Figure 6. Effect of increased functional connectivity in secondary atrophy sites.

Theoretical interpretation of simultaneous longer atrophy and shorter functional path length in AD. Initial correlated atrophy between vertices (1) is decoupled due to compensatory functional connectivity involving secondary atrophy vertices (2). The appearance of new functional edges (3 - shorter functional L) results in preserved functionality of secondary atrophy vertices (4) and the disappearance of cortical thickness edges linking to the primary atrophy vertex (5 - longer structural L). The rerouted functional flow could still gain partial access to the primary atrophy site and the rest of the network (6).