Transient global amnesia will obviously present with acute memory loss and temporarily affected cognition. There is no other pertinent organ involvement unless there is an underlying organic cause like brain tumor or hepatic cancer on chemotherapy. The following signs and symptoms can present in patients with transient global amnesia:
Patients are evaluated extensively on neurologic examination to rule out organic brain disorders like stroke, concussion, and seizure that can mimic the signs of transient global amnesia. Cognitive test of judgment and memory may also be applied routinely. These imaging test will confirm brain pathology like tumors, impaired blood circulation and electrical activity:
Transient global amnesia requires no treatment. The amnesia resolves on its own with no known side effects.
The prognosis for transient global amnesia is generally good. Loss of memory is usually short-lived and lasts within 24 hours from the attack. The state of amnesia may improve upon resolution but recent memory lost during the attack may never be remembered by the patients. The recurrence rate for the disorder is only 5-25% which are usually found in migraine and seizure cases. Transient global amnesia does not increase the likelihood of cerebrovascular disease like stroke.
Transient global amnesia has no direct medical complication. However, patients who undergo the episode may feel anxious because of the fear of recurrence or the fear of a more serious underlying neurologic disease like brain tumor may be at play. A strong emotional support or an encompassing psychotherapy may allay the anxiety which may lead to depression if left unchecked.
The exact etiology of transient global amnesia is still unclear. There has been some strong correlation with the occurrence of migraines but direct linkage is still not well-established. The following common events has been observed to trigger attacks of transient global amnesia:
In the United States, the current incidence of transient global amnesia reaches 5.2 cases per 100,000 population. However, elderly people beyond age 50 years old may reach a case specific incidence rating of up to 23.5 cases per 100,000 annually . Internationally, studies in Alcoi, Spain has a lower incidence of 2.9 cases per 100,000 citizens .
The Italians in Belluno were noted to have a higher incidence reaching up to 10 cases of transient global amnesia out of 100,000 population . Although attacks of transient global amnesia rarely recurs, studies have shown that it may reach a recurrence rate of up to 24% in one lifetime.
There are no observable racial and sexual predilection of the disease across all cultures. Transient global amnesia typically occurs at the age of fifty years old. Females usually incurs transient memory loss following an emotional distress, or severe anxiety, while male counterparts succumbs to transient amnesia following a strenuous physical activities like sports.
The definite pathophysiology of transient global amnesia remains unclear up to this point. However, advances in neurology research and real-time imaging techniques have elucidated some plausible theories on occurrence and pathology. Real time positron emission tomography (PET) and diffuse weighted magnetic resonance imaging (DWI) have demonstrated a transient ischemia in the brain regions of the thalamus and the mesial temporal structures involved in memory processing.
However, DWI may have a lower yield in picking up transient global amnesia when performed early in its course . Other studies reveal that minute lesions of the hippocampus as revealed by DWI has been associated with transient global amnesia .
Other dominant theories suggest the role of edema and the spreading depression in the left frontal cortex of the brain contribute to the transient memory loss . Single photon emission computed tomography (SPECT) has demonstrated real time hypoperfusion of the cerebral mater coincides with the transient global amnesia attacks . In the same way, cerebellar hypoperfusion may also give out similar transient neurologic deficits.
There is no modifiable lifestyle approach to prevent transient global amnesia.
Transient global amnesia (TGA) is clinical disease characterized by a sudden loss of memory which lasts temporarily that is not a part of any organic neurologic illnesses like cerebrovascular disease (stroke) or epilepsy.
Transient global amnesia injures memory loss of recent memory or events that happens within hours (within 24 hours) from the attack. Immediate memory recall and distant memory are usually preserved during the paroxysmal attacks of memory loss. Attacks of transient global amnesia may be short and fleeting and may rarely recur in patients.
Transient global amnesia is a temporary loss of memory that resolves within 24 hours. This disorder is not serious and is not associated with any brain pathology.
The exact cause is unknown but it is associated with conditions like emotional outbreak and strenuous physical activity.
Paroxysmal or transient loss of recent memory that resolves within 24 hours. The past memory are preserved in all cases.
A meticulous history taking and interview of witnesses may suggests the diagnosis of transient global amnesia. Imaging techniques and electroencephalogram can rule out other organic causes like stroke, tumor or seizure disorders.
Treatment and follow-up
No treatment is required for it resolves spontaneously. Recurrence is relatively rare.