Here’s something I’ve been working on sporadically for months. It’s a diagram providing a quick-and-easy guide to the major neurodegenerative diseases from the standpoint of PSP and CBD. It’s designed to show laypersons that while PSP and CBD are rare, they can provide researchers important insights into the more frequent diseases. It’s kind of like how an advertisement for a retail business shows how centrally located it is through careful centering of the map.

The diagram’s overall concept should be self-explanatory, though most people will have to hit Wikipedia to learn what many of these specific diseases are. At the lower left is a key showing which colors are diseases and which are commonalities and differences (with respect to PSP/CBD).

Don’t interpret the relative positions of the diseases to mean that one disease is a variant or subtype of the other. The lines only indicate similarity, not necessarily classification. The area where classification is justified, but only incidentally, is that “frontotemporal disorders” is an umbrella term for all of the diseases to which that label is connected, including PSP and CBD.

Also, please be aware that the “Genetic” label means “single genetic causation.” In the case of trisomy 21, it’s a whole chromosome and for NPC, it’s a mutation in one gene acting via a recessive mechanism. Many of these disorders have more subtle contributions to their causation from multiple variant genes in the same individual, each mutation contributing a slight degree of risk.