This is a copy (below) of my reply to a similar question this week from another Mom. I think it applies in your situation as well as it seems like much more than typical night terrors. From the time I was a small child I was always known to make tons of noise while asleep, talking, crying, yelling out, etc. and also thrashing about while asleep. I wish I had been assessed by a sleep doc decades before I was, as on the worst nights I was always tired and had a lack of energy the following day.
Best wishes ~ J
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Hi,
I suffer from a sleep disorder (a hereditary one) called parasomnia. It is as she described, that during REM sleep when most people are 'paralyzed' I have full motor function, see things that aren't there, talk, walk around the house, etc. While it has provided much content for family jokes over the years, I wasn't diagnosed until my mid-twenties. It's a simple medication taken at bedtime (and anti-convulsive) which doesn't make me drowsy but simply helps the part of my brain that needs to tone itself down to indeed do so at the correct time during my sleep cycle.
When I was diagnosed (during an overnight sleep study) and started the treatment I never realized how much of my energy and life I had been missing since I was a child. Since my Mom has been subsequently diagnosed (10 years after I was), it seems we both thought that our many awakenings during the night and strange vivid dreams were just normal, and what everyone has! How wrong we were :)
My suggestion is to get to a sleep specialist, typically they are also neurologists. If you are in the DC area, the best of the best is Dr. Helene Emsellem's practice, in Bethesda. It's called the Center for Sleep and Wake Disorders, and their website is www.sleepdoc.com. It is a nice practice, and they treat many children - I would not hesitate taking my daughter there, but so far at 7 months she seems to have gotten her sleep habits from her father :) {if you are not able to come to MD, then I would suggest asking this doc for a referral to a practitioner in your area.}