On the plus side, Mike's impairments played no substantive role in any of the stories or scenes, while still being noticeable. The only time in the whole episode I laughed was at the single direct Parkinson's joke, but that was mainly a nicely-delivered one-liner. Mike throws a napkin at his son, Ian, who is texting at the dinner table:
"If that was Parkinson's, we're cool. If not, what the hell Dad?"
Otherwise, Mike Henry's Parkinson's is just there in Mike Henry's body language and voice. Neither of which are distracting, but I don't "forget" about them, either.
Over time, this approach, with an occasional Parkinson's-centered plot thrown in, can really help "normalize", de-mystify, and de-romanticize this kind of disability. The show has to be funny though to survive, and it's got to make sense, both of which it mostly failed to do this week.