Transient Global Amnesia

Overview

What is transient global amnesia (TGA)?

Transient global amnesia (TGA) is a rare medical condition in which a person experiences a sudden episode of memory loss. During a TGA episode, a person cannot form new memories (a condition called anterograde amnesia) and has difficulty recalling recent memories (a condition called retrograde amnesia). Transient means “passing,” and TGA episodes usually last no more than several hours. In rare cases, TGA lasts up to 24 hours.

People with TGA remember who they are and can remember their friends and family members. They can still perform complex daily tasks, such as cooking or driving. They also retain their language and social interaction skills. However, during a TGA episode, they may not know where they are or the day or time.

Who is likely to have transient global amnesia (TGA)?

This condition usually occurs in people between the ages of 50 and 70.

How common is transient global amnesia (TGA)?

Transient global amnesia (TGA) occurs in approximately 3 to 10 people out of every 100,000.

Symptoms and Causes

What causes transient global amnesia (TGA)?

The exact cause of transient global amnesia (TGA) is unknown. However, some research suggests that TGA results from lack of sufficient blood flow (a condition called ischemia) or oxygen flow (a condition called hypoxia) to the brain. In some cases, TGA may be related to seizure activity in the brain.

Migraine headache appears to be a risk factor for developing TGA. Psychological factors, such as anxiety, may also make TGA more likely.

For some people, TGA may occur as a result of certain triggers or events, including:

  • Physical exertion
  • Emotional or psychological stress
  • Sudden immersion in cold or hot water
  • Head trauma
  • Pain
  • Sexual intercourse
  • Performing the valsalva maneuver. This is a breathing technique purposely performed by a person as part of a medical test or to slow a rapid heart rate and other uses. It is performed by closing your mouth and pinching your nose and bearing down as if having a bowel movement.

One type of TGA results from excessive alcohol consumption, large doses of barbiturates, illicit “street” drugs or small doses of benzodiazepines.

What are the symptoms of transient global amnesia (TGA)?

Transient global amnesia (TGA) involves a sudden inability to form new memories. Some people also cannot recall memories from hours, days, or longer in the past.

People experiencing a TGA episode may appear disoriented and confused. They know who they are and know their friends and family members, but may repeat questions about the time or date. Other complex mental tasks, such as the ability to drive a car or cook, are not affected.

Other symptoms that can occur with TGA include:

  • Headache
  • Dizziness
  • Nausea and vomiting
  • Anxiety
  • Confusion
  • Tingling in the feet, legs, hands, or arms

In most cases, TGA episodes last 1 to 10 hours (6 hours is average). In rare cases, symptoms may persist for up to 24 hours.

Memory problems that develop gradually or last for more than a day are not part of TGA and are likely related to other causes.

Diagnosis and Tests

How is transient global amnesia diagnosed?

Doctors diagnose transient global amnesia with a thorough physical exam. Your doctor may order tests to rule out other conditions that may cause memory loss. These tests may include:

Management and Treatment

How is transient global amnesia (TGA) treated?

There is no treatment for transient global amnesia (TGA). The condition resolves on its own within 24 hours. However, treatment for a suspected cause may be recommended.

What complications are associated with transient global amnesia (TGA)?

In rare cases, TGA results in longer lasting memory problems. This problem generally occurs only for people who have repeated TGA episodes.

Prevention

Can repeated transient global amnesia (TGA) episodes be prevented?

It may be possible to prevent additional episodes of transient global amnesia (TGA) by avoiding triggers. These triggers may include:

  • Emotional or psychological stress
  • Physical exertion
  • Sexual intercourse
  • Sudden immersion in cold or hot water
  • Valsalva maneuver

Outlook / Prognosis

What is the prognosis (outlook) for people with transient global amnesia (TGA)?

In most cases, people experiencing TGA recover completely. When the episode is over, they can form new memories, but they won’t remember what happened during the episode. Any other recent memories generally return within 24 hours.

In rare cases (less than 10%), TGA recurs (happens again). A history of migraines may make it more likely that a person will have another episode of TGA.

Living With

When should I call my doctor?

Contact your doctor immediately if you experience sudden symptoms of TGA. Signs include not knowing where you are or what time it is, confusion, or being unable to recall memories from hours, days, or weeks in the past.

Last reviewed by a Cleveland Clinic medical professional on 09/13/2019.

References

  • Merck Manual Professional Version. Accessed 09/13/19.Transient Global Amnesia. (https://www.merckmanuals.com/professional/neurologic-disorders/function-and-dysfunction-of-the-cerebral-lobes/transient-global-amnesia)
  • Spiegel DR, Smith J, Wade RR. Neuropsychiatric Disease and Treatment. 2017;13:2691-2703. Accessed 09/13/19.Transient global amnesia: current perspectives. (https://www.dovepress.com/transient-global-amnesia-current-perspectives-peer-reviewed-article-NDT)
  • U.S. Department of Health and Human Services. Accessed 09/13/19.Transient global amnesia. (https://rarediseases.info.nih.gov/diseases/8172/transient-global-amnesia)

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