Short-term memory loss
A loss of short-term memory is similar to a sudden loss of memory, which limits the storage of new memory content. The affected person can therefore remember things for no longer than about 3 minutes. Therefore, the same questions about situation, place and space are asked again and again, such as “Why did I come here now?”.
“Where did I put the object?”. Even when these questions are answered, the answers are forgotten after a short time and the same questions are repeated. This time may be very distressing for the person concerned, but the symptoms usually disappear within the next 24 hours and a complete recovery is achieved.
Therefore, this form of amnesia is often called transient global amnesia, because the symptoms do not last forever but are temporary. Memories of actions such as driving or walking are not restricted. There are several possible causes of memory loss.This usually results in some kind of damage to the brain, which also causes nerve cells to die or affects brain regions responsible for learning and thinking processes.
For example, an accident or a fall can lead to a loss of memory, as it can cause severe injuries to the head or skull and thus also to the brain. This is often accompanied by a loss of consciousness or a comatose state. In general, a lack of oxygen and nutrients in the brain leads to a partially irreparable loss of nerve cells.
The longer this undersupply lasts, the more serious are the later consequences. In addition to craniocerebral trauma, dementia, meningitis, encephalitis (an inflammation of the brain) or an epileptic seizure can also cause a loss of memory. This is because all of these diseases cause a loss of brain structure, which can be rapid or slow, depending on the cause.
Although the exact relationship between damage in the brain and the exact effect on learning or thinking processes remains unclear, a disruption in attention and concentration performance can often be observed. Other possible triggers are poisoning with various substances that can enter the brain from the blood, such as drugs, medication or alcohol. In addition, severe psychological stress may also be a possible cause, in which, in order to protect the person concerned, the memories of these particularly stressful moments may be lost.
A serious accident can leave serious injuries to several organs and the brain. An overall severe blood loss can cause circulatory failure and shock. This leads to an undersupply of brain tissue with subsequent loss of nerve cells.
However, the trauma itself can also lead directly to damage to the head, e.g. if a concussion or even bleeding occurs in the brain as a result of strong acceleration and deceleration processes or an impact on the head. The connection between brain injury and the extent of memory loss is unclear. However, there is a disruption of those brain functions that are responsible for transferring information into long-term memory, or a failure to retrieve stored information.
For example, the affected person forgets the circumstances of the accident and often forgets a short time afterwards. Only over the course of the years do some of them develop individual memories. Furthermore, a fall can have serious consequences, especially for older people.
Due to the impact, the brain can hit the skull bone jerkily, which can lead to a concussion with short-term loss of consciousness. The unconsciousness often lasts only a few seconds and is accompanied by nausea, vomiting and a memory gap. Mental illnesses such as depression can lead to memory disorders.
In addition to a depressed mood, a lack of drive, disinterest and an inability to feel joy, depression also leads to concentration and sleep disorders. This can also explain why, for example, thinking processes can be blocked or made more difficult due to tiredness or reduced attention. Particularly in older people, where a decline in memory performance immediately leads one to think of dementia as the cause, it may just as well be age depression.
Rapid consumption of large amounts of alcohol carries the risk of a so-called film tear, so that the person affected cannot remember details of the previous evening, for example, after waking up the next morning. This is because alcohol influences the attention and learning processes via so-called GABA receptors. These receptors are jointly responsible for regulating the memory processes.
This effect of alcohol varies from person to person, so that memory gaps occur earlier in one person and later in another after large amounts of alcohol. In general, however, especially the fast and frequent drinking of large amounts of alcohol over a short period of time leads to a blackout even rather later. Furthermore, chronic alcohol consumption is harmful to memory processes.
In the case of alcoholics, malnutrition often occurs because the energy requirement is mainly covered by the consumption of alcohol. This leads to a so-called Korsakow syndrome, a vitamin B1 deficiency.Vitamin B1, known as thiamine, controls various processes in the human body, including those in nerve cells. Therefore, an insufficient supply leads to the destruction of important brain structures, such as the so-called mammary body.
