Transient Global Amnesia

Amnesia, sclerosis, memory loss, or lapses are very common terms used by patients to describe memory disorders. An extremely interesting issue from the point of view of neuropsychology and issues related to memory disorders is the phenomenon of transient global amnesia.

What is transient global amnesia?

This concept was first described in 1956 by Bender and Courjon and Guyotat. Two years later, in 1958, the disorder was also described by Adams and Fisher, who proposed the name transient global amnesia (TGA) for the described memory disorder.

Considering the fact that transient global amnesia (TGA) was described in the second half of the 20th century, i.e. relatively late, this does not mean that it did not occur earlier.

Most likely, transient global amnesia could have been overlooked, disregarded or overlooked, given the relatively short duration of the disorder and the lack of severe consequences.

It is now believed that transient global amnesia is relatively common and easy to diagnose.

An attack of transient global amnesia in its essence consists of short-term but transient memory disturbances. They are global in nature, as indicated by the very name of the described disorder.

This shows that they are not limited to just one type of material, such as verbal and non-verbal. As a rule, disorders are selective and are limited to the sphere of memory.

In addition, patients suffering from transient global amnesia are disoriented, constantly asking questions, but unable to remember any new information. In parallel, retrograde amnesia occurs, which lasts for several days, and sometimes even for several years.

However, as the anterograde amnesia and disorientation recede, the period of retrograde amnesia shortens to include only the duration of the seizure itself.

Most often, no additional neurological symptoms associated with the disorder are found.

Transient global amnesia (TGA) is most often observed in people between 50 and 80 years of age, i.e. middle-aged and elderly, with the average age being 61-62 years. If we were to differentiate the incidence by sex of people affected by this disorder, we could see that it is similar among both women and men, but with a slight numerical advantage of the former group.

How to recognize transient global amnesia?

This disorder occurs suddenly, violently, and unexpectedly, and is not preceded by neurological or prodromal symptoms.

Apart from the aforementioned disorientation and the inability to remember new information, there are no disorders of consciousness, autopsychic orientation, or difficulties in performing everyday activities.

Semantic knowledge, procedural and autobiographical memory are preserved, so the patient is able to provide his/her personal data.

The return to fully normal functioning of the patient's memory takes place after a few or several hours, the literature gives the duration of the episode from 1 to 24 hours, but the individual does not remember the duration of the amnesia episode.

The diagnostic criteria for transient global amnesia additionally state that memory disorders should not be accompanied by any significant disorders of other mental functions and neurological symptoms. The patient does not show disturbances of consciousness either.

When diagnosing transient global amnesia, it is necessary to exclude injuries, especially to the neck and head, loss of consciousness associated with diseases of the blood vessels and heart, and epileptic seizure.

Due to the disorientation occurring during the attack and memory loss, eyewitness accounts become crucial, especially when excluding these injuries.

When conducting a neuropsychological diagnosis of a patient with suspected TGA, tests should be performed to check auditory and visual-spatial delayed and immediate memory as well as the effectiveness of assimilating new material, both non-verbal and verbal.

The results obtained during the examination should be compared with the results of tests that assess verbal fluency, eye-hand coordination, executive functions and working memory.

When checking the effectiveness of memory processes, one should focus, among others, on the range of memory, assessed on the basis of the number of elements reproduced after a single exposure.

We check the speed of remembering new material by assessing the time and number of exposures needed to remember information, and memory durability by the time period in which information is stored in it.

Transient global amnesia can be treated as an extremely interesting example of the brain's self-repairing activities, thanks to which it regains full efficiency after the end of the disorder, as evidenced by successful prognoses.

People who have experienced transient global amnesia (TGA) have no increased risk of brain vascular disease related to the disorder later in life. There are also no cognitive problems in the form of memory deterioration and a decrease in the level of general mental performance.

Although the disorder is short-term and transient, the patient should be provided with psychological and psychotherapeutic care. The patient's family should also not be left alone, it is also advisable to provide psychological support and explain the course of the disorder in detail.