My BIL is an amazing GP - he told me once that most neuros can accurately spot a neurological condition within about 5 minutes of office tests. It sounds like you've been to a few neuros, none of which have seen anything wrong with you. Sure, they're taking your symptoms seriously, but that's because that's what neuros do. They assume if someone is coming to them with symptoms, it could be something serious.
That said, I agree with Shawn that either this guy is a quack or you are misinterpreting what he said. Many common things can cause muscle twitches and spasms that aren't ALS - vitamin issues (very common), stress, lack or sleep, anxiety, exercise, hormones, benign conditions - you name it.
I had this once, by the way. After reading an article about a guy who had ALS, I realized that I'd been having these weird, continuous twitches in my leg. My twitches lasted for weeks, but then they went away. That was about 15 years ago. I think they had something to do with my running and possibly a vitamin issue.
Anyway, stop worrying; stop watching the ALS bucket challenge videos and stop seeing neuro after neuro! Or if you can't stop worrying, set a follow-up appointment for 3 months from now. If it is ALS (and it isn't), you'll notice progressive weakness. If you don't feel any weakness (and you won't), you can cancel your appointment.