hypersomnia
"I had undiagnosed Lyme Disease (and Babesia) for years which created all manner of complications for me.  The fatigue is crippling and I can sleep 16 hours on a bad day, 10-12 average. I took Provigil 200mg twice a day and feel a small effect 3 hours after taking it but it would only last a few hours if it was working at all.  I tried Nuvigil a few days ago.  I know the drug is largely the same with just the delivery system slightly different but it has an enormously different and positive effect on me.  It provides much greater relief from fatigue and much sooner (no more waiting 3 hours to see how Provigil will do for me on any given day).  Unfortunately, Nuvigil hasn't let me sleep much... only about 3 out of the last 38 hours."