Very worrying for those who suffer from it and those around it, transient global amnesia corresponds to a sudden loss of memory for a short time, less than 24 hours. This benign disorder, although spectacular, should always be followed by a medical visit.
Nicole, 71, was at the beach with her family when suddenly she became confused about what she was doing there. “Have we been here for a long time?” she asked repeatedly. Fearing the worse, her family members became highly concerned. After a visit to the nearest hospital emergency room, the reassuring verdict came: Nicole had suffered from transient global amnesia.
What is transient global amnesia
Transient global amnesia is a neurological disorder characterized by a sudden and brief loss – 6 hours on average – of memory. This “breakdown” is spectacular: since it occurs suddenly, often for no apparent reason. It can be confused with a cerebrovascular accident (stroke).
The patient seems lost, forgets what he or she has just done, and asks the same questions repeatedly.
Given the shock and unexpected appearance, those around the victim can quickly panic. Often the patient is taken to the hospital where the tests will show that there is… nothing to worry about. This will rule out other diagnoses such as amnesic stroke or seizure.
How transient global amnesia works
To date, the mechanisms behind transient global amnesia are not clear. However, we know that it all plays out in the hippocampus, this small area of the brain that houses episodic memory.
Episodic memory is that which corresponds to our personal memories. In an amnesic stroke, it is this type of memory that is affected: the brain no longer records what is happening to us. During this same acute phase, there is also retrograde amnesia, which corresponds to the inability to search for an old memory.
On the other hand, procedural memory, which corresponds to the actions that we perform automatically (driving, cycling, swimming…), is spared. This explains why some people with transient global amnesia may continue to do what they were doing at the time of the stroke.
Causes of transient global amnesia
To this day, the exact causes of amnesic stroke are still unknown. However, some triggering factors have been identified. This sudden loss of memory mainly affects people between the ages of 50 and 70 and can occur after
• Sexual intercourse
• A swim in very cold water
• Stress or emotional shock
• Intense physical effort
Finally, transient Global Amnesia can be iatrogenic, that is to say, linked to the intake of certain substances such as alcohol, illicit drugs, barbiturates, or anticholinergic drugs such as sleeping pills, antihistamines, anti-nausea, etc.
Consequences of transient global amnesia
Fortunately, transient global amnesia is mild and the patient regains full capacity within a few hours. When the amnesia episode is over, it’s the black hole: you can’t remember what happened.
If the person is alone at the time of the seizure, they may not even have noticed their amnesia, only feeling unwell or anxious.
Eight out of ten times someone who suffered from an episode of transient global amnesia will not experience another ever again. If the patient expresses concern to the doctor or neuropsychologist about the future development of their memory, no more cases of Alzheimer’s disease have been observed in victims of transient global amnesia than in the rest of the population.
The only sequel to transient global amnesia is therefore psychological: people who have suffered from it may experience great anxiety following this fortunately momentary episode in the black hole.