I don't know if it's excatly the same, but I have been awake but unable to move the body sometimes, during the moments before/when I fall asleep. When it's happened, I've sometimes seen or - more often - heard persons/objects in my room or outside the window which aren't there. It hasn't been a joy. I cannot recommend this, I use lots of energy to get moving and wake up, and am exhausted afterwards. It's quite normal, or so I've heard, and a friend of mine linked it to astral projection.