Table 2.
Case-Control mixed model analyses of white matter microstructure – ComBat corrected.
| HC | OCD | Group difference (crude model) | Group difference (adjusted model)* | |||||
|---|---|---|---|---|---|---|---|---|
| M ± SD | M ± SD | B [SE] | 95% CI | P (unc) | B [SE] | 95% CI | P (unc) | |
| CC genu | ||||||||
| Overall diffusion | 0.046 [0.050] | −0.06 | 0.15 | 0.905 (0.389) | 0.023 [0.050] | −0.08 | 0.12 | 0.940 (0.652) | ||
| AD | 1.522 ± 0.052 | 1.523 ± 0.050 | 0.004 [0.090] | −0.17 | 0.18 | 0.963 (0.963) | −0.019 [0.090] | −0.19 | 0.15 | 0.831 (0.831) |
| FA | 0.749 ± 0.036 | 0.753 ± 0.034 | 0.096 [0.090] | −0.08 | 0.27 | 0.664 (0.279) | 0.073 [0.090] | −0.10 | 0.24 | 0.753 (0.403) |
| MD | 0.732 ± 0.035 | 0.730 ± 0.036 | 0.052 [0.090] | −0.12 | 0.22 | 0.638 (0.559) | 0.029 [0.090] | −0.14 | 0.20 | 0.833 (0.740) |
| RD | 0.339 ± 0.046 | 0.336 ± 0.044 | 0.073 [0.090] | −0.10 | 0.25 | 0.608 (0.410) | 0.050 [0.090] | −0.12 | 0.22 | 0.726 (0.565) |
| ND | 0.646 ± 0.040 | 0.649 ± 0.038 | 0.082 [0.090] | −0.09 | 0.26 | 0.898 (0.355) | 0.059 [0.090] | −0.11 | 0.23 | 0.906 (0.499) |
| OD | 0.086 ± 0.009 | 0.086 ± 0.010 | −0.032 [0.090] | −0.20 | 0.14 | 0.833 (0.720) | −0.054 [0.090] | −0.22 | 0.12 | 0.879 (0.533) |
| CC body | ||||||||
| Overall diffusion | 0.083 [0.050] | −0.02 | 0.19 | 0.905 (0.127) | 0.068 [0.050] | −0.04 | 0.17 | 0.940 (0.211) | ||
| AD | 1.508 ± 0.046 | 1.512 ± 0.046 | 0.086 [0.090] | −0.09 | 0.26 | 0.454 (0.333) | 0.070 [0.090] | −0.10 | 0.24 | 0.570 (0.426) |
| FA | 0.735 ± 0.042 | 0.742 ± 0.037 | 0.172 [0.090] | 0.00 | 0.34 | 0.468 (0.052) | 0.156 [0.090] | −0.02 | 0.33 | 0.693 (0.077) |
| MD | 0.727 ± 0.035 | 0.725 ± 0.033 | 0.051 [0.090] | −0.12 | 0.22 | 0.638 (0.567) | 0.035 [0.090] | −0.14 | 0.21 | 0.833 (0.688) |
| RD | 0.353 ± 0.051 | 0.347 ± 0.047 | 0.135 [0.090] | −0.04 | 0.31 | 0.603 (0.126) | 0.120 [0.090] | −0.05 | 0.29 | 0.690 (0.174) |
| ND | 0.655 ± 0.034 | 0.656 ± 0.033 | 0.026 [0.090] | −0.15 | 0.20 | 0.898 (0.772) | 0.010 [0.090] | −0.16 | 0.18 | 0.906 (0.906) |
| OD | 0.083 ± 0.009 | 0.083 ± 0.009 | 0.030 [0.090] | −0.14 | 0.20 | 0.833 (0.735) | 0.015 [0.090] | −0.16 | 0.19 | 0.879 (0.867) |
| CC splenium | ||||||||
| Overall diffusion | 0.029 [0.060] | −0.08 | 0.14 | 0.944 (0.604) | 0.016 [0.060] | −0.09 | 0.12 | 0.940 (0.780) | ||
| AD | 1.586 ± 0.051 | 1.591 ± 0.051 | 0.091 [0.090] | −0.08 | 0.26 | 0.454 (0.303) | 0.077 [0.090] | −0.10 | 0.25 | 0.570 (0.380) |
