Transient Global Amnesia (TGA) as First Presenting Sign of Neurodegenerative Disorders

Abstract

Transient global amnesia (TGA) is a clinical syndrome characterized by the sudden onset of anterograde amnesia, accompanied by repetitive questioning, sometimes with a retrograde component, lasting up to 24 hours, without compromise of other neurologic functions. Although various factors, such as migraine, focal ischemia, venous flow abnormalities, and epileptic phenomena, can be considered as 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. We report three cases on neurodegenerative disorders presenting with transitory global amnesia, all evaluated at the department of emergency of Esine Hospital (Brescia), who developed all neurodegenerative disorders. It is important, when performing neurological evaluation in the department of emergency, to consider the possible presence of underlying cognitive impairment or behavioral symptoms especially in older people. Neurological evaluation should take into consideration the presence of piramidal, extrapiramidal or frontal sign release positivity or the presence of higher cortical functions impairment. It should be important to refer these patients to appropriate neurological evaluation in appropriate Centers for Neurodegenerative Disorders.