Amnesia is a term used to cover the partial or complete loss of memory. It is most often a temporary condition and covers only a part of a person's experience, such as immediate memory.
Amnesia - causes and risk factors
The main types of amnesia are:
Anterograde amnesia: People who find it hard to remember ongoing events after suffering damage to the head. They do not tend to forget their childhood or who they are, but have trouble remembering day-to-day events.
Retrograde amnesia: People who find it hard to retrieve memories prior to an incident in which they suffer damage to the head. Sometimes people never remember the seconds leading up to the incident.
Korsakoff's psychosis: Memory loss caused by alcohol abuse. The person's short-term memory may appear normal, but they will have severe problems recalling a simple story, lists of unrelated words, faces and complex patterns. ‘Confabulation’, where sufferers make up stories to fill the gaps in their memory is typical of this type of amnesia.
This tends to be a progressive disorder and is usually accompanied by neurological problems, such as uncoordinated movements and loss of feeling in the fingers and toes. Even after 5 years of abstinence from alcohol, memory can still be affected.
Traumatic amnesia: This follows brain damage caused by a severe non-penetrative blow to the head, such as in a road accident. It can lead to anything from a loss of consciousness for a few seconds to coma.
Infantile/childhood amnesia: This refers to a person's inability to recall events from early childhood. There are many theories on this, for example, Freud put it down to sexual repression but modern research has disputed the existence of such ‘buried memories’.
Transient global amnesia: This covers episodes of amnesia mostly linked to psychological trauma but sometimes following a medical procedure or vigorous exercise. Typically, it causes repetitive questioning and sometimes confusion but the person knows who they are. It lasts for 4-12 hours with a full recovery. If there is a loss of personal identity, then this is known as a fugue amnesia and due to severe psychological trauma. Usually, the memory comes back slowly or suddenly a few days later, although memory of the trauma may remain incomplete.
Amnesia treatment and prevention
Treatment varies according to the type of amnesia and the suspected cause. Anyone suffering any symptoms of amnesia should seek medical attention.