simple absence vs pure absence

simple absence and pure absence both are nouns.

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

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

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

simple absence (noun)	pure 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