Hi Mary Beth,
It is a very complex topic but an interesting one…
To the extent that holistic means integrated, then some multi pronged approaches fall in that category. On a slightly more esoteric note, has anyone ever heard about the law of attraction?
It is the idea that our thoughts can influence outcomes eg make us sick as well as help us recover (or can change other outcomes in the quantum world of infinite possibilities). I think that instinctively most of us will be ready to believe that negative emotions can create illness. However, possibly fewer of us would dare to say openly that positive thoughts can make us better, especially when approaching complex diseases such as PD.
I am personally very open to such approaches and aim to put them in practice through meditation. I have several experienced partners in this area, who have practiced and taught meditation for many years. This is often associated to concepts such as remote healing that probably gets close to what you referred to.