All About the Different Types of Amnesia

Amnesia is a memory disorder. People with amnesia cannot remember past experiences, form new memories, or both. Several factors can cause memory loss, such as physical injury, infection, psychological causes, or other traumatic experiences that prevent normal brain function and trigger memory loss.

There are different types of amnesia. In some cases, the memory loss is temporary, and the patient eventually recalls the information they lost. But in other cases, the memory loss is permanent. Patients may even lose their ability to make new memories.

Many myths and misconceptions about amnesia exist. This article will review the truth about amnesia causes, characteristics, and treatments.

Misconceptions 

Misconception #1: Having amnesia always means you forget who you are.

In rare cases, a person with amnesia can forget who they are. When that happens, the cause is often severe brain trauma or brain disease.

However, most people with amnesia still remember who they are. In most cases, people who have amnesia cannot recall information from the past or cannot remember new information.

Misconception #2: There is only one type of amnesia.

One common misconception about amnesia is that there is only one type that affects all past memory. On the contrary, there are several types of amnesia that can affect various parts of past and future memories.

Misconception #3: Amnesia is like dementia.

Amnesia is not the same thing as dementia. Amnesia is memory loss that is a symptom of a more significant medical issue.

Dementia is a disease that causes degenerative memory loss. Dementia patients also suffer from other cognitive issues that don't occur in people with amnesia.

Stages of Memory

Memory involves holding on to information from the past and can also affect memories you make in the future.

The three stages of memory are:

• Encoding: When the brain decodes new information
• Storage: When the brain stores information
• Retrieval: When the brain reactivates the information for use in the future

There are also three types of memory:

• Short-term memory (working memory): These are thoughts that usually last 10–30 seconds. The frontal and parietal lobes are most responsible for short-term memory.
• Long-term memory: These are thoughts that last for a minute or longer. The hippocampus and temporal lobes are responsible for long-term memory.
• Sensory memory: This lasts for less than a second. Visual, auditory, and tactile sensory input is briefly attended to and mostly forgotten or passed on for further processing.
  

Amnesia Types

Amnesia can affect your past or future memories. For that reason, amnesia has two main categories, which are:

• Retrograde amnesia is the inability to remember old memories.
• Anterograde amnesia is the inability to form new memories. People with anterograde amnesia might remember a birthday party they went to 30 years ago but might have difficulty recalling what they ate for breakfast.

People who have anterograde amnesia have problems with short-term memory. When you can't remember an event in the short term, it may be harder for your brain to store that information and process it for long-term retrieval in the future.

Many additional types of amnesia can involve forming both old and new memories. The kind of amnesia a person has depends on different factors, such as how the amnesia presents and the events happening around the time of the amnesia.

Dissociative Amnesia 

Dissociative amnesia is when a person is unable to recall important information about their life, such as their history or identity.

Dissociative amnesia is a type of dissociative disorder, a mental health illness that affects the consciousness, awareness, and perception of a person. In some cases, it can be limited to specific areas. But in more severe cases, a person may forget almost all of their identity, including their name, family members, and personal history. They might even take on an entirely new identity.

Dissociative amnesia is often caused by extreme stress or trauma. Traumatic events such as abuse, war, natural disasters, or other stressful experiences may cause a person to dissociate, or disconnect, themselves from the traumatic event.

Post-Traumatic Amnesia

Post-traumatic amnesia (PTA) is amnesia that comes after a brain injury. In some cases, it is considered a normal part of the recovery process following a stroke, head trauma, or coma. PTA may also cause memory loss from before the brain injury occurred.

PTA is a state of disorientation to time, place, and person. Patients with PTA may have difficulty understanding what happened to them, who they are, where they are, or the date. Memory recovery can take weeks or months. In some cases, it may be permanent.

Infantile Amnesia

Infantile amnesia is an adult's inability to remember their first few years of life as a baby and toddler. Some researchers believe this occurs due to the underdevelopment of the infant's brain.

But even though adults cannot remember their infant lives, studies show that abusive events and neglect that occurred in childhood can still impact mental health later in life.

