Background: To evaluate the prevalence and to identify the risk factors of silent brain infarction (SBI) in patients with ischemic stroke.
Methods: A total of 395 consecutive patients with first-ever ischemic stroke that underwent brain MRI were enrolled in this study. The prevalences of vascular risk factors in a SBI-positive (n=132) and in a SBI-negative group (n=263) were compared. The prevalences and characteristics of SBI were further evaluated with respect to stroke subtype and periventricular white-matter hyperintensity (PWMH) lesion.
Results: The frequency of SBI among the 395 study subjects was 33.4%, and 10.1% of the study subjects had multiple-SBI lesions. The most common lesion site was basal ganglia (47%). Multiple logistic regression analysis showed that hypertension (OR: 1.94, 95% CI: 1.22-3.07, P=0.005) and the presence of an advanced PWMH lesion (OR: 1.77, 95% CI: 1.06-2.96, P=0.030) were significantly associated with SBI. Furthermore, an advanced PWMH lesion (OR: 2.88, 95% CI: 1.19-6.95, P=0.010) was more associated with multiple-SBI lesions than with a single-SBI lesion. The frequency of SBI was higher among those with the small-vessel disease type (45.5%) than in those with the large-artery disease (32.5%) or cardioembolic stroke type (25.6%) (P=0.04).
Conclusions: The prevalence of SBI in patients with ischemic stroke was found to be high, and hypertension was found to be the most important risk factor of SBI. Small-vessel disease and a diffuse white-matter lesion were found to be closely associated with SBI, and especially with multiple-SBI lesions.
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