Analysis of longitudinal head impact exposure and white matter integrity in returning youth football players

OBJECTIVE The objective of this study was to characterize changes in head impact exposure (HIE) across multiple football seasons and to determine whether changes in HIE correlate with changes in imaging metrics in youth football players. METHODS On-field head impact data and pre- and postseason imaging data, including those produced by diffusion tensor imaging (DTI), were collected from youth football athletes with at least two consecutive seasons of data. ANCOVA was used to evaluate HIE variations (number of impacts, peak linear and rotational accelerations, and risk-weighted cumulative exposure) by season number. DTI scalar metrics, including fractional anisotropy, mean diffusivity, and linear, planar, and spherical anisotropy coefficients, were evaluated. A control group was used to determine the number of abnormal white matter voxels, which were defined as 2 standard deviations above or below the control group mean. The difference in the number of abnormal voxels between consecutive seasons was computed for each scalar metric and athlete. Linear regression analyses were performed to evaluate relationships between changes in HIE metrics and changes in DTI scalar metrics. RESULTS There were 47 athletes with multiple consecutive seasons of HIE, and corresponding imaging data were available in a subsample (n = 19) of these. Increases and decreases in HIE metrics were observed among individual athletes from one season to the next, and no significant differences (all p > 0.05) in HIE metrics were observed by season number. Changes in the number of practice impacts, 50th percentile impacts per practice session, and 50th percentile impacts per session were significantly positively correlated with changes in abnormal voxels for all DTI metrics. CONCLUSIONS These results demonstrate a significant positive association between changes in HIE metrics and changes in the numbers of abnormal voxels between consecutive seasons of youth football. Reducing the number and frequency of head impacts, especially during practice sessions, may decrease the number of abnormal imaging findings from one season to the next in youth football.

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Motor cortex gliomas induces microstructural changes of large fiber tracts revealed by TBSS

Scientific Reports ◽

10.1038/s41598-020-73746-1 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Xiangdong Wang ◽

Chunyao Zhou ◽

Lei Wang ◽

Yinyan Wang ◽

Tao Jiang

Keyword(s):

White Matter ◽

Motor Cortex ◽

Diffusion Tensor ◽

Early Stage ◽

Mean Diffusivity ◽

Cerebral White Matter ◽

Control Group ◽

Fiber Tracts ◽

3.0 T ◽

White Matter Fiber Tracts

Abstract Gliomas grow and invade along white matter fiber tracts. This study assessed the effects of motor cortex gliomas on the cerebral white matter fiber bundle skeleton. The motor cortex glioma group included 21 patients, and the control group comprised 14 healthy volunteers. Both groups underwent magnetic resonance imaging-based 3.0 T diffusion tensor imaging. We used tract-based spatial statistics to analyze the characteristics of white matter fiber bundles. The left and right motor cortex glioma groups were analyzed separately from the control group. Results were statistically corrected by the family-wise error rate. Compared with the controls, patients with left motor cortex gliomas exhibited significantly reduced fractional anisotropy and an increased radial diffusivity in the corpus callosum. The alterations in mean diffusivity (MD) and the axial diffusivity (AD) were widely distributed throughout the brain. Furthermore, atlas-based analysis showed elevated MD and AD in the contralateral superior fronto-occipital fasciculus. Motor cortex gliomas significantly affect white matter fiber microstructure proximal to the tumor. The range of affected white matter fibers may extend beyond the tumor-affected area. These changes are primarily related to early stage tumor invasion.

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In-season variations in head impact exposure among youth football players

Neurology ◽

10.1212/01.wnl.0000550621.28386.81 ◽

2018 ◽

Vol 91 (23 Supplement 1) ◽

pp. S1.3-S2

Author(s):

Jillian Urban ◽

Mirellie Kelley ◽

Mark Espeland ◽

Elizabeth Davenport ◽

Christopher T. Whitlow ◽

...

