scholarly journals Longitudinal changes of brain microstructure and function in nonconcussed female rugby players

Neurology ◽  
2020 ◽  
Vol 95 (4) ◽  
pp. e402-e412 ◽  
Author(s):  
Kathryn Y. Manning ◽  
Jeffrey S. Brooks ◽  
James P. Dickey ◽  
Alexandra Harriss ◽  
Lisa Fischer ◽  
...  
Keyword(s):  
White Matter ◽  
Assessment Tool ◽  
Network Connectivity ◽  
Resting State Fmri ◽  
Longitudinal Diffusion ◽  
Cross Sectional ◽  
Longitudinal Changes ◽  
Brain Microstructure ◽  
And Function ◽  
Rugby Players

ObjectiveTo longitudinally assess brain microstructure and function in female varsity athletes participating in contact and noncontact sports.MethodsConcussion-free female rugby players (n = 73) were compared to age-matched (ages 18–23) female swimmers and rowers (n = 31) during the in- and off-season. Diffusion and resting-state fMRI (rs-fMRI) measures were the primary outcomes. The Sports Concussion Assessment Tool and head impact accelerometers were used to monitor symptoms and impacts, respectively.ResultsWe found cross-sectional (contact vs noncontact) and longitudinal (in- vs off-season) changes in white matter diffusion measures and rs-fMRI network connectivity in concussion-free contact athletes relative to noncontact athletes. In particular, mean, axial, and radial diffusivities were increased with decreased fractional anisotropy in multiple white matter tracts of contact athletes accompanied with default mode and visual network hyperconnectivity (p < 0.001). Longitudinal diffusion changes in the brainstem between the in- and off-season were observed for concussion-free contact athletes only, with progressive changes observed in a subset of athletes over multiple seasons. Axial diffusivity was significantly lower in the genu and splenium of the corpus callosum in those contact athletes with a history of concussion.ConclusionsTogether, these findings demonstrate longitudinal changes in the microstructure and function of the brain in otherwise healthy, asymptomatic athletes participating in contact sport. Further research to understand the long-term brain health and biological implications of these changes is required, in particular to what extent these changes reflect compensatory, reparative, or degenerative processes.

The Development and Validation of a Subjective Assessment Tool for the Hip in the Athletic Population

2017 ◽  
Vol 45 (11) ◽  
pp. 2517-2523 ◽  
Author(s):  
Dean N. Papaliodis ◽  
Michael B. Banffy ◽  
Orr Limpisvasti ◽  
Karen Mohr ◽  
Nima Mehran ◽  
...  
Keyword(s):  
Assessment Tool ◽  
Scoring Systems ◽  
Harris Hip Score ◽  
Level Of Evidence ◽  
Cross Sectional ◽  
Outcome Assessments ◽  
Athletic Population ◽  
Injury Category ◽  
Hip Function ◽  
And Function

Background: No validated functional assessments are available that are designed specifically to evaluate the performance and function of the athletic hip. Subsections of some validated outcome assessments address recreation, but a full assessment dedicated to athletic hip function does not exist. Current hip scoring systems may not be sensitive to subtle changes in performance and function in an athletic, younger population. Hypothesis: The patient-athlete subjective scoring system developed in this study will be validated, reliable, and responsive in the evaluation of hip function in the athlete. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Based on the results of a pilot questionnaire administered to 18 athletic individuals, a final 10-item questionnaire was developed. Two hundred fifty competitive athletes from multiple sports completed the final questionnaire and 3 previously validated hip outcome assessments. Each athlete was self-assigned to 1 of 3 injury categories: (1) playing without hip/groin trouble; (2) playing, but with hip/groin trouble; and (3) not playing due to hip/groin trouble. The injury categories contained 196, 40, and 14 athletes, respectively. Correlations between the assessment scores and injury categories were measured. Responsiveness testing was performed in an additional group of 24 injured athletes, and their scores before and after intervention were compared. Results: The Kerlan-Jobe Orthopaedic Clinic (KJOC) Athletic Hip Score showed high correlation with the modified Harris Hip Score, the Nonarthritic Hip Score, and the International Hip Outcome Tool. The new score stratified athletes by injury category, demonstrated responsiveness and accuracy, and varied appropriately with improvements in injury category after treatment of injuries. Conclusion: The new KJOC Athletic Hip Score is valid, reliable, and responsive for evaluation of the hip in an athletic population. The results support its use for the functional assessment of the hip in future studies.

