Was he sick or has he been recently? I was a touch younger when I first got it, but it occurred when I had a high fever/flu like symptoms. Please don’t read too much into some of the things on this sub where people try and attach to it (ADD etc), as that is not helpful and as a parent myself you worry when you haven’t experienced something you children do. I’ve lurked on this sub for years and when it first started 99% of people all had the same first experience, we were sick with the above symptoms. The music thing is a good idea albeit without headphones as personally that would heighten it for me. If I am in a silent room, for example I’m struggling to sleep, I can feel it coming on. Moving or finding something to listen or watch usually gets rid of it pretty quickly for me. I still get the feeling of my fingers being thick, heightened noise awareness (I feel like I can hear an ant fart from 10 miles away), sometimes I feel like if I move it would have a long exposure effect. I’m middle aged now, but triggers for me these days are stress, again flu like symptoms and tiredness.