonance imaging (fMRI) to examine whether there were shared and/or unique regions of activation between an ecologically valid semantic generation task and a motor task in the parietal-frontocentral network (PFN), as a function of stimulus format (pictures versus words) for two stimulus types (hand and foot). Unlike other methods for neuroimaging analyses involving subtractive logic or conjoint analyses, this method first isolates shared and unique regions of activation within-participants before generating an averaged map. The results demonstrated shared activation between the semantic generation and motor tasks, which was organized somatotopically in the PFN, as well as unique activation for the semantic generation tasks in proximity to the hand or foot motor cortex. We also found unique and shared regions of activation in the PFN as a function of stimulus format (pictures versus words). These results further elucidate embodied cognition in that they show that brain regions activated during actual motor movements were also activated when an individual verbally generates action-related semantic information. Disembodied cognition theories and limitations are also discussed.

FARTHING, J. P., J. R. KRENTZ, C. R. MAGNUS, T. S. BARSS, J. L. LANOVAZ, J. CUMMINE, C. ESOPENKO, G. E. SARTY,and R. BOROWSKY. Changes in Functional Magnetic Resonance Imaging Cortical Activation with Cross Education to an ImmobilizedLimb.Med.Sci. Sports Exerc., Vol. 43, No.8,pp. 1394–1405,2011. Purpose: Thepurposeof this studywas to assesscortical activationassociated with the cross-education effect to an immobilized limb, using functional magnetic resonance imaging. Methods: Fourteenright-handed participants were assigned to two groups. One group (n = 7) wore a cast and strength trained the free arm (CAST–TRAIN).The second group (n = 7) wore a cast and did not strength train (CAST). Casts were applied to the nondominant (left) wrist and hand.Strength training was maximal isometric handgrip contractions (right hand) 5 dIwk j1 . Peak force (handgrip dynamometer), musclethickness (ultrasound), EMG, and cortical activation (functional magnetic resonance imaging) were assessed before and after the in-tervention. Results: CAST–TRAIN improved right handgrip strength by 10.7% (P G 0.01) with no change in muscle thickness. Therewas a significant group time interaction for strength of the immobilized arm (P G 0.05). Handgrip strength of the immobilized armof CAST–TRAIN was maintained, whereas the immobilized arm of CAST significantly decreased by 11% (P G 0.05). Muscle thicknessof the immobilized arm decreased by an average of 3.3% (P G 0.05) for all participants and was not different between groups afteradjustingfor baseline differences. There was a significant group time interaction for EMG activation (P G 0.05),where CAST–TRAINshowed an increasing trend and CAST showed a decreasing trend, pooled across arms. For the immobilized arm of CAST–TRAIN, therewas a significant increase in contralateral motor cortex activation after training (P G 0.05). For the immobilized arm of CAST, therewas no change in motor cortex activation. Conclusions: Handgrip strength training of the free limb attenuated strength loss duringunilateral immobilization. The maintenance of strength in the immobilized limb via the cross-education effect may be associated withincreased motor cortex activation. Key Words: BRAIN ACTIVATION, CASTING, LIMB UNLOADING, ATROPHY, HANDGRIPSTRENGTH, CROSS-LIMB TRANSFER