Sherwood,
Sinemet is often prescribed as a 'test' to see if one responds to it. Often times if the response is positive, the diagnosis is Parkinson's disease.
It sounds like your hubby did not have a positive response to Sinemet. Therefore, I would encourage his doc/neuro to investigate further. You are your hubby's best advocate. Educate yourself by reading, surfing reliable sources on the internet, and questioning the neuro/doc/etc. Ask, ask, ask questions. Learn. Share. Don't assume. YOU are the one in charge of his treatment options, etc. Make sure you are making an educated one (decision).
lizzy4451