What is the reason for some people suffering from “transient global amnesia”? What are the factors leading to this transient condition, what are its pathological manifestations, and are there medical explanations for the mechanisms of this temporary problem?
These and other perplexing questions are what Professor Alan H. Roper, Executive Vice President of Neurology at Harvard Medical School, answers according to the latest medical knowledge we know about this condition to date. This was part of his scientific review published in the current February 16 issue of the New England Journal of Medicine (NEJM).
Roper reports that the term “global and temporary amnesia” first appeared in 1958 when Drs. Mother. Fisher, and R. d. Adam details this nervous condition. Describing its clinical manifestations, Professor Roper said: “The condition is characterized by a sudden and complete inability to retain new information. And it lasts for several hours, and that is in middle-aged or elderly people, but while they maintain alertness, mental awareness, and all other cognitive functions (Cognitive Functions).
Two memories “advance” and “retro”
And the researcher added in describing confusing aspects in understanding this condition: “During a seizure, anterograde amnesia occurs, with the inability to retain new information for more than a few seconds, while retrograde amnesia extends back for hours. Several days or more, which gradually decreases to hours or minutes as the episode of amnesia ends.
And to clarify; For there is a “new, advanced memory” that one forms, and another that is “previously reactionary” that was formed before. Neurologists define anterograde amnesia as the patient’s inability to form new memories after the event that caused the amnesia, resulting in the inability to remember the recent past, while long-term memories (pre-existing) remain intact.
In contrast; The opposite occurs in other patients, which is “retrospective amnesia”, where memories formed prior to the event that caused the amnesia are lost, but new memories can still be formed. In some patients, both can happen.
The mechanisms for the occurrence of these complex aspects within the brain regions involved in memory remain unclear. For a simple reason; It is that the exact mechanism for storing and retrieving memories is not well understood by doctors until today, although researchers have identified the brain regions involved in memory.
Professor Roper explained another important aspect, compared to what stories and films commonly present in cases of “Psychogenic Amnesia”, that the person with “global and temporary amnesia” does not lose knowledge of his personal identity; Rather, he can provide his name, date of birth, how old he is, and the names of his wife and children, and he can identify these people. But in cases of “psychogenic amnesia”, there is a sudden loss of previous memory (for a period of time ranging from hours to years to decades), which also includes the inability to remember personal information. At the same time, there is no organic pathological cause that leads to this condition, but rather it is the result of psychological stress.
Clinical manifestations
Professor Roper said: “This health predicament that the patient suffers from is often revealed through the repetition of the patient asking repeated stereotyped questions, which he may sometimes ask hundreds of times, and at irregular intervals of about 30 seconds, such as the frequency of asking questions of the type: How got here? Where are we? What’s happened? what is the time? These questions are pronounced with the same rhythm and tone each time and immediately after answering the question. But he explained directly: “All other functions are normal. Affected people can complete complex musical performances or perform chess games.
He added, “The attacks last for 6 hours on average, and the period ranges between 2 and 12 hours in most cases. And men have more than women. The risk of (transient global amnesia) is higher among patients who suffer from migraine, compared to those who do not suffer from migraine.
He added that there is a notable advantage; It is that this bout of amnesia may be preceded by physical or mental trauma, or severe exertion. such as immersion and bathing in cold water, receiving news of a death, having sex, undergoing medical procedures (such as surgery or an endoscopy of the gastrointestinal tract), or experiencing severe pain. But most cases have no clear cause. Some studies attributed “transient global amnesia” to drugs used for general anesthesia or narcotic drugs being taken or smoked. Professor Roper referred to a study by researchers from the Mayo Clinic. In it, they reported that cases in the study were preceded by the patient doing hard agricultural gardening work, in about 20 percent of the patients. And that the possibility of recurrence of suffering from this case of “global and temporary amnesia” later, may be repeated in 15 percent of those who had these temporary bouts of memory loss.
