Table 3.
Results of the post hoc comparisons in the significant tractometric cluster.
| Cluster size (k) | PD-NC (n = 39) | PD-FS (n = 15) | PD-PC (n = 23) | PD-MS (n = 30) | Post hoc comparisons | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| PD-NC/PD-FS | PD-NC/PD-PC | PC-NC/PD-MS | PC-FS/PD-PC | PD-FS/PD-MS | PD-PC/PD-MS | ||||||
| FA—Right superior longitudinal fascicle (part III) | k = 7 | 0.395 (0.035) | 0.389 (0.039) | 0.348 (0.031) | 0.345 (0.032) | pFDR = 0.655 | pFDR = 0.116 | pFDR = 0.072 | pFDR = 0.255 | pFDR = 0.060 | pFDR = 0.071 |
| FA—Right inferior fronto-occipital fascicle | k = 9 | 0.521 (0.061) | 0.497 (0.031) | 0.495 (0.036) | 0.490 (0.054) | pFDR = 0.390 | pFDR = 0.016* | pFDR = 0.016* | pFDR = 0.906 | pFDR = 0.667 | pFDR = 0.451 |
| FA—Left striato-parietal tract | k = 9 | 0.423 (0.030) | 0.412 (0.046) | 0.410 (0.038) | 0.401 (0.041) | pFDR = 0.320 | pFDR = 0.065 | pFDR = 0.002* | pFDR = 0.746 | pFDR = 0.079 | pFDR = 0.274 |
| FA—Tract connecting the isthmus to parieto-temporal cortex | k = 12 | 0.454 (0.049) | 0.443 (0.027) | 0.436 (0.031) | 0.433 (0.030) | pFDR = 0.555 | pFDR = 0.026* | pFDR = 0.006* | pFDR = 0.348 | pFDR = 0.332 | pFDR = 0.706 |
| FA—Tract connecting the genu to frontal cortex | k = 6 | 0.317 (0.028) | 0.303 (0.018) | 0.312 (0.031) | 0.296 (0.022) | pFDR = 0.171 | pFDR = 0.883 | pFDR = 0.002* | pFDR = 0.574 | pFDR = 0.113 | pFDR = 0.090 |
| MD—Tract connecting the posterior midbody of the corpus callosum to postcentral cortex | k = 17 | 0.881 × 103 (0.875 × 104) | 0.891 × 103 (0.574 × 104) | 0.927 × 103 (1.231 × 104) | 0.950 × 103 (1.083 × 104) | pFDR = 1.000 | pFDR = 0.056 | pFDR = 0.004* | pFDR = 0.454 | pFDR = 0.062 | pFDR = 1.000 |
Cluster size (k) represents the number of consecutive segments in the cluster. Columns 3–6 present the mean (and standard deviations) FA or MD values in each cluster for each subtype. FA, fractional anisotropy; MD, mean diffusivity; PD-NC, Parkinson’s disease—normal cognition; PD-FS, Parkinson’s disease—frontostriatal subtype; PD-PC, Parkinson’s disease—posterior cortical subtype; PD-MS, Parkinson’s disease—mixed subtype; FDR, false discovery rate *pFDR < 0.05 (corrected for age, sex, years of formal education, and center).