I have a good friend who also has Parkinsons. He fights it really hard. He takes boxing lessons, dances, hunts both birds and big game. He also works very harden his memory.
None-the-less at this time it is progressive.

I was reading some literature a few months ago and they have discovered a very important break through. They now believe Parkinsons is caused by a bacteria in the gut. Hopefully new medicines will be on the market shortly.

Nothing is foolproof to a sufficiently talented fool.