Wednesday, March 14, 2012
ROCHESTER, Minn. — A one-time memory loss — for up to 24 hours — might not be a sign of a brain injury or dementia. Instead, it could be transient global amnesia. The March issue of Mayo Clinic Health Letter covers this uncommon and puzzling form of amnesia.
People with transient global amnesia experience sudden loss of recent memory and can't form new memories. The episode usually lasts six to 12 hours but may last up to 24 hours. During that time, people know who they are and recognize family and friends. Complex tasks, such as driving, are still possible. In the midst of transient global amnesia, those affected don't know where they are or how they got there. They would likely ask the same questions repeatedly. Once the episode is over, life returns to normal — absent any memories from that short time.
This form of amnesia is most common in adults age 50 and older and usually occurs only once. The underlying cause is unknown. There's debate about what triggers an episode. Reported events have been linked to sudden immersion in cold or hot water, strenuous physical activities, emotional or psychological stress, and pain. Some have found an association with migraines.
Although temporary, transient global amnesia warrants immediate medical attention. Diagnosis is based on excluding more serious neurological conditions such as stroke, seizure or head injury. Transient global amnesia is not a predictor of future memory loss or a risk factor for other more serious conditions.
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