 Early on, if you're just presented with hallucinations, that could be a variety of things, or just the cognitive problems, that could be Alzheimer's versus Parkinsonism, and that becomes a little nebulous. But once you start manifesting the hallmark motor symptoms, slow movement, rigidity, mass facies, hypophonia, I mean, if a med student did not pick Parkinson's on the test, they'd be remediated. Welp.