F.A.
Hi - I'm sorry for the trouble your little one is having! My son experienced night terrors beginning around 9 mos old. You can tell the difference between night terrors and night mares b/c they occur at different stages of the sleep cycle. Night terrors happen early in the sleep cycle, maybe an hour or two after going to sleep. Nightmares happen later, I think close to when you're waking up. I remember w/ my son, when he was having night terros, his eyes would be open like he was awake, but it was clear he was not. His pupils were really small and unfocused.
At the time this was happening to my son (almost 7 yrs ago), I did some research at the time and found a suggestion that seemed a little like an old wives tale, but harmless so I decided to try it. The suggestion was posted by a parent of a child w/ night terrors that I believe was also a Dr. They said not to try to wake a child during a night terror. The suggestion was to pick up the child and put his/her feet into warm running water. I know it sounds strange! But, I thought it couldn't hurt - so I did. The next time he had a night terror, I picked him up and put his feet under warm running water. He never had another one. Maybe it was a coincidence, but it could be worth a try.
My niece also had night terrors and she had them for years. Eventually, she did outgrow them. Maybe by the time she was 5. I also remember reading that they can be brought on when the child is overly tired.
On a side note: my son has an autism spectrum disorder and had issues calming down at night and falling asleep. I have been using 1 mg chewable melatonin with him for a number of years, and it has been a life saver. It helps him tremendously and it's obvious when he doesn't take it. Melatonin is a natural substance made by the body at night that regulates the sleep cycle. Kids w/ ASD have been found to have melatonin deficiencies.
I hope this helps! good luck!
F.