I think if you're lacking sleep for a long time you go into kind of an auto-pilot mode. Be careful, though. Lack of sleep can mess with your mind and trigger and episode.

My uncle used to tell me that even if I couldn't sleep, laying down in a dark room and just being "restful" was better than nothing. As long as you can do that, I think you are okay. If your mind is not letting you sleep, that's when I'd really start worrying.