Overview
Kleine-Levin syndrome (KLS), sometimes called 'Sleeping Beauty syndrome,' is a rare neurological disorder that causes repeated episodes of extreme sleepiness and other unusual behaviors. During an episode, a person may sleep 15 to 20 hours a day for days, weeks, or even months at a time. When they are awake during an episode, they often feel confused, act childlike, eat much more than usual, and may behave in ways that are out of character — including saying or doing things that are sexually inappropriate. Between episodes, most people feel and act completely normal. KLS mainly affects teenagers and young adults, though it can start in childhood or adulthood. Episodes can come and go for years, often triggered by infections, alcohol, sleep deprivation, or stress. The exact cause is not fully understood, but researchers believe it involves abnormal activity in certain parts of the brain that control sleep, appetite, and behavior. There is no cure for KLS, and no treatment has been proven to reliably stop episodes. Some medications are used to try to shorten episodes or prevent them, but results vary. The good news is that most people with KLS eventually see their episodes become less frequent and less severe over time, and many go into long-term remission.
Key symptoms:
Extreme sleepiness lasting days to weeks, sleeping up to 20 hours a dayConfusion or feeling 'in a fog' when awake during an episodeEating much more than usual, often craving sweet or junk foodsChildlike or unusual behavior during episodesInappropriate sexual comments or actions during episodesFeeling detached from reality or like things seem unrealIrritability or aggression when disturbed during sleepMemory problems during and sometimes after episodesDifficulty speaking or finding words during episodesHallucinations in some casesComplete return to normal between episodesMood changes such as depression or anxiety after episodes end
Clinical phenotype terms (35)— hover any for plain English
Sporadic
Usually appears on its own, not inherited from a parent
Juvenile
Begins in the teen years
Treatments
No FDA-approved treatments are currently listed for Kleine-Levin syndrome.
View clinical trials →Clinical Trials
View all trials with filters →No actively recruiting trials found for Kleine-Levin syndrome at this time.
New trials open frequently. Follow this disease to get notified.
Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Travel Grants
No travel grants are currently matched to Kleine-Levin syndrome.
Community
No community posts yet. Be the first to share your experience with Kleine-Levin syndrome.
Start the conversation →Latest news about Kleine-Levin syndrome
No recent news articles for Kleine-Levin syndrome.
Follow this condition to be notified when news becomes available.
Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Questions for your doctor
Bring these to your next appointment
- Q1.How confident are you in the diagnosis of KLS, and what other conditions have been ruled out?,Should I start any medication to try to prevent future episodes, and what are the risks and benefits?,What should I do — and what should I avoid — when an episode starts?,Are there any known triggers I should try to avoid, such as alcohol, sleep deprivation, or infections?,How long do most people with KLS have episodes, and what are the chances of going into remission?,What accommodations can you help me get at school or work during and between episodes?,Are there any clinical trials or research studies I could participate in?
Common questions about Kleine-Levin syndrome
What is Kleine-Levin syndrome?
Kleine-Levin syndrome (KLS), sometimes called 'Sleeping Beauty syndrome,' is a rare neurological disorder that causes repeated episodes of extreme sleepiness and other unusual behaviors. During an episode, a person may sleep 15 to 20 hours a day for days, weeks, or even months at a time. When they are awake during an episode, they often feel confused, act childlike, eat much more than usual, and may behave in ways that are out of character — including saying or doing things that are sexually inappropriate. Between episodes, most people feel and act completely normal. KLS mainly affects teenag
How is Kleine-Levin syndrome inherited?
Kleine-Levin syndrome follows a sporadic inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Kleine-Levin syndrome typically begin?
Typical onset of Kleine-Levin syndrome is juvenile. Age of onset can vary across affected individuals.
Which specialists treat Kleine-Levin syndrome?
16 specialists and care centers treating Kleine-Levin syndrome are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.