He Had a Temporary Blast of Amnesia. What Was Going On?
Zuchowski had seen a couple of cases of this neurological oddity when she was in medical school in Syracuse, N.Y. But because it was such an unusual diagnosis, she had felt hesitant to suggest it. Still, she was fascinated by how, seemingly out of the blue, patients just forgot the past day, week or year. They don’t forget who they are or any of the basic skills they’ve acquired, like cooking or driving. But they can’t remember the recent past, and they can’t form new memories. This may explain why they so often ask the same questions over and over. The desire to know is there. The ability to hold onto the answer is not.
An Unusual Memory Disorder
T.G.A. was first described in 1956. Why or even how it happens is still not understood. On average, people who experience it are in their 60s. The episodes of memory loss typically last from four to eight hours and are mostly resolved within 24 hours. After that, the ability to form new memories comes back, and memories of the past are restored. The patient, however, will never be able to remember his or her experiences during the hours of memory loss. The events that occurred during that time period were simply never recorded by their brains.
Emotional and physical stress are often associated with T.G.A. This man had been experiencing both: He was going through a difficult divorce, and he had been lifting boxes all morning.
Distinguishing a T.G.A. From a Stroke
How can T.G.A. be distinguished from a stroke? Both can initially show up on an M.R.I. But there are other clues — and Zuchowski thought that in this case, they pointed toward T.G.A. rather than a stroke. First, most strokes are associated with changes in how the body works as well as how the brain works. And those changes are usually limited to one side of the body. In this patient, the only symptom was the memory loss. He was examined many times, by many doctors. None noted any changes in the way his body functioned.
The second characteristic was the repetitive questioning over many hours. That’s rarely seen in strokes and frequently seen in memory disorders like dementia or T.G.A. To the neurologist who was asked to see the patient with the profound but transient loss of memory, this was a classic case of T.G.A. No further testing was needed. In cases in which the symptoms are not as typical, a repeat M.R.I. will show another difference. In a stroke, the lesion revealed by M.R.I. will still be there on the next scan. In T.G.A., the lesion will simply disappear — like the symptoms themselves.
A ‘Twilight Zone’ Feeling
The patient has completely recovered. He remembers everything right up to when he got out of the car at the grocery store. The next thing he remembers is finding himself in a hospital bed, listening to a bunch of doctors. It was as if he walked into the middle of a conversation; as if he were transported in time and space, from the parking lot to the E.R., instantaneously.
The patient is still anxious about his brief episode of amnesia. Why him? Why then? And he is worried that it could happen again. For up to 92 percent of patients with T.G.A., it’s a one-shot deal — it’s the other 8 percent that worries him. The only thing he knows for sure about this weird episode is that he’ll never know what happened in those few lost hours.