Carotid Stenosis: A Risk Factor for Cerebral White-matter Disease

Background We sought to study the association between carotid stenosis and white-matter hyperintensity (WMH) among patients without intracranial large-vessel stenosis. Methods This was a prospective study of patients with acute lacunar infarcts without concomitant intracranial large-vessel stenosis having undergone carotid ultrasonography. WMH was quantified using the modified Fazekas scale. Patients were grouped into quartiles based on the degree of carotid stenosis. The association among carotid stenosis, vascular risk factors, and WMH were modeled using logistic regression analysis. Results In all, 100 patients with a mean age of 56.2 ± 11.7 years were studied. The quartile with the greatest carotid stenosis had a mean internal/common carotid artery peak systolic velocity ratio of 2.36. Total WMH was 4.64 in the highest quartile and 2.52 in the lowest quartile of carotid stenosis. Periventricular (pv)-WMH was significantly greater between the highest and lowest quartiles (2.80 versus 1.28, P = .025). No significant difference was observed for deep subcortical WMH (1.84 versus 1.24, P = .281). With increasing carotid stenosis, increase in both ipsilateral and contralateral pv-WMH was observed. When patients with significant carotid stenosis were compared to those without significant carotid stenosis, pv-WMH was significantly higher in the group with significant stenosis even after correcting for age and comorbid vascular risk factors (odds ratio 1.24; confidence interval 1.0-1.54). Conclusions Carotid stenosis is an important risk factor for WMH. Volumes of pv-WMH significantly increase with higher grades of carotid stenosis.