My son is 3 years 9 months old since he turned 3 he has had these night terrors on and off but recently they are nearly every night! They terrify me. He will sit up eyes wide open, staring into space looking terrified, points in the corner shouts random things and throws himself about. He goes all stiff as well and shakes sometimes. Literally like he is possessed. He can sometimes have more than one a night. He also sometimes just sits up in his bed talking and then lies back down. He never remembers the next day. It is always an hour or 2 after bed they start has anyone else experienced this and any tips how to help him ?