I had the same problem and I really worried about it, when I explained to my anxiety councillorshe said it was from being worried and tense all day about the bf symptoms and that when I wasjust about to fall asleep my neck muscles would finally relax and it would cause that jerking or falling sensation, scares the heck out of you. She also said it was common with anxiety and shouldhelp convince me even more that its all about anxiety (which is fear or worry which we all have).So now when I get that sensation I feel reassured!This was all told to me months ago and now I see she was right about everything, anxiety is a realkick, go down the path and just see what can happen when anxiety becomes a condition! Twitching,cramping, eye problems,ect... Good Luck, Lefty