Hippocampal reversible lesions in a case of transient global amnesia

We report the case of 55-year-old man that after an emotional stress showed retrograde and anterograde amnesia with impairment of orientation in space and time but undisturbed consciousness. A neurological examination excluded other neurological signs or symptoms. The amnesic syndrome resolved spontaneously within 24 hours and the hypothesis of transient global amnesia was placed. Brain CT scan and conventional MRI sequences did not show any relevant pathological findings but diffusion-weighted imaging (DWI) showed two millimetric bright spot of restricted diffusion in the right hippocampus; in a brain MRI follow-up those findings were no more appreciable. The diagnosis of transient global amnesia is primarily clinical, and MRI can give a positive diagnostic support. For a best detection of lesions is very important to respect the right time of imaging and the optimal DWI protocol. Here we highlight the importance of a prompted, well-timed imaging and an appropriate protocol, to ensure a correct and defined detection of the lesions.