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Kleine Levin syndrome

Kleine-Levin syndrome is a rare neurological disorder characterised by recurrent episodes of excessive sleep and altered behaviour. People affected by this syndrome may sleep for up to 20 hours per day (hypersomnia), waking only to eat or go to the bathroom. 

The start of each episode is characterised by progressive drowsiness and episodes may last for days, weeks, or even months. During episodes, other symptoms experienced may include:  

  • Compulsive overeating
  • Irritability
  • Disorientation
  • Lack of energy
  • Lack of emotion
  • Hypersensitivity to noise and light
  • Impulsive behaviour
  • Hallucinations
  • Abnormally uninhibited sex drive.
Episodes are debilitating and during an episode normal daily activities, such as work or school, stop.  On recovery, total or partial loss of memory (amnesia) of what has happened is usual. There may be a short period of depression, or sometimes euphoria and sleeplessness. 
Episodes may not occur for weeks, months or even years, but then reappear without warning.  Between episodes, physical and mental health is usually normal. There appears to be no relationship between Kleine-Levin syndrome and other neurological disorders, such as epilepsy.

This syndrome occurs mostly in young males between the ages of 15 and 25 years. It is uncommon after the age of 40 years. The cause of Kleine-Levin syndrome is unknown.  However, symptoms may be related to malfunction of the hypothalamus and thalamus - parts of the brain that control appetite and sleep. 

Diagnosis and treatment

As disturbance of sleep and altered behaviour may accompany a number of physical and psychiatric conditions, diagnosis of Kleine-Levin syndrome is often difficult and delayed. In order to make an accurate diagnosis a careful medical history needs to be taken and tests to rule out other conditions should be performed. These tests may include blood tests and sleep studies.

The person may be referred to various specialists, including a psychiatrist and neurologist. The neurologist will undertake an evaluation of the nervous system to exclude structural abnormalities of the brain. The psychiatrist will look at any underlying behavioural problems.

Currently there is no formal treatment for Kleine-Levin syndrome due to the lack of knowledge regarding its underlying cause. Stimulant medications, such as amphetamines, may be prescribed to treat sleepiness. Medications to treat mood disturbances and depression may also be recommended.  


Kleine-Levin Syndrome Foundation (2009) Kleine-Levin Syndrome. Kleine-Levin Syndrome Foundation Inc. San Jose.
National Institute of Neurological Disorders and Stroke (2009) Kleine-Levin Syndrome Information Page. National Institutes of Health. Bethesda.
Stanford University School of Medicine School of Narcolepsy (2013) Kleine-Levin Syndrome. StanfordUniversitySchool of Medicine. Stanford.
Last Reviewed – 20 August 2013


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