I have this problem too and yes, it comes and goes. For me, stress has a lot to do with it. I did find that when I was trying different antidepressants, Paxil really bothered me, but I haven't tried lexapor.
I talked to my dr and asked about Requip but she said I would need to see a neurologist first, so I haven't acted on that.
Like Rowan, I try massaging, baths, walking. I have found that Advil can help sometimes, but I agree it's a nuisance.