I don't think that anyone who knows about Parkinson and related diseases could believe someone would be able to fake this over the years. And certainly nobody would WANT to do that. There are much nicer ways to get attention.

BTW it is classical that there are phases in which the meds work better than in others (I believe they talk about being "on" and "off").

Let's hope that this Limbaugh guy (whom I don't know and whom I don't want to know) does not get one of the more fancy neurogenerative diseases that are likely to come up more often as we all become older.