Almost exactly a year ago, I woke up on a Saturday morning, and my
husband "reminded" me that we had the care of our eleven year old
grandson that day because his parents had a party to go to 500 miles distant. (They were taking the younger
child, age 2, with them.)
I didn't remember when he said that that we had agreed to take care of the 11 year old.
Upon further inspection it turned out that I didn't remember much of anything that had happened during the previous five days or so.
So stop now, no one is going anywhere but to the Emergency Room. The son and his wife cancelled their flight plans, and my son showed up at the ER in due course.
Now much of the rest of this story is what people have told me, because not only did I not remember most of the previous week, I was not laying down current memories either.
I apparently kept saying, "Where am I?"
Husband: "The Emergency Room."
Me: "Why am I here?"
Him: "Because you have lost your memory."
Me: "I can't have had a stroke, I have low blood pressure."
Five minutes would pass, and then I would say, "Where am I?" and the whole thing would start over. Such perserveration, I have since learned, is typical, and is in fact diagnostic.
American emergency rooms being what they are, everything proceeded at a snail's pace, since I obviously was in no danger of dying upon the instant. People in the ER are subject to triage and on that scale I fell to a low level of priority. My son showed up in the ER, having already diagnosed the condition on his smart phone (which is even more strange than the event itself if you think about it).
I had Transient Global Amnesia.
"Transient Global Amnesia" is a "diagnosis" only if "my car won't start" is a diagnosis. Neither one of them are, if you think about it. It is not so much a diagnosis as it is a description of the symptoms. It is a "diagnosis" of exclusion, so every test known to modern science was done. MRI. CT Scan. Plus the obvious one-on-one questioning. When nothing whatever can be found we say, but very formally, "this patient has lost some memories but we don't know why."
I can now assure you that there is absolutely nothing wrong with my brain which would show up on any of these high-tech scans.
As the morning and early afternoon wore on, gradually I became able to understand and remember what was happening. The CT Scan I have no memory of. The MRI, which was later, and which required transport to a different hospital, I do remember. Also the anxious faces of my husband and my son. (My husband said later, I thought my whole life had ended.)
By 2 PM I was back. We went to a diner for a hamburger, and everyone went home. I got the week back. All that I lost was most of Saturday morning.
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Transient Global Amnesia (TGA) is by no means rare, occurring at approximately 1 per 100,000 persons. This number is probably understated, since so many cases go unreported. (For some reason the rate is 2 per 100,000 in Scandinavia, possibly merely because of better reporting.) The event typically lasts between 2 and 8 hours, so I was in the median. It has no relationship to later cardiovascular events like stroke or other brain disorders. It does not tend to recur. There does seem to be a weak correlation between TGA and a tendency to migraine headaches, but since we do not have a clue as to what causes migraines this supposed correlation is useless. (I do not get migraines.) There are no after-effects.
Since we are nearly entirely ignorant as to what memory is all about, we are even more ignorant about what happens when it temporarily fails. Since the condition is perfectly harmless, and since research dollars are limited, no one has put a lot of energy or money into figuring out what exactly is going on here.
Just an incident. Like seeing a rare animal in the woods, who immediately vanishes. A fleeting glimpse of mortality.
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Meaning nothing, meaning everything.
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Lots of stuff on the internet. Since no one knows much, a lot of "we are pretending we know something but we don't."