Outside the Baby...Cataplexy.
Cataplexy usually happens when there is sudden weakness of the muscles of the body.
Look at this way, the muscles of the body just suddenly relax, give way, the person just falls and then wakes up.
Before it was poorly understood but now we know what causes it.
There is a small part of the brain called "Hypothalamus" (see pic) that produces a substance called "Hypocretin" which helps in wakefulness, hunger and more.
When this substance is low it can happen.
A notorious condition that can have Cataplexy is a Sleep problem called "Narcolepsy"
You must have seen videos where someone was driving , just falls asleep and has an accident. Yes that is Cataplexy at play in the scenario of Narcolepsy which where they have Sleep problems and Hallucinations.
Other things like brain tumors, brain diseases can cause it etc can
Cataplexy can be dangerous because imagine being at work or working on a staircase, having an episode and falling off.
Needs a Medical intervention