| FA | 0.834 ± 0.024 | 0.835 ± 0.021 | 0.073 [0.090] | −0.10 | 0.25 | 0.664 (0.411) | 0.059 [0.090] | −0.11 | 0.23 | 0.753 (0.502) |
| MD | 0.699 ± 0.023 | 0.699 ± 0.026 | −0.001 [0.090] | −0.17 | 0.17 | 0.990 (0.990) | −0.015 [0.090] | −0.19 | 0.16 | 0.868 (0.868) |
| RD | 0.243 ± 0.030 | 0.242 ± 0.027 | 0.049 [0.090] | −0.12 | 0.22 | 0.650 (0.578) | 0.036 [0.090] | −0.14 | 0.21 | 0.773 (0.687) |
| ND | 0.724 ± 0.031 | 0.724 ± 0.03 | −0.011 [0.090] | −0.18 | 0.16 | 0.898 (0.898) | −0.025 [0.090] | −0.2 | 0.15 | 0.906 (0.778) |
| OD | 0.070 ± 0.010 | 0.070 ± 0.010 | −0.025 [0.090] | −0.20 | 0.15 | 0.833 (0.775) | −0.039 [0.090] | −0.21 | 0.13 | 0.879 (0.659) |
| Dorsal cingulum | ||||||||
| Overall diffusion | 0.026 [0.070] | −0.11 | 0.16 | 0.944 (0.702) | 0.025 [0.060] | −0.10 | 0.15 | 0.940 (0.703) | ||
| AD | 1.269 ± 0.057 | 1.274 ± 0.055 | 0.102 [0.090] | −0.07 | 0.28 | 0.454 (0.248) | 0.101 [0.090] | −0.07 | 0.27 | 0.570 (0.243) |
| FA | 0.588 ± 0.045 | 0.591 ± 0.044 | 0.068 [0.090] | −0.10 | 0.24 | 0.664 (0.443) | 0.067 [0.090] | −0.10 | 0.24 | 0.753 (0.441) |
| MD | 0.720 ± 0.025 | 0.722 ± 0.026 | −0.068 [0.090] | −0.24 | 0.10 | 0.638 (0.444) | −0.069 [0.090] | −0.24 | 0.10 | 0.710 (0.430) |
| RD | 0.445 ± 0.038 | 0.445 ± 0.037 | −0.012 [0.090] | −0.18 | 0.16 | 0.896 (0.896) | −0.012 [0.090] | −0.18 | 0.16 | 0.887 (0.887) |
| ND | 0.598 ± 0.033 | 0.598 ± 0.033 | 0.016 [0.090] | −0.16 | 0.19 | 0.898 (0.860) | 0.015 [0.090] | −0.16 | 0.18 | 0.906 (0.866) |
| OD | 0.138 ± 0.018 | 0.138 ± 0.017 | 0.048 [0.090] | −0.12 | 0.22 | 0.833 (0.584) | 0.048 [0.090] | −0.12 | 0.22 | 0.879 (0.584) |
| Ventral cingulum | ||||||||
| Overall diffusion | 0.002 [0.060] | −0.11 | 0.11 | 0.968 (0.968) | 0.004 [0.050] | −0.10 | 0.11 | 0.940 (0.940) | ||
| AD | 1.247 ± 0.082 | 1.255 ± 0.079 | 0.101 [0.090] | −0.07 | 0.27 | 0.454 (0.255) | 0.103 [0.090] | −0.07 | 0.27 | 0.570 (0.240) |
| FA | 0.490 ± 0.0470 | 0.490 ± 0.044 | 0.001 [0.090] | −0.17 | 0.17 | 0.988 (0.988) | 0.003 [0.090] | −0.17 | 0.17 | 0.997 (0.971) |
| MD | 0.745 ± 0.051 | 0.749 ± 0.044 | −0.087 [0.090] | −0.26 | 0.09 | 0.638 (0.327) | −0.085 [0.090] | −0.26 | 0.09 | 0.710 (0.332) |
| RD | 0.49 ± 0.053 | 0.493 ± 0.047 | −0.063 [0.090] | −0.24 | 0.11 | 0.608 (0.473) | −0.062 [0.090] | −0.23 | 0.11 | 0.720 (0.480) |
