Transient Global Amnesia Recurrence: Prevalence and Risk Factor Meta-analysis

Transient global amnesia (TGA) is an acute amnestic disorder with unclear pathophysiology. Although considered a benign phenomenon, the possibility of a recurrence is a major concern for the patient. Our objective is to identify the prevalence and risk factors of relapse to help clinicians counsel patients about it.

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidance, we screened 1,658 studies from MEDLINE, Lilacs, and Embase databases, published from 1985 to April 2021, in English or Spanish. We included 36 observational case-control and cohort studies that included patients with TGA according to the Caplan or Hodges and Warlow diagnostic criteria. We performed a meta-analysis with a random effect model for proportions and calculation of odds ratio (OR) for identified risk factors. Methodological quality was assessed according to the Newcastle-Ottawa scale.

We identified 4,514 TGA cases and 544 recurrence events (12.73%). A follow-up had no effect on its variance. We identified a statistically significant association between recurrence and sexual activity as a trigger, a personal history or current state of migraine and depression (OR 1,481 95% CI [1.0341-2.1222] p = 0.04; OR = 2.0795 95% CI [1.3892-3.1128] p = 0.003; and OR = 4.4871 95% CI [1.890-10.651] p = 0.0288, respectively).

The analysis showed that approximately 1 of 8 participants may experience recurrence, with an increased risk in the case of a history or current state of migraine, depression, or sexual intercourse before the event. A personal history of migraine and depression was associated with 2 and 4 times risk, respectively.