Transient global amnesia: current perspectives

Abstract

Transient global amnesia (TGA) is a clinical syndrome characterized by the sudden onset of an extraordinarily large reduction of anterograde and a somewhat milder reduction of retrograde episodic long-term memory. Additionally, executive functions are described as diminished. Although it is suggested that various factors, such as migraine, focal ischemia, venous flow abnormalities, and epileptic phenomena, are involved in the pathophysiology and differential diagnosis of TGA, the factors triggering the emergence of these lesions are still elusive. Recent data suggest that the vulnerability of CA1 neurons to metabolic stress plays a pivotal part in the pathophysiological cascade, leading to an impairment of hippocampal function during TGA. In this review, we discuss clinical aspects, new imaging findings, and recent clinical-epidemiological data with regard to the phenotype, functional anatomy, and putative cellular mechanisms of TGA.

Keywords: migraines; psychiatric; transient global amnesia; vascular.

Figure 1

Diagnostic algorithm of anterograde amnesia. Abbreviations: AAm, anterograde amnesia; EEG, electroencephalogram; HSE, herpes simplex encephalitis; LE, limbic encephalitis; LOC, loss of consciousness; PCA, posterior cerebral artery; PTA, posttraumatic amnesia; RAm, retrograde amnesia; TBI, traumatic brain injury.