These are part of the limbic system, which plays an important role in learning and thinking processes, especially for storing new memory content. High blood pressure is known to have many secondary damages. Since it also frequently occurs with diabetes or a lipid metabolism disorder, the risk of pathological changes in small and large blood vessels is increased.
Over time, this leads to arteriosclerosis, i.e. calcification of the arteries. In the brain, the lack of oxygen and nutrients due to constricted small vessels can now lead to memory disorders. For example, so-called vascular (= vascular) dementia occurs.
Typical symptoms are personality changes, disorientation and speech disorders as well as memory disorders, especially difficulties in remembering new things, decreasing judgement and problems with everyday activities, because certain devices can no longer be operated. Emotional or physical stress has many effects. For example, severe mental stress can increase the probability of sudden memory loss or psychologically triggered amnesia, now called dissociative amnesia.
This is the forgetting of severe traumatic experiences. The brain blocks, so to speak, these contents or the recall of these memories in order to protect the patient from the enormous psychological burden of processing them. In addition, chronic stress with permanently elevated stress hormone levels, such as cortisone, can lead to brain damage.
A stroke leads to different symptoms and consequential damage depending on which brain region is affected. Thus, different memory functions can be restricted. For example, a stroke in the left temporal lobe leads to a reduced memory of factual knowledge.
This is where the so-called semantic memory is located, and if it is lost, everyday words, for example, are no longer understood. If the right hemisphere of the brain is affected, the affected person loses his so-called episodic memory, i.e. one no longer remembers personal events, such as the last birthday. The consequences are often temporary and can improve over time.
Therefore it is crucial to have a rehab where the other symptoms are treated as well. The anesthesia required during an operation can lead to memory loss. In the case of an operation, this is even a desired effect of the anaesthetics, so that the patient does not remember the operation and thus the pain that occurred during the operation.
On the one hand, the anaesthetics block the transmission of pain, on the other hand, they eliminate consciousness. The applied drugs lead to the fact that certain receptors, so-called GABA-receptors, are influenced. As a result, the storage of new information in the long-term memory is hindered and a temporary loss of consciousness is induced.
This influence is usually only present during the drug’s period of action and disappears after the drug has been broken down and excreted, so that there is usually no need to fear subsequent effects on memory function. However, in addition to the anaesthetics, the operation itself can also be a trigger for memory loss, especially if brain surgery is required. If a stem cell or bone marrow transplantation is carried out as a therapy for leukemia, this can lead to limitations in mental performance.
The exact effects on memory performance are not known, but in some studies, for example, changes in concentration, memory and attention have been observed. These occurred more frequently when complications occurred during therapy. In addition, radiotherapy of the head or local chemotherapy of the spinal cord represented risk factors.
Not every Parkinson’s patient suffers from memory impairment, but some are affected. The more advanced the disease is, the more likely memory loss or other signs of dementia are to occur. It affects about one quarter of Parkinson’s patients.Typical symptoms of Parkinson’s dementia are attention deficit disorders, slowed thinking, personality changes, depression and memory disorders.
Above all, the retrieval of new information is more difficult, but the learning process itself is usually not restricted. Furthermore, the medications used for Parkinson’s disease can aggravate dementia, making the treatment of Parkinson’s dementia difficult. An epileptic seizure leads to the fact that after the event, the person affected does not remember the time during the seizure and shortly before.
There is therefore a loss of memory for this past period of time, so it is retrograde amnesia. In older people, memory disorders should also be considered as epilepsy. In this case, atypical symptoms such as short-term clouding of consciousness, speech disorders, confusion or a temporary loss of memory can also indicate epilepsy, so that a typical seizure does not necessarily occur.
A heart attack can lead to cardiovascular arrest. This leads to a lack of oxygen in all organs and in the brain. If the brain is undersupplied for a long time, the probability of brain damage is higher because nerve cells die. As a result, memory performance can also be reduced. About half of all patients suffer from forms of memory loss after a heart attack.
