Transient Global Amnesia

Transient global amnesia (TGA) is a rare medical condition in which you experience a sudden episode of memory loss.

During a TGA episode, you can’t form new memories (a condition called anterograde amnesia), and you have difficulty recalling recent memories (a condition called retrograde amnesia). “Transient” means passing. Transient global amnesia episodes usually last no more than several hours. In rare cases, they last 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.

Even though researchers have been studying transient global amnesia for over 50 years, they’re still not sure what causes it or why it happens.

Who does transient global amnesia affect?

Transient global amnesia mainly affects people between the ages of 50 and 80 (75% of cases). It rarely affects people younger than 40.

Some studies suggest that people who have a history of the following health conditions may be more at risk for developing transient global amnesia:

• Heart disease.
• Migraine.
• Hyperlipidemia (high cholesterol).

How common is transient global amnesia?

Transient global amnesia is rare. It affects about 5 to 10 people per 100,000 per year in the general U.S. population.

For people aged 50 and older, it affects 23 to 32 people per 100,000 a year.