Veteran journalist Katie Couric says a frightening health scare left her unable to form new memories for several hours, an episode doctors later diagnosed as transient global amnesia, a rare condition that typically resolves within one to 24 hours.
In a Substack post published this week, the former “Today” show co-host said at one point during the incident, she struggled to recall who the president was ― naming Joe Biden instead of Donald Trump.
The temporary memory lapse occurred during the Aspen Ideas Festival, where Couric had moderated a panel on artificial intelligence with futurist Amy Webb and later appeared on a discussion about the future of journalism. Couric said she remembers the day’s events until about noon, but everything after that remained “a big, black hole” until around 7 p.m.
“I have no idea what we talked about, or what occurred when the panels ended,” she wrote.
Couric’s husband, John Molner, didn’t pick up anything unusual during her conversations at the conference, but noticed that she appeared “weak and dizzy” after her final panel. Molner took Couric to the hospital, where doctors evaluated the reporter for a possible stroke after she had trouble recalling the date, the president and the names of some family members.
An MRI found no evidence of a stroke. Instead, the doctors diagnosed her with transient global amnesia (TGA).
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How does transient global amnesia occur?
Transient global amnesia, which most commonly affects middle-aged and older adults, is “an episode of confusion that comes on suddenly in a person who is otherwise alert,” according to the Mayo Clinic. The condition is not caused by epilepsy or a stroke.
TGA affects 3.4 to 10.4 people per 100,000 per year, according to the National Institutes of Health. Once you hit 50, the rate of TGA jumps to 23.5 to 32 per 100,000 per year, the NIH said.
People experiencing a bout of TGA remain conscious and alert but temporarily stop forming new memories, explained Dr. Shaheen E. Lakhan, a neurologist in Miami, Florida, affiliated with Beth Israel Deaconess Medical Center.
During all of this, the person remains awake, speaks normally, recognizes loved ones, knows who they are and retains their personality, Lakhan told HuffPost.
“That’s because memory is only one specialized function of the brain, and the rest of the brain continues working remarkably well,” he said.
“Few neurological conditions are as dramatic to witness,” he added. “Family members often describe it as watching someone become trapped in an endless loop, asking, ‘Where are we?’ or ‘What happened?’ every few minutes.”
Lakhan said he tells patients who’ve experienced TGA to imagine their brains as libraries: If you’re experiencing TGA, the books haven’t disappeared, the shelves haven’t collapsed and the lights are still very much on ― it’s just that for a few hours, the librarian can’t shelve any new books.
“Everything else keeps working,” he explained. “You know who you are. You recognize your family. You can carry on a conversation, walk, and perform routine tasks. But because your brain can’t ‘save’ new memories during that window, you repeatedly ask the same questions as though you’re hitting refresh every few minutes.”
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What are the triggers of transient global amnesia?
Lakhan said that one of the fascinating things about TGA is that it often follows moments when life briefly “hits the accelerator.”
It can happen after strenuous exercise, lifting something heavy, sudden immersion in cold water, sexual activity, emotional shock (experiencing grief or joy) or any other particularly straining physical or emotional experience, he said.
“These events all temporarily change pressure and blood-flow dynamics around the brain, particularly in the hippocampus ― the structure responsible for forming new memories ― although we still don’t know the exact mechanism,” he explained.
If you experience transient global amnesia once, how likely is it to occur again?
Scary as that all sounds, for most people TGA is fortunately a one-time event. Roughly 85% to 95% never have another episode, Lakhan said.
“I tell patients to think of it as a software glitch, not hardware damage,” he said. “The brain briefly stops saving new memories, then reboots without leaving permanent injury. It’s generally considered a benign neurological syndrome.”
Evidence does not show that it increases the risk of Alzheimer’s disease, dementia, or long-term cognitive decline, according to Dr. May Kim-Tenser, a neurologist and professor of clinical neurology and neurosurgery at Keck School of Medicine of USC.
It’s also not considered a warning sign of an impending stroke once the diagnosis has been confirmed.
Here’s what to do if you think you’re experiencing transient global amnesia.
Any sudden, unexplained memory loss warrants immediate emergency evaluation.
A doctor will want to rule out stroke, seizures, brain hemorrhage, infections and other neurological emergencies, Kim-Tenser said.
“It is considered benign once diagnosed; however, it is essential that we treat this as a neurological emergency initially to rule out more serious conditions, including a head trauma, if the person was in a motor vehicle accident, or fell and hit their head,” she said.
Once those more dangerous conditions have been excluded, Lakhan said the “good news is that TGA is one of the most reassuring diagnoses a neurologist can make.”