The Significance of Atrial Fibrillation in Patients With Transient Global Amnesia

Abstract

Background and purpose: The etiology of transient global amnesia (TGA) remains unclear in a large subset of patients. We aimed to determine the clinical and radiological characteristics of TGA-patients with suspected acute micro-embolic stroke on diffusion-weighted imaging (DWI).

Methods: TGA-patients that had new DWI hippocampal lesions (DWI+) were compared to DWI negative TGA-patients (DWI-). Demographics, risk factors, clinical data, radiological data, and mortality were analyzed.

Results: Out of 83 patients diagnosed with TGA, 56 (65%) underwent MRI during the acute hospitalization and 26 (46%) had new hippocampal DWI lesions. DWI+ patients more often had a history of atrial fibrillation (AF, 26 vs. 7%, p = 0.04) but the frequency of other risk factors did not differ. None of the patients died, however, two DWI+ patients had subsequent stroke during a 2-year follow up and both had AF. In contrast, none of the DWI- patients had recurrent events.

Conclusion: AF is common among DWI+ TGA-patients. The presence of AF in patients with TGA could suggest an increased risk of subsequent stroke.

Keywords: atrial fibrillation; diffusion-weighted imaging; hippocampal lesions; micro-embolic stroke; transient global amnesia.

Figure 1

MRI image showing DWI hyperintense lesion in the right hippocampus (A), also seen by the corresponding ADC maps which display diffusion restriction (B). Subcortical FLAIR lesions were also found in the same patient with a Fazekas score 2 (C). Red arrows point to specific lesions.