Bilateral Hippocampus Changes on MRI in Transient Global Amnesia

Transient Global Amnesia (TGA) is a dynamic condition. An undefined event causes anterograde amnesia (sometimes with retrograde amnesia) that lasts in a day and preserves of self-identity and of consciousness. Epilepsy, migraine and ischemic events are the possible causes for different hypothesis but still unproven. Sixty three years old woman admitted to emergency department because of amnesia. She felt ill herself and was repeatedly asking similar questions and making same sentences in that period. She was not remember doing things nearby, but she was fully conscious to time, places, herself and her relatives. Neurological examination was normal except the anterograde and partly retrograde amnesia. Within amnesic period, Isotropic Diffusion Weighted Imaging (DWI) and ADC (Apparent Diffusion Coefficient) maps revealed hyper and hypo intensities on MRI respectively at both hippocampus (slightly more prominent at left side) while T1, T2 weighted and Fluid Attenuated Inversion recovery (FLAIR) images were normal. T1W+C images revealed bilateral contrast enhancements at hippocampus, and more prominent at the left side. Bilateral hippocampus MRI signal changes in our patient within the amnesic period are the reflections of the abnormal cellular functions in a TGA patient.