What is Transient Global Amnesia: A Sudden Loss of Memory
In order to explain Transient Global Amnesia (TGA), I’ll tell you about my personal story*.
A few months ago, my mom had a sudden and temporary memory loss. I can’t begin to try to understand how scared my father must have been when we got home and found my mom scared and nervous, not knowing who turned on the washing machine, who turned on the stove, and who took all of the pictures off the wall (she angrily asked who took the picture of her siblings off the wall and wanted to know where they put it). She said the same things over and over again. The same questions, the same answers. It was like she couldn’t remember what she did that morning. My dad tried to reason with her, but even though she seemed to know more or less where she was, who my father was, and talked coherently, she couldn’t remember what she did over the past few hours, and she couldn’t create new memories.
My dad was so nervous that he didn’t even call to tell us he had taken her to the hospital. When he finally told me what was going on, I was so scared. What happened? Is it serious? Did she have a stroke, or maybe early onset dementia? Could it be a brain tumor? I had so many things going on in my head and I couldn’t even stop to think how serious it really must be because a sudden loss of memory like that can’t be good.
When I got to the hospital hours after the symptoms had started, my mom was quite a bit better. She still couldn’t remember what happened that morning and her memories of the previous day were murky, but it seemed like she was finally able to remember things and, little by little, return to normal. They did various tests on her including a memory test to discard other pathologies, and the doctors decided that it was a Transient Global Amnesia episode.
What is Transient Global Amnesia?
Transient Global Amnesia (TGA) is a neurological syndrome that involved a temporary loss of short-term memory. The person isn’t able to create new memories and they have trouble remembering things from the recent past. The rest of the cognitive functions (consciousness, personal identity, attention…) remain intact. Even though the memory loss is very serious, it is temporary and will go away suddenly. In just a few hours, the person will go back to normal.
It’s a more common disorder than it seems and usually, happens to people over 50. Even though it’s possible to have recurring episodes, it usually only happens once in a lifetime (85%).
What are the Transient Global Amnesia symptoms?
- Complete loss of short-term memory (they are unable to create new memories) and variable loss of recent past memory.
- The memory loss doesn’t last for more than 24 hours.
- They ask and say the same things repetitively (ask where they are or what they’re doing).
- The patients feel odd or uncomfortable. They know something has happened, but they don’t know what.
- They may have some spatial disorientation, but will more so have temporal disorientation. They can, however, make some inferences based on previous experience.
- They are able to talk and perform complex tasks (turn on the washing machine, have a meeting…) because the rest of their cognitive functions, like attention and state of alertness, are working.
- Changes in expression, attitude, or behavior. For example, they may be irritated, or conversely, they may be apathetic.
What can be confused with Transient Global Amnesia?
There are many disorders that have memory loss as a symptom, which is why before giving you a diagnosis of TGA, the doctors should first rule out all other possibilities. Some of these disorders are:
- Traumatic brain injury (TBI)
- Cerebrovascular accident
- Syncope and paroxysmal attacks
What causes Transient Global Amnesia?
Doctors and researchers still don’t know what causes TGA attacks (if it is due to a vascular problem, some type of epilepsy, or a migraine), but it has been associated with some kind of precipitating event. Let’s take a look at the possible causes of transient global amnesia.
Transient global amnesia has been associated with vigorous exercise (including sexual intercourse), temperature changes or emotionally traumatic or stressful events. Researchers have linked it to medical procedures or certain disease states. Other situations like economic hardship, anxiety, and depression may cause this type of amnesia.
In the 90’s it was thought that cerebral vascular disease was the cause of transient global amnesia, however, it was discarded. Nonetheless, another theory remains that patients with TGA have jugular vein valve insufficiency, which can lead to ischemia of the structures involved in memory (hippocampus).
In a recent study, it was discovered that 14% of people with TGA had a history of migraines. It is not a precipitating event for TGA and there is still research to be done since the connection still remains a conceptual one.
Researchers have been investigating if there is a nonconvulsive epileptic state in TGA. Transient epileptic amnesia shares memory loss with TGA and scientist are starting to believe TGA may be a subtype of epilepsy, however, nothing is proven yet.
What should you do if a family member shows Transient Global Amnesia or sudden memory loss?
- The first thing is to stay calm. They are probably agitated or confused, so it’s better to talk calmly and not yell. Don’t get worried if they repeat the same questions.
- Don’t wait to see if it’ll pass. Sudden memory loss is never normal. Go to the nearest hospital.
- Even though many neurological disorders have memory loss as a symptom, don’t think about the worst-case-scenario. Wait to see what the doctors say before jumping to conclusions. Take a cognitive test.
- Don’t get nervous after they are admitted, the doctors will still want to run tests. It doesn’t mean that they think it’s something more serious, just that they want to make sure that it’s not something different. The emergency room doesn’t have the tools to be able to run all of the tests.
- After a TGA episode, your family member may feel weird or have a headache for a few days. Don’t get over-worried, there’s no reason why it would happen again. In fact, Transient Global Amnesia is quite a benign syndrome and doesn’t usually leave any lingering problems, and in the most cases, it doesn’t happen again. Don’t panic!
Here is a video that briefly explains what transient global amnesia is and what happens to the patient.