It appears my DS1 (18months) has been having night terrors.
It started out as only around once a month. But since DS2 has arrived, he seems to be having them every couple of nights. (Uncontrollable screaming and kicking out. Doesn't respond to me or DH. We switch on all the lights, sing but it's like he is in a trance of crying. However from what I've read they are only supposed to last up to15 mins, but DS could be crying for upto 2 hours.
If you had a toddler who had night terrors how did you deal with it? I feel terrible just leaving him. But advice says don't wake them up... 
Tried a bottle of milk, dummy, cuddles in our bed, lights on, story, singing, dancing around while holding him. When he screams sometimes he is waking up DS2 and having two up at the same time is such hard work.