Introduction: To describe the clinical presentation of ‘Kleine-Levin syndrome’ in a child, who presented with recurrent episodes consistent with encephalopathy, associated with excessive sleepiness, cognitive and behavioural disturbance and hyper sexuality.

Case description: 14 years old boy presented acutely with excessive tiredness, sleeping excessively, abnormal behaviour and hypersexuality following a viral throat infection.

On examination he was sleepy. His neurological examination including fundoscopy and systemic examination was unremarkable. All initial investigation including electrolytes, LFTs, CSF, virology screen and MRI brain scan were normal. Detailed autoimmune screening was negative. EEG showed non-specific diffuse slowing consistent with encephalopathy.

His excessive sleepiness gradually improved together with his altered behaviour in about two weeks after presentation. Hyper sexuality became more overt during this phase. All these symptoms completely disappeared three weeks after his presentation and he attended school as before.

Result: His recurrent symptoms were consistent with ‘Kleine-Levin syndrome (KLS)’ or ‘sleeping beauty syndrome’.

KLS is a rare disorder which mainly affects adolescent males. Common symptoms include hypersomnia (100%), cognitive changes (96%), eating disturbances (80%), hypersexuality, compulsions, and depressed mood. The syndrome usually lasts for 8 years, with on an average seven episode of 10 days each recurring every 3.5 months. It is most frequently precipitated by infections and somnolence decreases using stimulants in nearly 40% of cases.

Conclusion: We believe neurologists should be aware of this (KLS) rare but distinct syndrome as early diagnosis will help us in reassuring patients and their families and will prevent unnecessary investigations.