Kleine–Levin Syndrome (KLS)

Kleine–Levin Syndrome (KLS) is a rare neuropsychiatric disorder characterized by persistent episodic hypersomnia, hyperphagia, cognitive impairment, and mood changes. Individuals can also experience hypersexuality, personality changes, and behavioural changes.

• The prevalence of KLS is thought to be extremely rare, perhaps 1 in 1 million.

• Adolescent males are at the greatest risk, and is much more common in males than females.

• Individuals typically present with recurrent episodes of hypersomnia, sleeping up to 18 hours per day.
  • These episodes can last between days to weeks, and can occur between one to ten times per year.
  • During these episodes, individuals typically also have hyperphagia and hypersexuality.
  • Confusion, irritability, aggression, and hallucinations can also occur during these episodes.
• In between these episodes, individuals with have normal sleep and behaviours
• The average duration of these episodes is about 4 years.

• Case reports have suggested the use of gabapentin and carbamazepine, but there are no established treatments.^[1]