Absence seizure and Pure absence

Absence seizure noun - The occurrence of an abrupt, transient loss or impairment of consciousness (which is not subsequently remembered), sometimes with light twitching, fluttering eyelids, etc.; common in petit mal epilepsy.

Pure absence and absence seizure are semantically related. In some cases you can replace phrase "Pure absence" with "Absence seizure", this phrases are similar.

Pure absence noun - An absence seizure without other complications; followed by 3-per-sec brainwave spikes.

Absence seizure and pure absence are semantically related. You can use "Absence seizure" instead a noun phrase "Pure absence".