| ND | 0.508 ± 0.039 | 0.506 ± 0.035 | −0.034 [0.090] | −0.21 | 0.14 | 0.898 (0.705) | −0.032 [0.090] | −0.20 | 0.14 | 0.906 (0.717) |
| OD | 0.166 ± 0.022 | 0.164 ± 0.022 | 0.095 [0.090] | −0.08 | 0.27 | 0.833 (0.283) | 0.097 [0.090] | −0.07 | 0.27 | 0.879 (0.267) |
| Posterior thal rad | ||||||||
| Overall diffusion | −0.047 [0.060] | −0.16 | 0.06 | 0.905 (0.402) | −0.051 [0.060] | −0.16 | 0.06 | 0.940 (0.352) | ||
| AD | 1.370 ± 0.049 | 1.374 ± 0.045 | 0.086 [0.090] | −0.09 | 0.26 | 0.454 (0.332) | 0.081 [0.090] | −0.09 | 0.25 | 0.570 (0.354) |
| FA | 0.607 ± 0.030 | 0.605 ± 0.031 | −0.070 [0.090] | −0.24 | 0.10 | 0.664 (0.427) | −0.075 [0.090] | −0.25 | 0.10 | 0.753 (0.396) |
| MD | 0.771 ± 0.030 | 0.775 ± 0.029 | −0.142 [0.090] | −0.32 | 0.03 | 0.638 (0.109) | −0.146 [0.090] | −0.32 | 0.03 | 0.710 (0.096) |
| RD | 0.465 ± 0.034 | 0.469 ± 0.035 | −0.118 [0.090] | −0.29 | 0.06 | 0.603 (0.183) | −0.122 [0.090] | −0.29 | 0.05 | 0.690 (0.164) |
| ND | 0.569 ± 0.037 | 0.567 ± 0.036 | −0.056 [0.090] | −0.23 | 0.12 | 0.898 (0.530) | −0.060 [0.090] | −0.23 | 0.11 | 0.906 (0.495) |
| OD | 0.119 ± 0.012 | 0.119 ± 0.012 | 0.019 [0.090] | −0.15 | 0.19 | 0.833 (0.833) | 0.014 [0.090] | −0.16 | 0.19 | 0.879 (0.872) |
| Sag Stratum | ||||||||
| Overall diffusion | −0.012 [0.060] | −0.13 | 0.11 | 0.944 (0.839) | −0.009 [0.060] | −0.13 | 0.11 | 0.940 (0.886) | ||
| AD | 1.323 ± 0.046 | 1.329 ± 0.043 | 0.133 [0.090] | −0.04 | 0.31 | 0.454 (0.133) | 0.136 [0.090] | −0.04 | 0.31 | 0.570 (0.125) |
| FA | 0.571 ± 0.031 | 0.570 ± 0.032 | −0.004 [0.090] | −0.18 | 0.17 | 0.988 (0.965) | −0.000 [0.090] | −0.17 | 0.17 | 0.997 (0.997) |
| MD | 0.778 ± 0.027 | 0.781 ± 0.028 | −0.124 [0.090] | −0.30 | 0.05 | 0.638 (0.160) | −0.121 [0.090] | −0.29 | 0.05 | 0.710 (0.174) |
| RD | 0.510 ± 0.034 | 0.513 ± 0.034 | −0.067 [0.090] | −0.24 | 0.11 | 0.608 (0.449) | −0.063 [0.090] | −0.24 | 0.11 | 0.720 (0.475) |
| ND | 0.545 ± 0.034 | 0.542 ± 0.035 | −0.061 [0.090] | −0.23 | 0.11 | 0.898 (0.492) | −0.057 [0.090] | −0.23 | 0.12 | 0.906 (0.520) |
| OD | 0.142 ± 0.013 | 0.141 ± 0.012 | 0.050 [0.090] | −0.12 | 0.22 | 0.833 (0.575) | 0.053 [0.090] | −0.12 | 0.23 | 0.879 (0.550) |
| SLF | ||||||||
| Overall diffusion | −0.013 [0.060] | −0.13 | 0.11 | 0.944 (0.835) | −0.027 [0.060] | −0.15 | 0.09 | 0.940 (0.659) | ||
| AD | 1.117 ± 0.032 | 1.119 ± 0.034 | 0.082 [0.090] | −0.09 | 0.26 | 0.454 (0.353) | 0.068 [0.090] | −0.10 | 0.24 | 0.570 (0.443) |
