Transient global amnesia (TGA) refers to the abrupt onset of an inability to form new memories that lasts less than a day. Patients with TGA typically have no difficulties recognizing family members, and can recall things from the past. By definition, these problems clear over time.
There are several causes of TGA; the most common are migraine or a temporary interruption of the blood supply to the brain. Accurate diagnosis usually involves imaging of the brain to determine the status of the brain’s blood vessels.