G69(P) Narcolepsy – an important but rare paediatric diagnosis

Abstract

Aim To present patients investigated for narcolepsy in order to increase awareness of its clinical features. Methods 5 patients referred with possible narcolepsy to the sleep clinic. Results 1. 8 year old boy with excessive daytime sleepiness and cataplexy. HLA typing has shown HLA- DQB∗06:02. MSLT showed short sleep latency. Awaiting lumbar puncture for CSF analysis of orexin level. Commenced on methylphenidate with good response. 2. 6 year old boy with 4 year history of falling asleep quickly including very short distances in the car, at school, and before finishing meals. HLA typing is positive for DQB1∗06-02. Commenced on methylphenidate. 3. 13 year old boy with 5 year history of falling asleep several times a day often missing his bus stop and has recurrent naps in school. Commenced on methylphenidate. 4. 13 year old girl who falls asleep in lessons however related to boredom rather than irresistable desire to fall asleep. Found to be anaemic. Commenced on iron supplementation. 5. 8 year old girl initially presenting with excessive daytime sleepiness with hallucinations on sleeping and waking. She was HLA DQB∗06-02 positive suggesting narcolepsy with hypnagogic and hypnopompic hallucinations. MSLT not diagnostic of narcolepsy but had epileptiform changes on EEG. Commenced on clonazepam with improvement in hallucinations. Conclusion Narcolepsy is an autoimmune neurological disorder characterised by excessive daytime sleepiness associated with cataplexy, hypnagogic/hypnopompic hallucinations and sleep paralysis. This frightening onset of symptoms often occurs in childhood or adolescence with a 10-14 year diagnostic delay. Often multiple misdiagnoses such as hypothyroidism, depression and epilepsy are made along the way. By presenting these patients, the features of narcolepsy are highlighted enabling Paediatricians to consider this as a diagnosis. Better recognition and earlier diagnosis can lead to earlier onset of therapeutic intervention thus leading to a lower impact on academic performance and social development.