Figure 4.

Model of late-onset tau-first AD. The red, blue, and yellow curves represent the evolution of amyloid, tau, and neuronal biomarker levels, respectively, over the course of the disease. In (a) (adapted from [6] with permission), the blue and yellow lines are combined into a single purple line, per the original theory in which tau was considered a neurodegenerative marker. The green curves represent cognition in two hypothetical high- and low-risk groups, based on cognitive reserve. The CCM (b) closely matches the trajectories proposed in the literature (a).