One evening last fall, Dave*, in his early 60s, came downstairs for dinner, looked around the house he and his wife Nancy had lived in for nearly two decades, and said, “Where are we? I don’t recognize this place.”
Dave pointed to the dog in their kitchen and asked, “Who’s that?” The canine, Rosie, belonged to Nancy’s mom; the couple had taken care of her for three weeks during the summer. For a moment, Nancy thought her husband was joking or being difficult. He knew who she was, but she recognized genuine confusion in his eyes. Nancy got scared. As she drove Dave to the hospital, she thought of her father, who has Alzheimer’s disease. She wondered whether life was about to change forever. She became more frightened when, at the hospital, Dave kept repeating, “Why are we here?” even though she’d patiently explained dozens of times that they were there because he’d lost a big chunk of his memory.
[See: 13 Ways to Improve Your Memory.]
Sudden Memory Loss
Fortunately, Dave wasn’t suffering a stroke and he didn’t have dementia — both of which can cause memory loss. Doctors determined he’d had a bout of transient global amnesia, or TGA, a sudden, temporary loss of memory that’s typically short-lived, lasting about 24 hours. People experiencing TGA remember who they are and people they know well, but they can lose other recollections and can’t form new memories. They likely won’t know where they are or how they got there, and memory of recent events will appear to vanish. People with TGA might sound like a broken record, asking the same questions repeatedly.
In order to diagnose someone with TGA, physicians look for these symptoms: sudden memory loss, verified by a witness; the retention of personal identity despite the memory loss; normal cognitive abilities, such as being able to recognize and name familiar objects and follow simple directions; and an absence of problems like limb paralysis or involuntary movement, which suggest damage to a particular part of the brain, according to the Mayo Clinic.
There’s not an abundance of research on TGA, but people with a history of migraines have a significantly higher risk of developing the condition than those without. Other possible causes include mild head trauma from a fall, acute emotional distress (perhaps from working too hard), medical procedures such as an endoscopy and strenuous physical activity, according to the Mayo Clinic. “The answer is we don’t know everything,” says Dr. Clifford Segil, a neurologist at Providence Saint John’s Medical Center in Santa Monica, California.
The kind of amnesia we typically hear about, which refers to the loss of memories and can be permanent, is far more common than TGA.
[See: 9 Foods That Can Keep Your Brain Sharp.]
An Unusual Condition
TGA cases are unusual but not rare. “Almost all neurologists have seen cases like this,” says Dr. Mark Hallett, senior investigator at the National Institute of Neurological Disorders and Stroke at the National Institutes of Health. The incidence in the U.S. is about 5 to 10 cases for every 100,000 people in the population, according to research. That number spikes to 23 cases per 100,000 people age 50 and above, the research showed.
There’s no test for TGA; doctors diagnose it by ruling out other conditions, like stroke, and by confirming the symptoms that indicate transient global amnesia, experts agree. People who suffer a sudden loss of memory should go to the emergency room or see their physicians to get checked out. If you’re alone and suddenly lose your memory and can’t remember your doctor, “call 911 and go to a hospital and get checked out,” Segil advises. There’s no treatment for TGA, and the amnesia typically disappears without any lingering ill effects. “Compared to what it might have been — like a stroke — it’s comforting to get a TGA diagnosis,” Segil says.
Nancy and Dave didn’t know that as their drama unfolded. Dave, who’s in generally good health, doesn’t suffer from any chronic diseases. He drinks moderately — a few glasses of wine monthly — and is not obese. His good health made his sudden memory loss particularly jarring, Nancy recalls.
When patients go to the hospital for memory loss, doctors typically begin with a neurological exam, checking reflexes, muscle tone, muscle strength, sensory function, gait, posture, coordination and balance. They’ll likely ask questions to gauge the patient’s thinking, judgment and memory.
Once Dave and Nancy checked in at the hospital on that autumn day, for example, Dave continued to pepper his wife with questions. Every couple of minutes, he would ask, “How did I get here? Did I fall?” Dave asked those questions “over and over again, probably close to a hundred times,” Nancy says. “It was just constant. I was ready to cry.” The doctor assigned to the couple asked Dave who the president was and if he knew the date (he didn’t). After an initial exam, the physician said Dave most likely wasn’t suffering a stroke, though he ordered a blood test, CT scan and MRI to rule it out. When the results came in, the doctor diagnosed Dave with TGA and told Nancy the condition would probably dissipate within 24 hours; he also advised her to make an appointment with Dave’s primary care doctor.
[See: 8 Ways to Remember Something Right Now.]
A Quiet Resolution
Dave slept most of the following day, Nancy says. The next morning, he read some work emails, and though he didn’t recognize everyone’s name, he was able to retain the information in the messages, Nancy says. Dave saw his primary care physician that day and seemed to regain his full memory by that evening, 48 hours after he’d suddenly forgotten his own home. He returned to work a couple days later and has been fine since.
TGA isn’t likely to reoccur, and it’s not a risk factor for stroke. Dave’s doctor, for example, told the couple he’s treated several people for TGA and none have suffered it a second time. There’s no need to take special precautions after recovering from the incident.
Though fleeting, Nancy says the experience was terrifying. “I couldn’t understand what was going on and why this was happening,” she says. “I wondered if he’d be like this the rest of his life, completely dependent.” Dave has no memory of the episode, which is typical of people who experience TGA, experts say. “I don’t have any recollection, nothing at all,” he says.
*Editor’s note: Dave and Nancy are not the couple’s real names. The spouses, who live in an Eastern state, agreed to tell their story on the condition of anonymity. Dave is concerned his career could be damaged if his co-workers learn he suffered from amnesia.
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What It’s Like to Suffer From Temporary Amnesia originally appeared on usnews.com
