As a massage therapist i get many who sleep upon their hands and arms who also have neuropathy. none of their doctors have asked them about it, why?

It can happen: Certainly one can get transient paresthesia from such an action but frank neuropathy would seem odd. When you sleep on your hand you are causing a decreased blood flow to the area. In an extreme case this can cause damage and possible neuropathy. I can't say as I have ever had a patient have neuropathy without extensive damage being done to the muscles or skin.