Kleine Levin syndrome

Alternate names

Kleine-Levin hibernation syndrome; Familial Kleine-Levin syndrome; Familial hibernation syndrome

Definition

Kleine Levin syndrome is a rare disorder characterized by recurrent episodes of excessive sleep (hypersomnia) along with cognitive and behavioral changes.

Cause

• The underlying cause of this condition is unknown.
• Symptoms may be related to malfunction of the hypothalamus and thalamus, parts of the brain that govern appetite and sleep.

Signs and symptoms

• It is characterized by recurring but reversible periods of excessive sleep (up to 20 hours per day).
• Symptoms occur as "episodes," typically lasting a few days to a few weeks.
• Episode onset is often abrupt, and may be associated with flu-like symptoms.
• Excessive food intake, irritability, childishness, disorientation, hallucinations, and an abnormally uninhibited sex drive may be observed during episodes.
• Mood can be depressed as a consequence, but not a cause, of the disorder.
• Affected individuals are completely normal between episodes, although they may not be able to remember afterwards everything that happened during the episode.
• It may be weeks or more before symptoms reappear.

Diagnosis

• KLS can be diagnosed when there is confusion, apathy, or derealization in addition to frequent bouts of extreme tiredness and prolonged sleep.
• The earliest it can be diagnosed is the second episode, this is not common.
• The condition is generally treated as a diagnosis of exclusion.
• Because KLS is rare, other conditions with similar symptoms are usually considered first.

Treatment

• There is no definitive treatment for Kleine-Levin syndrome and watchful waiting at home, rather than pharmacotherapy, is most often advised.
• Stimulant pills, including amphetamines, methylphenidate, and modafinil, are used to treat sleepiness but may increase irritability and will not improve cognitive abnormalities.
• Because of similarities between Kleine-Levin syndrome and certain mood disorders, lithium and carbamazepine may be prescribed and, in some cases, have been shown to prevent further episodes.
• This disorder should be differentiated from cyclic re-occurrence of sleepiness during the premenstrual period in teen-aged girls, which may be controlled with birth control pills.
• It also should be differentiated from encephalopathy, recurrent depression, or psychosis.

NIH genetic and rare disease info

• NIH info on Kleine Levin syndrome

Kleine Levin syndrome is a rare disease.