Narcolepsy

Narcolepsy ... described as irresistible and may occur with or without warning when a person is driving, working, eating, talking, or engaging in any other activity. Most patients also experience persistent daytime drowsiness. Excessive daytime sleepiness is usually the first symptom of narcolepsy and often the most difficult symptom to control. The severity of excessive daytime sleepiness varies; some patients may have many sleep attacks each day and others only one or two sleep attacks per day.