The transient global amnesia is a transient, massive and pure memory disorder. Its pathophysiology is poorly known, but the disease process involves the Papez circuitry, and more specifically the medial part of the temporal lobes (hippocampi). It involves 3-8 per 100,000 people per year. The age of patients affected is between 50 and 70 years. Structural MRI can confirm the diagnosis by revealing a focal and selective lesion located on the CA1 region of the hippocampus better observed between 48h and 72h after onset of the episode.