Table 2.
Contrast | Cluster no. | Voxels | x | y | z | p-Value | White matter tract/region |
---|---|---|---|---|---|---|---|
Increased axial diffusivity | |||||||
All patients | 1 | 58,082 | 3 | −4 | 10 | <0.001 | Fornix |
bvFTD only | 1 | 50,442 | 2 | 2 | 15 | <0.001 | Fornix |
svPPA only | 1 | 27,988 | 12 | −7 | 3 | 0.002 | Right anterior thalamic radiation |
2 | 2852 | −38 | 1 | 27 | 0.02 | Left superior frontal lobea | |
3 | 36 | 37 | −79 | −2 | 0.05 | Right inferior occipital lobea | |
4 | 33 | 40 | −68 | −4 | 0.05 | Right inferior occipital lobea | |
Increased radial diffusivity | |||||||
All patients | 1 | 68,045 | 3 | −10 | 11 | < 0.001 | Right anterior thalamic radiation |
bvFTD only | 1 | 45,523 | 2 | 4 | 16 | <0.001 | Fornix |
svPPA only | 1 | 48,721 | 4 | −11 | 9 | 0.001 | Right anterior thalamic radiation |
bvFTD > svPPAb | 1 | 443 | 22 | −6 | 14 | 0.04 | Right anterior thalamic radiation |
2 | 361 | 46 | −10 | −22 | 0.05 | Right inferior longitudinal fasciculus | |
3 | 82 | 32 | −31 | 9 | 0.05 | Right inferior fronto-occipital fasciculus | |
Increased trace diffusivity | |||||||
All patients | 1 | 63,092 | 3 | −7 | 10 | <0.001 | Right anterior thalamic radiation |
Decreased fractional anisotropy | |||||||
bvFTD only | 1 | 1557 | −3 | 29 | 5 | 0.02 | Genu corpus callosum |
Diffusion tensor tractography (DTI) associations of altered white matter diffusivity metrics associated with TASIT emotion identification score are summarised. Cluster numbering indexes statistically independent anatomical associations within each contrast generated using the FSL cluster command. Results are corrected for multiple comparisons at whole brain level using family-wise error correction (p = 0.05) and ordered by statistical significance and size (number of voxels in the cluster). Peak co-ordinates and anatomical associations are based on centre-of-gravity of cluster and are displayed in MNI standard space.
bvFTD, behavioural variant frontotemporal dementia; svPPA, semantic variant primary progressive aphasia.
Cluster peak co-ordinates not within JHU ICBM-DTI-81 white-matter atlas (white matter region assigned on visual inspection; other coordinates within white matter tract identified using JHU ICBM-DTI-81 white-matter atlas).
Note here and in Fig. 1, this group interaction contrast is based on an inverse correlation with RD.