Chris Stimac was a typical high school freshman: athletic, friendly, into science. He loved football and hoped to play it in college. But in the winter of 2003, he got a flu-like illness, which left him somehow changed. Stimac descended into a dark, foul mood, and he couldn’t shake exhaustion. When he wasn’t sleeping, he’d sit in his room in a confused daze, emerging only to use the bathroom or eat insatiably. He could devour entire pizzas at once. And if he didn’t get exactly what he wanted, he would scream obscenities uncontrollably.
The episode lasted only a couple of weeks but the symptoms returned about a year later. After that, the spells recurred several times a year. Between episodes, Stimac labored through catch-up work and avoided dating. Doctors ran several sleep studies but couldn’t figure out what was wrong. Finally, one suggested he go to the Mayo Clinic in Minnesota, which diagnosed him with a classic case of a very rare sleep disorder: Kleine-Levin Syndrome (KLS).
KLS is more common in males and typically strikes in the mid-teens. Researchers are aware of only about 700 cases worldwide. There are two main hypotheses for what causes it, says Emmanuel Mignot, a sleep expert at Stanford University. KLS may be an autoimmune or infectious disease, because it often follows an infection and because it waxes and wanes like a viral illness. Or it may be a metabolic disorder, which would explain the excessive sleep and hunger. Mignot leads a team that is studying about 500 KLS patients to identify genes associated with the disorder. Those genes could help point to a cause and hopefully a treatment. The work could also provide some insight into how the brain controls basic behaviors like sleep, appetite, and sex (because hypersexuality can also be a symptom).
When Stimac reached college, KLS made him miss too much coursework and so he had to drop out his freshman year. “It was wearing me down, stressing me out,” he says. KLS usually fades in a person’s thirties, so although Stimac experienced three episodes last year, he’s cautiously optimistic they’ll soon disappear. Until then, he’s making the most of his time: At 24, he now has a steady job, a new house, and a fiancée.
This article originally appeared in the March 2014 issue of Popular Science.