Hypodensity of the cerebral white matter in patients with transient ischemic attack or minor stroke: Influence on the rate of subsequent stroke

In a prospective study of 3,017 patients with transient ischemic attack or minor ischemic stroke from the Dutch Transient Ischemic Attack Trial, the presence or absence of diffuse hypodensity of the white matter on a baseline computed tomography (CT) scan of the brain was related to the occurrence of subsequent stroke. On entry, 337 patients were judged to have diffuse hypodensity of the white matter on CT; they were older (71.4 ± 7.4 years versus 64.4 ± 9.9 years), more often had hypertension (50% versus 41%), and more often had lacunar infarcts on CT scan (40% versus 26%) than did patients with normal white matter. Strokes, fatal or nonfatal, occurred in 51 (15%) of the patients with diffuse hypodensity of the cerebral white matter, compared to 217 (8%) in the group with normal white matter (crude hazard ratio, 2.0; 95% confidence interval, 1.4–2.7). After adjustment for age and other relevant entry variables, the hazard ratio was 1.6 (95% confidence interval, 1.2–2.2). In patients younger than 70 years the crude hazard ratio was 2.7 (95% confidence interval, 1.7–4.2). The distribution between the main subtypes of stroke was similar for patients with and those without diffuse hypodensity of the cerebral white matter: Intracerebral hemorrhage occurred in 6 and 9%, cortical infarction in 47 and 45%, and lacunar infarction in 34 and 29%, respectively. We conclude that hypodensity of the cerebral white matter in patients with transient ischemic attack or minor stroke is associated with an extra risk of future stroke, from large as well as from small vessels, and particularly in patients under 70 years old; this increase of risk is independent of other risk factors for stroke.