Retrograde Amnesia Signs and Types

Retrograde amnesia is a form of memory loss that involves an inability to access memories formed before the onset of amnesia. It is caused by damage to the regions of the brain associated with memory storage. It affects retrograde memory, which is defined as information that occurred before a particular point in time, such as the onset of a brain injury or other type of condition.

Retrograde amnesia is sometimes temporary but can also be permanent or progressive. The severity and duration of this type of amnesia depend on what is causing it.

Retrograde amnesia can also be contrasted with anterograde amnesia. Anterograde amnesia is a type of memory loss that makes it impossible to form new memories. People with this form of amnesia have difficulty forming new memories following the onset of their memory loss. It is also possible for a person to have both retrograde and anterograde amnesia.

Symptoms of Retrograde Amnesia

The symptoms of retrograde amnesia can vary depending on the nature and severity of the injury. Common signs that a person may experience include:

• Not being able to remember events that occurred before the onset of amnesia
• Forgetting facts and general knowledge that they learned before the onset of amnesia
• Not being able to remember names, faces, places, dates, and other facts that were learned before the injury occurred
• Retaining skills and abilities that were burned before the onset of amnesia
• Being able to recall older long-term memories such as events that occurred during childhood

Some people only lose their memories of events that happened before they began to experience amnesia, which means they can form new memories. In other cases, people will have both retrograde amnesia and anterograde amnesia, which means they will also be unable to create new memories.

What Are Examples of Retrograde Amnesia?

There are a few different types of retrograde amnesia that a person may experience.

Focal Retrograde Amnesia

Focal retrograde amnesia is a type in which the individual does not experience symptoms of anterograde amnesia. People can form new memories and acquire new skills. This kind is also sometimes known as pure or isolated retrograde amnesia.

Temporally-Graded Retrograde Amnesia

Temporally graded retrograde amnesia is the most common form of retrograde amnesia. It strongly affects recent memories, while older memories may be minimally affected, while events closest to the onset of amnesia are heavily affected.

The extent of the lost memory depends on the source and severity of the amnesia. Sometimes people will be less severely affected and may be able to remember events that occurred a few years before their injury. In other cases, people may lose nearly all of their adult memories.

Dissociative Amnesia

Dissociative amnesia is a form of retrograde amnesia that may occur following some type of psychological trauma. The memory loss is due to emotional shock and is often temporary.

Following the event, people may struggle to remember details of what happened before or during the trauma. They may also struggle to recall autobiographical information.

This form of retrograde amnesia impacts a person's self-perception and self-awareness. Due to the severity of the stress or trauma a person faces, they dissociate from themselves and their own lives as a way to cope.

Post-Traumatic Amnesia

This type of retrograde amnesia can occur following a traumatic brain injury such as stroke or head trauma. People with this type of amnesia do not remember the injury or event that led to the amnesia. They may also have issues recalling their identity or orienting themselves in time and place.

Transient Global Amnesia

This form of retrograde amnesia occurs suddenly and prevents people from forming new memories while they are experiencing amnesia. People with this condition can recall who they are and recognize family members, but they may struggle to understand what they are doing or where they are.

TGA is temporary and relatively brief, often lasting from less than an hour to 10 hours. Symptoms of retrograde amnesia typically resolve within 24 hours.

What Is Retrograde Amnesia Caused By?

Retrograde amnesia is caused by damage to parts of the brain that play a role in memory and emotion. This may include injury, illness, and stress. Potential causes include:

• Cardiac arrest: A heart attack can lead to a temporary lack of oxygen to the brain, which may lead to retrograde amnesia, other cognitive problems, or brain damage.
• Disease: Progressive conditions such as Alzheimer’s, Huntington’s, and multiple sclerosis may lead to symptoms of retrograde amnesia. 
• Electroconvulsive therapy (ECT): ECT is a treatment for depression and other psychiatric conditions that involves inducing a seizure with a brief electrical current. It can cause retrograde memory loss. It may improve with time, but some people experience persistent memory gaps.
• Infections: Brain infections such as encephalitis can sometimes cause retrograde amnesia.
• Nutritional deficiencies: Excessive, chronic alcohol intake can lead to a thiamine (B12) deficiency called Korsakoff's syndrome. People with Korsakoff's syndrome experience symptoms of retrograde amnesia caused by decreased hippocampal volume.
• Seizures: Seizures due to epilepsy or other causes can also damage areas of the brain associated with memory.
• Traumatic brain injury (TBI): Damage to the brain due to stroke, injury, or other causes can lead to memory loss.

Diagnosing Retrograde Amnesia

If you are experiencing symptoms of retrograde amnesia, it is important to talk to your doctor. They will evaluate your condition and ask questions to learn more about your memory loss. Their assessment may include:

• A physical exam
• Blood tests
• Lumbar puncture to check for brain infections
• EEG (electroencephalogram) to look for seizures
• Other imaging tests, including MRI (magnetic resonance imaging) and CT (computed tomography), scans to look for other brain abnormalities

Your doctor will also perform a physical exam and a neurological assessment to check your general physical health and learn more about the nature, extent, and severity of your memory issues.

Treatment for Retrograde Amnesia

There is no specific treatment for retrograde amnesia. It is important to first understand what is causing this type of memory loss and then treat the underlying cause. 

In some cases, treatment may help reverse or halt the damage causing memory loss. For example, taking steps to relieve stress and treating thiamine deficiency may stop retrograde amnesia from worsening. In other cases, such as transient global amnesia or retrograde amnesia caused by ECT, the effects may only be temporary and will resolve on their own with time.

In other cases, the damage and memory loss may be permanent. While no treatment can cure degenerative conditions such as Alzheimer’s and Parkinson’s, some medications may help slow the progression of the disease.

Coping With Retrograde Amnesia

If you are experiencing retrograde amnesia, some strategies can help you cope with the symptoms and minimize their impact on your daily life. This type of memory loss can be challenging, particularly when it makes it difficult for people to understand precisely what has happened and what they have experienced. 

• Occupational therapy may help people relearn the information and knowledge lost due to retrograde amnesia. While they may not be able to regain their old memories, they can form new memories and often have a base of older ones they can build on.
• Psychotherapy can be helpful for people who are experiencing retrograde amnesia due to stress or trauma. By working with an experienced trauma therapist, people can process their experiences, learn new coping strategies, and find ways to deal with the emotional challenges caused by their memory loss.
• Social support can be an essential source of information, encouragement, and strength. In addition to leaning on people in your life, you might also consider joining a support group for people who have experienced memory loss.

You may also find it helpful to utilize technology tools to deal with the effects of retrograde amnesia. While you may have no memory of events that occurred before your amnesia began, you can use tools on your phone or tablet to keep track of important information that you need. Consider keeping notes, reminders, photographs, and other handy cues on your device to find names, dates, places, and other essential details.

Summary

Retrograde amnesia is a form of memory loss that causes an inability to remember events from the past. It can be caused by injury, illness, stress, infection, or other medical conditions that affect the brain. Such memory loss can be brief and temporary, but it can also be permanent. While there are no specific treatments for retrograde amnesia, there may be treatments for the conditions that are causing memory loss. 

A Word From Verywell

Experiencing retrograde amnesia can be confusing and distressing. Because the causes can vary, it is important to determine what is causing the problem so that you can get the appropriate help. While your memory loss may not be reversible, there may be strategies that can help you cope.