if you trust the author of this document, i think it shoots down some of your hypotheses.
not going to debate you on vascular pd, the MD you mention is well known, he's not hiding, he said he was going to do more operations, where's the beef?

from my personal experience, i had "brain fog" before taking any meds and one of the well documented symptoms of pd before a diagnosis is made is procrastination which i consider mental decline.

https://docs.google.com/viewer?a=v&q...CWmVbwLBC1biDA

if you google "
History, Progress, and Current Treatment of Parkinson's Disease," you can get a better view of the document.