Amnestic Disorder

Amnestic disorder, also called amnesia or amnestic syndrome, involves significant loss of memories that goes far beyond everyday forgetfulness—it can affect your ability to remember important events from your past or make it difficult to form and retain new memories.

Table of contents

• What is Amnestic Disorder?
• Types of Memory Loss
• Signs and Symptoms
• What Causes Amnestic Disorder
• How Doctors Diagnose Amnestic Disorder
• Treatment and Support
• Living With Memory Loss

What is Amnestic Disorder?

Amnesia, Amnestic syndrome

Amnestic disorder refers to a condition where a person loses the ability to remember information stored in their memory^[1]. This is not the same as simple forgetfulness, like misplacing your keys or forgetting to do something while running errands. When you have amnestic disorder, you cannot recall significant events or details from your life^[3].

Despite what movies and television often show, people with amnesia rarely forget who they are^[1]. Most people with this condition know their own identity. Instead, they typically have trouble learning new information and forming new memories. Their intelligence, general knowledge, awareness, and attention span remain intact^[1]. Judgment, personality, and identity are also not affected by memory loss alone.

Amnestic disorder is characterized by a persistent impairment in a person’s ability to learn new information or recall previously learned information^[4]. Unlike temporary episodes of memory loss, amnesia can be permanent^[1]. While amnesia itself is uncommon, it is a very common symptom of certain conditions that involve brain damage or disruptions in brain activity^[3].

Types of Memory Loss

There are two main forms of amnesia that describe which memories are affected^[3]. Retrograde amnesia means you cannot recall memories from your past—events and information that happened before an injury or illness. Anterograde amnesia means you cannot form new memories but can still remember things from before the condition developed.

A person can experience both types at the same time. There are also several other specific forms of amnesia^[3]:

• Post-traumatic amnesia develops after an injury and can involve multiple forms of memory loss
• Transient global amnesia is a short-lived condition that involves both retrograde and anterograde amnesia and almost always lasts less than 24 hours^[3]
• Dissociative amnesia happens because of a mental health-related cause, such as traumatic events, abuse, or severe psychological distress^[3]
• Infantile amnesia refers to the normal inability to remember events from early childhood, which almost everyone experiences

Chronic amnestic disorder includes several key features^[4]. It involves anterograde amnesia caused more by problems with learning than by problems retrieving information. People experience loss of both short-term verbal and nonverbal memory, which is called retrograde amnesia. However, long-term memory is usually maintained. The condition may also include confabulation, where the brain automatically tries to fill in memory gaps and makes mistakes, and general confusion^[3].

Signs and Symptoms

The two main features of amnestic disorder are trouble learning new information and trouble remembering past events and information that used to be familiar^[1]. Most people with amnesia have problems with short-term memory, meaning they cannot remember new information. Recent memories are most likely to be lost, while older or deeply ingrained memories may be preserved^[1].

For example, a person with amnesia may recall experiences from childhood or know the names of past presidents, but may not be able to name the current president, know what month it is, or remember what they ate for breakfast^[1].

Common symptoms you might experience include^[3]:

• Changes in your ability to remember events or things that happened to you
• Difficulty recalling names and faces
• Not remembering locations and how to get to them
• Forgetting about upcoming events that you planned to attend

People with amnesia may also experience confabulation. This is when the brain tries to fill in missing memory details but makes an error. A person might misremember what day something happened recently or mix up details from the past^[3]. People who confabulate believe their memory is genuine and accurate—they do not intend to lie or deceive. It is simply an error that happens without their awareness.

Other symptoms may appear depending on the cause of the amnesia, including false memories that are either completely made up or real memories placed at the wrong time, as well as confusion or disorientation^[1]. Patients may also show psychological symptoms such as apathy, blunted affect, lack of motivation, and bewilderment. Some individuals may be aware that they have a memory problem, but others may appear indifferent to it^[4].

What Causes Amnestic Disorder

Amnesia happens because of damage to areas of the brain that are vital for memory processing^[1]. Memory function involves many parts of the brain, and any disease or injury that affects the brain can affect memory. Amnesia often results from damage to brain structures that form the limbic system, which controls emotions and memories. These structures include the thalamus, located deep within the center of the brain, and the hippocampal formations found within the temporal lobes^[1].

Causes of amnesia fall broadly into two categories: neurological causes and psychological causes^[3].

Neurological causes involve damage to the brain or disruptions in brain activity. Possible causes include^[3]:

• Alcohol intoxication, which can temporarily block the formation of new memories
• Alzheimer’s disease and related diseases that involve the loss of brain cells important for memory
• Brain aneurysms
• Brain tumors, both cancerous and noncancerous
• Cerebral hypoxia, which is brain damage from lack of oxygen due to heart attack, breathing problems, or carbon monoxide poisoning
• Stroke, which disrupts blood supply to the brain
• Brain inflammation, which may be due to infection with a virus such as herpes simplex virus, or an autoimmune reaction
• Drugs and medications, especially certain sedatives and anesthesia medications
• Epilepsy and seizures, especially temporal lobe seizures
• Head injuries that cause a concussion
• Long-term alcohol misuse that leads to too little vitamin B-1 (thiamin) in the body, causing Wernicke-Korsakoff syndrome

The two most common substance-induced amnestic disorders arise from prolonged abuse of alcohol and benzodiazepines^[4].

