My toddler is 2 1/2. When she was startled awake the other day during her nap she got real shaky. It took her about 10 minutes for it to stop. She was'nt crying or sweaty or running a fever. She did this another time when she was an infant. Does anyone know what could be causing this? The sitter went to check in on her because she heard her start to cry and she rubbed her back and I think it woke her up when she was'nt ready. Has anyone ever heard of this trembling?