Veteran journalist Katie Couric has shared an account of a frightening health episode that left her unable to form new memories for several hours, an event doctors diagnosed as transient global amnesia (TGA). Couric described the incident in a recent Substack post, detailing how the temporary memory lapse occurred during the Aspen Ideas Festival.
Couric reported remembering events of the day until approximately noon, with everything thereafter becoming a "big, black hole" until around 7 p.m. During the episode, she struggled to recall basic information, including the name of the sitting president, mistakenly identifying Donald Trump as Joe Biden.
Her husband, John Molner, noticed she appeared "weak and dizzy" after her final panel at the festival. Concerned, he took Couric to the hospital, where medical professionals evaluated her for a potential stroke due to her difficulty recalling the date, the president, and names of family members. An MRI scan ruled out a stroke, and doctors instead diagnosed the condition as TGA.
Transient global amnesia is described by the Mayo Clinic as a sudden episode of confusion in an otherwise alert individual. It is not associated with epilepsy or stroke. According to the National Institutes of Health, TGA affects between 3.4 and 10.4 people per 100,000 annually, with the rate increasing to 23.5 to 32 per 100,000 for individuals over 50.
Neurologists explain that during a TGA episode, a person remains conscious and alert but temporarily loses the ability to create new memories. They typically retain their sense of self, recognize loved ones, and can converse, though they may repeatedly ask the same questions as they struggle to retain information. Dr. Shaheen E. Lakhan, a neurologist affiliated with Beth Israel Deaconess Medical Center, likens the experience to a library where the books and shelves are intact, but the librarian cannot shelve new books for a period.
Potential triggers for TGA are often linked to moments of significant physical or emotional strain. These can include strenuous exercise, lifting heavy objects, sudden immersion in cold water, sexual activity, or experiencing intense emotional shock, grief, or joy. These events are thought to temporarily alter pressure and blood-flow dynamics around the brain, particularly in the hippocampus, which is crucial for memory formation, though the exact mechanism remains unclear.
For most individuals, TGA is a singular event, with an estimated 85% to 95% never experiencing another episode. Lakhan characterizes it as a "software glitch" rather than "hardware damage" to the brain, typically resolving without permanent injury. Medical experts, including Dr. May Kim-Tenser, a professor at the University of Southern California Keck School of Medicine, state that TGA does not increase the risk of Alzheimer's disease, dementia, or long-term cognitive decline, nor is it considered a warning sign of an impending stroke once diagnosed.
Despite its generally benign nature, any sudden, unexplained memory loss should prompt immediate emergency medical evaluation to rule out more serious conditions such as stroke, seizures, or head trauma.