Okay. You probably can find this advice on line.. but I know from experience night terrors and active sleep events can be the result of many factors. I had them along with sleep walking, fighting and cleaning (my parents loved the 2 am vacuuming and clothes washing.. we had so many pink whites it wasn;t funny).. until I was 15 or 16 years of age. Mine were a side effect of sever sleep apnea that went undiagnosed until I was 32.
My sleep specialist gave me this information on it.. because my son started doing the same thing.. we caught his sleep apnea shortly after and when the tonsillectomy and adenoidectomy didn't cure it.. he was placed on a CPAP at 4 yr and 3 mo. Now he sleeps a solid 10 hours a night with the rare nightmare on occasion. The nightmares occur after growth spurts when the pressure needs to be readjusted to accommodate his growth. Let us first get the definition of Nightmare versus night terror straight between us...
What are nightmares?
Nightmares are scary dreams. Most children have them from time to time. One out of every 4 children has nightmares more than once a week. Most nightmares happen very late in the sleep period (usually between 4 a.m. and 6 a.m.). Your child may wake up and come to you for comfort. Usually, he or she will be able to tell you what happened in the dream and why it was scary. Your child may have trouble going back to sleep. Your child might have the same dream again on other nights.
What are night terrors?
Some children have a different kind of scary dream called a "night terror." Night terrors happen during deep sleep (usually between 1 a.m. and 3 a.m.). A child having a night terror will often wake up screaming. He or she may be sweating and breathing fast. Your child's pupils (the black center of the eye) may look larger than normal. At this point, your child may still be asleep, with open eyes. He or she will be confused and might not answer when you ask what's wrong. Your child may be difficult to wake. When your child wakes, he or she usually won't remember what happened.
Will my child keep having nightmares or night terrors?
Nightmares and night terrors don't happen as much as children get older. Often, nightmares and night terrors stop completely when your child is a teenager. Some people, especially people who have active imaginations and are creative, may keep having nightmares when they are adults. In other cases there is a physical cause for these occurances that need to be treated by a specialist.
When should I worry about nightmares or night terrors?
Night terrors and sleepwalking require that you protect your child during sleep. Be sure your home is safe (use toddler gates on staircases and don't use bunk beds for children who have nightmares or night terrors often).
My parents loved the time I slept walked out of the house and ran about in the pasture in my PJs with the neighbors horses and cows.. I woke up with my dad carrying me home and no clue what was going on.. from then on the kept chain locks out of my reach on the outer doors at night. Nightmares and night terrors in children are usually not caused by mental or physical illness. Often nightmares happen after a stressful physical or emotional event or as a result of severe sleep deprivation due to many common sleep disorders (obstructive sleep apnea being the most common). In the first 6 months after the stressor event, a child might have nightmares while he or she gets used to what happened in the event. If nightmares keep happening and disturb your child's sleep, they can affect your child's ability to function during the day and may be aggravated by a latent sleep disorder.
In the case of a sleep disorder there are over 80 recognized. Snoring is not a requirement.. but active sleep phases where injuries occur is a red flag for a sleep study. RLS, PLMD, OSA.. the list goes on and a one night sleep study can give you alot of answers. Sleep specialist never medicate before understanding ones sleep pattern. In the case of sleep paralysis, sleep apnea, hypopnea and many other sleep disorders.. sleep meds aggravate the situation making sleep deprivation worse and the symptoms worse. In children many sleep apnea patients are misdiagnosed as ADHD because of fatigue inattention and aggressive behavior. ADHD medication has severe side effects in these cases harming the child and aggravating the sleep disorder..
SO over all my advice.. since this has been going on more that 6 mo and your son has active sleep phases.. you need to get him to a sleep specialist for evaluation. See what is actually going on it his sleep states and then work with them on curing it. Why? Given your statements...
He will scream and kick/punch for over half of the night terror. The last 15 minutes or so he gets into a fetal position and cries like he is scared until he gets back to normal. He doesn't remember anything at all and he never really responds when I try and calm him.
This is classic night terror.. He is stuck in between sleep phases and needs proper stimulus to wake from it. Temperature shift is one of the best ways to do it. Have you tried the cold wet towel on the chest and forhead? Also motion change helps with toddlers.. you can pick them up and rock them trigger a reboot of their sleep phase.
These things scare the heck out of me because he will roll around in his sheets and I don't know how he does it but he can get himself into positions with the sheets that can choke him or limit his intake of air. I have to stay in his room each night after I heard him gasping for air just to not take chances. I used to stay out of the room (still looking in the room) for the first half hour unless I wanted bruises, my teeth knocked out or a bloody nose. They scare us all. My son has had sleep apnea since birth. His first 9 mo I slept with him on my chest in a recliner because he would catch and gasp and pause in his breathing. Little did I know this at the time.. that he was stopping breathing 30x and hour. I didn't even know I was stopping breathing over 60x an hour myself. Apnea.. sleep stoppages for any reason is a reason for concern.
Does your son still have his tonsils and adenoids? Does he catch his breathing often in his sleep? Snore? Was he a snorer before the age of 8? Does he sleep with his mouth open? Fall asleep easily on car rides 1 hr +. Do you have anyone in your family with sleep apnea? Even without it.. a CPAP may help keep him from getting stuck inbetween sleep phases and having these night terrors.
I've tried waking him up 20 minutes before he normally has the terrors only to find out it only just delays the night terror. No matter how many times I wake him up if he stays asleep for at least an hour he will have the night terror. Of course as you can guess I cannot stay awake all night nor wake up every 40 minutes from 9pm until 5am or I'll endup in a mental hospital.
There is something in his sleep pattern causing this.. I would bet he has a sleep disorder. Call and find an ABSM certified sleep specialist near you.
Congrats on your promotion.
Hope this was of some help.
Sincerely,
MG
The more I hear of this group the more I like it. In network for us is 10% out of our pocket. The fact that they are encouraging normal routine and follow up at home study speaks well for them.
I am sure you have been through those stages. 
Far too great of a risk riding them now as I'm not sure my heart would make it.
