Spatial Relationship between Acute Lacunar Infarction and White Matter Hyperintensities

BACKGROUND: White matter hyperintensities (WMH) predict incident strokes and new lacunes; moreover, WMH may also affect infarct locations. Our aim in this study was to examine the spatial relationship between WMH and acute lacunar infarction. METHODS: Five hundred and ninety patients with acute lacunar infarction in supratentorial region were included. Four situations between infarction and WMH were assessed by axial and coronal MRI: no contact (Grade 0), contact without overlap (Grade Ia), partial overlap (Grade Ib), and complete overlap (Grade II) with preexisting WMH. Furthermore, we defined infarctions in Grades Ia and Ib as edge-localized infarctions and investigated their predictors and short-term outcome. RESULTS: 47.9% (283) of the infarctions were edge-localized infarctions (Grade Ia = 27.6% and Grade Ib = 20.3%), 51.5% (304) were Grade 0, only 0.5% (3) were Grade II. Patients with edge-localized infarction had larger infarct size, more severe WMH, higher National Institutes of Health Stroke Scale (NIHSS) and lower Barthel index (BI) score at admission than those with non-edge-localized infarction. They also had lower BI score at discharge. Infarction in subcortical white matter, diffusion-weighted imaging infarct size, periventricular WMH and deep WMH were predictors for edge-localized infarction. CONCLUSIONS: Half of lacunar infarctions were located at the edge of WMH. Both periventricular WMH and deep WMH were predictors for edge-localized infarction.