narcolepsy
"I started Nuvigil 250 mg in the morning, two weeks ago after being diagnosed with narcolepsy. I went from sleeping all night and basically most of the day with extreme napping before the Nuvigil to no naps at all. I don't even feel sleepy. That is a plus.  The first three days were a miracle! I was alert. Colors seemed brighter. I felt focused for the first time in years.  Slowly, I started having afternoon side effects of a dull headache. I feel "car sick" and jittery, and my skull feels actually numb to touch. I hope this subsides soon or I may try halving my dose of 250mg."