Hi, watsonsh,
As someone with MS, I don't know a lot about Parkinson's but I'm wondering about the second opinion you're going for. Is that because there is some doubt about your mother-in-law's diagnosis?

Before you go or maybe while you're at the appointment, it might be a good idea to find out how many cases of Parkinson's the doctor treats on average, unless the doctor is already a specialist in Parkinson's. You might be surprised by the number of neurologists who don't really know that much about one particular disorder or other.

Older folks find it harder to tolerate new meds and new procedures. If the doctor wants to prescribe something or do a test that involves a lot of time and discomfort, I'd definitely find out all I could about just how necessary that suggestion is before taking it.

I wish you and your mother-in-law good luck and hope that she will be in the care of a doctor she can have confidence in.