Diagnostic difficulties
And according to what Professor Roper pointed out; The difficulty appears (in diagnosing) when the patient is seen for the first time some time after the onset of his seizure; Because there is difficulty in determining whether the problem is a transient confusional episode, or one due to severe hypoglycemia, alcohol, drug or hypnotic intoxication, or a similar disorder, rather than transient global amnesia. The presence of signs of mental confusion in the patient, such as inattention and incoordination, indicates that the condition is the result of a different disorder than the case of (transient global amnesia).
Then Professor Roper presented the proposed diagnostic criteria for cases of global and temporary amnesia, and stated: “The condition is easily identified; The differential diagnosis (from other types of amnesia) is limited, when the symptoms and features do not differ from the typical description (of the case of global and temporary amnesia). But things get complicated when there are other atypical features (for transient global amnesia), such as global mental confusion, seizures, ataxia, or vertigo (a sensation that surroundings are vertigo), or deficits in mental awareness of aspects other than memory.
Neurologists at the Mayo Clinic explain this aspect, saying: “To diagnose a disease (transient global amnesia), the doctor begins by ruling out more serious conditions, such as stroke, epileptic seizure, and head injury; These conditions can cause the same type of memory loss. A physical examination of the nervous system, muscle strength, involuntary reflexes, sensory function, gait, posture, coordination and balance is done. The doctor may also ask questions to assess your thinking, differentiation, and remembering. The next step will be tests to detect abnormalities in the brain’s electrical activity and blood circulation. The doctor may order one or more of these tests: computed tomography (CT scan) of the brain and skull, magnetic resonance imaging (MRI) of the brain, and electroencephalography (EEG).
6 different types of amnesia… memory loss
“Amnesia” and “dementia” are both cases of brain function disorders, but in reality the medical condition is two different conditions. Where “amnesia” is “just amnesia”. While “dementia” is characterized by a comprehensive and gradual loss of mental abilities in brain functions. Including memory, evaluation of things, arithmetic, learning, and mental awareness of time, place, and people… and others.
Doctors at the “Cleveland Clinic” say: “There are many different types of memory loss cases; Of which:
Retrospective amnesia: is the loss of recall of memories formed prior to the event that caused the amnesia, and usually affects past memories stored recently, not memories from years ago.
Advanced amnesia: is the inability to form new memories after the event that caused the amnesia, and advanced amnesia is more common than retrograde amnesia.
Post-traumatic amnesia: is the loss of memory that occurs immediately after a major head injury, and may include “retrograde amnesia” or “anterograde amnesia” or both.
Transient global amnesia: it is a temporary syndrome; Where the patient suffers from the loss of retrospective and advanced memory. Memory loss is sudden and only lasts up to 24 hours.
Infantile amnesia: This term is used to describe the fact that people cannot recall memories of events from early childhood. Few people have memories before the age of three to five; Because the areas of the brain that support memory are still developing.
> Dissociative amnesia – psychiatric amnesia: It is a mental health disorder, in which the sufferer suffers from memory loss after exposure to emotional trauma or severe psychological trauma.
10 possible causes of neurological amnesia
> According to what doctors at the Mayo Clinic indicate; “Normal memory function depends on many parts of the brain. and then; Any disease or organic injury that occurs in the brain can affect memory. Possible organic causes of neurogenic amnesia include:
– brain attack.
Encephalitis, such as a viral infection.
Not getting enough oxygen to the brain, for example, following a heart attack, shortness of breath, or carbon monoxide poisoning (burning firewood in enclosed spaces).
– Vitamin B-1 B-1 deficiency, or what is known as thiamine, in the body.
Tumors in the parts of the brain that control memory.
Alzheimer’s disease and other diseases that cause nerve tissue damage.
epileptic seizures
– some medicine; like sedatives.
Brain injuries that cause a concussion, such as car accidents or sports injuries.
Post-brain surgery.