Memory loss (amnesia) is unusual forgetfulness.

The cause determines whether amnesia comes on slowly or suddenly, and whether it is temporary or permanent.

Normal aging may lead to trouble learning new material or requiring a longer time to remember learned material. However, it does not lead to dramatic memory loss unless diseases are involved.

• Aging
• Alcoholism
• Alzheimer's disease
• Brain damage due to disease or injury
• Brain growths (caused by tumors or infection)
• Brain infections such as Lyme disease or syphilis
• Depression or emotional trauma
• Drugs such as barbiturates or benzodiazepines
• Electroconvulsive therapy (especially if it is long-term)
• Encephalitis of any type (herpes, West Nile, Eastern Equine)
• General anesthetics such as halothane, isoflurane, and fentanyl
• Head trauma or injury
• Hysteria, often accompanied by confusion
• Illness that results in the loss of nerve cells (neurodegenerative illness)
• Nutritional problems (vitamin deficiencies such as low vitamin B12)
• Seizures
• Stroke or transient ischemic attack (TIA)
• Transient global amnesia
• Temporal lobe brain surgery

The family should provide support. Reality orientation is recommended -- supply familiar music, objects, or photos, to help the person stay oriented. Some people may need support to help them relearn.

Any medication schedules should be written down so the person does not have to rely on memory.

Extended care facilities, such as nursing homes, should be considered for people whose basic needs cannot be met in any other way, or whose safety or nutrition is in jeopardy.

Call your health care provider if you have any unexplained memory loss.

The doctor will perform a thorough examination and take a medical history. This may require asking questions of family members and friends.

Medical history questions may include:

• Type
  • Can the person remember recent events (is there impaired short-term memory)?
  • Can the person remember events from further in the past (is there impaired long-term memory)?
  • Is there a loss of memory about events that occurred before a specific experience (anterograde amnesia)?
  • Is there a loss of memory about events that occurred soon after a specific experience (retrograde amnesia)?
  • Is there only a minimal loss of memory?
  • Does the person make up stories to cover gaps in memory (confabulation)?
  • Is the person suffering from low moods that impair concentration?
• Time pattern
  • Has the memory loss been getting worse over years?
  • Has the memory loss been developing over weeks or months?
  • Is the memory loss present all the time or are there distinct episodes of amnesia?
  • If there are amnesia episodes, how long do they last?
• Aggravating or triggering factors
  • Has there been a head injury in the recent past?
  • Has the person experienced an event that was emotionally traumatic?
  • Has there been a surgery or procedure requiring general anesthesia?
  • Does the person use alcohol? How much?
  • Does the person use illegal/illicit drugs? How much? What type?
• Other symptoms
  • What other symptoms does the person have?
  • Is the person confused or disoriented?
  • Can they independently eat, dress, and perform similar self-care activities?
  • Have they had seizures?

The physical examination will include a detailed test of thinking and memory (mental status test), and an exams of the nervous system. Recent, intermediate, and long-term memory will be tested.

Diagnostic tests that may be performed include the following:

• Blood tests for specific diseases that are suspected (such as low vitamin B12 or thyroid disease)
• Cerebral angiography
• Cognitive tests (psychometric tests)
• CT scan or MRI of the head
• EEG
• Lumbar puncture

Knopman DS. Regional cerebral dysfunction: higher mental functions. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 424.