High-Grade Internal Carotid Artery Stenosis and Chronic Brain Damage: A Volumetric Magnetic Resonance Imaging Study

Abstract

Background: Experimental data suggest that high-grade vascular stenosis may induce chronic cerebral tissue damage. Methods: We tested this hypothesis in 97 patients with a ≧70% unilateral internal carotid artery (ICA) stenosis (mean age: 69.1 ± 10.2 years), comparing intraindividual side-to-side differences in hemispheric brain and white matter hyperintensity (WMH) volumes. Patients with a supratentorial infarct exceeding 1.5 cm in diameter were excluded. Results: Overall, the median WMH volume was greater in the hemisphere ipsilateral to the stenotic ICA (1.13 ± 2.65 vs. 0.77 ± 2.26 cm³; p = 0.005), but there were no differences in hemispheric brain volumes between the stenotic and nonstenotic sides. In the subgroup of patients with moderate and severe WMH (n = 41), the hemispheric volume ipsilateral to the stenotic ICA was significantly smaller (543.46 ± 22.17 vs. 548.66 ± 26.7 cm³; p = 0.03). Multivariate linear regression analysis revealed an independent effect of WMH grade on interhemispheric volume differences relative to the side of stenosis. Conclusions: Chronic tissue damage may occur in a subset of individuals with ≧70% ICA stenosis, globally exhibiting more extensive WMH.