Amnesia

Amnesia, also called amnestic syndrome, refers to the loss of memories, including facts, information and experiences. Movies and television tend to show people with amnesia forgetting who they are. But that's not generally the case in real life.

Instead, people with amnesia typically know who they are. But they may have trouble learning new information and forming new memories.

Amnesia can be caused by damage to areas of the brain that are vital for memory processing. Unlike a temporary episode of memory loss, called transient global amnesia, amnesia can be permanent.

There's no specific treatment for amnesia. But if an underlying cause of amnesia is found, treatment often can be directed at that condition. Using strategies to enhance memory and getting support can help people with amnesia and their families cope.

The two main features of amnesia are:

• Trouble learning new information.
• Trouble remembering past events and information that used to be familiar.

Most people with amnesia have issues with short-term memory, so they can't remember new information. Recent memories are most likely to be lost. But people with amnesia may remember older or deeply ingrained memories.

For example, people with amnesia may recall experiences from childhood or know the names of past presidents. But they may not be able to name the current president, know the month or remember what they ate for breakfast.

Memory loss alone doesn't affect a person's intelligence, general knowledge, awareness or attention span. It also doesn't affect judgment, personality or identity. People with amnesia typically can understand written and spoken words. And they can learn skills such as bike riding or piano playing. They may understand that they have a condition that affects memory.

Amnesia isn't the same as dementia. Dementia often includes memory loss. But dementia also involves other changes in thinking that lead to a decline in daily functioning. These changes include having trouble with language, judgment, and visual and spatial skills.

Memory loss also is a common symptom of mild cognitive impairment. This condition involves memory loss and other cognitive issues that aren't as serious as those experienced in dementia.

Additional symptoms

Depending on the cause of the amnesia, other symptoms may include:

• False memories that are either completely invented or are real memories misplaced in time.
• Confusion or disorientation.

When to see a doctor

Anyone who has unexplained memory loss, a head injury or confusion needs medical attention right away.

People with amnesia may not know where they are or be able to seek medical care. If someone you know has symptoms of amnesia, help that person get medical attention.

Typical memory function involves many parts of the brain. Any disease or injury that affects the brain can affect memory.

Amnesia can result from damage to brain structures that form the limbic system, which controls emotions and memories. Those brain structures include the thalamus found deep within the center of the brain. They also include the hippocampal formations found within the temporal lobes of the brain.

Amnesia caused by brain injury or brain damage is known as neurological amnesia. Possible causes of neurological amnesia include:

• Stroke.
• Brain inflammation, which may be due to an infection with a virus such as herpes simplex virus. Or inflammation may be a result of an autoimmune reaction to cancer somewhere in the body. It also may be due to an autoimmune reaction without cancer in the body.
• Not enough oxygen in the brain. This may happen as a result of a heart attack, breathing trouble or carbon monoxide poisoning.
• Long-term alcohol misuse that leads to too little vitamin B-1, known as thiamin, in the body. This condition is called Wernicke-Korsakoff syndrome.
• Tumors in areas of the brain that control memory.
• Alzheimer's disease and related diseases that involve the loss of brain cells that are important for memory.
• Seizures.
• Medicine such as benzodiazepines and other medicines that act as sedatives.

Head injuries that cause a concussion can lead to confusion. They also can make it hard to remember new information. This is especially common in the early stages of recovery after a concussion. Mild head injuries typically don't cause lasting amnesia. But head injuries that are more serious may cause permanent amnesia.

Another rare type of amnesia, called dissociative amnesia, comes from emotional shock or trauma. It can result from being the victim of a violent crime or experiencing other trauma. In dissociative amnesia, people may lose personal memories and information about their lives. This type of amnesia typically doesn't last long.

The following conditions can raise the risk of developing amnesia:

• Brain surgery, head injury or head trauma.
• Stroke.
• Alcohol use disorder.
• Seizures.

How much amnesia affects memory is different from person to person. But even mild amnesia takes a toll on daily activities and quality of life. Amnesia can make it hard to function at work, at school and in social settings.

It may not be possible to recover lost memories. Some people with serious memory loss need to be supervised or need to live in a care facility.

Damage to the brain can be a root cause of amnesia. It's important to take steps to minimize your chance of a brain injury. For example:

• Don't drink large amounts of alcohol.
• Wear a helmet when bicycling and a seat belt when driving.
• Treat infections quickly so that they don't have a chance to spread to the brain.
• Get medical treatment right away if you have symptoms that suggest a stroke or brain aneurysm, including:
• A serious headache.
• Feeling numb on one side of the body.
• Not being able to move one side of the body.

A comprehensive evaluation is needed to diagnose amnesia. This evaluation can rule out other possible causes of memory loss such as Alzheimer's disease, other forms of dementia, depression or a brain tumor.

