Hi John,
I believe that the duodopa treatment acts on the enteric nervous system, and that is part of why it seems to be proving to be a very good treatment for PD. I guess it could be considered the ENS equivalent of DBS......

More than a few advocates would wish for changes in the way that PD is evaluated, and the systems generally used to 'score' it. So, probably, yes to your question on trials. It may also be one of the reasons that trials fail, such scoring systems may be useful in evaluating where the patient is in terms of his/her progression, but given the slow fluctuating nature of PD could be less effective in tracking how effective the treatment is. Throw into the pot the placebo effect, and things become even less certain...... all very debatable.....

It does not surprise me that the paper you refer to comes from a French team, they are much more relaxed on the continent with colonic stuff, and less prone to the 'yuk' factor. This may explain why duodopa seems to be more available in Europe than in the UK, and why the US is just getting around to making it more available (slow passage through the FDA . It seems to be expensive for what it is though, both to install, and for the running costs of treatment .......

Your other question about whether ldopa can be used for ENS issues is very interesting. There can be abdominal pain in PD that is related to this very problem, but I have not seen much that discusses it, or your question.....
perhaps Braak might go into it .........

Lindy