Article Figures & Data
Figures
- Figure 1.
Differences between IHTT-slow and control groups in FA. Whole-tract differences in FA between IHTT-slow and control. The p values are shown corresponding to the color bar, and results were FDR corrected across all points on all tracts tested (q < 0.05; critical p threshold = 0.0038). For simplicity, only tracts with at least 5% of the tract showing significant differences are displayed. IFO, Inferior fronto-occipital fasciculus; ILF, inferior longitudinal fasciculus.
- Figure 2.
Differences between IHTT-slow and control groups in MD. Whole-tract differences in MD between IHTT-slow and control groups. The p values are shown corresponding to the color bar, and results were FDR corrected across all points on all tracts tested (q < 0.05; critical p threshold = 0.0036). For simplicity, only tracts with at least 5% of the tract showing significant differences are displayed.
- Figure 3.
Differences between IHTT-normal and control groups. Whole-tract differences in FA between IHTT-normal and control groups across all tracts tested. The p values are shown corresponding to the color bar, and results were FDR corrected across all points on all tracts tested (q < 0.05; critical p threshold = 6.5 × 10−4). All tracts showing significant differences are shown. CST, Corticospinal tract; IFO, inferior fronto-occipital fasciculus.
- Figure 4.
Element-wise associations with cognitive performance. Significant associations between element-wise FA and our performance index, covarying for age, sex, and scanner. Results were FDR corrected across all points on all tracts tested (q < 0.05; critical p threshold = 4.42 × 10−4), with CC-frontal as the only tract showing significant effects.
- Figure 5.
Joint effects of FA and IHTT on cognitive performance. Significant results from the partial F test comparing a reduced model (age, sex, and IHTT group) with a full model (age, sex, IHTT-group, and element-wise FA) with cognitive performance as the response variable. For simplicity, only tracts with at least 5% of the tract significant are shown. The F statistic is shown along the tract corresponding to the color bar. PRCG, Precentral gyrus; ATR, anterior thalamic radiation; ILF, inferior longitudinal fasciculus; IFOF, inferior fronto-occipital fasciculus; CST, corticospinal tract.
Tables
TBI Control group (N = 31) Slow (N = 16) Normal (N = 16) Age (years) 13.9 (2.5) 14.5 (3.2) 14.9 (3.0) Gender Male 11 12 17 Female 5 4 14 IHTT (ms) 25.3 (6.2) 7.8 (5.2) 9.3 (5.4) TSI (weeks) 11.6 (4.8) 12.2 (5.2) SAH 4 6 IVH 2 3 EDH 7 5 SDH 6 5 ICH 7 5 Contusion 5 5 DAI 1 3 ICP ↑ 1 4 FX Dep 5 7 ND 6 3 Data are average (SD) or n. We had acute CT scan information for 15 of 16 IHTT-slow and 15 of 16 IHTT-normal participants. SAH, Subarachnoid hemorrhage; IVH, intraventricular hemorrhage; EDH, epidural hematoma; SDH, subdural hematoma; ICH, intracerebral hemorrhage; DAI, diffuse axonal injury; ICP ↑, increased intracranial pressure; FX, fracture; Dep, depressed; ND, nondepressed.
N Mean SD Minimum Maximum IHTT-slow 16 25.31 6.44 18 39 IHTT-normal 16 7.81 5.35 1 16.5 Control 31 9.27 5.45 1.5 19 Total 63 12.98 9.18 - Table 3.
Element-wise differences in WM integrity between the IHTT-slow and control groups, and between the IHTT-normal and control groups
IHTT-slow vs control group IHTT-normal vs control group FA MD FA Tract significance (%) Minimum p Tract significance (%) Minimum p Tract significance (%) Minimum p CC-frontal 18.6 1.86E-08 3.5 1.06E-05 5 1.28E-06 CC-prcg 1.2 1.74E-06 1.3 2.14E-05 CC-pocg 2.1 2.42E-04 8.7 1.69E-06 CC-parietal 2.9 1.94E-06 12.6 4.09E-06 CC-temporal 14 1.94E-06 3.8 2.09E-06 CC-occipital 17.5 5.02E-07 17 6.44E-08 atr_l 0.9 3.96E-04 atr_r 1.9 6.57E-05 2.2 5.26E-06 cgc_l 0.8 8.96E-05 cgc_r 0.9 2.28E-04 cst_l 2.8 3.34E-05 0.8 7.54E-05 cst_r 3.6 3.10E-05 3.2 1.86E-05 ifo_l 12.9 1.07E-06 14.2 4.00E-07 0.9 6.17E-05 ifo_r 7.9 1.09E-05 10.8 1.77E-06 ilf_l 3.8 8.61E-06 31.9 2.43E-09 ilf_r 6 7.31E-06 9.6 5.39E-06 slf_l 2.7 1.05E-04 3.5 7.31E-06 Fornix 1.7 2.67E-04 For each tract investigated, the percentage of the tract that passed the FDR threshold is given (FDR threshold for IHTT-slow vs control FA = 0.0038, for MD = 0.0036, and for IHTT-normal vs control FA = 6.5 × 10−4), as well as the minimum p value for group differences on each tract. pocg, Postcentral gyrus; prcg, precentral gyrus.
Performance index N Mean SD Minimum Maximum IHTT-slow 16 91.38 12.52 76.88 124.5 IHTT-normal 16 99.88 11.04 75.75 114.88 Control 31 104.08 10.75 74.25 128.5 Total 63 99.78 12.28 - Table 5.
The results of our partial F test comparing a reduced model (age, sex, and IHTT group) with a full model (age, sex, IHTT group, and element-wise FA) with cognitive performance as the response variable
Tract significance (%) Average F statistic CC-frontal 16.0 6.4 CC-parietal 3.3 5.2 CC-pocg 4.8 6.3 CC-prcg 5.1 5.3 CC-temporal 4.7 5.5 CC-occipital 2.8 6.5 atr_l 9.7 7.1 atr_r 10.0 7.0 cgc_l 4.9 5.6 cgc_r 6.7 5.4 cst_l 2.4 5.3 cst_r 10.5 6.1 Fornix 3.0 5.4 ifo_l 2.9 5.4 ifo_r 12.8 6.3 ilf_l 3.2 5.4 ilf_r 9.1 6.8 arc_l 4.6 5.4 For each tract investigated, the percentage of the tract with a significant F statistic is given, along with the average F statistic along the tract (nonzero elements). Results were FDR corrected (q < 0.05).
