[MiBeloved]

Do some research on the astral body and the kundalini force? I wrote a book* recently which has information about this but you can research on Internet and find information.
When your dream body fails to synchronize into your physical sleeping body, the physical body seems paralyzed. Usually this paralysis only last for a few minutes, and then you find that you can again wake as if you are the physical body with the usual control of its movements
Needles are felt, or there is electric sensation or sound sensations if the kundalini energy, the life force in the gross body is aroused.
The experience is vivid because you are in an objective state in reference to the gross body where you usually would get up in it and now you are unable to do so. The dream ended and so you are no longer synchronized over into the dream body, so in a way you are in a state of limbo between the physical reality and the astral one. That gives you the objectivity but it is uncomfortable because you are unable to do what you would do by instinct in such situations, which is to wake up the gross body and be your usual self in it

*Amazon.com: Meditation Pictorial: Michael Beloved: Books