Hi. I read everyones responses and believe you got some really good advice.
Google night terrors and read on it ... it's very interesting. I have three year old triplets and Jay consistently did this and is just now outgrowing it for the most part.
Our Pedi and what I read indicated that over tiredness can stimulate night terrors as well. We were able to pin point the nights Jay would "terror" ..
Be consistent with naps and don't let him get over tired and exhausted and wake him up after he goes to sleep to avoid the cycle he's in. Even if it's just to give him a drink of water ... keep the lights down and low tones, but get him awake, then tuck him back up.
This worked wonders for us. Funny thing is, Jay would be screaming hysterically and kicking and fighting us, before we knew what was going on, and Meg and Sam would never even wake up or hear him.
Like your son, he didn't recognize us and never remembered.
Good luck ... he will outgrow it. Just keep him safe so he doesn't himself. They also told us to try to not stimulate him during the terror.
Take Care,
T.
www.thesiekmantriplets.blogspot.com