Transient global amnesia usually affects patients between the ages of 40 and 80. Patients with this condition are often described – wrongly – as being confused. It presents classically with an abrupt onset of severe anterograde amnesia. It is usually accompanied by repetitive questioning. • Hakan et al demonstrated tiny increases in signal in the left parahippocampal gyrus and splenium of thecorpus callosum on DWI in one patient. This method of imaging allows detection of hyperacute ischemic change.
However, Eustache et al reported a PET study consistent with a spreading depression in the left lateral frontal cortex. This case also featured oligemia in the left occipital cortex. Strupp et al found mainly medial temporal changes on DWI in 7 of 10 patients with TGA. They suggested that cellular edema or spreading depression could be responsible, not just ischemia. Estimates vary, but Matiea-Guiu et al found a lower incidence in Alcoi, Spain, of 2.9 cases per 100,000 population.