Transient global amnesia

A distinctive syndrome: Transient global amnesia is a very distinctive amne sic syndrome. The attack begins abruptly with massive anterograde verbal an d non-verbal amnesia. Retrograde amnesia, variable in extent, is also prese nt. A repetitive questioning behavior is usual. The memory impairment gradu ally resolves after almost always less than 12 hours. Well-defined criteria: Specific criteria make it possible to distinguish tr ansient global amnesia from psychogenic amnesia, acute confusional state an d transient epileptic amnesia. "Pure" transient global amnesia is usually i diopathic and has a good prognosis. It is also distinguishable from symptom atic transient global amnesia. Pathogenesis: Functional imaging studies detect hippocampic or thalamic hyp operfusion. This oligemia may be secondary to neuronal dysfunction compatib le with spreading depression. The pathogenic mechanisms remain unclear. (C) 2000, Masson, Paris.