Evolution of cortical cerebral microinfarcts on 3T MRI: risk factors and clinical relevance

INTRODUCTION: Cortical cerebral microinfarcts (CMIs) are associated with cognitive dysfunction and dementia, while their evolution on sequential magnetic resonance imaging (MRI) remains unclear. METHODS: The study enrolled 490 patients (72.5 ± 7.9 years) from a memory-clinic cohort, with 5-year follow-up. Cortical CMIs were graded at baseline and year 2 to identify incident lesions and other evolutionary patterns. Cognitive function was assessed annually. Clinical events, including dementia, stroke, and mortality, were recorded with time to event. RESULTS: Forty-one (8.4%) patients showed incident cortical CMIs at year 2. Additionally, 12 had CMIs becoming invisible, and six showed CMIs incorporated into new large infarctions. Baseline cortical CMIs and large cortical infarcts showed the strongest association with incident CMIs. Incident cortical CMIs were associated with cognitive decline, white matter hyperintensity progression, and incident dementia, independent of prevalent lesions. DISCUSSION: Cortical CMI evolution may reflect dynamic changes in brain vascular pathology and represent a potential target for interventions aimed at preserving cognitive function.