Night TERROR!

We have entered a new phase in our house....and it isn't a pretty one.  NIGHT TERRORS!  Grant (almost 5), is waking about an hour or 2 after falling asleep at night.  His pillow and sheets are SOAKED with sweat, his eyes are WIDE with fear and he screams and shakes and looks utterly TERRIFIED!  He isn't easy to wake, almost looks THROUGH you to whatever is scaring him.  It is horrible to watch.  I understand it isn't supposed to be a big deal and that kids usually outgrow it, but I don't like it.  If it is a central nervous system response during sleep, then isn't there something we can do to aide his nervous system?  Scary stuff...will keep you posted.