[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.