What is KLS ?
KLS is a rare disorder characterised by recurrent episodes of excessive sleep, associated with reduced understanding and altered behaviour. KLS usually starts in the teenage years, but can occur in younger children and adults.
Each episode can last days, weeks or months. Individuals in episode are often not able to care for themselves, attend school or go to work. Between episodes they go back to being themselves with normal sleep, understanding and behaviour.
It can be difficult to diagnose and treat but the impact on young people and their families is devastating.
What are the main symptoms of KLS?
Symptoms vary between individuals with KLS but the following three symptoms have to be present in an episode for a diagnosis;
Excessive Sleep
Excessive Prolonged Sleep (Hypersomnia). Sleep 15 to 22 hours for days, weeks or even months.
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Cognitive Impairment
Confusion, Reduced understanding, feel in a dreamlike state (derealisation).
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Altered Behaviour
Behaviour becomes childlike or different to normal, apathetic and uncommunicative.
Learn MoreOther common symptoms during episode may include changed eating habits, irritable when prevented from sleeping, disinhibited behaviour (swearing, hypersexuality), migraines, hallucinations, anxiety. Some have little or no memory of events after an episode.
Some individuals, generally boys, experience hypersexuality or other disinhibited behaviour. Some experience migraine headaches with hypersensitivity to noise and light. If they are not in their home environment then some may become anxious, aggressive or irritable particularly if prevented from sleeping. Some have autonomic symptoms including disturbed body temperature control, and altered blood pressure and heart rate. Some may have hallucinations and delusions in some bouts. Towards the end of an episode some get depressed and some experience elation and insomnia for 1 to 3 days afterwards.
As KLS is a syndrome, symptoms vary between individuals and episodes.