Transient Global Amnesia

Today we discussed a case of a patient with witnessed abrupt onset confusion found to have temporary anterograde amnesia--overall consistent with transient global amnesia. Some learning points: 

1) Illness script: In patients over 50, often with a triggering event (in 33-89% of patients such as emotional stress, strenuous activity), transient global amnesia is thought to result from a vascular phenomenon (either arterial or venous), a migrainous event, cortical spreading depression, epilepsy, or possibly a psychogenic disorder--resulting clinically in prominent anterograde amnesia (the inability to form new memories) and disorientation while other cognitive functions are spared lasting for approximately 1 to 10 hours (6 mean). Associated symptoms of headache, nausea, vomiting, and dizziness have been reported.

2) Treatment is not required as by definition this condition is benign and self-limited. However, patients should be observed until the episode resolves (usually several hours). 

3)  Additional workup to rule out alternative causes should include: labs assessing for intoxication, infection, and metabolic derangements--as well as MRI to exclude stroke or structural causes.

Diffusion-weighted imaging can depict small punctate hyperintense lesions in the hippocampus in transient global amnesia (TGA).

Diffusion-weighted imaging can depict small punctate hyperintense lesions in the hippocampus in transient global amnesia (TGA).