[Transient global amnesia].

UNLABELLED: A DISTINCTIVE SYNDROME: Transient global amnesia is a very distinctive amnesic syndrome. The attack begins abruptly with massive anterograde verbal and non-verbal amnesia. Retrograde amnesia, variable in extent, is also present. A repetitive questioning behavior is usual. The memory impairment gradually resolves after almost always less than 12 hours. WELL-DEFINED CRITERIA: Specific criteria make it possible to distinguish transient global amnesia from psychogenic amnesia, acute confusional state and transient epileptic amnesia. "Pure" transient global amnesia is usually idiopathic and has a good prognosis. It is also distinguishable from symptomatic transient global amnesia.

PATHOGENESIS: Functional imaging studies detect hippocampic or thalamic hypoperfusion. This oligemia may be secondary to neuronal dysfunction compatible with spreading depression. The pathogenic mechanisms remain unclear.