My reason for asking is that the main problem I had when I first went to the doctor, was that one morning I couldn't raise my head off the bed. I eventually managed it but it juddered into position. I did have neck pain - but that was all it got put down on my records as - which wasn't my concern really, it was the fact that for quite a few days when I tried to raise my head from a lying position I got this strange juddering. I (much) later realised that it corresponded to cogwheeling in limbs but as yet I have never had any clinician do any kinds of tests on my neck.
The funny thing is that this has happened for years but in a different scenario. When at the dentists and they tip the chair back, they usually ask at some point if you will sit up and spit into a cup (sorry!) but they don't raise the chair. When I did that, my head wouldn't come up in the same way and my neck would judder my head. It made me look very, very nervous - but it was a purely physical thing.
Maybe it's not related to Parkinson's, maybe I just have a weak neck!
And yes, I have trouble reversing. Turning my head to the left means it doesn't go very far at all.