Ron said: Is it related to time scale in how long the BBB has been "leaky", ie a very long history of low porosity leakage,l letting in small molecule toxins may give PD, whilst a short term major damage may open the floodgates and admit larger molecules which can cause AZ. It matters whether the compound has an electrical charge, and the size of the molecule.

Is it feasible to think that at any time the "damn could burst" a nd even if just some, not all of it leaks, that could represent the "big drop" that many neuros have warned us about at diagnosis.

Well I guess we have our own little ozone layers.

Can you please explain: "depends on whether the compound has an electrical charge?'

thank you,
paula