NEW RESEARCH: From Dr. Berislav Zlokovic at USC. It's all coming together. Leaky blood vessels, created by pericyte and endothelial cell death, cause neurodegeneration. The Gladstone Lab has published about this in MS. Fibrinogen and plasma particles from a leaky blood brain barrier cause brain damage.
Here's more on Dr. Zlokovic from my blog: http://ccsviinms.blogspot.com/2018/02/400-miles-of-blood-vessels.html

Scientists say leaky blood vessels and the accumulation of fibrinogen in the brain underpin the development of Alzheimer's disease and other dementias