I too have a normal blood pressure of 90/60 or lower. I ended up with PD anyway. But that doesn't contradict Ron's assertions.

I didn't know that stress can increase the permeability of the BBB. It can sure explain a lot. The idea of leakage of carbidopa and dopamine is also most enlightening. I have told my various doctors for years that stress impacts my symptoms.

Sometimes, I can feel my symptoms get worse as I experience stress. Last week while talking with my psychologist, I became upset about something and within minutes (maybe seconds) I could feel the pain and stiffness in my neck and shoulders increase. I even told the doctor. This is a case in point of the fact that stress has been a major part of my experience with PD.

Karl