I also noticed it happens more often when bending, leaning, turning, or twisting and it does happen in the middle of the night if I were to roll over and twist ... I too compared
it to a leg cramp in my head when that happened.
My doctor did bloodwork and didn't mention any deficiencies, so I'm not sure what to think here, but I'd really like this to stop happening. I'd say it's happening once or twice a week no matter what I try to change or do to improve it.