20 month old night terrors

I have a 20 month old daughtor who has been having night terrors since she was 5 months old.  they started after our 3 year old daughtor died of a brain tumor.  they have not been to much of a problem for her just leaves my wife and I without much good sleep as she sometimes has up to 4 in one night.  they have also become more consistant and she has now started to wake up and stay awake for sometimes hours crying and throwing fits.  We are not sure what to do with her or hoe to help her with this problem.  If there is any advice I would greatly appreciate it.

[Encephalomalcia]

Usually night terrors are not continuous for this long of a period of time.  My daughter had night terrors when she was about 5 months, then about 10 months, and then about 14 months.  They were spaced apart.  They are really scary when they look right through you and act like they do not see you.  Have you had her checked by her doctor to make sure there is nothing physical going on?  My daughter would only have one a night, but it lasted anywheres from 1 to 3 hours.  I can imagine how drained you are.  Take care and try to get some sleep when you can.