scholarly journals Force Production during the Sustained Phase of Rugby Scrums: A Systematic Literature Review

2020 ◽  
Author(s):  
Eric Martin ◽  
George Beckham
Keyword(s):  
Literature Review ◽  
Systematic Literature Review ◽  
Statistical Power ◽  
Assessment Tool ◽  
Body Position ◽  
Body Height ◽  
Force Production ◽  
Cross Sectional ◽  
Testing Procedures ◽  
Rugby Players

Abstract Background: Since World Rugby changed the laws regarding scrums in the 2013-2014 season, the sustained push phase of the scrum has increased in tactical importance. Therefore, the purpose of this systematic literature review was to examine the biomechanical demands during the sustained push phase of individual, unit, and full pack scrummaging. Methods: Pubmed, EBSCO (specifically and simultaneously searching Academic Search Premier, CINAHL, and SPORTDiscus), and Google Scholar were searched for any research that presented force production in a live or simulated rugby scrum. Study quality was appraised using the National Institute of Health's Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Recorded scrum forces, positioning of players including joint angles, and testing procedures were extracted and narratively synthesized. Results: Twenty six studies were included in the review. 50% of included studies were rated good, 31% fair, and 19% poor. Major limitations included not reporting any effect size, statistical power, or reliability. Reported group mean values for average sustained forces against a machine generally ranged from 1000-2000 N in individual scrums and 4000-8000 N for full packs of male rugby players older than high school age. Individuals seem to optimize their force generation when their shoulders are set against scrum machine pads at approximately 40% of body height, with feet parallel, and with knee and hip angles around 120°. A 10% difference in pack force seems to be necessary for one pack to drive another back in the scrum, but little data exist to quantify differences in force production between winning and losing packs during live scrums. Data collection within studies was not standardized, making comparisons difficult. There is a lack of data in live scrums, and the current research indicates that machine scrums may not replicate many of the demands of live scrums. There is a lack of data for female rugby players. Conclusions: This review indicates an optimal individual body position for players to strive to achieve during scrummaging, consisting of a low body height (40% of stature) and large extended hip and knee angles (120° each).

scholarly journals The effect of global signal regression on DCM estimates of noise and effective connectivity from resting state fMRI

2019 ◽  
Author(s):  
Hannes Almgren ◽  
Frederik Van de Steen ◽  
Adeel Razi ◽  
Karl Friston ◽  
Daniele Marinazzo
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Effective Connectivity ◽  
Network Connectivity ◽  
Resting State Fmri ◽  
Measurement Noise ◽  
Resting State Networks ◽  
Cross Sectional ◽  
Global Signal ◽  
Leibler Divergence

AbstractThe influence of the global BOLD signal on resting state functional connectivity in fMRI data remains a topic of debate, with little consensus. In this study, we assessed the effects of global signal regression (GSR) on effective connectivity within and between resting-state networks – as estimated with dynamic causal modelling (DCM) for resting state fMRI (rsfMRI). DCM incorporates a forward (generative) model that quantifies the contribution of different types of noise (including global measurement noise), effective connectivity, and (neuro)vascular processes to functional connectivity measurements. DCM analyses were applied to two different designs; namely, longitudinal and cross-sectional designs. In the modelling of longitudinal designs, we included four extensive longitudinal resting state fMRI datasets with a total number of 20 subjects. In the analysis of cross-sectional designs, we used rsfMRI data from 361 subjects from the Human Connectome Project. We hypothesized that (1) GSR would have no discernible impact on effective connectivity estimated with DCM, and (2) GSR would be reflected in the parameters representing global measurement noise. Additionally, we performed comparative analyses of the informative value of data with and without GSR. Our results showed negligible to small effects of GSR on connectivity within small (separately estimated) RSNs. For between-network connectivity, we found two important effects: the effect of GSR on between-network connectivity (averaged over all connections) was negligible to small, while the effect of GSR on individual connections was non-negligible. Contrary to our expectations, we found either no effect (in the longitudinal designs) or a non-specific (cross-sectional design) effect of GSR on parameters representing (global) measurement noise. Data without GSR were found to be more informative than data with GSR; however, in small resting state networks the precision of posterior estimates was greater using data after GSR. In conclusion, GSR is a minor concern in DCM studies; however, individual between-network connections (as opposed to average between-network connectivity) and noise parameters should be interpreted quantitatively with some caution. The Kullback-Leibler divergence of the posterior from the prior, together with the precision of posterior estimates, might offer a useful measure to assess the appropriateness of GSR, when nuancing data features in resting state fMRI.

scholarly journals Can exercise make our children smarter?

