Cortical cerebral microinfarcts (CMIs) have been linked with dementia and impaired cognition in cross-sectional studies. However, the clinical relevance of CMIs in a population-based setting is lacking. We examine the association of CMIs detected on 1.5T MRI with cardiovascular factors, cerebrovascular disease, and brain-tissue volumes. We further explore their association with cognitive decline and risk of stroke, dementia, and mortality in general-population.
2156 participants with clinical history and baseline MRI were included. CMIs were graded based on a previously-validated method. Markers of cerebrovascular disease and brain tissue volumes were assessed on MRI. Cognition was assessed using a detailed neuropsychological test at baseline and at five years of follow-up. Data on incident stroke, dementia, and mortality were included until January 2016.
227 individuals (10.5%) had ≥1 cortical CMIs. The major risk factors of cortical CMIs were male sex, current smoking, history of heart disease, and stroke. Furthermore, presence of cortical CMIs was associated with infarcts and smaller brain volume. Persons with cortical CMIs showed cognitive decline in Stroop Tests. During a mean follow-up of 5.2 years, 73 (4.3%) individuals developed incident stroke, 95 (5.1%) incident dementia, and 399 (19.2%) died. People with cortical CMIs were at an increased risk of stroke (HR:1.18,95%CI:1.09-1.28) and mortality (HR:1.09,95%CI:1.00-1.19).
Cortical CMIs are highly prevalent in a population-based setting and are associated with cardiovascular disease, cognitive decline and increased risk of stroke and mortality. Future investigations will have to show whether cortical CMIs are a useful biomarker to intervene upon to reduce the burden of stroke.
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