How often does Benign Cramp Fasciculation Syndrome turn out to be ALS?

[Kim610]

Hi, I'm a 40-year-old woman. I'm having a lot of cramping and some random twitching and it seems that BCFS fits with my symptoms. I've already been evaluated for numbness and tingling that started about nine months ago in my foot and eventually moved to both legs and arms intermittently. For the past two months, my upper arms have been very tight and sore. For about one month, my thigh muscles have very tight as well.  I have some short cramps, but mostly a very tight feeling and soreness, like the muscles are about to cramp.

I'm very worried because I've read a number of studies discussing cases where people were first diagnosed with BCFS, then years later found to have ALS.  Their first symptoms seem to be fasciculations and cramps, suggesting that ALS can and often does first present this way.  To say that I'm terrified is an understatement.   Tyroid, B12, MS have all been ruled out.  Ive called to make an appointment with my neurologist, but I was wondering if anyone here had any knowledge about this.

Thanks,
Kim