2020 ◽  
Vol 10 (2) ◽  
Author(s):  
Nenad Stojiljković ◽  
Petar Mitić ◽  
Goran Sporiš
Keyword(s):  
White Matter ◽  
Brain Structure ◽  
Methodological Approach ◽  
Brain Structures ◽  
Structure And Function ◽  
Healthy Children ◽  
Cross Sectional ◽  
Brain Structure And Function ◽  
And Function ◽  
The Brain

Purpose. The aim of this study is to reveal the effects of exercise on the brain structure and function in children, and to analyze methodological approach applied in the researches of this topic. Methods. This literature review provides an overview of important findings in this fast growing research domain. Results from cross-sectional, longitudinal, and interventional studies of the influence of exercise on the brain structure and function of healthy children are reviewed and discussed. Results. The majority of researches are done as cross sectional studies based on the exploring correlation between the level of physical activity and characteristics of brain structure and function. Results of the studies indicate that exercise has positive correlation with improved cognition and beneficial changes to brain function in children. Physically active children have greater white matter integrity in several white matter tracts (corpus callosum, corona radiata, and superior longitudinal fasciculus), have greater volume of gray matter in the hippocampus and basal ganglia than their physically inactive counterparts. The longitudinal/interventional studies also showed that exercise (mainly aerobic) improve cognitive performance of children and causes changes observed on functional magnetic resonance imaging scans (fMRI) located in prefrontal and parietal regions. Conclusion. Previous researches undoubtable proved that exercise can make positive changes of the brain structures in children, specifically the volume of the hippocampus which is the center of learning and memory. Finally the researchers agree that the most influential type of exercise on changes of brain structure and functions are the aerobic exercises. 

scholarly journals Longitudinal changes of ADHD symptoms in association with white matter microstructure: a tract-specific fixel-based analysis

2021 ◽  
Author(s):  
Christienne G Damatac ◽  
Sourena Soheili-Nezhad ◽  
Guilherme Blazquez Freches ◽  
Marcel P Zwiers ◽  
Sanne de Bruijn ◽  
...  
Keyword(s):  
White Matter ◽  
Fiber Density ◽  
Cross Sectional ◽  
White Matter Microstructure ◽  
Brain Structure And Function ◽  
White Matter Development ◽  
And Function ◽  
Symptom Trajectory ◽  
Over Time

Background: Variation in the longitudinal course of childhood attention deficit/hyperactivity disorder (ADHD) coincides with neurodevelopmental maturation of brain structure and function. Prior work has attempted to determine how alterations in white matter (WM) relate to changes in symptom severity, but much of that work has been done in smaller cross-sectional samples using voxel-based analyses. Using standard diffusion-weighted imaging (DWI) methods, we previously showed WM alterations were associated with ADHD symptom remission over time in a longitudinal sample of probands, siblings, and unaffected individuals. Here, we extend this work by further assessing the nature of these changes in WM microstructure by including an additional follow-up measurement (aged 18-34 years), and using the more physiologically informative fixel-based analysis (FBA). Methods: Data were obtained from 139 participants over 3 clinical and 2 follow-up DWI waves, and analyzed using FBA in regions-of-interest based on prior findings. We replicated previously reported significant models and extended them by adding another time-point, testing whether changes in combined and hyperactivity-impulsivity (HI) continuous symptom scores are associated with fixel metrics at follow-up. Results: Clinical improvement in HI symptoms over time was associated with more fiber density at follow-up in the left corticospinal tract (lCST) (tmax=1.092, standardized effect[SE]=0.044, pFWE=0.016), and improvement in combined symptoms over time was associated with more fiber cross-section at follow-up in the lCST (tmax=3.775, SE=0.051, pFWE=0.019). Conclusions: Aberrant white matter development involves both lCST micro- and macrostructural alterations and its path may be moderated by preceding symptom trajectory.

scholarly journals Force Production during the Sustained Phase of Rugby Scrums: A Systematic Literature Review

2020 ◽  
Author(s):  
Eric Martin ◽  
George Beckham
Keyword(s):  
Literature Review ◽  
Statistical Power ◽  
Assessment Tool ◽  
Body Position ◽  
Body Height ◽  
Force Production ◽  
Cross Sectional ◽  
Mean Values ◽  
Testing Procedures ◽  
Rugby Players

