hi
in jan of this year ,i had symptoms simular to hers,,i had drank diet sodas for 15 years,,,i had terrible headaches and nerve issues,,i had a mri,and cat scans and was ruled out for MS,all bloodwork came back normal,,,,It was the aapartame,and it is the worst thing to withdrawel from,,,it took me 2 and a half months to get it out of my system,,google it and read up on it,,,some people can get relief in 2 to 4 weeks,,but i was drinking about 10 cans a day,,i was a sports player,,,,i feel confident,,this is whats going on,,,read about it on the internet,,,the down side is the withdrawel is long,,but its worth it,,,good luck,,i had a lot of dr;s that couldnt figure it out,,,,,,,,but its sounds like it to ,,,get her off that stuff,and encourage here that headaches are normal and tingling,,anf ringing of the ears,,nerve tremors,ect,ect,,google it,,,,pm ,me if you want,,and ill give you my cell number,,,,,,,,,,,,bobber