As a parent, night terrors in our children can be very upsetting. Our youngest daughter came to us at nine months of age. She would scream the most piercing scream in the middle of the night waking our other children. Our daughter who shares a room with our youngest spent many nights in a sleeping bag on our bedroom floor. I associated her night terrors to her start in life and not getting the attention she needed even though she came to us from a caring foster home. These night terrors have come and gone in her 3 1/2 years of life. Besides hugging her and telling her "mommy's here" and "I love you", I have found that if she can get back to sleep on her own, she sleeps better the rest of the night.
Here are a couple of great articles on night terrors and children.
http://www.babycenter.com/refcap/142.html
http://familydoctor.org/handouts/566.html
Blessings to you,
sherryk