The percent change in regional volumetric data from baseline to 24 months are plotted comparing the three FTD variants, bvFTD (blue), nfvPPA (orange), and svPPA (green), with healthy control subjects (gray) across a subset of the cortical and subcortical regions. The individual dots represent individual subject data, and the lines are simple linear regressions fitted to the change in volume over time for each diagnostic group.
The t-statistic and p-values for the regional volumetric data modeled between 24 months compared to baseline for the three diagnostic groups. The regional data is normalized for intracranial volume, and the statistical analysis model uses both age and sex as covariates. The t-statistics are highlighted in red for regions that are expanding, and from green to purple for regions that show significant atrophy.
The graphs at the top of the page show the regional atrophy across the three FTD variants where we assessed the percent change in volume over a 24 month period. The hippocampus, temporal cortex, and amygdala show rapid atrophy in semantic variants illustrated in green, whereas the behavioral and progressive aphasia variants, blue and orange respectively, progress more moderately. Across most regions, the semantic variants show the most rapid atrophy with up to 15% change from baseline in the hippocampus over the two year period, compared to the 6-8% change observed in the behavioral and progressive aphasia variants. The amygdala mirrors this pattern, showing up to 15% change in semantic variants versus 4-5% in others. The frontal cortex, though less rapidly changing with 5-8% alterations, is more affected in progressive aphasia variants.
The table at the bottom of the page summarizes the t-statistics and p-values for the regional volumetric changes across the three FTD variants. While all regions show statistically significant changes over the 24 month period, the spatial differences across the variants are readily apparent.