TRANSIENT GLOBAL AMNESIA: CURRENT DIAGNOSTIC APPROACH

Abstract

Transient global amnesia (TGA) is a rare neurological disorder, occurring predominantly in patients 50-70 years old. It consists of a reversible anterograde (and to a lesser degree retrograde) amnesia of an abrupt onset, lasting 2-24 hours. It is not associated with any residual cognitive deficit, and the possibility of recurrence is small. The diagnosis is primarily clinical. However, a specific neuroimaging finding is the presence of a small diameter, high signal intensity lesion in the DWI (Diffusion Weighted Imaging) sequence, in a region corresponding to the hippocampal CA1 cells. It is usually detected between 48-72 hours after symptoms onset. The pathophysiology of TGA has not been elucidated, although various alternative mechanisms (ischemic, epileptic, migrainous, venous insufficiency, metabolic stress) have been proposed. The present review summarizes the current literature regarding epidemiology, clinical presentation, neuroimaging findings and pathophysiology of this disorder.