Relationship between risk factors of silent brain infarctions and focal brain lesions detected by magnetic resonance imaging in apparently normal Mongolian adults

Abstract

Background: Recent studies demonstrated that the risk factors for silent brain infarction (SBI) vary depending on the location of the imaging and it is important to identify the risk factors and localization of silent brain infarction (SBI) in the apparently normal adults. Aim: The purpose of this study was to examine the characteristics and risk factors for SBI in apparently normal adults, with particular attention to localization of SBI. Materials and Methods: Subjects of this study were 200 adults without a history of stroke or transient ischemic attack and without any stroke symptoms on a neurological examination who underwent brain magnetic resonance imaging (MRI) at the First Central Hospital between May 2021 and January 2022. Subjects included 66 men and 134 women ranging in age from 33 to 83 years (mean age 54.72±10.65 years). SBI was defined as a focal lesion 3-30 mm in diameter that was hypernitense on both T2-weighted and diffuse-weighted images. Risk factors of SBI were assessed by interview, physical examination and blood test. Pearson’s chi-square test and two-sample t-test for univariate analysis and multiple logistic regressions for multivariate analysis were performed to evaluate risk factors of SBI for analysis. Results: A total of 90 participants were found to have a SBI by MRI scan, 29 (32.2%) in the subcortical white matter, 23 (25.56%) in the cerebral cortex, and 38 (42.2%) other location (in the basal ganglia, thalamus, pons, and cerebellum) were identified. On univariate analysis showed that the risk of SBIs in the subcortical white matter was over 60 years of age, female sex, BP> 130/80 mmHg, in the cerebral cortex over 60 years of age, hypertension, BP> 130/80 mmHg, but the risk of SBIs in other locations of the brain was shown in those over 60 years of age, migraine, family history of vascular disease, and diabetes. Multivariate analysis revealed that age over 60 years (OR 3.64-7.23, 95% CI, 1.28-19.12, p<0.05) was independent predictors of SBIs in the subcortical white mather and cerebral cortex, while hypertension (OR 3.48, 95% CI, 1.24-12.66, p<0.05), and migraine (OR 10.61-12.24, 95% CI 1.97-76.08, p = 0.007), were predictors of SBIs in the cerebral cortex and other brain locations respectively. Diabetes (OR 5.72, 95% CI 1.17-28.04, p = 0.032) was significant predictor of SBIs in the other brain locations. Conclusions: The present study indicated that the relevant risk factors for SBIs in the subcortical white mather, cerebral cortex and oher brain locations were different. Our results suggest that SBIs are prone to first appear in the subcortical white mather in association with aging and the additional appearance of SBIs in the cerebral cortex, other brain locations predict a progression of small vessel disease associated with hypertension, migraine and diabetes.