Abstract
BACKGROUND: Data on the evolution of recent small sub-cortical infarcts are limited, especially in the Chinese. Previous studies have reported a large heterogeneity in cavitation and infarct location; therefore, the present study assessed the morphology of small sub-cortical infarcts in the basal ganglia in a Chinese cohort. METHODS: Patients who had experienced a recent, single, small sub-cortical infarct in the basal ganglia and received at least one follow-up magnetic resonance imaging (MRI) scan were retrospectively identified from January 2014 to June 2018. Time to follow-up imaging, baseline infarct size, vascular risk factors, and other clinical data, as well as the morphologic changes of the index infarct and surrounding white matter were recorded. Demographic, clinical and MRI characteristics were respectively compared among three groups (white matter hyper-intensitie [WMH] vs. cavitation vs. absent) and between with and without new WMH formation groups. In addition, logistic regression analyses were performed in investigating the determinate independent predictors for new WMH formation. RESULTS: Seventy-eight subjects were included with a median follow-up time of 304 days (range: 124-552 days). We found a significant reduction in infarct size at follow-up: 46 of 78 (59.0%) infarctions showed some degree of cavitation, 19 of 78 (24.4%) index lesions resembled non-cavitated WMH, and 13 of 78 (16.7%) infarcts had disappeared at follow-up MRI. No factors were found to be associated with differential outcomes of the infarcts. In addition, 8 of 78 (10.3%) patients demonstrated new WMH formation surrounding the index infarct; white matter progression (odds ratio = 15.95, 95% confidence interval = 1.65-153.99; P = 0.017) was an independent risk factor of new WMH formation. CONCLUSIONS: More than half of the small sub-cortical infarcts in the basal ganglia progressed to cavities, demonstrating that these infarcts can be reduced and go undetected. The presence of new WMH around the infarct may be indicative of the worsening progression of cerebral small vessel diseases. Additionally, white matter progression is an independent risk factor, which may be a potential therapeutic target.