Mind & Brain / Mental Health

The disease sounds as if it came straight out of Grimms’ fairy tales. Teens fall into a slumber, dozing weeks or even months at a stretch. Marathon sleeping spells come and go, cropping up intermittently for roughly a decade. Then, symptoms vanish as mysteriously as they first appeared.

Called Kleine-Levin syndrome, the condition is so rare that only a few cases have been reported in the world medical literature. Though the disorder is little known or understood, a flurry of recent research could change that. A few centuries ago, KLS might have been attributed to a witch’s curse. Now the hunt for its cause focuses on genes and infectious agents.

Stephen Maier is among the unlucky few who know the groggy misery of KLS firsthand. He developed the disorder at age 13, after what seemed like a severe case of the flu. “My parents couldn’t wake me up, and even when they succeeded, I was incoherent,” says Maier. “So they took me to an emergency room.”

Maier was subjected to a battery of tests, but they all came back negative. Two weeks later, he finally woke up and returned to normal life. But the bad dream wasn’t behind him: Extended sleeping episodes of about 10 to 20 days’ duration recurred about every six months throughout his teens. When they occurred, he would spend about 22 hours a day in a haze of sleep. He slept through his high school basketball team’s tournament and his senior prom. Like Rip Van Winkle, Maier emerged from these long spells in bed plagued by a sense of time warp. “Friends and family have to fill me in on what’s been going on in the world,” he says.

By his early twenties, the episodes gradually became less frequent, with his sleep time reduced to about 16 hours a day. During these relapses, though, even when he was awake, he felt like a zombie. “You could drag me to the doctor, but I could barely string together a sentence,” Maier recalls. “Sometimes I’d speak in baby talk.”

Now a 33-year-old accountant in San Jose, California, Maier has not had a recurrence in five years. He hopes that’s the end of it—and he could be right. KLS typically comes on with a vengeance at puberty, gradually abates by the midtwenties, and vanishes altogether by about 30.

“Owing to its rarity, few sleep specialists have seen a single case of the disorder,” says Emmanuel Mignot, an authority on KLS at Stanford University. “For that reason there is skepticism about it in the medical profession, but KLS is without question a distinct disorder, with symptoms that are unique and very consistently manifested by those who fit the diagnosis.”

Like Maier, sufferers often report that the onset of the illness coincides with a flulike infection, leading many doctors initially to mistake the disorder for mononucleosis or viral encephalitis. At regular intervals after that the patient is afflicted by hypersomnia—a sleeping bout that typically lasts around 10 days. In one of the longest episodes on record, one young woman slept nearly a year.

During these periods of hypersomnia, patients usually get up only to shovel food into their mouths, bathe, and take care of bodily functions. Even then, they’re in a hazy, confused state. Light and sound may be irritating, and they have tremendous difficulty focusing. Reading or even holding a conversation is a challenge. A common complaint is that the world seems unreal or strangely off-kilter. “About the only thing I can do during episodes, apart from sleep, is watch mindless videos that I’ve seen a dozen times,” says 17-year-old Eric Haller of Placentia, California, who has suffered bouts of KLS since age 12. “Anything new is too taxing on my brain.”