Hi Peg,
A few research groups have picked up on it, but very little work is being done compared to the millions being spent on stem cells and the rest.
Maybe my post on "The Role of the BBB in PD" was a bit too long and boring.
If anyone wants to be bored again, it is at
http://neurotalk.psychcentral.com/sh...rier+Ronhutton
and a follow up at,
http://neurotalk.psychcentral.com/sh...rier+Ronhutton
I can't understand why the topic is not investigated more. When I worked in research, the theory that answered the most questions was the front runner. The BBB theory answers the following.

1. Why is PD predominently an old persons disease?
A. Because the BBB ages and becomes more porous with age.
The threshold is passed beyond a certain permeability and you have PD

2 Why does stress accentuate symptoms?
A Because stress has been shown to widen the BBB and a temporary surge of toxins can enter the brain. There is also the possibility that dopamine itself could leak out through the opened BBB into the bloodstream,
robbing you of what little L-Dopa you have, and causing a freeze.

3. Why do the following chemicals cause an exacerbation of PD symptoms?
Nitric oxide, carbon monoxide, organo phosphates (eg sheep dip), etc
A Because they all widen the BBB permeability.

4 Why is curcumin, citicoline, alpha lipoic acid, GDNF, bilberry extract etc
credited with improving symptoms
A They all reduce the BBB permeability

There are other examples, but above are the main ones. If the answer is not the BBB idea, then how else do you explain these facts.
I am continuing to meet and correspond with academics, and I will keep pushing the idea.
Ron