i have idiopathic hypersomnia too!!! you are actually the first person in a very long time that i have heard of with this as well, seeing as this is not so commonly found. I had very similar sleep study results, though my record of continued sleep without wakening is 19 hours consecutively. When I fall in these extreme situations I only wake up starving hungry or I have to desperately go to the bathroom, but then I just immediately fall back asleep once I've finished; do you find this similar to your own situation? I have even been known on more than one occasion to fall asleep on the toilet, in my plate of food, and on my textbook with pencil still in hand. I need on average 12-13 hrs nightly else I build up a sleep deficit, probably only so high because I haven't finished growing yet! But I would love to hear back soon!!!!