I dont' know either, but will say this:

1. our former neuro thought it was a horrible idea to let the patient be in charge of the button that dispensed fast ldopa....

2. we thought this odd, since the patient is already in charge of how much ldopa they get-most neuros give patients quite a bit of leeway (for example, the script might be for 8 sinemet a day but you usually only need six, but can take 8 if you need it that day, etc.)

3. ...until we read reviews of folks in Europe who'd gotten it...almost all of the patients were using way more drug than before, typically 40% more! I think most PWP would feel a lot better too if they were walking around with 40% more ldopa in their system.

So now we understand the concern of our former neuro...also it's major surgery and you have a tube sticking out of you that needs to be kept sanitary, etc. There are downsides.

And, of course, probably what is the real reason: the ldopa gel is horribly expensive and only the wealthy will be able to afford this treatment, it'll run over 100K/year....unless covered by insurance, which gets us to why this hasn't been approved yet in the USA for PD....no insurer wants to have to cover it.