Microbleeds and Silent Brain Infarctions Are Differently Associated with Cognitive Dysfunction in Patients with Advanced Periventricular Leukoaraiosis

Background: Leukoaraiosis, microbleeds, and silent brain infarctions are phenotypes of small vessel disease. Leukoaraiosis is the most prevalent, and advanced periventricular leukoaraiosis is regarded as a strong predictor of cognitive dysfunction. Microbleeds and silent brain infarctions sometimes coexist with leukoaraiosis. This study aims to analyze the effects of microbleeds and silent brain infarctions on cognitive function of patients with advanced periventricular leukoaraiosis. Methods: 227 patients with advanced periventricular leukoaraiosis were divided into control, MB, SBI, and MB&SBI groups. The presence and locations of microbleeds and silent brain infarctions were evaluated. Mini-Mental State Examination, Montreal Cognitive Assessment, Clock Drawing Test and Verbal Fluency Test were performed. Chi-square test and ANOVA to compare the characteristics of four groups, multiple linear regressions to identify the risk factors for cognitive dysfunction. Results: The scores in all four tests were lower in the MB and MB&SBI groups while only the scores in Clock Drawing Test and Verbal Fluency Test were lower in the SBI group than in the control group. Age and the presence of microbleeds were independent risk factors for the lower scores in all four tests, whereas the presence of silent brain infarctions was the only independent risk factor for the lower scores in Clock Drawing Test and Verbal Fluency Test. Lobar microbleeds had the most significant effect on cognitive function. Conclusion: Microbleeds and silent brain infarctions were associated differently with cognitive impairment of patients with advanced periventricular leukoaraiosis. The effect of lobar microbleeds was the most significant.