Cortical cerebral microinfarcts and risk of stroke, dementia and mortality: The Rotterdam study

Abstract

AbstractBackgroundCortical cerebral microinfarcts (CMIs) –a novel MRI marker of cerebral vascular pathology have been linked with dementia and impaired cognition in cross‐sectional studies. However, it is unknown if cortical CMIs are an indicator of further cognitive decline and incident clinical outcomes. We examine the risk factors of CMIs on 1.5T MRI and their association with cognitive decline and risk of stroke, dementia and mortality.Method2156 participants (median age: 74.6 (range: 70.7‐79.3 years, women 55.6%) with baseline MRI (acquired between January 2009‐December 2013) and no prevalent dementia were included. Data on incident clinical outcomes were available (until January 2016) were included. CMIs on 1.5T were graded based on a previously validated criterion on 3T and were defined as the hypointense lesions on T1‐weighted images, <5mm in diameter, restricted to cortex and perpendicular to the cortical surface Markers of cerebrovascular disease (cortical infarcts, white matter hyperintensities, lacunes, cerebral microbleeds) and neurodegeneration (volumes of total brain and hippocampus) were collected. Cognition was assessed using a detailed neuropsychological test at baseline and at follow‐up after five years.Result227 individuals (10.5%) had one or more cortical CMIs. The main risk factors of cortical CMIs were male sex (OR: 1.86, 95%CI: 1.23‐2.82), heart disease (OR: 1.81, 95%CI:1.24‐2.63), cortical infarcts (OR: 6.03, 95%CI:3.79‐9.58) and lacunes (OR: 1.12, 95%CI: 1.03‐2.29). Persons with cortical CMIs showed cognitive decline albeit non‐significant. During a mean follow‐up of 5.2 years, 14 (6.5%) individuals with cortical CMIs developed incident stroke, 10 (4.6%) incident dementia and 76 (3.5%) died. People with cortical CMIs at baseline had an increased risk of strokes (Risk Ratio (RR): 1.66, 95%CI:0.8‐3.11), mortality (RR: 1.18, 95%CI:0.97‐1.43) compared to individuals with no CMIs, unlike the risk of dementia (RR: 0.72, 95%CI: 0.27‐1.30) albeit non‐significant.ConclusionCortical CMIs are highly prevalent in a population‐based setting and are associated with cardiovascular risk factors and increased risk of stroke and mortality albeit non‐significant. These findings provide new insights into the etiologic and prognostic significance of cortical CMIs. Future investigations will have to show whether screening and treating persons with cortical CMIs can effectively reduce the burden of stroke.