Just seen your post. My son suffered from night terrors for about 18 months. We eventually consulted a so-called specialist at Great Ormond St. Hospital, who gave him medication. After one dose, I threw them away because it made him scream with pains in his head! I suffered sleepless nights - literally sleepless - all that time and ended up in hospital myself with suspected MS! Eventually, the terrors ceased as quickly as they started and I started to have good nights too! My so-called MS symptoms stopped!
Years later, I asked my son if he could remember the terrors (we'd never mentioned them to him before) and, to my surprise, he said he could. He explained that he always imagined a brick wall in front of him, which he had to run at quickly in order to smash it down and run through. (That exactly explained his behaviour.) I was amazed that a) he remembered it and b) he recounted it so matter-of-factly.
My advice is stay away from specialists, who want to treat children with drugs. It you can ride the storm, it will pass. I still look back, 24 years later, on a nightmarish time. I think that had I thought more about the way I managed the situation in order to save myself, I might have been spared the illness it caused. Many people will throw their hands up in horror at this but, when my daughter was born, 3 years after my son, I was determined it wasn't going to happen again and she slept in our bed whenever she was upset. Bliss! We all had good nights and everyone was happy. Let's face it, it's only western culture that separates young children from their parents at night!