Figure 1. Resting-state connectivity differences between primary progressive aphasia with suspected underlying Alzheimer disease (PPA) compared to dementia of the Alzheimer type (DAT).

(A) Loss of functional connectivity between the inferior frontal gyrus seed is greater in the left hemisphere for the PPA group than the DAT group. (B) Comparing PPA to DAT, the connectivity from left hippocampus to areas of left parietal and frontal cortex is more disrupted in the DAT group and a small region of left posterior lateral temporal lobe is significantly less connected in PPA. (C) There is no difference in functional connectivity between PPA and DAT groups when seeding a node of the default mode network.