Interested to hear about your diagnosis, after the shoulder and neck pain. What are your PD symptoms? I have had chronic arthritis for some years, including shoulder and neck stiffness. It was a hand tremor that caused me to ask about PD, and a Datscan confirmed moderate PD in January. It seems I have probably had it for 5-7 years. My walking is not brilliant, but has not changed much, and most of my symptoms are much as before, although I now have the PD label as well. I am trying to do more exercise which, hopefully, will delay things getting worse.
It seems impossible to separate one problem from the other and to know which needs most treatment. and indeed what treatment. I have been taking Sinemet plus for a month, and imagine that I am walking better - the family says so anyway.
Keep us posted with your progress.