I also talked to my neurologist about dance as a therapy for P.D. He agrees that it is very beneficial but does not believe that it slows the progression of the disease. My relative's husband was recently diagnosed (he is in his late 60) and I recommended dancing to him and he will go to a special dance class for P.D. So my neurologist added to that the recommendation of no-contact boxing, again specifically for P.D. See
Page not found - Rock Steady Boxing it started in Indianapolis and now is everywhere. And he added a recommendation of a local personal trainer who comes to the homes of patients with P.D. All of these things, per my neurologist, are great to make the disease functionally less debilitating, but they do not slow the progression.
I guess in the end what is important is the burden of the disease, how a person can function and to what extent the person can still enjoy life.