What is Narcolepsy?

Narcolepsy is a disorder of the nervous system in which there is immune system mediated destruction of brain cells that contain hypocretins (aka orexins).  These brain cells are located in a brain region called the hypothalamus (see Figure) and are critical to maintenance of wakefulness, continuity of sleep, and coordination the timing and features of dream sleep (i.e., rapid-eye-movement, or REM, sleep).

Figure. Hypocretin neural pathways