Transient global amnesia (TGA) is characterized by an attack of temporary antero- grade amnesia without other focal neurological deficits. Characteristic magnetic resonance imaging (MRI) findings include small, punctate, unilateral or bilateral diffusion restriction in the lateral aspect of the hippocampus, which mostly occurs within 48 hours after symptoms onset. The outcome of TGA is usually excellent. The pathophysiology of TGA remains uncertain, but recent evidence suggests that this disorder may result from the inability to generate new memory in the hippocampus due to vulnerability of CA-1 neurons to metabolic stress.
transient global amnesia; MRI, hippocampus