Acute Silent Brain Infarction in Monocular Visual Loss of Ischemic Origin

Non-arteritic branch/central retinal artery occlusions (BRAO/CRAO) and amaurosis fugax (AF) are predominantly caused by embolism. Additionally, transported embolic material could cause ischemic stroke. The aim of the study was to investigate the prevalence, pattern and underlying cause of concurrent acute brain infarctions in unselected patients with RAO and AF.

A total of 213 consecutive patients with BRAO (20.7%), CRAO (47.4%), or AF (31.9%) were retrospectively studied from 2008 to 2013. Magnetic resonance imaging (MRI) was used to detect acute brain infarctions and a cardiovascular workup was performed to detect underlying etiologies according to the Trial of Org 10172 in Acute Stroke Management (TOAST).

MRI was obtained after 23.78 (±32.26) hours from the time of symptom onset. Acute brain infarctions were detected in 49 patients (23%); 44 of them (89.8%) did not experience any additional neurological symptoms. Older age (p < 0.001/p < 0.001), hypertension (p = 0.01/p = 0.03), atrial fibrillation (p = 0.006/p = 0.03) and type of RAO (p = 0.02/p = 0.016) were associated with total/silent stroke, respectively. In multivariate analysis, only age and type of occlusion remained positive predictors for silent stroke. Etiology of BRAO/CRAO and AF remained undetermined in 124 patients (58.2%). This rate was lower in patients with acute stroke (40.8 vs. 63.4%).

Silent brain infarction is a frequent finding in unselected patients with BRAO/CRAO and AF. Etiology remains undetermined in approximately every second case. Because silent brain infarctions bear a high risk of future stroke, patients with BRAO/CRAO and AF should undergo prompt neuroimaging and cardiovascular checkup, preferably on a stroke unit.