A patient with transient global amnesia was studied during the acute phase of the attack. The condition is a definite and easily recognized entity characterized by two phases. There is inability to encode recent memories, accompanied by retrograde amnesia of variable duration, with remarkable preservation of recall of distant events. In the recovery phase, the patient regains the ability to encode recent memories but still has amnesia for the events during the acute phase.
Patten BM. Transient Global Amnesia Syndrome. JAMA. 1971;217(5):690-691. doi:10.1001/jama.1971.03190050146016