Behavioral variant (bvFTD)
Non-fluent variant primary progressive aphasia (nfvPPA)
Semantic variant primary progressive aphasia (svPPA)
Axial images of the significant change in mean diffusivity over a 12 month period in the three common FTD variant groups after false discovery rate (FDR) correction. These results highlight the increase in mean diffusivity (yellow to red) throughout the brain, particularly in the frontal white matter and cortex for the behavioral variant (bvFTD) group, and in the temporal white matter and cortex for the semantic variant (svPPA) group.
Voxelwise mean diffusivity changes over a 12 month period highlight the rapid changes apparent in the subjects from all three FTD variant groups. The yellow and red colors indicate significantly increased mean diffusivity over the 12 month period after false discovery rate (FDR) correction. In comparison, the control group did not show any significant change over the same period. The exploratory voxelwise analysis highlights a clear spatial distinction of the effects between the three variant groups, with the more frontal lobe changes appearing in the behavior variant group, and the more temporal lobe changes appearing in the semantic variant group, which emphasizes the need for treating them separately in clinical trials.