I, too, have been more and more interested in inflammation's role in PD. I am convinced that the immune and endocrine systems are at the heart of the problem. A model with prenatal exposure to bacterial endotoxins results in a hypersensitivity to future exposures that triggers the innate defenders in the brain but leaves them with an impaired ability to shut down normally. The same fetus can be exposed to maternal stress hormones and be born with a poorly regulated endocrine system. The natural response to inflammation is for the endocrine system to pump out stress hormones which signals the immune system to cool it. But the altered immune system responds poorly if at all in the brain, so the hormones keep coming until they become a problem themselves. They are cut back but then the immune response flares up again and so a new round begins. This see-saw goes on and on alternately damaging the brain and exhausting the system via the stress response.

By the time we know something is wrong, the immune system has done enough damage to start our motor symptoms and the endocrine system, the most marvelous control network I could ever imagine, is badly out of adjustment and causing all kinds of problems. The net result is our sorry selves, overachieving heroes who collapse at the gates of Moscow or Troy or whatever metaphor suits you.

Every facet of PD that I know of can be explained by this model. For example-
1) PD is common at the community level but rare at the individual level. That is, you aren't likely to have it but are very likely to know someone who does. This is an odd pattern if there is a single cause, but if seen as the end result of a chain of variables it makes sense. Prenatal immune problems won't do it, nor will maternal stress, nor will the two together. Otherwise PD would be more common. But if the timing for both is perfect synchronized with times of fetal vulnerability then the child is vulnerable to further insults and PD exists as a potential. At some point the potential is realized as the scales are tipped by the sum of environmental toxins, stress, pathogens, hyperglycemia, etc etc

Lord, I do go on. But it isn't a simple matter. But, then, we've all noticed that.