You are in a difficult situation. I'm sorry that your doctor isn't more helpful. Being misdiagnosed seems to be quite common with PD. There really aren't any definitive tests that can diagnose it.

My symptoms started in my late 40's and I saw numerous neurologists who thought perhaps it was early-stage MS or some other neurological disorder. It took about 10 years before I began falling and then I met a neurologist who suggested I try Sinemet to see if it would help. When it did make a difference in my symptoms, it was decided that I had PD.

Just a thought: Can you travel to a Parkinson's Center of Excellence? It might be worth a one-time consultation to be sure that everything that needs to be tried has been tried. After the initial consultation, perhaps virtual visits might be an option.

Mayo Clinic has three locations, in AZ, MN as well as FL and they treat PD. If you look at the websites that I suggested, you will see other Parkinson's Centers of Excellence as well.

I look forward to hearing from you again. I hope that you are able to find some help for your wife.