Abstract Background: Since World Rugby changed the laws regarding scrums in the 2013-2014 season, the sustained push phase of the scrum has become of greater tactical importance. Therefore, the purpose of this sytematic literature review was to examine the biomechanical demands during the sustained push phase of individual, unit, and full pack scrummaging. Methods: Pubmed, EBSCO (specifically and simultaneously searching Academic Search Premier, CINAHL, and SPORTDiscus), and Google Scholar were searched for any research that presented force production in a live or simulated rugby scrum. Study quality was appraised using the National Institute of Health's Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Recorded scrum forces, positioning of players including joint angles, and testing procedures were extracted and narratively synthesized. Results: Twenty six studies were included in the review. 50% of included studies were rated good, 31% fair, and 19% poor. Major limitations included not reporting any effect size, statistical power, or reliability. Reported group mean values for average sustained forces against a machine generally ranged from 1000-2000 N in individual scrums and 4000-8000 N for full packs of male rugby players older than high school age. Individuals seem to optimize their force generation when their shoulders are set against scrum machine pads at approximately 40% of body height, with feet parallel, and with knee and hip angles around 120°. A 10% difference in pack force seems to be necessary for one pack to drive another back in the scrum, but little data exist to quantify differences in force production between winning and losing packs during live scrums. Data collection within studies was not standardized, making comparisons difficult. There is a lack of data in live scrums, and the current research indicates that machine scrums may not replicate many of the demands of live scrums. There is a lack of data for female rugby players. Conclusions: This review indicates an optimal individual body position for players to strive to achieve during scrummaging, consisting of a low body height (40% of stature) and large extended hip and knee angles (120° each).

scholarly journals Maturation and interhemispheric asymmetry in neurite density and orientation dispersion in early childhood

2019 ◽  
Author(s):  
Dennis Dimond ◽  
Stella Heo ◽  
Amanda Ip ◽  
Christiane S. Rohr ◽  
Ryann Tansey ◽  
...  
Keyword(s):  
Early Childhood ◽  
White Matter ◽  
Hemispheric Asymmetry ◽  
Rapid Development ◽  
Transitional Period ◽  
Cross Sectional ◽  
White Matter Tracts ◽  
Longitudinal Changes ◽  
Neurite Density ◽  
Diffusion Weighted Images

ABSTRACTBackgroundThe brain’s white matter undergoes profound changes during early childhood, which are believed to underlie the rapid development of cognitive and behavioral skills during this period. Neurite density, and complexity of axonal projections, have been shown to change across the life span, though changes during early childhood are poorly characterized. Here, we utilize neurite orientation dispersion and density imaging (NODDI) to investigate maturational changes in tract-wise neurite density index (NDI) and orientation dispersion index (ODI) during early childhood. Additionally, we assess hemispheric asymmetry of tract-wise NDI and ODI values, and longitudinal changes.MethodsTwo sets of diffusion weighted images (DWI) with different diffusion-weighting were collected from 125 typically developing children scanned at baseline (N=125; age range=4.14-7.29; F/M=73/52), 6-month (N=8; F/M=8/0), and 12-month (N=52; F/M=39/13) timepoints. NODDI and template-based tractography using constrained spherical deconvolution were utilized to calculate NDI and ODI values for major white matter tracts. Mixed-effects models controlling for sex, handedness, and in-scanner head motion were utilized to assess developmental changes in tract-wise NDI and ODI. Paired t-tests were used to assess interhemispheric differences in tract-wise NDI and ODI values and longitudinal changes in cross-sectional and 12-month longitudinal analyses, respectively.ResultsMaturational increases in NDI were seen in all major white matter tracts, though we did not observe the expected tract-wise pattern of maturational rates (e.g. fast commissural/projection and slow frontal/temporal tract change). ODI did not change significantly with age in any tract. We observed higher cross-sectional NDI and ODI values in the right as compared to the left hemisphere for most tracts, but no hemispheric asymmetry for longitudinal changes.ConclusionsThese findings suggest that neurite density, but not orientation dispersion, increases with age during early childhood. In relation to NDI growth trends reported in infancy and late-childhood, our results suggest that early childhood may be a transitional period for neurite density maturation wherein commissural/projection fibers are approaching maturity, maturation in long range association fibers is increasing, and changes in limbic/frontal fibers remain modest. Rightward asymmetry in NDI and ODI values, but not longitudinal changes, suggests that rightward asymmetry of neurite density and orientation dispersion is established prior to age 4.

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