I know i am so very late to this but im so happy i finally found something that explains whatever this is. I've been having the same thing, and I've been so confused because no one else gets what I'm talking about! Does your brain feel weird though when you do the sensation? For me it feels like the back of brain goes a bit numb and and the sensation will start usually in my chest area but I can move the feeling. And I definitely get the twitching too, it's only if I do it for too long and let it grow too fast though. I get light headed when I do it though specifically on the right side of my head and lose focus in my eyes. Does your heart beat go faster at all- the twitching and all of this is only if I lose control of the sensation.
Also sorry if I sound stupid at all im just excited to know someone else knows about this too. I will say it's fun to experiment with.
Thank you for sharing this!!