Paroxysmal memory loss is a frequent cause for consultation of a neurologist in the emergency room of a general hospital. Transient global amnesia (TGA) is characterized by temporary loss of anterograde and recent memory affecting all memory contents visual, tactile, and verbal with preserved consciousness and self-awareness. Retrograde amnesia diminishes in parallel to the increasing ability to form new memories; however, permanent amnesia persists for the duration of TGA. The diagnosis of TGA is based on the neurological examination and neuropsychological findings. In patients with typical TGA, no further diagnostic measures are required. The temporal evolution of the apparent diffusion coefficient (ADC) changes in the hippocampus shows a time course previously described for ischemic lesions in human stroke patients. In view of the fact that TGA is frequently associated with a Valsalva-like mechanism, increased intrathoracic pressure might temporarily reduce the cerebral venous outflow.