Parkinson’s usually impacts just a physical muscle/motor , and usually people with Parkinson’s patient are sharp so they ought to own up to this as an execuse but they are so used to lying
My brother-in-law has Parkinson’s. He needs a walker to get around and has trouble using his cell phone because of the tremors. His mind is still there. Too bad he’s a strong democrat. He also has some incontinence problems, so his outings have to be planned carefully. He is aware of what’s going on fairly well.
It affects sufferers differently, I guess.