January 2021 | Reviewed by: Anne M. Morse, DO and Imran Shaikh, MD
What is Kleine-Levin Syndrome?
Kleine-Levin Syndrome (KLS) is a central disorder of hypersomnolence where patients have periods of severe sleepiness alternating with periods of normal sleep need and wakefulness. You may sleep for as long as sixteen to eighteen hours per day and this can last for a few days or for several weeks. This explains why KLS is often referred to as “Sleeping Beauty Syndrome”. Alternate names include recurrent hypersomnia or periodic hypersomnolence. Despite the prolonged bouts of sleep, you will wake up only to eat and use the bathroom. These episodes can appear weeks or months apart and occur one to ten times a year.
In addition to the severe sleepiness patients may also experience other atypical behaviors such as overeating, aggressive behavior, and other psychiatric features during these episodes. The combination of features can be very distressing and have a negative impact on quality of life. Your sleep and general behavior, however, are normal before and after the episodes.
Severe sleepiness is also a sign of other sleep disorders. It can be a sign of sleep apnea or narcolepsy. In these cases, the complaint of sleepiness is daily. It does not come and go for extended periods of time.
KLS is not caused by something else that disturbs your normal pattern of sleep. It is not a sign of a sleep disorder to sleep all day after having surgery. Maybe you slept all day after staying up all night with a sick child. This is also not an example of a sleep disorder.