I'm also really new to all this -- I will say, that what took me to the dr. in the first place was a concern over heart problems. A lot of a very, almost 'metalic' nerve pain in my left breast/chest and down my left arm into my middle and ring fingers. Some days the pain was so bad I thought I was having a heart attack, but it always felt buzzy, like nerve pain. After going to the ER twice and having three different work-ups, the dr. assured me something else was going on. That pain, combined with a lot of other strange symptoms -- tingling, hot spots, cold spots, numbness, dizziness -- led them to start all the testing for MS. BUT, I personally started to recognize that on the days that I had a lot of diet drinks (and I mean 4-5 in a day), that pain in my chest and arm got much worse. I cut out the diet drinks at the beginning of Sept. and after about a month, that pain started to go away -- now, instead of having that pain 3-4 times a day, I'm getting it only once every couple of weeks. That being said, I don't know if that pain was ms, and the other symptoms have not subsided -- if anything, they've gotten worse -- and that was before my lumbar puncture and mri. But it was that pain that made the dr. think ms in the first place. So, I certainly don't think that diet drinks cause MS, but since they don't know what does, maybe some people are sensitive to certain chemicals that exacerbate the symptoms??