This post is on narcolepsy.
For those who don't know, narcolepsy is characterized by:
Excessive daytime sleepiness (Associated with dozing off, or so-called "sleep attacks")
Hypnagogic hallucinations occurring when falling asleep (GOing to bed)
Hypnopompic hallucinations occurring when waking up (POMPing out of bed)
Cataplexy (emotionally triggered transient muscle weakness)
Sleep paralysis (Inability to move for one or two minutes immediately after awakening.)
It is caused by decreased hypocretin / orexin production by the lateral hypothalmus.
Orexin, also called hypocretin, is a neuropeptide that regulates arousal, wakefulness, and appetite.
Here's a mnemonic!
Fun fact: Orexin, from orexis, means "appetite" in Greek. Probably, anorexia is derived from no orexis! :D