Last two nights my child woke up with quivering bottom lip, mouth full of saliva,unable to speak and in a trancelike state for several minutes until he becomes aware of his surroundings. He tries to speak but cannot and after several moments when he can it is garbled sounding. His lip quivering is not controllable and he spits out large amounts of saliva. Both times these episodes lasted 20 mins until normalcy returns. This May or may not be related but he often makes a clicking noise while he is sleeping.
Kindly mention age of your child. Is he attending school?These episodes are recent - speak with him if he has some bad Chat Doctor.  Reassure him. Child may not open up in one go. Spend some time with him to find what is happening in his life. If he tells some things believe him and let him know that you truly believe him. Clicking noises made are quite possibly due to the same reason, or you may even check for worm infestation. Keep a close watch on him and his surroundings. If any the symptom arises consult a local doctor.