A diagnosis of exclusion: Transient global amnesia, often called T.G.A. It is a temporary lapse in memory that can never be retrieved. “It’s as if the brain is on overload and takes a break to recharge,” Dr. Brockington said in an interview. She likened it to rebooting a computer to eradicate an unexplainable glitch. Those with T.G.A. do not experience any alteration in consciousness or abnormal movements. Only the ability to lay down memories is affected. All other parts of the brain appear to be working normally.
Though T.G.A. is relatively rare — it affects about five people in 100,000 in the general population — given her specialty Dr. Brockington said she sees one or two patients a week with T.G.A. Nearly all are over 50, and among older adults the incidence is more like 23 cases per 100,000 persons per year, with men and women affected equally.
As one patient, Frank McAndrew, a professor of psychology at Knox College in Galesburg, Ill., reported in Environmental Psychology, his wife became alarmed when he appeared disoriented and confused, and kept asking the same questions over and over again.
Dr. McAndrew wrote, based on his wife’s recall, “Each time I asked a question, I used exactly the same words, voice inflection, and hand gestures. I knew who I was, I knew who my wife was, and I knew who my dog was. The problem was that I could not put anything new into my memory or keep track of anything that had transpired more than a minute or two ago. It was as if my memory erased everything and reset every 90 seconds.” At the emergency room, all tests came back negative, and 24 hours later, he was back to normal.
[Read more about people’s experiences with transient global amnesia, or T.G.A.]
“When T.G.A. happens to people, it’s more terrifying to the people around them,” Dr. Brockington said. “Later, after the event is over and they can’t retrieve the lost memories, it’s more terrifying to the patients. They need to know they have to let it go — their brain wasn’t recording at the time.” No matter how hard they may try, there’s nothing in their memory bank to be recalled.