Do you mean it's like a jerk, jolt awake for a moment and then into sleep? If so, I've had that on and off most of my life from when I can remember. I will often clench my hands so tight the nails dig in my palms and hurt for a moment. It does have a name and is entirely sleep related. It's kind of a mini-moment of epilepsy as the brain goes to sleep. I haven't had it since I've been menopausal. Perhaps because I don't dream anymore either. I miss dreaming.