Thanks for your reply.
No, there's no connection to the taking of meds; it happens at any time of day. Yesterday I had it a lot, today only this evening so there's no pattern to it. (I'm taking meds 3 times a day)
I often get a stiff neck but this is completely different. It's at the front, like it's caving in. It's a very uncomfortable feeling. I guess it's not a common PD symptom as no-one else has replied; so I don't know if it is the PD causing it or if there's something else. I suppose I'll give it another couple of days and maybe go and see the doctor (if I can get in!)
I was hoping someone might have recognised the description.