Medical Spanish's word of the day is "el conocimiento," meaning consciousness. To ask, "did you lose consciousness," one would ask, "Perdio usted el conocimiento?" [sic] (I left out the accents.)
I've never heard that used. It's the first time I've come across a phrase on medical Spanish's page that I did not previously know and will have use for.
It makes sense. I think of conocimiento as meaning knowing - not knowledge, really - but being familiar with. So if I think of it in terms of if you've lost the ability to know - that makes sense.