pure absence vs simple absence

pure absence and simple absence both are nouns.

Word	Noun	Adjective	Verb	Adverb
pure absence	Yes	No	No	No
simple absence	Yes	No	No	No

As nouns, pure absence and simple absence are synonyms defined as:

pure absence and simple absence: an absence seizure without other complications; followed by 3-per-sec brainwave spikes

pure absence (noun)	simple absence (noun)
an absence seizure without other complications; followed by 3-per-sec brainwave spikes	an absence seizure without other complications; followed by 3-per-sec brainwave spikes