A sudden temporary episode of memory loss and confusion is called transient global amnesia. The criteria for its diagnosis is that it must not be attributed to any other neurological condition. Those affected by the condition cannot recall recent events and are unable to make new memories. This often leads sufferers to repeat the same question despite already having been given the answer. However, affected individuals can know who they are and can recognize people they know well.
This condition is rare and is generally considered harmless and unlikely to reoccur after the first incident. Episodes tend to be short-lived, lasting only a couple of hours, with memory being fully intact once regained.
Prevalence of Transient Global Amnesia
In the United States, cases of transient global amnesia are estimated at 5.2 cases per 100,000 population. Among older adults – over 50 years – cases jump to 23.5 per 100,000 meaning that this condition is more prevalent for older adults.
Transient global amnesia affects both men and women somewhat equally but either gender has different triggers. For men, it occurs most likely after a physical precipitating event, and for women, it can occur after emotionally precipitating events, a history of anxiety, or a pathological personality.
Causes, Risk Factors, and Complications of Transient Global Amnesia
The cause of transient global amnesia is not well understood, but there appears to be a link between the condition and a previous history of migraines—this correlation is not well understood either. The following are commonly reported events that have led to a global transient amnesia episode:
- Strenuous physical activity
- Sexual intercourse
- Mild head trauma
- Sudden immersion in cold or hot water
- Medical procedures
- Acute emotional distress
What Are the Risk Factors of Transient Global Amnesia?
While a direct cause for global transient amnesia is relatively unknown, it may be associated with some risk factors. The clearest risk factors appear to be:
- Age over 50 years
- History of migraines
Complications of Transient Global Amnesia
Experiencing a condition such as this may lead to a bevy of complications, but none of which occur as a direct cause of the amnesia itself. Not knowing what is happening around you can lead to severe emotional distress, and this may lead to more rash and unsafe decision if no one you know is around to help you. Experiencing such a phenomenon may raise questions of a more serious underlying condition that may prompt neuro examination and tests by a physician.
Transient Global Amnesia Symptoms
Transient global amnesia is defined as a sudden but temporary loss of memory. This includes the inability to form new memories and recall events that happened after the amnesia occurred. There are no physical symptoms present aside from the one affected looking more alert and anxious than usual. This symptom of memory usually lasts one to eight hours but can last as little as 30 minutes or as long as 24 hours, albeit rarely.
To be diagnosed with global transient amnesia, a doctor would have to see the following necessary symptoms:
- Sudden onset of memory loss, verified by a witness
- Retention of personality, despite the amnesia
- Normal cognition, as in retaining the ability to recognize and name familiar objects and follow simple directions
- Show no signs of damage to any part of the brain, such as limb paralysis, involuntary movement, or impaired world recognition
Additional symptoms include:
- Amnesia for less than 24 hours
- Gradual return of memory
- No evidence of seizure during amnesia period
- No history of epilepsy
Diagnosing Transient Global Amnesia
Unfortunately, there is no single test to diagnosing transient global amnesia, but instead, it is considered a clinical diagnosis through the documentation of various clues and ruling out other potential causes of symptoms. If a person were to present with the condition, the attending physician may perform the following to reach a diagnosis:
Physical exam: Consists of a neurological exam that tests reflexes, muscle tone, muscle strength, sensory function, gait, posture, coordination, and balance. Questions regarding thinking, judgment, and memory may also be asked.
Brain and imaging tests: These are primarily looking for any pathology that may be causing the memory loss. Looking at the structure of the brain may give clue to a potential stroke event or a tumor growth can be easily observed via computerized tomography (CT) or magnetic resonance imaging (MRI). An electroencephalogram (EEG) may also be used to look for seizure activity.
Treatment and Prevention of Transient Global Amnesia
There is no treatment available for transient global amnesia as from all previous cases documented, they have simply resolved on their own with no lingering effects noted. During ongoing cases, in which an individual is currently suffering from the condition, all one can do is support the individual, reassuring them about the present situation, and possibly scheduling for at least one follow-up with a neurologist in the future.
Prognosis of Transient Global Amnesia
Although patients with transient global amnesia aren’t at a higher risk of stroke or other vascular condition, some studies have shown that patients do seem to have lingering memory deficits while others have not.
Reoccurrence of symptoms are rare but not impossible, and so if they do come back speak to your doctor right away.