i don't know for sure but i am newly diagnosed and i have been having neck pain for about 3 weeks.. i have never had neck pain before. it started on one side then went to the other and now all over. i used heating pad and took tons of motrin. non worked and then my husband gave me a muscle relaxer. i never take anything like this and i am super sensitive to medications. i took half and had a great deal of relief.!! it is great. it may come back but help for short term. i guess you need to know if it is muscle pain or bone pain. muscle aches are part of hypothyroid. since you say spasm i assume you mean muscle.. see the doc and a muscle relaxer may help.
Neck was a bit stiff for a couple of weeks then it started spams about five or six weeks ago and hasn't let up since,, doesnt do it when she is sleeping and takes about a half hour to get going in the morning.
Nothing works, muscle relaxers, valium, pain killers, nothing, massage does nothing, her neck keeps moving and she walks with it bent to the left.
Xrays show nothing, thyroid checks out, spine is fine, spacing of spine is fine. Doctor called it general anxiety and keeps giving her valium which is hard on her because she isn't used to taking any medications.
Not sure what to do now, she is 45 and needs to get this fixed because she can't go to work now and it is very uncomfortable.