i believe the twitches your talking about is your body's way of seeing whether or not you are still awake, i get it as well sometimes but i think the key is to, even is your attention is drawn to them, try to ignore them. I know this is very hard to do because the more you think about NOT thinking about it, the worse u feel the need address the problem.

I find that personally when this occurs to me i concentrate on my breathing for a while, not too much though, just enough to forget about the twitching whilst still keeping your mind active.

again im no way an expert on anything but i have read alot and i hope this helps