Home » Sleep Disorders » Kleine-Levin Syndrome

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.

What are symptoms of Kleine-Levin Syndrome?

Signs of illness often show up just before the first attack. You can have headaches and feel very tired just before a sleep attack. These headaches might last for a few hours. Patients often have a red face and sweat a lot during an episode. They can also gain a few pounds of weight. KLS has the most negative impact upon your work and social life.

Patients show odd behavior during the sleep attacks. This includes:

  • Unrestrained “binge” eating
  • Hypersexuality – excessive sexual desire and activity
  • Irritability
  • Aggression
  • Feelings of unreality
  • Confusion
  • Hallucinations

Menstrual-related hypersomnia is a subtype of KLS. Sleep attacks occur at the same time as the menstrual cycle. It shows up just months after the first menstrual period. Episodes tend to last one week and end very quickly. It is likely caused by a hormonal imbalance.