What is Kleine-Levin Syndrome?

Tricia Christensen
Tricia Christensen

Kleine-Levin Syndrome (KLS) is a mystifying neurological disorder most affecting young men and women in adolescence and lasting into young adulthood. KLS produces extended bouts of extreme sleepiness and impaired cognition that is paired with significant reduction in emotional sensitivity. These bouts can last for weeks to months, making it impossible for a person to participate in normal activities, and they can recur, with the condition lasting as long as ten years. With little successful treatment for Kleine-Levin Syndrome, a person may be robbed of their ability to be a full participant in life for years, until recovery occurs.

Long periods of sleep might be caused by Kleine-Levin Syndrome.
Long periods of sleep might be caused by Kleine-Levin Syndrome.

KLS has also been called Sleeping Beauty syndrome and of its symptoms, the most recognizable is hypersomnolence, or very long periods of sleep. A person with this disease may only wake to use the restroom or to eat something, and when awake, behavior is very different than normal. People in the awake state, when experiencing a bout of hypersomnolence, usually are apathetic or unfeeling, and the expression “spaced out” has been used to describe cognitive range.

During these bouts it isn’t possible to simply talk the person out of being sleepy or adopt a “bootstraps” mentality to make them get up. Apathy means emotion can’t be appealed to and the level of understanding may be poor in any case. Even with use of stimulants to wake the person up, the behavioral features may remain present and participating in normal activities could still be difficult or impossible.

In some people, the features of Kleine-Levin Syndrome go farther during the most active bouts of the condition. Some people become hypersexual and they may be less able to observe normal boundaries regarding sex during this time. There’s also higher incidence of overeating, which may correlate to higher weight levels if bouts last long or occur often.

The causes of Kleine-Levin Syndrome aren’t fully understood and some feel the condition is related to disorders like bipolar disorder. To this end, some doctors may treat KLS with mood stabilizers like lithium or carbamazepine. It’s not clear if these are fully successful, though they do prove useful for some people. What is most puzzling is that ultimately, people recover from this disease, usually when they are in their 20s, though some people might still have occasional, less severe episodes.

When KLS does resolve, this often means people must do a lot more to attempt to recover some of the things they’ve lost as a result of the disease. Many people with Kleine-Levin Syndrome have missed out on being able to complete important milestones like high school and college graduation. They may need support to make up for these things so they can pursue life fully. Psychological support is advised, as people with KLS may feel isolated or grieve some of the life they have lost while they suffered these episodes.

Tricia Christensen
Tricia Christensen

Tricia has a Literature degree from Sonoma State University and has been a frequent wiseGEEK contributor for many years. She is especially passionate about reading and writing, although her other interests include medicine, art, film, history, politics, ethics, and religion. Tricia lives in Northern California and is currently working on her first novel.

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Discussion Comments


As someone with KLS, I have not seen any published primary research suggesting it is similar to bipolar disorder. Due to the rarity, medical professionals -- even consultants -- frequently misdiagnose the condition, often believing it to be a psychiatric disorder such as bipolar or chronic fatigue syndrome. However, KLS is a distinct neurological disorder (it is thought to be a dysfunction of the hypothalamus - this regulates sleep, hunger and temperature).

Others with KLS, like me, do not find drugs useful during full blown episodes, stimulants may stop sleep, but still leave severe cognitive and behavior impairment and still need to be cared for to remain safe during this time.

This is a horrid condition to have, especially before it's diagnosed. If you mostly live by yourself it can be difficult to know what's happened since recollection of memory and time are affected.


@stormyknight: I have heard about the KLS foundation. I think that they partnered with Stanford University Sleep Center to start a clinical research program on KLS.

They took clinical data and blood samples from 108 people that have been diagnosed with Kleine-Levin Syndrome. They even took samples from the patients’ parents to study the genetics of it. So far, they have found that 15% of U.S. patients with KLS were of Jewish heritage. That suggests a genetic founder effect with the Jewish population.


There was a foundation established in 1999 called the Kleine-Levin Syndrome Foundation, Inc. to identify and support people affected by KLS. They are trying to raise awareness of KLS. As a matter of fact, they joined in with a FoxTV News affiliate to air a show about a 15 year old boy suffering from KLS. He was in a KLS hypersomnia episode and the family allowed the filming of it.

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