Asymmetrical Gadolinium Leakage in Ocular Structures in Stroke Due to Internal Carotid Artery Stenosis or Occlusion.

Abstract

Gadolinium leakage in ocular structures (GLOS) on fluid-attenuated inversion recovery images (FLAIR) is anovel imaging marker in acute ischemic stroke. The present study sought to investigate the frequency and pattern of blood-retina barrier impairment in acute ischemic stroke due to internal carotid artery (ICA) stenosis or occlusion as demonstrated by GLOS. From a magnetic resonance imaging (MRI) report database patients were identified with acute ischemic stroke due to ICA stenosis/occlusion who underwent repeated MRI with intravenous contrast agent administration and FLAIR and MR angiography (MRA). On FLAIR the presence of GLOS was noted in the vitreous body. Overall 51patients with a median age of70 years (interquartile range, IQR 63-77 years) were included. Of these, 22 (43.1%) patients had an ICA stenosis and 29 (56.9%) an ICA occlusion. On contrast-enhanced FLAIR, GLOS was observed in 29 (56.9%) patients: in 7 (13.7%) unilateral, in 15 (68.2%) bilateral asymmetrical and in 7 (31.8%) bilateral symmetrical. In unilateral asymmetrical GLOS, more pronounced enhancement was always found ipsilateral to ICA stenosis/occlusion. In 4 (5.9%) patients with asymmetrical GLOS apre-existing signal increase in the vitreous body was found on native FLAIR. The presence of GLOS was associated with an impaired collateralization through the circle of Willis (p < 0.001) and external carotid artery branches (p = 0.03). In patients with ischemic stroke due to ICA stenosis/occlusion, GLOS is frequent, commonly unilateral or bilateral asymmetrical, and in some patients associated with pre-existing ocular signal abnormalities. An insufficient collateralization may contribute to the development of unilateral/asymmetrical GLOS.