Types of Amnesia 

Memory loss can take the form of amnesia. Some amnesics find it challenging to create fresh memories. Others struggle to recollect details or prior events. People who have amnesia typically still know who they are and their motor skills.

Amnesia is a memory impairment brought on by brain injury, illness, or psychological trauma. Anterograde amnesia and retrograde amnesia are the two basic categories of amnesia. The inability to recall knowledge that was learned before to a specific date, typically the date of an incident or procedure, is known as retrograde amnesia.

These may include significant life experiences, cherished memories, significant figures, and essential truths we have been given or taught.

Types of Amnesia

Amnesia comes in a variety of forms. Here is a list of some of the more typical ones:

Anterograde amnesia is the inability to recall recent information. Recent events and knowledge that have to be stored in short-term memory vanish. This typically happens after a brain trauma, such as when a hit to the head results in brain damage. The individual will recall information and occasions that occurred prior to the injury.

Retrograde amnesia is somewhat the reverse of anterograde amnesia in that the affected individual can recall events that happened after the trauma but not those that occurred before it. Anterograde and retrograde amnesia can very rarely happen simultaneously.

Transient global amnesia: including the ability to make new memories in some cases of transient global amnesia. The likelihood of this is higher in older persons with vascular (blood vessel) illness and is extremely rare.

Traumatic amnesia: Memory loss occurs after a severe brain injury, such as one sustained in a vehicle accident. The person could briefly lose consciousness or go into a coma. The amnesia is typically transient, although the length of time it lasts typically depends on the severity of the injury. Amnesia is a crucial sign of a concussion.

·       Hysterical (fugue or dissociative) amnesia:  It is extremely rare for someone to lose both their identity and their past. It's possible that when they wake up, they have no idea who they are. They do not even recognise their own reflection when they glance in the mirror. An ID card, credit card, or driver's licence will be useless. It is typically brought on by a situation that the person's mind is unable to adequately handle. Within a few days, the memory normally slowly or unexpectedly returns, but the memory of the frightening experience might never fully return.

·          Childhood amnesia, also known as infantile amnesia, is the inability to recall past events. This condition may result from difficulties with language acquisition or from the brain's memory centres not fully developing while the person is still a child.

       Posthypnotic amnesia: The inability to recollect hypnotic events.

       When someone has source amnesia, they can recall certain facts but not how or from where they learned them.

DSM Criteria

A. The primary disturbance is one or more episodes of amnesia that are too severe to be explained by regular forgetfulness. These episodes typically involve the inability to recall significant personal information and are of a traumatic or stressful nature.

B. The disturbance is not solely caused by Dissociative Identity Disorder, Dissociative Fugue, Posttraumatic Stress Disorder, Acute Stress Disorder, or Somatization Disorder. It is also not brought on by a neurological or other general medical condition, or by the direct physiological effects of a substance (such as a drug of abuse or medication) (e.g., Amnestic Disorder Due to Head Trauma).

C. The symptoms hinder social, vocational, or other critical areas of functioning or cause clinically substantial distress.

Symptoms

Amnesia is a rare condition.

The following signs of amnesia are typical:

• In anterograde amnesia, the capacity to learn new information is diminished.
• Retrograde amnesia impairs one's capacity to recall prior events and previously known knowledge.
• There could be confusion or disorientation.
• There could be issues with short-term memory, as well as partial or complete memory loss.
• The individual might not be able to place places or identify people.

   Causes

Memory impairment may result from any brain disorder or injury. The process of remembering involves the simultaneous use of numerous brain regions.

Amnesia can result from damage to the hippocampus and thalamus, two brain regions that make up the limbic system, which regulates our emotions and memories.

Medical amnesia

Amnesia brought on by brain damage or injury.

Some causes include:

Stroke

• Brain inflammation known as encephalitis brought on by a bacterial, viral, or autoimmune infection
• A lack of oxygen brought on by, for instance, a heart attack, respiratory problems, or carbon monoxide poisoning
• Certain drugs, including the sedative Ambien
• Subarachnoid haemorrhage, often known as brain bleeding between the skull and the brain,
• A brain tumour that affects the memory-related area of the brain
• There are a few seizure disorders.
• Temporary memory loss may occur as a result of electroconvulsive therapy (ECT), often known as electroshock therapy, a type of psychiatric treatment that induces seizures for therapeutic purposes.
• Head injuries can result in temporary memory loss, though this is not always the case.

 

Psychological amnesia

This is brought on by an emotional shock and is also referred to as dissociation amnesia, such as:

• a crime with violence
• Sexual or other forms of maltreatment
• Conflict in the armed forces
• a disaster of the natural kind
• a terrorist incident

Any unbearable life circumstance that results in intense psychological stress and internal strife can create amnesia to some extent. Instead of interfering with the formation of new memories, psychological stressors are more likely to disturb existing, intimate memories.

Treatment

Amnesia typically goes away on its own without any medical assistance. However, therapy can be required if there is an underlying physical or mental condition.

Some patients can benefit from psychotherapy. Memories that have been forgotten may be recalled with success through hypnosis.

Family assistance is essential. Music, fragrances, and images could be helpful.

Techniques and ideas to aid with memory impairment are frequently used in treatment.

This may involve:

Collaborating with an occupational therapist to learn new information to supplement lost memories or to build on already-learned material to learn new information.

Acquiring techniques for information organisation to make it simpler to store.

Making use of technological tools, like cellphones, to assist with daily duties and remind patients of significant occasions, when to take medications, and other such reminders. A contact list featuring pictures of people's faces could be useful.

For amnesia-related memory loss, there are currently no medications available.

A thiamin (vitamin B1) shortage can cause memory loss in Wernicke-Korsakoff syndrome or malnutrition, thus tailored nutrition can be beneficial.