Introduction to Kleine-Levin Syndrome

Kleine-Levin syndrome is an episodically recurrent hypersomnia characterized by increased sleepiness, cognitive disturbances, and paradoxical behaviors during waking hours. There is probably a central nervous system cause. Because of the low prevalence, there is currently no established treatment option.

What is Kleine-Levin Syndrome?

Kleine-Levin syndrome is characterized by recurrent periods of significantly prolonged sleep needs. The periods vary in duration from days to whole months. See AbbreviationFinder for abbreviations related to Kleine-Levin Syndrome.

Doctors know the Kleine-Levin syndrome as periodic hypersomnia in childhood or adolescence. More than two-thirds of those affected are male. Recurring periods of sleepiness are among the cardinal symptoms of the syndrome. The periods of increased need for sleep last around two weeks and are accompanied by disturbances in perception or behavior.

With a prevalence of 1:1,000,000 to 2,000,000, Kleine-Levin syndrome is a rather rare disease whose cause has not yet been fully clarified. Due to the low prevalence, there are hardly any studies or tangible research results. The syndrome is assigned to hypersomnias of central nervous origin. #

So far, science has disagreed on the further classification of the disease. While some understand the syndrome as an autoimmune disease caused by infection, for others the Kleine-Levin syndrome is one of the genetic hereditary diseases.


The cause of Kleine-Levin syndrome is controversial. For example, there is speculation about an autoimmunological cause. The onset of the disease is often associated with an infection. However, it is not yet known exactly which infection could cause the disease.

Since familial accumulation has been observed in the past, a genetic component is also conceivable. Affected people with the corresponding genes do not necessarily have to become ill. However, the genetic disposition for the disease, in combination with an infection, could lead to the onset of autoimmune and central nervous hypersomia.

However, the heredity has not yet been confirmed. A primary infectious cause is also not conclusively secured. A craniocerebral trauma or alcohol addiction could also be observed in connection with the disease. It also remains unclear to what extent and to what extent the increased incidence of illness in male adolescents is related to the cause.

Symptoms, Ailments & Signs

Kleine-Levin syndrome is characterized by recurrent periods of significantly prolonged sleep needs. The periods vary in duration from days to whole months. On average they are two weeks long. Those affected sleep for a large part of the day during these periods and are only awake for two hours a day in acute phases.

In the waking phases, communicativeness and orientation ability suffer. Those affected appear apathetic and lethargic and suffer from food cravings. They can be woken up from sleep, but fall asleep again immediately. They are hypersensitive to noise and light. Hypersexual behavioral disorders are often associated with the main symptoms.

According to their own statements, during acute phases the patients have the feeling that they are actually dreaming. Loss of memory or hallucinations often occur during waking hours. If there are criminal acts in the acute phase, the diagnosis is therefore relevant to reduce the sentence.

Diagnosis & course of disease

The Multiple Sleep Latency Test (MSLT) is the main tool used to diagnose Kleine-Levin syndrome. In addition to a shortened sleep onset latency, the disease shows up in this test as a longer total sleep time and especially as a longer deep sleep phase and the first sleep stage. There is a shortage of SWS phases.

SPECT shows hypoperfusion of the thalamus, basal ganglia, and frontotemporal brain regions. Despite the neurological cause, the findings of the CT or MRI remain unremarkable. In terms of differential diagnosis, the disease must be differentiated from other hypersomnias of central nervous origin. Psychiatric or internal hypersomnias of the secondary form must also be ruled out. The prognosis is considered favorable. Hypersomnia usually subsides in adulthood and only rarely increases symptomatically over the course of the disease.


Unfortunately, Kleine-Levin syndrome cannot be treated causally. This leads to considerable limitations in the life of the patient and also to a reduced quality of life. Most of those affected suffer from sleep disorders, disturbances of perception and imbalanced behavior. The behavior can appear funny and bizarre, especially to outsiders, which often leads to exclusion and other social complaints.

This can lead to bullying or teasing, especially in children. In most cases, the effects of Kleine-Levin syndrome are only felt for a few hours on a few days of the month. This can also lead to ravenous hunger and those affected are extremely sensitive to light. Strong sexual disorders and urges can also occur.

Most patients suffer from memory loss and hallucinations. It can also lead to involuntary injuries or accidents. Some symptoms can be reduced with the help of medication. However, taking the medication can have side effects. It is not uncommon for the parents and relatives of those affected to be affected by mental health problems and require psychological treatment. However, a general prediction of the course of the disease and life expectancy is not possible.

When should you go to the doctor?

People who have phases of increased tiredness or a significantly prolonged need for sleep at recurring intervals should see a doctor. If the waking time is less than 3 hours per day, there is cause for concern. If those affected appear lethargic, have little communication skills or are disoriented, they need help. A doctor’s visit is recommended so that the cause of the behavioral problems can be diagnosed.

