Lack of relationship between leukoaraiosis and carotid artery disease. The North American Symptomatic Carotid Endarterectomy Trial

J. Y. Streifler, M. Eliasziw, O. R. Benavente, V. C. Hachinski, A. J. Fox and H. J. Barnett
Department of Clinical Neurological Sciences, University of Western Ontario, London.

OBJECTIVE: Leukoaraiosis (LA) (white matter changes) is frequently observed on computed tomographic scans of the brain of elderly patients at risk of stroke. A localized vascular-ischemic cause has been suggested for its underlying mechanism. Our aim was to assess whether high-grade carotid stenosis is associated with LA. DESIGN/SETTING: Patients enrolled in the North American Symptomatic Carotid Endareterectomy Trial (also known as NASCET) were evaluated for LA using a recently proposed grading scale. Ordinal regression analysis was used to assess the association between the severity of carotid artery stenosis and the extent of LA observed on computed tomographic scans. The patients' brain hemisphere was selected as the unit of analysis. RESULTS: Of the 2394 brain hemispheres contributed to the analyses, 352 (14.7%) had signs of LA. After controlling for known stroke risk factors in the ordinal regression analysis, only the history of stroke and increasing age were significantly related to LA. Severity of stenosis was observed to be unrelated (odds ratio [severe vs mild stenosis] = 1.08; 95% confidence interval, 0.73-1.62; P = .952) as were a history of hypertension and a history of myocardial infarction. CONCLUSION: Leukoaraiosis is not associated with severe carotid artery stenosis.