Keyword(s):

Head Impact ◽

Cumulative Exposure ◽

Football Players ◽

Sample Mean ◽

Head Impacts ◽

Youth Football ◽

Single Number ◽

Practice Time ◽

Time Frames ◽

Season Variations

Sport-related head impacts are of increasing concern as early evidence has demonstrated a relationship between subconcussive head impact exposure (HIE) experienced in contact sports, such as football, and changes in pre-to post-season imaging and cognitive measures. Cumulative HIE is often measured with a single number that amounts to the total exposure measured over the season and does not give any indication as to how the exposure was accumulated, nor how it varies during the season. Therefore, the objective of this study was to compare HIE during preseason, the first and second halves of the regular season, and playoffs in a sample of youth football players (n = 119, ages 9–13). Athletes were divided into 1 of 4 exposure groups based on quartiles computed from the distribution of risk-weighted cumulative exposure (RWECP). The mean 95th percentile linear and rotational accelerations and impacts per session in practices and games were compared across 4 exposure groups and time frames using mixed effects models. Within games, the sample mean 95th percentile linear and rotational accelerations ranged from 47.2 g and 2,331.3 rad/s2 during preseason to 52.1 g and 2,533.4 rad/s2 during the second half of regular season. Mean impacts per practice increased from preseason to the second half of regular season and declined into playoffs among all exposure groups; however, the variation between time frames was not greater than 2 impacts per practice. Time of season had a significant effect on mean 95th percentile linear and rotational acceleration in games (both p = 0.01) but not on practice accelerations or impacts/session. Mean 95th percentile accelerations for games showed significant interaction effects between exposure group and season segment (linear p = 0.05 and rotational p = 0.04). The results of this study improve our understanding of in-season variations in youth football HIE and may inform important opportunities for future interventions.

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Thalamic and thalamic projection abnormalities on DTI and NODDI analysis following acute concussion

Neurology ◽

10.1212/01.wnl.0000580864.41102.8d ◽

2019 ◽

Vol 93 (14 Supplement 1) ◽

pp. S4.2-S5

Author(s):

James Houston ◽

Frank Skidmore ◽

William Monroe ◽

Jon Amburgy ◽

Mitchell Self

Keyword(s):

White Matter ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Oculomotor System ◽

White Matter Injury ◽

Football Players ◽

Cortical Regions ◽

The Right ◽

Collegiate Football ◽

Concussive Injury

ObjectiveTo compare preseason and post-concussive MRI in a cohort of collegiate football players utilizing Diffusion Tensor Imaging (DTI) and Neurite Orientation Dispersion and Density Imaging (NODDI) post processing.BackgroundAcute post-concussive symptoms can vary in clinical characteristics and severity. However, vestibular and ocular dysfunction in particular, has been associated with poor clinical outcomes. The vestibular system comprises a complex network of projections from peripheral vestibular organs to thalamic relay systems and numerous cortical regions. The visual/oculomotor system is also complex, involving brainstem, subcortical-cortical and thalamo-cortical connections. Oculomotor deficits are thought to involve the midbrain and the visual and parietal association cortices, both of which have thalamic projections.Design/MethodsWe gathered pre-season MR diffusion weighted imaging on a cohort of 30 collegiate football players. We performed repeat imaging within 36 hours of any diagnosed concussion in the same subject cohort. DTI metrics: mean diffusivity (MD), axial diffusivity (AD), fractional anisotropy (FA), and radial diffusivity (RD) along with NODDI metric: orientation dispersion index (ODI), were analyzed for statistical comparisons between groups.Results4 subjects with pre-season MRI underwent repeat MRI within 36 hours of concussive injury. A paired t-test between these two groups using DTI and NODDI metrics showed significant (p < 0.05) decreases in: AD and MD in the left posterior thalamic radiations, FA in the column and body of the fornix, and MD in the right anterior corona radiata and superior fronto-occipital fasciculus, and a significant decrease in ODI in the anterior thalamus.ConclusionsDisruptions in the thalamus and its white matter projections may play a role in the vestibular/ocular dysfunction associated with acute concussive injury. While our numbers are small, the findings suggest that DTI and NODDI processing techniques have the capability to locate and measure grey and white matter injury patterns after concussive injury.

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Repetitive Head Impacts in Youth Football: Description and Relationship to White Matter Structure

Sports Health A Multidisciplinary Approach ◽

10.1177/1941738119865264 ◽

2019 ◽

Vol 11 (6) ◽

pp. 507-513 ◽

Cited By ~ 3

Author(s):

Kurt J. Nilsson ◽

Hilary G. Flint ◽

Yong Gao ◽

Leslie Kendrick ◽

Steve Cutchin ◽

...

