Asymptomatic moderate carotid artery stenosis with intraplaque hemorrhage: onset of new ischemic stroke.

Abstract

The degree of stenosis of carotid arteries is recognized as an important risk factor for ischemic stroke. However, high-grade stenosis does not always cause cerebrovascular events, whereas low- to moderate-grade stenosis may often cause strokes. It has been reported that there is an association between carotid intraplaque hemorrhage (IPH) and new brain ischemic events. We present three patients with asymptomatic moderate carotid artery stenosis and carotid IPH who underwent both neurological and MRI at baseline and after at least 1 year's follow-up. These patients were admitted to our hospital (after 15-35 months of follow-up) because of neurological deficits. Diffusion-weighted MRI of the brain showed ipsilateral new ischemic lesions due to carotid artery plaques. The patients were treated with carotid artery stenting and discharged uneventfully. Whether plaques with severe stenosis already had severe stenosis at the onset of events or plaques with moderate stenosis progressed owing to an acute change, such as growth of an IPH, remains unclear, because no carotid imaging was carried out just before the events. This is the first case report which presents neurological symptoms and MRI at both baseline and follow-up in patients with asymptomatic moderate carotid artery stenosis and carotid IPH.