I get mindstate-related twitching sometimes, though not to the degree you're describing, and I'm not entirely confident that it's the same phenomenon.

In my case, the mindstate-part that correlates with twitching is very subtle. I wouldn't expect someone who's unfamiliar with closely observing their own mind to be able to notice it at all.

It does seem to correlate with stress, for me, so if you've been pushing yourself a lot in general recently you may want to back off on that for a couple days and try again. You may also want to try emergen-c vitamin supplement or a generic version thereof; a friend of mine suggested that to me when I was dealing with a particularly bad round of stress-related twitchyness, and it helped rather a lot, though that could obviously be psychosomatic.