Health issues
What is Kleine–Levin syndrome?
Kleine-Levin syndrome (KLS) is a rare intermittent neuropsychiatric disorder (approximately 3 cases per million) that predominantly affects adolescents and young adults. It is characterised by symptomatic periods (“episodes” or “attacks”) lasting from one to several weeks, combining severe hypersomnia with cognitive, behavioural and psychiatric disorders.The episodes are separated by intercritical periods lasting from several weeks to several months, with a return to normal functioning.The course is variable, averaging around twenty episodes, and is often favourable: the disorder frequently disappears after the age of thirty.This favourable prognosis should not obscure the fact that some patients experience very distressing episodes (marked derealisation, sometimes severe behavioural disorders involving hyperphagia, hypersexuality, aggression, delusions or suicidal thoughts), prolonged episodes (lasting more than a month) or very frequent episodes, which affect their school, professional and family life.Furthermore, around one-third of young people develop, as a result of experiencing repeated episodes, persistent mild cognitive impairment between attacks, sleep disorders, anxiety or mood disorders. This is why it is important to make the diagnosis and, often, to treat these disorders.
What are the symptoms?
The classic presentation is that of an adolescent with no previous medical history who suddenly begins sleeping continuously (18 hours or more per day), stays in their room, lying down, confused, slowed down and apathetic (for example, no longer using their mobile phone), and experiences derealisation (the feeling of being in a dream). The episode lasts one or two weeks, after which the young person returns to completely normal. During the episode, varying degrees of severe anxiety, sadness, disinhibited behaviour (megaphagia, hypersexuality, rudeness) or delusional ideas may also occur. Since the first episode is often triggered by an infection or alcohol consumption, the doctor often suspects a viral illness or substance use, performs a brain MRI (normal), sometimes a lumbar puncture (normal), or recommends consulting a psychiatrist. A recurrence of the same symptoms several weeks or months later should suggest Kleine–Levin syndrome.
How is the diagnosis carried out at Erasme?
The diagnosis is mainly clinical: description, observation or video recording of the episodes by the family, and exclusion of other more common diagnoses. However, frequent abnormalities may be observed on the EEG during an episode and on functional brain imaging (PET scan), even during asymptomatic periods: hypometabolism of the posterior association cortex or hippocampus in 70% of cases. Predisposing factors include male sex and neonatal disorders. The cause is unknown, but some indirect evidence suggests that this is a recurrent inflammatory encephalopathy.
What treatments are available?
General management- Explanation of the disease: current knowledge and patient association.- Reduction of factors that trigger episodes: no alcohol or cannabis, sufficient and regular sleep, preventive measures, seasonal influenza and COVID-19 vaccination, and treatment of infections.- In the event of an episode: keep the patient at home, resting quietly in bed and often in the dark, under the supervision of the family, ensuring that they drink enough and eat a little. Urination is maintained. Never drive a vehicle during an episode (risk of an accident). Bring the patient home if an episode begins abroad.- Hospitalisation: only if there is a risk to the patient or others (severe delirium, suicidal thoughts, aggression).Drug treatmentThe treatment is selected and regularly reassessed by the neurologists responsible for the patient’s care. No treatment is also an option. However, on a case-by-case basis, depending on the degree of disability, particularly if the episodes are frequent (> 3/year), prolonged (> 1 month), or involve significant psychiatric symptoms, the following is recommended:Lithium at a therapeutic dose: beneficial in more than 83% of cases. It requires drinking plenty of fluids (water!), regular monitoring of lithium levels, TSH and creatinine levels, and an annual reassessment of its effectiveness. Please note that this disease is unrelated to bipolar disorder. Lithium is then gradually discontinued after 3 years without an episode.Treatment during an episode: intravenous methylprednisolone may be started at a dose of 1 gram/day for 3 consecutive days, with gastric protection.
Who are the professionals involved in your care?
NeurologistsCare pathway coordinator: Prof. Mélanie Strauss. Dr Faustine Lebout Experts in diagnosis, treatment and specialised follow-up.General practitionerFirst-line follow-up and coordination with the specialist.NeuropsychologistComprehensive neuropsychological assessment and coordinated support by Mr Hichem SlamaPsychoeducation. Support in coping with the impact of the disease, self-esteem and social life.Psychologist / child and adolescent psychiatristIn the event of anxiety or depressive symptoms, or difficulties adapting related to the disease.
Useful links
Orphanet (medical information, ORPHA code)
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