Fig. 4
Regional [18 F]-FDG PET hypometabolism in bvFTD PPA patients compared to AD PPA patients. Regions of significant differences in hypometabolism between bvFTD PPA patients and AD PPA patients were analysed using conjunction analysis. Results shown at P < 0.001. AD = Alzheimer’s disease; bvFTD = Behavioral variant frontotemporal dementia; PPA: primary progressive aphasia. It can be appreciated that in bvFTD PPA patients, a significantly lower metabolism was observed in the bilateral olfactory cortex, right temporal pole and right superior frontal gyrus (green clusters, indicated with gold arrows) compared to the metabolism observed in AD PPA patients. In AD PPA patients, on the other hand, a significantly lower metabolism was observed in the bilateral parahippocampal gyrus, bilateral lingual gyrus, left posterior cingulate cortex, left supramarginal gyrus, left superior parietal lobule. Additionally, a significantly lower metabolism was observed in AD PPA patients central in the midbrain, located in the region of the mamillotegmental tract