Medical history

The evaluation starts with a detailed medical history. Because the person with memory loss may not be able to provide thorough information, a family member, friend or another caregiver often may be needed to provide that information.

Your healthcare professional may ask questions to help understand the memory loss. Issues that might be addressed include:

• The type of memory loss and whether it's recent or long term.
• When the memory loss started and whether it's gotten worse over time.
• Factors that may have triggered memory loss, such as a 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 not being able to perform self-care.
• History of seizures, headaches, depression or cancer.

Physical exam

The physical exam may include a neurological exam to check reflexes, sensory function and balance.

Cognitive tests

The exam typically includes tests related to thinking, judgment and memory. You'll likely be asked about your knowledge of general information, such as the name of the current president. You also may be asked about personal information and past events. You may be asked to repeat a list of words.

The memory evaluation can help show how serious memory loss is. It also can help your healthcare professional decide what kind of care you may need.

Diagnostic tests

Your healthcare professional may order the following tests:

• Imaging tests to check for brain damage or changes such as shrinking of the brain. The imaging tests may include an MRI and a CT scan.
• Blood tests to check for infection, low levels of important nutrients in the body or other issues.
• An electroencephalogram (EEG) to check for seizure activity.

Treatment for amnesia focuses on strategies to help make up for the trouble with memory. It's also important to address any underlying diseases that could be causing amnesia.

Occupational therapy

You may work with an occupational therapist to learn new information and replace information that has been lost. Or you may use the memories you still have as a basis for taking in new information.

Memory training may include strategies for organizing information so that it's easier to remember and for better understanding when talking to others.

Technological assistance

Many people with amnesia find it helpful to use smart technology, such as a smartphone or a hand-held tablet. With some training and practice, even people with serious amnesia can use electronic organizers to help with day-to-day tasks. For example, smartphones can be programmed to give reminders about important events or to take medicines.

Other helpful memory aids include notebooks, wall calendars, pill minders, and photographs of people and places.

Medicines or supplements

No medicines currently are available for treating most types of amnesia.

If Wernicke-Korsakoff syndrome is the cause of the amnesia, treatment can help prevent more damage. But most people won't recover all of their lost memory. Treatment includes replacing thiamin in the body, providing proper nutrition and not drinking alcohol.

If Alzheimer's disease is the cause of the amnesia, treatment with medicines called cholinesterase inhibitors can help with symptoms.

Research may one day lead to new treatments for conditions that affect memory. But the complexity of the brain processes involved makes it unlikely that a single medicine will be able to resolve trouble with memory.

Living with amnesia can be frustrating for those with memory loss and for their family and friends too. People with serious forms of amnesia may require direct assistance from family, friends or professional caregivers.

It can be helpful to talk with others who understand what you're going through. They may be able to provide advice or tips on living with amnesia. Ask your healthcare professional to recommend a support group in your community or online for people with amnesia and their loved ones.

If an underlying cause for the amnesia is found, there are national organizations that can provide more information and support. Examples include:

• Alzheimer's Association, 800-272-3900 (toll-free).
• Brain Injury Association of America, 800-444-6443 (toll-free).

You may start by seeing your primary healthcare professional. Or, you may be referred to a specialist in conditions of the brain and nervous system, also called a neurologist.

Here's some information to help you get ready for your appointment.

What you can do

When you make the appointment, ask if there's anything you need to do in advance, such as not eating or drinking before a test. Make a list of:

• Your symptoms, including any that do not seem related to the reason for your appointment.
• Key personal information, including major stresses, recent life changes and family medical history.
• All medicines, vitamins and other supplements you take, including the doses.
• Questions to ask your healthcare professional.

Take a family member or friend along, if possible, to help you remember the information you're given.

For amnesia, some basic questions to ask your healthcare professional include:

• What's the most likely cause of my symptoms?
• Are there other possible causes for my symptoms?
• What kinds of tests do I need? Do these tests require any special preparation?
• Will my memory ever come back?
• What treatments are available, and which do you recommend?
• I have other health conditions. How can I best manage them together?
• Do I need to restrict any activities?
• Are there any brochures or other printed material that I can take home? What websites do you recommend?

Be sure to ask any other questions you may have.

What to expect from your doctor

Your healthcare professional is likely to ask you a number of questions, including:

• When did you first notice your memory loss?
• Did you experience any other symptoms at that time?
• Were you involved in any trauma? For example, a car accident, a violent collision in sports or an assault?
• Did an illness or another event seem to trigger the memory loss?
• Does anything help improve your memory?
• What, if anything, appears to make the memory loss worse?
• Does the trouble with memory come and go or it is constant?
• Has the memory loss stayed the same or is it getting worse?
• Did the memory loss come on suddenly or slowly?