Silent lacunar infarction on magnetic resonance imaging (MRI): Risk factors

We investigated the risk factors for silent lacunar infarction and état criblé detected by magnetic resonance imaging (MRI). Previous reports have evaluated white matter hyperintensities (WMHs) and periventricular hyperintensities (PVHs) on T2-weighted images, but have not distinguished between lacunar infarcts, état criblé, and leukoaraiosis of Binswanger's type. MRI scans were performed in 270 subjects without neurological deficits over the age of 40 years. They were classified into four subtype groups based on MR findings: normal group (n=60), état criblé group (n=69), silent lacunar infarct/PVH(−) group (n=61), and silent lacunar infarct/PVH(+) group (n=80). We examined the following biochemical variables and other potential risk factors by ordinary logistic regression analysis to identify independent and significant risk factors for silent lacunar infarction: serum levels of total cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, lipoprotein(a), HbA_1c, age, sex, systolic blood pressure, diastolic blood pressure, duration of hypertension, family history, smoking habits, alcohol intake, obesity (body mass index), and atrial fibrillation. Subjects in the silent lacunar infarct/PVH(−) (P<0.01) and PVH(+) (P<0.001) groups were significantly older than normal subjects. The systolic blood pressure was also significantly higher in the silent lacunar infarct/PVH(−) (P<0.04) and PVH(+) (P<0.01) groups compared with the normal group. The duration of hypertension was significantly longer in the silent lacunar infarct/PVH(+) group (P<0.02). There were no significant differences in other risk factors between the normal group and the other groups. Ordinary logistic regression analysis showed that age (chi-square 51.8, P<0.0001) and systolic blood pressure (chi-square 5.7, P<0.02) were significant and independent risk factors for silent lacunar infarction. Aging and hypertension were shown to be independent risk factors for silent lacunar infarction.