[Robin]

David,

The best book I know of that explains much of this (in lay terms) is Brain Storms by Jon Palfreman. It explains the process of prionization (how misfolded proteins go on to misfold other proteins, spreading like a virus in the body). All of the protein misfolding diseases have this feature (Alzheimer’s, ALS, etc).

https://us.macmillan.com/books/9780374536596

But there is alot of research about PD as an auto-immune disease, where our immune system begins to attack things (like neurons in our brains) it should not be attacking. PD is now considered a constellation of symptoms/syndromes. There is a wealth of info here (and a webinar specifically on the immune system):

https://www.michaeljfox.org/webinars

When I was diagnosed 4 years ago with  young onset, I did a ton of research and immediately started high intensity interval training and eating an anti-inflammatory, autoimmune type diet. I reversed and eliminated all of my non-motor symptoms (which for me looked like Fibromyalgia). Every now and then I get a flare up of non-motor symptoms if I am especially stressed and/or I let up on the exercise and diet. My tremor has progressed, however, because right now there is no known way to stop the prionization process. But what I have seen is that the disease trajectory is highly individualized.

Hope this helps.