Keyword(s):

White Matter ◽

Diffusion Tensor ◽

Brain Magnetic Resonance Imaging ◽

The Body ◽

Football Players ◽

Head Impacts ◽

Number Magnitude ◽

Youth Football ◽

Total Magnitude ◽

Tackle Football

Background: Few studies have examined white matter with diffusion tensor imaging in 8- to 12-year-old collision sport (CS) athletes. Hypothesis: Youth CS athletes will demonstrate change in brain fractional anisotropy (FA) after a season of CS compared with an age-matched noncollision sport (NCS) cohort, and the number, magnitude, and location of hits will correlate with changes in the brain determined via FA for CS athletes. Study Design: Prospective cohort study. Level of Evidence: Level 3. Methods: Thirty-five 8- to 12-year-old males in a youth tackle football league (CS) and 12 males from local swim teams (NCS) were recruited. Participants underwent brain magnetic resonance imaging with FA before and after the football season. Number, magnitude, and direction of head impacts were recorded for CS participants throughout the season. Results: A total of 1905 hits were recorded in the CS group for the season, 341 (17.9%) collected during 7 games and 1564 (82.1%) observed during 31 practices. No significant interaction between group (CS and NCS) and time (pre- and postseason) was observed for FA ( P > 0.05). Correlation analysis revealed a significantly positive and moderate relationship between increase of left cingulate cortex (CgC) FA from pre- to postseason and the total magnitude of lateral head impacts ( r = 0.40; P = 0.03). Conclusion: There was no significant change in FA measurement of white matter integrity in a cohort of 8- to 12-year-old males after a season of youth football, nor was any difference detected in FA between youth football players and an age-matched cohort of swimmers. There was a significant correlation between total magnitude of hits sustained by youth football players and an increase in FA in the left CgC; whether this is adaptive or pathologic remains unknown. Clinical Relevance: These data can be used within the body of knowledge to counsel patients regarding the known risks of youth tackle football regarding brain health.

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Quantitative Diffusion Tensor Imaging (DTI) Analysis Reveals Different Infiltrative Patterns of Oligodendrogliomas and Astrocytomas in Peri-Tumour White Matter

Neurosurgery ◽

10.1093/neuros/nyz001.ni2 ◽

2019 ◽

Vol 84 (5) ◽

pp. E273-E273

Author(s):

Christopher Murphy ◽

Erjon Agushi ◽

Zhangjie Su ◽

Rainer Hinz ◽

Federico Roncaroli ◽

...

Keyword(s):

Diffusion Tensor Imaging ◽

White Matter ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Control Group ◽

Control Data ◽

Primary Brain Tumours ◽

Diffusion Parameters ◽

Grade Ii ◽

Diffusion Tensor Imaging Dti

Abstract INTRODUCTION Gliomas are highly infiltrative primary brain tumours. Glioma infiltration is difficult to identify clinically using conventional diagnostic imaging. We used diffusion tensor imaging (DTI) to identify glioma infiltration in peritumour white matter (WM) and characterized differences between histological subtypes. METHODS We recruited 8 patients with a histological diagnosis of grade II or III glioma and 10 healthy controls. We compared fractional anisotropy (FA) maps of each patient against the control group using SPM8 (Matlab 2014a) to identify regions of glioma infiltration. The FA and mean diffusivity (MD) of formerly WM matter tumour regions, infiltrated WM and normal appearing WM were compared with a 2-sample t-test and characterized with respect to normal control data. RESULTS Our results have identified radiological evidence of infiltration in the peri-tumour WM of glioma patients. The infiltrated region of oligodendrogliomas extended further than that of astrocytomas. Oligodendrogliomas preferentially infiltrated larger WM tracts, whereas astrocytomas infiltrated more peripheral WM. In all grades, the 3 regions had significantly different diffusion parameters and there were significant differences between oligodendrogliomas and astrocytomas. CONCLUSION We identified previously unrecognized study wide significant changes in the peri-tumour WM of gliomas. Despite the known propensity of these tumours to infiltrate WM we found no significant DTI changes distant to the tumour. Our DTI results suggest oligodendrogliomas and astrocytomas demonstrate different infiltrative patterns, which highlights the need for astrocytomas and oligodendrogliomas to be studied separately.

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Does antipsychotic medication affect white matter in schizophrenia and bipolar disorder? a review of diffusion tensor imaging literature

European Psychiatry ◽

10.1016/s0924-9338(11)72985-6 ◽

2011 ◽

Vol 26 (S2) ◽

pp. 1280-1280 ◽

Cited By ~ 8

Author(s):

M. Kyriakopoulos ◽

L. Samartzis ◽

D. Dima ◽

D. Hayes ◽

R. Corrigall ◽

...

