Amnesia

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KEY POINTS

• Amnesia is loss of memory that means you cannot remember anything that happened during a specific time period.
• Treatment depends on the cause. Treatment may include counseling, medicines, or occupational therapy.

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What is amnesia?

Amnesia is loss of memory. It is not the same as simple forgetfulness. If you have amnesia, you cannot remember anything that happened during a specific time period. However, you do not forget everything about the past.

There are different types of amnesia:

• Retrograde amnesia. This is a loss of memory before an event. For example, you forget what happened right before being hit on the head.
• Anterograde amnesia. This is a loss of memory that happens after an event. For example, you forget what happened right after having surgery. Many people in severe car accidents have amnesia that affects the time just before the accident and also for a time afterwards.
• Transient global amnesia (TGA). TGA may be caused by decreased blood flow in the brain. The amnesia can last from 1 to 24 hours.

What is the cause?

Amnesia may be caused by:

• Damage to the brain caused by a stroke, Alzheimer’s disease, a seizure, a brain infection, or a head injury
• A horrifying event, such as a rape or seeing a murder or suicide
• Medicines such as sleeping pills and anesthesia used in surgery
• Certain kinds of mental illness
• Poisons such as carbon monoxide
• Alcohol or substance abuse

What are the symptoms?

Besides not being able to remember certain events, amnesia can make it hard to learn new things. You may be confused and feel out of touch with reality.

If you have TGA, you may have a headache, dizziness, and nausea, or you may have only memory loss. It may happen only once or many times.

How is it diagnosed?

Your healthcare provider will ask about your symptoms, activities, and medical history, and examine you. You may have tests such as:

• Blood tests
• EEG, which measures and records the electrical activity in your brain
• CT scan, which uses X-rays and a computer to show detailed pictures of your brain
• MRI, which uses a strong magnetic field and radio waves to show detailed pictures of your brain
• Tests to evaluate how well you can concentrate, remember, understand, and make decisions.

How is it treated?

Treatment depends on the cause.

Therapy can be helpful if your amnesia is caused by abuse or having seen a horrifying event.

Medicines may be used to treat infections or to relax blood vessels and improve blood flow to the brain.

Treating alcohol and substance abuse can prevent further damage, but you usually will not recover lost memory.

In most cases, amnesia is short-term and only lasts a few seconds to a few hours. As you recover, older memories usually come back first, and then more recent memories. However, it may last a few weeks or even months. For long-term memory loss, you may need occupational therapy. Occupational therapy can help you learn to do things differently or use tools to help you remember people or daily tasks.

How can I take care of myself?

Follow the full course of treatment prescribed by your healthcare provider. Ask your healthcare provider:

• How and when you will get your test results
• How long it will take to recover
• If there are activities you should avoid and when you can return to your normal activities
• How to take care of yourself at home
• What symptoms or problems you should watch for and what to do if you have them

Make sure you know when you should come back for a checkup. Keep all appointments for provider visits or tests.