Transient Global Amnesia

Transient global amnesia (TGA) is sudden and temporary memory loss. TGA comes on suddenly and usually lasts between one to 10 hours.

While experiencing TGA, a person cannot make new memories or recall events during the period of TGA. People can remember who they are and who their family members are during a TGA event, but they often are unaware of where they are and the time.

TGA usually resolves on its own, and researchers are unclear of the cause. But some have suggested that other psychological disorders, venous flow abnormalities (problems with blood flow), or epilepsy (abnormal brain activity that can cause seizures) may be to blame.

Drug-Induced Amnesia

Drug-induced amnesia is a common medical practice during surgery or other health procedures that would otherwise cause pain or discomfort.

For instance, a person who has surgery to remove their appendix would receive amnesia-inducing medication, or general anesthetic, that would put the patient in a sleeplike state.

Selective Amnesia

Selective amnesia is when a person can recall some events of a traumatic event or other situation, but not others.

Causes

There are many causes of amnesia, but most fall into two categories: neurological and functional.

Neurological amnesia is caused by various brain diseases, infections, or other medical conditions. Functional amnesia is usually related to psychiatric issues or emotional trauma.

Possible causes of neurological amnesia include:

• Brain injuries from blunt force, such as head injury from a car crash or bullet wound
• Brain diseases, such as dementia, strokes, seizures, or a brain tumor
• Brain infections, such as encephalitis
• Oxygen deprivation
• Thyroid issues
• Alcoholism
• Vitamin deficiency
  

The most common cause of functional amnesia is emotional trauma. Functional amnesia usually also causes retrograde amnesia and doesn't affect the formation of future memories. However, in severe cases, patients with functional trauma can forget who they are.

Consulting a Specialist 

The type of amnesia a person has will determine the kind of care they will receive. Many patients with amnesia start by talking to their regular healthcare provider. Patients may also see a psychotherapist or a neurologist (a doctor who specializes in the brain and nervous system).

Treatment and Prevention 

In many cases, amnesia is not preventable. However, research shows that there are several ways you can keep your mind sharp as you age that could prevent age-related memory loss, such as:

• Staying social
• Exercising regularly
• Getting quality sleep
• Eating nutritious food
• Treating any chronic medical conditions
• Staying mentally active by reading or playing mind-stimulating games

Brain damage can cause amnesia. Therefore, protecting your brain can help to prevent amnesia associated with brain trauma.

Some tips include:

• Wear protective headgear while biking, motorcycling, or playing sports such as football.
• Avoid excessive alcohol drinking.
• Wear a seat belt in the car.
• For any infections, take medications as prescribed by your healthcare provider.
• Get emergency treatment for stroke symptoms, aneurysms, or other head injuries.
• Exercise to lower your risk of stroke.

Therapy

Amnesia caused by a neurological disease or infection requires treatment for the underlying medical cause of amnesia. Therapy for neurological amnesia can take time, and in some cases, memories may never return. If you or a loved one has amnesia due to a neurological condition, talk to your healthcare provider about what types of therapy can help you manage your amnesia.

Since most functional amnesia results from emotional trauma, healthcare providers may recommend finding a way to deal with those traumatic events safely, which can include therapy.

The best therapy approach will depend on the patient and what is causing the amnesia. Some treatments available include:

• Psychotherapy
• Cognitive behavioral therapy (CBT)
• Family therapy
• Art or music therapy
• Meditation
• Clinical hypnosis
• Medications to treat any underlying mental disorders

Having a Support System 

Amnesia can be a frightening and confusing experience that can lead to anger, anxiety, and depression. Isolating oneself can make this worse. A strong support system of family, friends, and healthcare professionals can help make the experience less stressful.

Summary

Amnesia is a memory disorder that can affect the ability to remember old memories (retrograde amnesia) and the ability to form new memories (anterograde amnesia). Several factors can contribute to this memory loss, such as physical injury, infection, or emotional trauma. In some cases, the memory loss is temporary, and the patient eventually recalls the information they lost. But in other cases, the memory loss is permanent.