| FA | 0.512 ± 0.028 | 0.511 ± 0.026 | −0.031 [0.090] | −0.20 | 0.14 | 0.936 (0.728) | −0.045 [0.090] | −0.22 | 0.13 | 0.784 (0.610) |
| MD | 0.693 ± 0.022 | 0.694 ± 0.022 | −0.068 [0.090] | −0.24 | 0.10 | 0.638 (0.442) | −0.082 [0.090] | −0.26 | 0.09 | 0.710 (0.352) |
| RD | 0.480 ± 0.028 | 0.482 ± 0.026 | −0.070 [0.090] | −0.24 | 0.10 | 0.608 (0.430) | −0.084 [0.090] | −0.26 | 0.09 | 0.720 (0.341) |
| ND | 0.672 ± 0.031 | 0.672 ± 0.031 | −0.019 [0.090] | −0.19 | 0.15 | 0.898 (0.833) | −0.033 [0.090] | −0.21 | 0.14 | 0.906 (0.709) |
| OD | 0.196 ± 0.012 | 0.195 ± 0.013 | 0.028 [0.090] | −0.14 | 0.20 | 0.833 (0.753) | 0.013 [0.090] | −0.16 | 0.19 | 0.879 (0.879) |
| uncF | ||||||||
| Overall diffusion | 0.079 [0.060] | −0.05 | 0.21 | 0.905 (0.228) | 0.072 [0.070] | −0.06 | 0.20 | 0.940 (0.272) | ||
| AD | 1.246 ± 0.061 | 1.248 ± 0.052 | 0.026 [0.090] | −0.15 | 0.20 | 0.864 (0.768) | 0.020 [0.090] | −0.15 | 0.19 | 0.831 (0.825) |
| FA | 0.503 ± 0.049 | 0.508 ± 0.046 | 0.112 [0.090] | −0.06 | 0.28 | 0.664 (0.205) | 0.106 [0.090] | −0.07 | 0.28 | 0.753 (0.234) |
| MD | 0.767 ± 0.033 | 0.765 ± 0.032 | 0.070 [0.090] | −0.10 | 0.24 | 0.638 (0.427) | 0.064 [0.090] | −0.11 | 0.24 | 0.710 (0.473) |
| RD | 0.532 ± 0.045 | 0.527 ± 0.044 | 0.113 [0.090] | −0.06 | 0.29 | 0.603 (0.201) | 0.107 [0.090] | −0.07 | 0.28 | 0.690 (0.230) |
| ND | 0.503 ± 0.032 | 0.506 ± 0.032 | 0.084 [0.090] | −0.09 | 0.26 | 0.898 (0.341) | 0.078 [0.090] | −0.10 | 0.25 | 0.906 (0.382) |
| OD | 0.154 ± 0.019 | 0.152 ± 0.016 | 0.066 [0.090] | −0.11 | 0.24 | 0.833 (0.458) | 0.059 [0.090] | −0.11 | 0.23 | 0.879 (0.506) |
Reported Tensor/NODDI measures are adjusted for site using Combat and Z-transformed. MD, RD and OD values are inverted so that higher values represent better microstructural integrity. False Discovery rate (FDR) significant differences are marked in bold. P < 0.05, uncorrected significant results are underlined. *Corrected for age, sex and education in years; FA fractional anisotropy, MD mean diffusivity, RD radial diffusivity, AD axial diffusivity, ND neurite density, OD orientation dispersion, SLF superior longitudinal fascicle, CC genu genu of the corpus callosum, CC body body of the corpus callosum, CC splenium splenium of the corpus callosum, uncF uncinate fascicle, Sag Stratum sagittal stratum, Posterior thal rad posterior thalamic radiation.