Amnesia – The Non-existent Memory
Amnesia occurs when various memory retrieval, storage and formation centers of the brain are tampered with and consequently working below full capacity. The limbic system of the brain comprising of the amygdala, parts of the cortex, and the hippocampus is responsible for the retrieval of stored memories and interference with any part of this system can render one amnesiac.
It may be worth noting that interestingly procedural memory is rarely ever lost. While amnesiacs can forget everything about their lives both the past and unable to retain anything new, they will surprisingly retain the skills they had before the amnesia such as bike riding, playing a sport or musical instrument, or singing.
Storage of memories happens in various parts of the brain. Visual and auditory are stored in the temporal lobe, and comprehension, language, speech, and word usage are stored in the parietal lobe. Amnesia is when memories cannot be retrieved from storage due to one reason or another and can be divided into two major categories:
This is where the patient is unable to form any new memories; they will remember their past up until the onset of the forgetfulness but will be unable to retain any new information. Somehow the new memories are not successfully being transferred from the short term to the long term memory centers. It primarily affects old men and they can lose upto hours where they cannot remember anything that happened during that time.
A subset of this is the transient global amnesia where one temporarily loses all memory, unable to form new ones and remembers little or nothing of the past. It can last for a couple of hours and is caused by seizures in the temporal lobe or a migraine. It is common among the older generation and will resolve on its own in most cases.
In this kind of situation the person is able to form new memories but cannot remember their past. Commonly affecting the autobiographical memory, it mainly starts with the most recent of memories going backwards and the extent of erosion is dependent on the severity of the situation. Sometimes people will remember things that do not concern them specifically like the current president but will be unable to remember their own name or their parents. This kind often occurs after a head injury, though it has been identified among insulin dependent diabetic patients.
Here are some reasons as to why one may suffer from amnesia:
Alzheimer’s disease – a genetic disease affecting the brain where one slowly but progressively loses all brain-related functions including memory.
Head trauma or brain injury either directly as a result of brain surgery or traumatic accident to the head – anything that affects the memory centers of the brain is likely to cause one form of amnesia or another. These also include seizures, brain infection like meningitis, dementia, or stroke.
Less likely causes but also possible are related to psychiatric causes such as psychogenic amnesia that comes as a result of going through a traumatic incident and one is unable to remember anything that happened from the incident. Others are schizophrenia and depression.
There are many suggested treatments to help deal with memory loss but there is no known cure. Most of them are simply to ease the life of the patient but nothing can really be done to help one who has lost their memory gain it back. In some cases the patient may regain their memory and in others they do not gain back what they lost. As care takers it is your responsibility to be there for the patient as and when they need help because while memory may seem irrelevant when you have it, its importance is quite clear when you don’t.