If everyday tasks can no longer be carried out as usual, a doctor should be consulted. In case of apathy, loss of appetite or reduced food intake, a doctor should be consulted. There is a risk of an undersupply of the organism, which can lead to further complications. Alternatively, food cravings can be observed in the waking phase of the patient. If the affected persons can only be awakened with difficulty and then suddenly fall asleep again, a medical clarification of the observations is advisable.

Hypersensitivity to noise or light influences are further indications of a health impairment. Patients are often unable to distinguish between dreams and reality. In most cases, a temporary spontaneous healing of the symptoms occurs. Since the symptoms recur at periodic intervals, a doctor should be consulted even if you are already free of symptoms.

Treatment & Therapy

There is no uniform therapy for Kleine-Levin syndrome due to the small number of cases and research opportunities. Since the cause is unknown, there can be no question of a causal therapy. The symptoms can sometimes be treated and relieved with medication. Various medications are available to choose from.

Mood-stabilizing substances include, for example, lithium and carbamazepine or phenytoin. Psychostimulants can also be considered, since their stimulating influence on the nervous system can reduce the patient’s general drowsiness. Substances such as methylphenidate come into question with this aim. The drugs are used off-label and therefore on an experimental basis.

The patient and the parents must be made aware of the experimental basis. Studies have shown that neuroleptics and antidepressants are not promising treatment options. In the past, they hardly showed any therapeutic effect on Kleine-Levin syndrome. Studies have shown that the effects of stimulants such as amphetamines, on the other hand, can reduce the general need for sleep.

Suppression of sleep episodes was also often observed under the administration of lithium. If drug therapy is not desired by the patient or their parents, then supportive therapy can take place. A psychotherapist is made available to the relatives in particular, but also to those affected themselves as part of this therapy. However, the psychotherapeutic care of patients cannot usually take place in acute phases.

Outlook & Forecast

The prognosis of Kleine-Levin syndrome is poor. Despite medical progress and different therapeutic approaches, no optimal treatment option for the disease has yet been found. A healing is therefore not taking place under the current circumstances.

Patients receive individual care after diagnosis. The focus of treatment lies on the one hand in clarifying the possible symptoms and on the other hand in a needs-based approach to the outbreak of symptoms. The difficulty for an optimized prognosis lies in the fact that the cause of the health disorder has not been clarified to this day.

Various observations could be documented as the reason for the disease. Since the disease occurs only to a small extent, open questions, the clarification of which contributes to the progress of finding a solution, can only be answered hesitantly. This circumstance makes it difficult for scientists and researchers to find more concrete approaches to a comprehensive cure.

So far it has been established that a healthy lifestyle contributes to an improvement in development. The mental and psychological well-being should be stable so that a decrease in the symptoms can be mounted. However, there is no recovery. It is helpful and supportive for the further course of the disease if a doctor is consulted at an early stage and thus at the first symptoms. This enables rapid intervention to alleviate existing symptoms.


The etiology of Kleine-Levin syndrome is unknown. Since medicine is unclear about the causes, the syndrome cannot be prevented so far.


In most cases, those affected with Kleine-Levin syndrome have no direct follow-up measures available, so that an early diagnosis by a doctor is primarily necessary for this disease. As a rule, self-healing cannot occur, so that the affected person should consult a doctor as soon as the first symptoms appear. In many cases, a complete cure is not possible because the disease is still largely unexplored.

Those affected are usually dependent on taking various medicines. It is always important to ensure regular and correct intake, whereby the appropriate dosage should also be observed. If anything is unclear or if you have any questions or if you have any undesirable side effects, you should first contact a doctor so that the symptoms do not continue to worsen.

Contact with other people affected by Kleine-Levin syndrome can also be very useful, as it is not uncommon for information to be exchanged, which can further alleviate the symptoms. The loving support and help of one’s own family and friends also has a positive effect on the course of the syndrome. It cannot be universally predicted whether Kleine-Levin syndrome will reduce a person’s life expectancy.

You can do that yourself

Patients with Kleine-Levin syndrome can largely go about their daily lives as normal if the symptoms associated with the disease do not occur. Without acute symptoms, those who are ill can live symptom-free and are completely unremarkable in their feelings, thoughts and social behavior.

However, during the excessive sleep phases, patients can sleep for up to 20 hours, which significantly restricts everyday life. They only get up to eat and drink. As a result, those affected are usually dependent on help. In order to alleviate the phases of the symptoms, patients can avoid specific triggers. These include heavy drinking and lack of sleep. Stress and physical exertion can also trigger the symptoms. Feverish infections should also be avoided, so it is important to strengthen the immune system. A healthy lifestyle with enough sleep and a balanced diet will help.

The drug lithium can help many patients minimize the frequency and severity of symptoms during the sleep phase. It is also important for relatives and friends not to leave those affected alone during the sleep phases. This is also important to avoid patient depression, frustration and isolation. Exchanging ideas with other people affected can be of great benefit.

Kleine-Levin Syndrome