Symptoms of narcolepsy in children misinterpreted as epilepsy

Differentiating an epileptic seizure from some other paroxysmal event is a common challenge in clinical practice. Many paroxysmal events mimic epileptic seizures and misdiagnosis can have disastrous consequences. Incorrectly identifying an event as an epileptic seizure can lead to unnecessary investigations and instigation of inappropriate treatment regimes. We report five patients referred to regional Paediatric Neuroscience Centres for investigation of events initially suspected of being epileptic seizures. All five patients were subsequently diagnosed as having narcolepsy. Suspected diagnoses were absence epilepsy (four patients), generalized epilepsy with astatic seizures (two patients) and focal epileptic seizures (two patients). Diagnostic confusion arose because lack of responsiveness due to excessive sleepiness was mistaken for epileptic absences, and cataplexy was confused with a variety of seizure types. In each case, videotape recording of clinical events aided in making the diagnosis of cataplexy. At presentation, all five children had excessive daytime sleepiness with cataplexy. Following correct diagnosis and appropriate management, an improvement in symptoms was reported in all cases. Narcolepsy/cataplexy should be included in the differential diagnoses of paroxysmal disorders, particularly if there are associated sleep symptoms or behavioural difficulties. It is important to take a sleep history when evaluating any disorder of the central nervous system.