Psychological causes of amnesia involve mental health conditions. Dissociative amnesia stems from emotional shock or trauma, such as traumatic events, abuse, and other severe sources of psychological distress^[3]. Experts suspect it is a defense mechanism the brain uses to protect you from what you experience.

How Doctors Diagnose Amnestic Disorder

A comprehensive evaluation is needed to diagnose amnesia and rule out other possible causes of memory loss, such as Alzheimer’s disease, other forms of dementia, depression, or a brain tumor^[6].

The evaluation starts with a detailed medical history. Because the person with memory loss may not be able to provide complete information, a family member, friend, or caregiver often needs to help^[6]. The doctor may ask questions to understand the memory loss, such as:

• The type of memory loss and whether it is recent or long-term
• When the memory loss started and whether it has gotten worse over time
• Factors that may have triggered memory loss, such as head injury, stroke, or surgery
• Family history, especially of neurological disease
• Drug and alcohol use
• Other symptoms such as confusion, trouble with language, personality changes, or inability to perform self-care
• History of seizures, headaches, depression, or cancer

The physical exam may include a neurological exam to check reflexes, sensory function, and balance^[6]. The exam typically includes tests related to thinking, judgment, and memory. You may be asked about general information, such as the name of the current president, as well as personal information and past events. You may be asked to repeat a list of words. These memory tests help show how serious the memory loss is and help the doctor decide what kind of care is needed.

Diagnostic tests may be ordered, including imaging tests to check for brain damage or changes, such as shrinking of the brain^[6]. These tests may include computed tomography (CT) scans or magnetic resonance imaging (MRI). Blood tests may be done to check for infections, vitamin deficiencies, or other issues.

Treatment and Support

There is no specific treatment for amnesia itself^[1]. However, if an underlying cause of amnesia is found, treatment can often be directed at that condition. Treating the underlying cause may reverse the amnesia in some cases, but some causes are permanent^[3].

Treatment approaches include^[9]:

• Treatment of underlying medical conditions that lead to memory loss, such as low thyroid function, liver and kidney disease
• Treatment of stroke, head injury, blood clots in the brain, and bleeding within the brain to reduce memory loss caused by these conditions
• Treatment of accompanying psychiatric illness, including depression, anxiety, bipolar disorder, and schizophrenia
• Treating alcoholism and preventing alcohol and illicit drug abuse

Cognitive therapy using speech or language therapists can help patients with mild to moderate memory loss^[9]. In many cases, mild memory loss may persist even with treatment.

For treatment to be effective, it is important to determine the underlying cause of the amnesia. If amnesia is caused by a neurological disease such as stroke or brain inflammation, these underlying diseases should be treated first. Additionally, therapists work with patients using tasks and activities to train memory^[12]. Every memory is like a muscle that can be challenged and trained.

If a patient is severely cognitively impaired due to their neurological disease, they learn individual compensation strategies during therapy to make everyday life easier. Experienced therapists may include electronic reminders via apps to help patients manage daily tasks^[12].

Using strategies to enhance memory and getting support can help people with amnesia and their families cope^[1]. Treatment may also include therapy focused on trauma if the amnesia has a psychological cause.

Living With Memory Loss

Managing amnesia at home requires several important steps. Basic home care and prevention of complications are essential^[9].

Safety measures at home include:

• Prevention of falls through good lighting and avoiding clutter. Doors should be left open, and dangerous materials should be locked up
• Rooms can be labeled to prevent patients from getting lost
• To prevent patients from getting lost outside, wanderer’s alarms, tags, and transmitters may help
• Patients should carry some form of identification with their name, address, or contact number
• Install hot water shut-downs and thermostats to prevent scalding
• Use stove cut-offs to turn off gas or power after a specified time
• Install smoke alarms

Memory aids can be very helpful^[9]:

• Medication organizers with compartments for regular doses and electric pill reminders with alarms
• All important numbers, such as family and emergency contacts, should be near the telephone
• Clocks with large numbers and calendars with large print help keep the person oriented to time and place, reducing anxiety and frustration

Support from family and friends is essential when coping with amnesia. Loved ones can provide a compassionate and patient ear to listen, encourage professional treatment, participate in therapy, and help with the transition back home. They can support healthy lifestyle changes and positive coping mechanisms for past trauma^[18].

Preventing memory loss involves healthy living and reduction of risk factors for heart disease, diabetes, and other conditions. This includes lowering cholesterol and high blood pressure, which also reduces risk of stroke and Alzheimer’s disease^[9]. Excessive alcohol consumption, smoking, and use of illicit drugs should be avoided. Regular physical activity helps maintain blood flow to the brain and supports overall health.