I came aboard this site looking for the same thing... I had really bad HA in 2006 with all the normal symptoms (chest pain, can't breathe, heavy arms/legs, spaciness, dizzy, etc), but I just had a m/c followed by an immediate pregnancy and I believe the crazy ups and downs of hormones has triggered my anxiety after it was 4yrs dormant.
I have been under a TREMENDOUS amount of stress the past few months from losing a pregnancy, to getting pregnant, to raising my other 4 children, running a business, marital and money problems - etc. I could feel myself started to lose it... then, when I was just sitting there online I realized - wow, my legs and arms would just jerk for no reason. I didn't pay much attention before because I thought it was my coffee, but the panic set in when I realized that I hadnt HAD any coffee in several days due to my new pregnancy. The twitching and jerks then got worse, much more apparent, and turned into jerking while trying to fall asleep.
For two weeks now, things got worse and the anxiety following obsession followed. I have been worried about a neurological problem for weeks now, and that made things worse. I've finally got a grip on things and have been able to make progress in that it's just anxiety and it's subsiding. If I'm moving around, I don't really feel it at all, but when I'm sitting or trying to sleep, of course its there in my face. Getting better by the day, but still, freaky. I'm with you on this one!! So reassuring I'm not the only one, so thanks for helping! :)
I get them in my legs, shoulders/arms, hands, sometimes stomach, and my head will go off to the left. Anxiety, I know it.