Keyword(s):

Bipolar Disorder ◽

Diffusion Tensor Imaging ◽

White Matter ◽

Antipsychotic Medication ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Cumulative Exposure ◽

Current Evidence ◽

Antipsychotic Treatment ◽

Cross Sectional

IntroductionWhite matter (WM) abnormalities are considered integral to the pathophysiology of Schizophrenia (SZ) and Bipolar Disorder (BD), but there is ongoing uncertainty about the contribution of medication to these findings.ObjectivesDiffusion Tensor Imaging (DTI) is a neuroimaging technique that provides quantitative indices of the structural and orientational characteristics of WM. These indices include mean diffusivity (MD), which is a directionally averaged measure of the apparent diffusion coefficient, and fractional anisotropy (FA), which summarizes the orientational dependence of diffusivity. We wanted to determine if these indices are affected by antipsychotic medication.AimsOur aim was to examine the available literature in order to differentiate antipsychotic effects from disorder-specific WM abnormalities on DTI measures.MethodsWe conducted a systematic qualitative review of the DTI literature in Bipolar Disorder (BD) and Schizophrenia (SZ), between 1998 and 2010 and included only studies where the relationship between DTI measures and antipsychotic medication was explicitly examined and reported.ResultsWe identified 40 studies in SZ and 8 in BD. All studies were cross-sectional and involved relatively small patient samples. 32 studies (80%) did not find any relationship between antipsychotic medication (dose, cumulative exposure) and FA or MD.ConclusionsCurrent evidence does not indicate a major impact of antipsychotic treatment on DTI indices of WM integrity. However, the lack of longitudinal, within-subject designs is a major gap in the current literature.

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Abnormal Integrity of White Matter Tracts in Acute Lacunar Stroke Patients

Brain Impairment ◽

10.1017/brimp.2018.10 ◽

2018 ◽

Vol 20 (1) ◽

pp. 49-57 ◽

Cited By ~ 1

Author(s):

Yifei Zhu ◽

Yana He ◽

Karen M. von Deneen ◽

Ming Zhang

Keyword(s):

White Matter ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Radial Diffusivity ◽

Lacunar Stroke ◽

Imaging Data ◽

Stroke Patients ◽

Superior Longitudinal Fasciculus ◽

Als Patients ◽

Diffusion Tensor Imaging Data

Background/Study Concept: Acute lacunar stroke (Als) plays a role in death/disability worldwide. Aphasia refers to chronic difficulty with communication in >20% of patients post stroke. We describe pathophysiological features of white matter (WM) abnormalities and their relationship between WM changes and aphasia quotient (AQ) scores in Als.Methods: Diffusion tensor imaging data were acquired in 37 Als patients and 28 healthy controls. Tract-based spatial statistics (TBSS) and correlation analyses were used.Results: Consistent with the hypothesis, Als had decreased fractional anisotropy (FA) and increased mean diffusivity, axial diffusivity and radial diffusivity in the genu, body and splenium of the corpus callosum (CC), superior longitudinal fasciculus (SLF) and corona radiata in the bilateral hemisphere. Reduced FA of SLF was correlated with AQ scores in Als patients.Conclusion: It is hoped that TBSS could shed new insights into aphasia mechanisms in Als to help promote aging-related disease studies.

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Diffusion tensor imaging in hyperthyroidism: assessment of microstructural white matter abnormality with a tract-based spatial statistical analysis

Acta Radiologica ◽

10.1177/0284185120909960 ◽

2020 ◽

Vol 61 (12) ◽

pp. 1677-1683 ◽

Cited By ~ 1

Author(s):

Kerim Aslan ◽

Hediye Pinar Gunbey ◽

Sumeyra Cortcu ◽

Onur Ozyurt ◽

Ugur Avci ◽

...

Keyword(s):

Diffusion Tensor Imaging ◽

White Matter ◽

Corpus Callosum ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Imaging Study ◽

Internal Capsule ◽

Control Group ◽

Corona Radiata ◽

Microstructural Alterations

Background Metabolic, morphological, and functional brain changes associated with a neurological deficit in hyperthyroidism have been observed. However, changes in microstructural white matter (WM), which can explain the underlying pathophysiology of brain dysfunctions, have not been researched. Purpose To assess microstructural WM abnormality in patients with untreated or newly diagnosed hyperthyroidism using tract-based spatial statistics (TBSS). Material and Methods Eighteen patients with hyperthyroidism and 14 age- and sex-matched healthy controls were included in this study. TBSS were used in this diffusion tensor imaging study for a whole-brain voxel-wise analysis of fractional anisotropy, mean diffusivity, axial diffusivity (AD), and radial diffusivity (RD) of WM. Results When compared to the control group, TBSS showed a significant increase in the RD of the corpus callosum, anterior and posterior corona radiata, posterior thalamic radiation, cingulum, superior longitudinal fasciculus, and the retrolenticular region of the internal capsule in patients with hyperthyroidism ( P < 0.05), as well as a significant decrease in AD in the anterior corona radiata and the genu of corpus callosum ( P < 0.05). Conclusion This study showed that more regions are affected by the RD increase than the AD decrease in the WM tracts of patients with hyperthyroidism. These preliminary results suggest that demyelination is the main mechanism of microstructural alterations in the WM of hyperthyroid patients.

