I may sound totally ignorant here, b/c I do not have MS, I have MG, but when my meds, etc., caused terrible muscle spasms, my neuro recommended potassium. Again, I do not know a whole lot about MS, but am hoping that (maybe) this will help!

Did your neuro want to do a doppler on your leg? When I had my calf problems, he was worried about blood clots and made me go in that day............

Hope this helps!
Take care!
Erin