Development and progression of leukoaraiosis in patients with brain ischemia and carotid artery disease

Background and Purpose-Leukoaraiosis (LA) or the presence of white matter changes, a frequent finding on brain CT scans of elderly individuals, is a risk factor for stroke and vascular death. The aim of the study was to seek development and progression of LA and associated risk factors in patients with symptomatic carotid artery disease. Methods-Presence and extent of LA were determined on entry and follow-up CT scans from 685 patients in the North American Symptomatic Carotid Endarterectomy Trial. Results-Among 596 patients without LA at entry, 107 (18.0%) developed restricted LA and 18 (3.0%) developed widespread LA during a mean follow-up of 6.1 years (range, 3.0 to 9.6 years). Older age was associated significantly with LA development (P<0.001). History of hypertension, diabetes mellitus, ischemic heart disease, and intermittent claudication had weak associations with LA development. During follow-up, 36.0% of patients who developed LA had 1 or more strokes, particularly of the lacunar type, in comparison to 23.5% of patients who did not develop LA (P=0.01). In patients who developed LA, the percentage with small deep infarcts (diameter <= 1.5 cm) increased from 34.4% on entry to 45.6% on follow-up CT scans compared with no increase (20.4% and 20.4%, respectively) in patients who did not develop LA. Among 89 patients who had restricted LA at entry, 28 (31.5%) progressed to widespread LA. Progression was associated with occurrence of strokes. Conclusions-LA is common in elderly patients with symptomatic cerebrovascular disease. Its development and progression are associated with higher occurrence of strokes, mainly of the lacunar type.