In humans, signs of narcolepsy usually begin during a person's teens or early 20s. On occasion, narcolepsy is accompanied by catalepsy, in which a person goes limp without losing consciousness. In every case, however, the attack ends seconds to minutes after it begins. The only known triggers are sudden emotion, such as surprise, laughter, anger, or fear. Patients can experience narcoleptic episodes several or many times a day for life, and while certain drugs can decrease the number of episodes, there is no cure.
Narcolepsy affects males and females equally, and the condition tends to run in families.
They may also shed light on the control of normal patterns of sleep and wakefulness as well. Yanagisawa said his first thought was that the knockout mice were having seizures. The investigators expected that the needles of the EEG would spike wildly during an attack, signaling that the mice were having epileptic-like seizures. The spikes never appeared. A narcoleptic person lapses directly from wakefulness to REM sleep and back to wakefulness.