Although I find the subject of the causes of PD fasciating, and it has practical applications, since it would provide the key to protection against PD, I find I'm way out of my depth in trying to understand, much less evaluate and compare, the Jenner/Marsden/ Olanow et. al. mainstream research theory of a combination of unknown genetic and/or environmental factors vs. the Tanner environmental causes theory vs. the Prusiner prion theory vs. the Suzman virus theory. (Are there any more?) There is a knowledge gap between what is going on in research today compared to what the PWP like me who is trying to follow it all is able to comprehend. I run up against unfamiliar terms such as alpha-synuclein, reactive quinones, Complex I activity of the mitochondrial respiratory chain, microglia, etc., etc. How am I to comprehend the operation of causes, whetever they might be? And what of those lucky people who are exposed to the same causes who never develop the disease? Right now I feel capable of joining the conversation about constipation. Maybe. Phil Tompkins Hoboken NJ age 61/dx 1990