Fasciculations are listed as LMN signs. I may be an odd case, but one of my first indications of ALS was fasiculations in my left arm. The muscles between the thumb and wrist form what is called the thenar eminence and that was among the first areas where I showed atrophy. Later I had lots of fasciculations in my legs, but thirty years of very, very slow progression later, guess which muscles are hanging in there? Yes, my left lower arm is the strongest of my extremities! My leg strength went first, and now my right arm doesn't have any functional ability -- but my left lower arm can still move enough to push a mouse around! I can't lift it but it is a big help in using the computer. I am not a typical ALS patient in terms of speed of progression, but the order of areas affected has been very typical. So as far as fasciculations being predictive, they weren't for me. This little bit of anecdotal evidence, is, like all anecdotal evidence, not proof, but maybe enough to hang a bit of hope on.