WordNet records no synonym and no antonym for transient global amnesia. It is the only member of its synset, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
memory disorder seen in middle aged and elderly persons; characterized by an episode of amnesia and bewilderment that lasts for several hours; person is otherwise alert and intellectually active
Synonyms, antonyms and the broader and narrower relations for transient global amnesia come from Princeton University’s WordNet. Full sources and licences.