AMNESIA

The two main features of amnesia are:

• Impaired ability to learn new information following the onset of amnesia (anterograde amnesia)
• Impaired ability to recall past events and previously familiar information (retrograde amnesia)

Most people with amnesia have problems with short-term memory — they can’t retain new information. Recent memories are most likely to be lost, while more remote or deeply ingrained memories may be spared. Someone may recall experiences from childhood or know the names of past presidents, but not be able to name the current president or remember what month it is or what was for breakfast.

Isolated memory loss doesn’t affect a person’s intelligence, general knowledge, awareness, attention span, judgment, personality or identity. People with amnesia usually can understand written and spoken words and can learn skills such as bike riding or piano playing. They may understand they have a memory disorder.

Amnesia isn’t the same as dementia. Dementia often includes memory loss, but it also involves other significant cognitive problems that lead to a decline in the ability to carry out daily activities.

A pattern of forgetfulness is also a common symptom of mild cognitive impairment (MCI), but the memory and other cognitive problems in MCI aren’t as severe as those experienced in dementia.

Additional signs and symptoms

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

• False recollections (confabulation), either completely invented or made up of genuine memories misplaced in time
• Confusion or disorientation

When to see a doctor

Anyone who experiences unexplained memory loss, head injury, confusion or disorientation requires immediate medical attention.

A person with amnesia may not be able to identify his or her location or have the presence of mind to seek medical care. If someone you know has symptoms of amnesia, help the person get medical attention.

DIAGNOSIS

To diagnose amnesia, a doctor will do a comprehensive evaluation to rule out other possible causes of memory loss, such as Alzheimer’s disease, other forms of dementia, depression or 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 generally takes part in the interview as well.

The doctor will ask many questions to understand the memory loss. Issues that might be addressed include:

• Type of memory loss — recent or long term
• When the memory problems started and how they progressed
• Triggering factors, such as head injury, stroke or surgery
• Family history, especially of neurological disease
• Drug and alcohol use
• Other signs and symptoms, such as confusion, language problems, personality changes or impaired ability to care for self
• History of seizures, headaches, depression or cancer

Physical exam

The physical examination may include a neurological exam to check reflexes, sensory function, balance, and other physiological aspects of the brain and nervous system.

Cognitive tests

The doctor will test the person’s thinking, judgment, and recent and long-term memory. He or she will check the person’s knowledge of general information — such as the name of the current president — as well as personal information and past events.

The memory evaluation can help determine the extent of memory loss and provide insights about what kind of help the person may need.

Diagnostic tests

Imaging tests — including MRI and CT scan — may be ordered to look for damage or abnormalities in the brain. Blood tests can check for infection, nutritional deficiencies or other issues. An electroencephalogram may be ordered to look for the presence of seizure activity.

TREATMENT

Treatment for amnesia focuses on techniques and strategies to help make up for the memory problem.

Occupational therapy

A person with amnesia may work with an occupational therapist to learn new information to replace what was lost, or to use intact memories as a basis for taking in new information.

Memory training may also include a variety of strategies for organizing information so that it’s easier to remember and for improving understanding of extended conversation.

Technological assistance

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

Low-tech memory aids include notebooks, wall calendars, pill minders, and photographs of people and places.

Medications or supplements

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

Amnesia caused by Wernicke-Korsakoff syndrome involves a lack of thiamin. Treatment includes replacing this vitamin and providing proper nutrition. Although treatment, which also needs to include alcohol abstinence, can help prevent further damage, most people won’t recover all of their lost memory.

Researchers are investigating several neurotransmitters involved in memory formation, which may one day lead to new treatments for memory disorders. But the complexity of the brain processes involved makes it unlikely that a single medication will be able to resolve memory problems.