A Prospective Functional MR Imaging Study of Mild Traumatic Brain Injury in College Football Players
Kelly J. Jantzena,
Brian Andersonb,
Fred L Steinbergc and
J. A. Scott Kelsoa
a Florida Atlantic University, Center for Complex Systems and Brain Sciences, Boca Raton, FL
b Athletic Department, Boca Raton, FL
c University MRI and Diagnostic Imaging Centers, Boca Raton, FL
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FIG 1. Average performance scores (percentages) for concussed players do not change between baseline (white) and postconcussion (dark gray) sessions. Similarly, no change was observed for the control players when we compared the first baseline session (light gray) with the second baseline session (black). Performance on the digit span and addition tasks were similar and consistently above 80% correct for all sessions. The subtraction task appeared considerably more difficult with percentages of correct values well below those for the other tasks.
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FIG 2. Significant mean task-related BOLD responses for all subject and all tasks except addition, which failed to show any consistent activity. Maps were derived from the average of the baseline images of each subject. Activity is overlaid in color on a 3D rendering of a single subject’s brain viewed from the top. Activity displayed for the sequencing tasks include contralateral precentral and postcentral gyrus, bilateral middle frontal gyrus (MFG), medial frontal gyrus (medFG), and inferior parietal lobe (IPL). The subtraction and digit span tasks activated similar areas, including prefrontal cortex (PFC), IPL, amd MFG. The digit span task also recruited areas in visual cortex.
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FIG 3. Representative individual Z-score differences between baseline and either a postconcussion session (concussed, left) or postseason baseline sessions (control, right). Colored areas show regions of activity that significantly increased from the baseline value of the bimanual sequencing task. Although both concussed and control subjects demonstrate some increases, those of the concussed player are considerably larger. Activity is significantly increased in the medial frontal gyrus (medFG), middle frontal gyrus (MFG), inferior parietal lobe (IPL), and bilateral cerebellum.
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FIG 4. The mean voxel volume of significant, within-subject BOLD increases in specific ROIs. Error bars show the between-subject standard error. Each plot shows activity changes for each task in an ROI. Stylized images on the left show the regions encompassed by each ROI for two axial sections. The volume of increase was greater for the concussed players (black) than for the control players (gray), particularly for sequencing tasks. Differences between groups were most prominent in frontal and parietal regions. Biman indicates bimanual; DSpan, digit span; Subt, subtraction.
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FIG 5. Amplitude difference (mean voxel intensity) between baseline and postbaseline sessions averaged within ROI and across subjects. Each plot shows activity changes for each task in an ROI. Stylized images on the left show the regions encompassed by the ROI for two axial sections. In general, concussed players (black) showed greater increases in amplitude compared with control subjects (gray); this was particularly evident in the bilateral lateral frontal and parietal regions. Biman indicates bimanual; DSpan, digit span; Subt, subtraction.
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