I'm sure the latter is possible in some way but the common prion-based diseases kill by misfolding functional proteins in the body (or in this case the brain).

I'm sure the latter is possible in some way but the common prion-based diseases kill by misfolding functional proteins in the body (or in this case the brain). As the misfolding spreads, the cells in the immediate vicinity are destroyed and ultimately the surrounding tissue. You can google it if you want, but the end result is a brain that is essentially turned into a sponge with voids throughout.