Transient global amnesia (TGA) is a clinical syndrome of reversible anterograde amnesia accompanied by repetitive questioning that occurs in middle-aged and elderly individuals [1,2].
The etiology of TGA remains obscure. While the prognosis for TGA is generally benign, other diseases in the differential diagnosis carry potential for serious long-term sequelae, making it important for clinicians to be familiar with the diagnosis and evaluation.
In the general population, the incidence of transient global amnesia (TGA) has been estimated as 5.2 to 10 per 100,000 per year [3-6]. Among those 50 years and older, it is 23.5 to 32 per 100,000 per year.
The majority of episodes occur in individuals between the ages of 50 and 80 years, with a mean age of onset between 60 and 65 years [2,3]. The incidence of TGA does not differ according to gender [2,4,5].
Atherosclerotic risk factors (eg, hypertension, diabetes, hypercholesterolemia) are not believed to be associated with TGA. While common in this aged population, most case-control studies find no difference in the prevalence of these risk factors between TGA patients and age and gender-matched controls [2,7-14]. In contrast, in one large case-control study, TGA patients were more likely than age and sex-matched controls to have hyperlipidemia, previous ischemic stroke, and ischemic heart disease . Compared with a cohort of patients with TIA admitted over the same time period, patients with TGA were less likely to have hypertension, diabetes, a history of ischemic stroke, and atrial fibrillation.