Transient Global Amnesia Recurrence

Abstract

Background: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.Methods:According to PRISMA guidance, we screened 1658 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 Caplan’s or Hodges and Warlow’s diagnostic criteria. We performed a meta-analysis with a random effect model for proportions and calculation of odds ratio for identified risk factors. Methodological quality was assessed according to the Newcastle-Ottawa Scale.Results:We identified 4514 TGA and 544 recurrence events (12.73%). Follow-up had no impact on its variance. We identified a statistically significant association between recurrence and sexual activity as a trigger, past or present personal history of migraine and depression (OR 1,481 95%CI [1,0341; 2,1222] p=0,04; OR=2,0795 IC95% [1,3892; 3,1128] p=0,003; and OR=4,487195%CI [1,890; 10,651] p=0,0288, respectively).Conclusions:The analysis showed that about 1 out of 8 subjects may have recurrence, with an increased risk in case of past or present history of migraine, depression or sexual intercourse prior to the event. Personal history of migraine and depression are associated with two and four times risk, respectively.

Guideline “Transient Global Amnesia (TGA)” of the German Society of Neurology (Deutsche Gesellschaft für Neurologie): S1-guideline

“… Recent data show that the risk of TGA recurrence ranges from 12 to 27% [ 3 – 5 ]. Patients with TGA are significantly more likely (OR 2.5) to have a history of migraine [ 6 ].…”

“…A meta-analysis of 36 studies found a significant association between TGA recurrence risk and migraine, depression, and sexual activity as trigger factors [ 5 ].…”

“…• The risk for TGA is higher in the morning (10)(11) a.m.) and late afternoon (5-6 p.m.) [7]. • A meta-analysis of 36 studies found a significant association between TGA recurrence risk and migraine, depression, and sexual activity as trigger factors [5]. • Functional and morphometric MRI studies [8,9] and quantitative EEG analyses [10] have demonstrated changes in functional connectivity in the limbic system and hippocampus.…”

“…The risk of recurrence during the course ranges from 12 to 27% [3][4][5], with most patients (85%) experiencing 3 or fewer recurrences [3]. Predisposing factors for recurrence include the presence of migraine (odds ratio, OR 2.1), depression (OR 4.5), and sexual activity as a trigger factor (OR 1.5) [5]. There is a clustering of TGA in the morning (10-11 am) and late afternoon (5-6 pm) [7].…”

“…Between 12 and 27% of affected individuals [3][4][5] suffer at least one additional TGA subsequently, which is perceived as dramatic by both patients and relatives despite the benign nature of the syndrome. Since the pathomechanism of TGA has not yet been definitively clarified, it is probably a multifactorial or multicausal process, and empirical data are also lacking, no sufficiently evidence-based recommendations can be made regarding prophylaxis.…”