I'm very familiar with them, and I had this exact thing when I took a boat load of meth and didn't sleep for days; I mean, anyone who takes meth doesn't sleep for days and I'd done plenty before and it didn't happen, but I mean... I took insane amounts in every which way and then I started spasiming like this...
Shit was scary felt like I'd permanently damamged myself or was developing parkinson's no shit, couldn't stop.
Also from ecstasy.
But, only ever a few times... and from INSANE amounts, like, lucky I'm not dead... so seems to be something with like, high levels of stimulants x no sleep. He's done a bananas amount of something here.