A report in the British Medical Journal has highlighted cases where patients with narcolepsy have been mis-diagnosed as having epilepsy.
Narcolepsy is a disorder of sleep associated with excessive daytime sleepiness, involuntary daytime sleep episodes, disturbed nocturnal sleep and cataplexy.
Researchers from Falkirk Royal Infirmary and Edinburgh's Western General Hospital and Royal Infirmary explained that where all the symptoms of narcolepsy were present, diagnosis was straight-forward. However, when patients present with isolated symptoms, epilepsy was sometimes diagnosed in error.
One case study in the report was that of a 26 year old woman who was found in the bath "unable to move, speak or get out". Her husband reported flickering eyelids and muscle twitching. Her speech was slurred, but recovered in the minutes following. When referred to a specalist, it emerged that she had a short history of apparent daytime sleep (occasionally at inappropriate times) and a tendency to "go weak and limp... if she is having a carry-on or laughing heartily". At the time, she was diagnosed with complex partial seizures and was prescribed sodium valproate.
It was later discovered that she had been able to recall the period of immobility in the bath and also described sleep paralysis, hallucinations and that she tended to sleep poorly at night. After tests, it was confirmed that she had narcolepsy. The sodium valporate was withdrawn and she was prescribed Clomipramine which has controlled her cataplexy and her daytime sleepiness has improved on treatment with stimulants.