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Microstructural properties of major white matter tracts in constant exotropia before and after strabismus surgery

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2020-317948 ◽

2021 ◽

pp. bjophthalmol-2020-317948

Author(s):

Yanming Wang ◽

Xiaoxiao Wang ◽

Hongmei Shi ◽

Lin Xia ◽

Jiong Dong ◽

...

Keyword(s):

White Matter ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Strabismus Surgery ◽

Microstructural Properties ◽

Imaging Data ◽

Absolute Value ◽

Microstructural Alterations ◽

Before And After ◽

The Absolute

AimsThe purpose of this study was to explore the microstructural properties of the major white matter (WM) tracts in constant exotropia (XT) before and after strabismus surgery, and further investigate the association between microstructural alterations and the ocular dominance (OD).MethodsWe collected diffusion tensor imaging data of patients with XT before (n=19) and after (n=15) strabismus surgery and 20 healthy controls and evaluated OD and stereopsis. The probabilistic streamline tractography of the 24 major WM tracts was reconstructed by using the automated fibre quantification package. Fractional anisotropy and mean diffusivity (MD) along each tract were estimated, and their differences between the groups were examined. Furthermore, we evaluated the relationship between OD and the absolute value of altered microstructural parameters.ResultsWhile all postoperative XT patients restored normal stereopsis, most of their OD remained aberrant (9 out of 11). Compared with that of preoperation, the MD of postoperative patients decreased significantly along left anterior thalamic radiation (ATR), left arcuate fasciculus (AF), left corticospinal tract (CST), left cingulum cingulate (CGC) and left inferior fronto-occipital fasciculus. Moreover, OD was negatively correlated with the absolute value of MD changes in left ATR, left AF, left CST and left CGC.ConclusionMicrostructural alterations after surgery in the visuospatial network tracts may contribute to the stereopsis restoration. Additionally, the results of the correlation analysis may signify that the balanced binocular input may be more conducive for the restoration and improvement of binocular visual function, including stereopsis. Thus, restoring normal ocular balance after surgical correction may be necessary to achieve more substantial improvements.

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Diffusion tensor imaging revealed different pathological processes of white matter hyperintensities

BMC Neurology ◽

10.1186/s12883-021-02140-9 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Zhi-gang Min ◽

Hai-rong Shan ◽

Long Xu ◽

Dai-hai Yuan ◽

Xue-xia Sheng ◽

...

Keyword(s):

Diffusion Tensor Imaging ◽

White Matter ◽

Frontal Lobe ◽

Effect Size ◽

White Matter Hyperintensities ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Control Group ◽

Diffusion Weighted Images ◽

Fazekas Scale

Abstract Background Although increasing evidence showed the correlations between white matter hyperintensities (WMHs) and cognitive impairment, the relationship between them is still modest. Many researchers began to focus on the variation caused by the heterogeneity of WMH. We tried to explore the pathological heterogeneity in WMH by using diffusion tensor imaging (DTI), so as to provide a new insight into the future research. Methods Diffusion weighted images (DWIs) of the brain were acquired from 73 patients with WMH and 18 healthy controls, which were then modeled by DTI. We measured fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) of white matter of the periventricular frontal lobe (pFL), periventricular occipital lobe (pOL), periventricular parietal lobe (pPL) and deep centrum ovales (dCO), and grouped these measures according to the Fazekas scale. Then we compared the DTI metrics of different regions with the same Fazekas scale grade. Results Significantly lower FA values (all p < 0.001), and higher MD (all p < 0.001) and RD values (all p < 0.001) were associated with WMH observed in the periventricular frontal lobe (pFL) compared to all other regions with the same Fazekas grades. The AD of WMH in the pFL was higher than that of pPL and dCO, but the differences between groups was not as high as of MD and RD, as indicated by the effect size. In the normal control group, DTI metrics between pFL and other regions were not significantly different or less significant different. The difference of DTI metrics of WMH between pPL, pOL and dCO was lower than that of normal white matter, as indicated by the effect size. Conclusion Distinct pathological processes can be revealed by DTI between frontal periventricular WMH and other regions. These processes may represent the effects of severe demyelination within the frontal periventricular WMH.

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